Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек

Aim. DNA-encoded libraries technologies (DELT) are gradually becoming an important part of standard drug discovery toolbox. DELT is looking to find its place between classic low-molecular-weight drug candidates on the one hand, and high-molecular-weight antibodies and peptides on the other hand. On...

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Published in:Журнал органічної та фармацевтичної хімії
Date:2023
Volume:21
Issue:1
Pages:3-19
ISSN:2518-1548
Author Affiliations:
  • Oleksandr V. Oksiuta — Institute of Organic Chemistry of the National Academy of Sciences of Ukraine; Chemspace LLC
  • Alexander E. Pashenko — Institute of Organic Chemistry of the National Academy of Sciences of Ukraine; Enamine Ltd.; Taras Shevchenko National University of Kyiv
  • Radomyr V. Smalii — Enamine Ltd.
  • Dmitry M. Volochnyuk — Institute of Organic Chemistry of the National Academy of Sciences of Ukraine; Enamine Ltd.; Taras Shevchenko National University of Kyiv
  • Serhii V. Ryabukhin — Institute of Organic Chemistry of the National Academy of Sciences of Ukraine; Enamine Ltd.; Taras Shevchenko National University of Kyiv
Main Authors: Oksiuta, Oleksandr V., Pashenko, Alexander E., Smalii, Radomyr V., Volochnyuk, Dmitry M., Ryabukhin, Serhii V.
Format: Article
Language:English
Published: National University of Pharmacy 2023
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Online Access:https://ophcj.nuph.edu.ua/article/view/275133
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Journal Title:Journal of Organic and Pharmaceutical Chemistry
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Journal of Organic and Pharmaceutical Chemistry
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author Oksiuta, Oleksandr V.
Pashenko, Alexander E.
Smalii, Radomyr V.
Volochnyuk, Dmitry M.
Ryabukhin, Serhii V.
author_facet Oksiuta, Oleksandr V.
Pashenko, Alexander E.
Smalii, Radomyr V.
Volochnyuk, Dmitry M.
Ryabukhin, Serhii V.
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description Aim. DNA-encoded libraries technologies (DELT) are gradually becoming an important part of standard drug discovery toolbox. DELT is looking to find its place between classic low-molecular-weight drug candidates on the one hand, and high-molecular-weight antibodies and peptides on the other hand. On its natural path to overcoming the “childhood diseases” typical for every novel technology, DELT has reached a point where the chemical diversity of DNA-encoded libraries (DELs) becomes an important factor to look out for. In this paper, we aim to take a closer look at the chemical diversity of DELs in their present state and find the ways to improve it.Results and discussion. We have identified the DEL-viable building blocks from the Enamine Ltd. stock collection, as well as from Chemspace Ltd. virtual collection, using the SMARTS set, which takes into account all the necessary structural restrictions. Using modern cheminformatics tools, such as Synt-On, we have analyzed the scaffold diversity of both stock and virtual core bi- and tri-functional building blocks (BBs) suitable for DNA-tolerant reactions. The identification of scaffolds from the most recently published on-DNA heterocyclization reactions and analysis of their inclusion into the existing BBs space have shown that novel DNA-tolerant heterocyclizations are extremely useful for expanding chemical diversity in DEL technologies.Conclusions. The analysis performed allowed us to recognize which functional groups should be prioritized as the most impactful when the new BBs are designed. It is also made clear that the development of new DNA-tolerant reactions, including heterocyclizations, have a significant potential to further expand DEL molecular diversity.
doi_str_mv 10.24959/ophcj.23.275133
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fulltext ISSN 2308-8303 (Print) / 2518-1548 (Online) 3 Advanced Research http://ophcj.nuph.edu.ua UDC 615: 54.057:547.833:577.113 O. V. Oksiuta1,2, A. E. Pashenko1,3,4, R. V. Smalii3, D. M. Volochnyuk1,3,4, S. V. Ryabukhin1,3,4 1 Institute of Organic Chemistry of the National Academy of Sciences of Ukraine, 5 Academician Kukhar str., 02660 Kyiv, Ukraine 2 Chemspace Ltd., 85 Winston Churchill str., 02094 Kyiv, Ukraine 3 Enamine Ltd., 78 Winston Churchill str., 02094 Kyiv, Ukraine 4 Taras Shevchenko National University of Kyiv, 60 Volodymyrska str., 01033 Kyiv, Ukraine Heterocyclization vs Coupling Reactions: A DNA-Encoded Libraries Case Abstract Aim. DNA-encoded libraries technologies (DELT) are gradually becoming an important part of standard drug discovery toolbox. DELT is looking to find its place between classic low-molecular-weight drug candidates on the one hand, and high-molecular- weight antibodies and peptides on the other hand. On its natural path to overcoming the “childhood diseases” typical for every novel technology, DELT has reached a point where the chemical diversity of DNA-encoded libraries (DELs) becomes an important factor to look out for. In this paper, we aim to take a closer look at the chemical diversity of DELs in their present state and find the ways to improve it. Results and discussion. We have identified the DEL-viable building blocks from the Enamine Ltd. stock collection, as well as from Chemspace Ltd. virtual collection, using the SMARTS set, which takes into account all the necessary structural restric- tions. Using modern cheminformatics tools, such as Synt-On, we have analyzed the scaffold diversity of both stock and virtual core bi- and tri-functional building blocks (BBs) suitable for DNA-tolerant reactions. The identification of scaffolds from the most recently published on-DNA heterocyclization reactions and analysis of their inclusion into the existing BBs space have shown that novel DNA-tolerant heterocyclizations are extremely useful for expanding chemical diversity in DEL technologies. Conclusions. The analysis performed allowed us to recognize which functional groups should be prioritized as the most im- pactful when the new BBs are designed. It is also made clear that the development of new DNA-tolerant reactions, including heterocyclizations, have a significant potential to further expand DEL molecular diversity. Keywords: DNA-encoded libraries technology; orthogonal functional groups; coupling reactions; polyfunctional building blocks; heterocyclizations; chemoinformatics; scaffold diversity О. В. Оксюта1,2, A. Є. Пащенко1,3,4, Р. В. Смалій3, Д. М. Волочнюк1,3,4, С. В. Рябухін1,3,4 1 Інститут органічної хімії Національної академії наук України, вул. Академіка Кухаря, 5, м. Київ, 02660, Україна 2 ТОВ «Кемспейс», вул. Вінстона Черчилля, 85, м. Київ, 02094, Україна 3 НВП «Єнамін», вул. Вінстона Черчилля, 78, м. Київ, 02094, Україна 4 Київський національний університет імені Тараса Шевченка, вул. Володимирська, 60, м. Київ, 01033, Україна Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек Анотація Мета. Технології ДНК-кодованих бібліотек (DELT) поступово стають важливою частиною стандартного набору інстру- ментів для пошуку нових лікарських субстанцій. Наразі DELT прагне знайти своє місце у просторі між класичними низькомолекулярними кандидатами у ліки з одного боку та високомолекулярними антитілами й пептидами з іншого. На своєму шляху до подолання «дитячих хвороб», характерних для кожної нової технології, DELT досягли того мо- менту, коли хімічна різноманітність ДНК-кодованих бібліотек (DEL) стає важливим фактором, на який варто звернути увагу. У цій статті ми прагнемо ближче розглянути хімічне різноманіття ДНК-кодованих бібліотек у їхньому поточному стані та знайти можливості для його покращення. Результати та їх обговорення. Ми визначили DEL-життєздатні будівельні блоки з наявної колекції Enamine Ltd., а також із віртуальної колекції Chemspace Ltd., використовуючи набір SMARTS, який враховує всі необхідні структурні обмеження. ISSN 2308-8303 (Print) / 2518-1548 (Online) 4 Журнал органічної та фармацевтичної хімії 2023, 21 (1) За допомогою таких сучасних інструментів хемоінформатики, як Synt-On, ми проаналізували різноманітність каркасів як уже синтезованих, так і віртуальних бі- та трифункціональних білдинг-блоків (BB), придатних для реакцій, у яких ДНК залишається інтактною. Ідентифікація молекулярних скафолдів, використовуваних у нещодавно опублікованих «on-DNA» реакціях гетероциклізації, та аналіз їх внесення до простору BB, який існує, засвідчили, що нові толерантні до ДНК гетероциклізації є надзвичайно корисними для розширення хімічної різноманітності в технологіях DEL. Висновки. Виконаний аналіз дозволив нам визначити, яким функціональним групам варто віддати пріоритет як най- більш впливовим у процесі дизайну нових BB. Також стало зрозуміло, що розвиток нових толерантних до ДНК реакцій, зокрема й гетероциклізації, має значний потенціал для подальшого розширення молекулярного різноманіття DEL. Ключові слова: технологія ДНК-кодованих бібліотек; ортогональні функціональні групи; реакції каплінгу; поліфункціо- нальні білдинг-блоки; гетероциклізації; хемоінформатика; разноманітність молекулярних каркасів Citation: Oksiuta, O. V.; Pashenko, A. E.; Smalii, R. V.; Volochnyuk, D. M.; Ryabukhin, S. V. Heterocyclization vs Coupling Reactions: A DNA-Encoded Libraries Case. Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1), 3 – 19. https://doi.org/10.24959/ophcj.23.275133 Supporting information: The links to source databases: Enamine Ltd. DEL-viable stock bi- and tri-functional core building blocks (freely available at https://cloud.chem-space.com/s/zk7QraSYsrcn7c4); ChemSpace tangible virtual DEL-viable bi- and tri-functional core building blocks (freely available at https://cloud.chem-space.com/s/ePmFyzNYj6bQbci). The set of SMARTS used for separating the abovementioned sub-sets is available free of charge at https://cloud.chem-space.com/s/3DbC7KZeKGK4ZaW. Received: 14 January 2023; Revised: 23 February 2023; Accepted: 5 March 2023 Copyright© 2023, O. V. Oksiuta, A. E. Pashenko, R. V. Smalii, D. M. Volochnyuk, S. V. Ryabukhin. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0). Funding: The authors received no specific funding for this work. Conflict of interests: The authors have no conflict of interests to declare. ■ Introduction DNA-Encoded Libraries Technology (DELT) was first proposed as an idea by Brenner and Lerner back in 1992 [1]. Since then it has become an ac- tively developing tool for Drug Discovery, which allows to generate the multi-billion screening mo- lecules collection in a single vial [2] and identify the hit molecules by decoding their unique DNA tags. The synthesis of DNA-encoded chemical lib- raries (DECLs) [3] is based on the split-and-pool strategy [4, 5], which is a common combinatorial chemistry approach topped with DNA fragments as chipping tags. The most general sequence for a DNA-encoded library synthesis is schematically presented in Figure 1. Building-blocks and the corresponding DNA tags are repeatedly connec- ted to DNA primers from the opposing end (Figu- re 1). The most common approach to screening the DNA-encoded libraries [6, 7] demands placing the protein target of interest (POI) on the solid sup- port bed and exposing it to the action of the set of DNA-tagged molecules from the library (Figu- re 2). The binders remain connected to the pro- tein, and the non-binding molecules are washed away (Figure 2). Then the binders (potential hits) are eluted, their chemical structures are disclo- sed using PCR sequencing of the coding DNA- tags, and the data obtained is analyzed. At the current stage of the DELT development, it is gra- dually beginning to expand into more complex biological assays, for instance cell-based assays [8 – 11], which is a positive sign indicating the fle- xibility and translation potential of DELT-based platforms. It is notable that the size of libraries created using the DEL technology nowadays exceeds the size of the conventional high-throughput screen- ing (HTS) combinatorial libraries by several or- ders of magnitude. The HTS libraries almost ne- ver exceed one million individual compounds, while 3- and 4-cycle DNA-encoded libraries with the input size of 1000 molecules on each cycle ge- nerate a billion and a trillion molecules, respec- tively. The typical sequence for the four-cycle assem- blies is given in Figure 3. It is worth mentioning that there are also several approaches to DNA- tagging, likewise double-strand [4, 12] and single- strand [13] technologies. However, this technical aspect is non-important for the current discus- sion. Although traditionally viewed as the major advantage, the gigantic size of the DELs also in- troduces several risks and drawbacks. First of all, chemical diversity of such libraries relies heavily on the pool of reactions available for the DNA- friendly environment [7, 14], as well as on the sufficient number of suitable and available bi- and tri-functional core building blocks (BBs) with or- thogonal functional groups (FGs), and diverse mono- functional molecules (capping agents) [15 – 19]. Another important factor influencing the success of DEL-derived screening campaigns is the de- velopment of the readout methods [4, 20, 21] and statistical analysis of the hits [21 – 23]. ISSN 2308-8303 (Print) / 2518-1548 (Online) 5 Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1) DNA primer first generation second generation Figure 1. Schematic representation of the split-and-pool process for the DNA-encoded library synthesis Step 2. Screening of the DEL for affinity to Protein-of-Interest (PoI) on the solid support Step 1. Taking previously synthesi ed DEL for affinityz selection solid support Step 3. Washing inactive molecules out Elution from PoI Step 4. Identifying active molecules solid support PCR amplification Sequencing Data analysis Figure 2. Workflow for identifying an active molecule from DEL Linear Branched Cyclic Mono-functional Bi-functional Tri-functional Conserved scaffold Figure 3. Typical DEL sequence for a 4-step cycle with examples of mono-, bi-, tri-functional BBs ISSN 2308-8303 (Print) / 2518-1548 (Online) 6 Журнал органічної та фармацевтичної хімії 2023, 21 (1) As it is mentioned above, the main limitation for DELT is the demand to use only such chemi- cal transformations, which leave DNA fragments intact. At the early stages of development, DELT was used as a platform for amide couplings only [24]; however, the overall advances in organic synthesis techniques enabled the application of a broad spectrum of chemical transformations in DNA-tolerant conditions, including classical C-C and C-N cross-couplings [25], metathesis [26, 27], click reactions [17, 28 – 33], photoredox reactions [34], and many others. Now that the vast majority of common transformations used in the cross-couplings has been successfully trans- lated into on-DNA chemistry, and DELT is ap- proaching the moment when the search for new chemotypes again becomes a limiting factor. In this connection, the cheminformatic algorithms, such as eDESIGNER [35], which helps to design libraries accounting both diversity and reaction applicability factors, have been developed and re- ported recently. Eventually, in the “maturation” [36] process DELT replicates the evolutionary route of traditional HTS-derived combinatorial chemistry [37, 38] and is on a track from amide coupling to more complex cross-coupling reac- tions [39] and, finally, to the on-DNA heterocy- cles formation. One can find a comprehensive re- view on DNA-tolerant couplings described in mul- tiple review articles [3, 14, 39, 40], however, the works focused on the on-DNA heterocycles for- mation started to show up in the periodical press on a regular basis only recently. In this paper, we aim to give an overview on the diversity of DELT-suitable BBs for “traditional” cross-coupling reactions based on the catalogue of stock mole- cules provided by Enamine Ltd., and virtual set provided by Chemspace Ltd., and evaluate the potential contribution of the chemotypes emerg- ing from the most recent discoveries in the field of on-DNA heterocyclizations. ■ Results and discussion For the decomposition of the pool of stock (Enamine) building blocks we used the SMARTS set (see the experimental part for details) specially designed to account orthogonality of FGs in the multifunctional compounds, the absence of unde- sired functions (alkylators, moisture-sensitive groups, etc.), and find compatible mono-functional molecules or “capping agents” [19]. We distri- buted the molecules obtained according to the combination of functional and protective groups. In case of stock polyfunctional cores, 11 classes of bi-functional and 8 classes of tri-functional mo- lecules were identified. We decided not to inclu- de capping agents to our analysis. This is the most widespread group having a decent overlap with “traditional” monofunctional BBs commonly used for combinatorial chemistry, and it hardly con- tributes much to the chemical diversity, in con- trast with rather scarce suitable multifunctional core molecules. In case of stock BBs (Enamine), 26816 bi- and 1438 tri-functional “core” compounds were obtained (Figures 4 and 5, respectively). We performed the same type of extraction using SMARTS and further analysis in Chem- space (virtual) database. Additionally, the Synt- On software package was used for this analysis [41, 42]. Using Synt-On, 43 848 442 molecules in 33 sub-classes of, bi- and 3 119 488 molecules in 25 sub-classes of tri-functional BBs were iden- tified. Low-reactive BBs and those with non- orthogonal functional groups were removed. The molecules obtained were combined into broa- der classes as we did previously for stock com- pounds. This approach allows to evaluate which FGs and, consequently, which reactions contri- bute the most to the DEL-derived chemical space. Despite the insignificant shuffle in the “lower bracket” of the histogram for bi-functional mole- cules (Figure 6), the proportion between the most widespread chemotypes in virtual space remains close to the stock case (Figure 4). However, in case of tri-functional cores, the fraction of acids, which fulfill the selection criteria on the virtual side (Figure 7), is significantly smaller than in the stock (Figure 5). In all the remaining class- es, the general trend for virtual structures cor- relates with the stock. This observation led to the conclusion that despite many reactions were optimized for DNA-friendly conditions, the che- mical diversity of DELs remains to the most part to be limited to either amide- or ArX-amine cross-couplings. Introducing heterocycle formation reactions is a beneficial way to expand the chemical space of combinatorial chemistry-derived molecules, which have proven itself in the HTS develop- ment [43, 44]. It is also true that with the deve- lopment of organic synthesis many heterocyclic cores became readily available as scaffolds for classical combinatorial chemistry, as well as DEL-chemistry. Considering the growing num- ber of publications focused on the on-DNA cycle formation we assumed that DELT is about to cross the same frontier as traditional combinatorial ISSN 2308-8303 (Print) / 2518-1548 (Online) 7 Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1) chemistry did at the time when heterocycliza- tions became noticeable part of the combinato- rial reaction toolkit. In order to have a closer look at this tendency, we studied the literature sour- ces over the period from 2016 to 2020. We ob- served the growing number of such publications over time: a single one in 2015, and 14 in 2020. We also identified 26 distinct types of the on-DNA heterocycle formation reactions. They are sum- marized in Table 1. With this in mind, we wanted to study in more detail if scaffolds from on-DNA heterocycliza- tions occur as scaffolds in cross-coupling based DEL builds. In other words, we wanted to look at the population of heterocyclization-derived scaf- folds in the bi- and tri-functional core BBs sub- sets, and evaluate the potential contribution of he- terocyclizations to the DELT-relevant chemical space diversity. We used Synt-On to identify scaffolds in both stock and virtual bi- and tri- functional BBs sets, as well as in heterocycliza- tion reactions products in Table 1. The latter pro- vided 30 separate heterocyclic scaffolds. The scaf- fold-inclusion analysis for the scaffolds from Ta- ble 1 relative to bifunctional cores subclasses (Table 2) and trifunctional core subclasses (Ta- ble 3) was performed. The structure of Tables 2 and 3 is as follows: entry (subclass) number in the first column; subclass abbreviation and an overall number of compounds in the subclass; “scaffolds in ref” shows how many times scaf- folds from Table 1 are included “as is” or as sub- structures to the BBs subclass scaffolds; in the “molecules in ref” the number of molecules with “sub-class” scaffolds, which contain the exact structure of scaffolds from the heterocyclic set, 13472 9673 8418 8363 6109 2141 1041 704 573 427 260 0 2000 4000 6000 8000 10000 12000 14000 16000 Amine_FG NHPG_FG ArX_FG Acid_FG Ester_FG Aldehyde_FG Nitro_FG Alkyne_FG Boronate_FG SO2X_FG Azide_FG Figure 4. Enamine stock bifunctional DEL-viable BBs, 26816 molecules in 11 classes 996 821 651 506 210 184 40 22 0 200 400 600 800 1000 1200 ArX_(FG)2 Acid_(FG)2 NHPG_(FG)2 Amine_(FG)2 Ester_(FG)2 Nitro_(FG)2 Aldehyde_(FG)2 Alkyne_(FG)2 Figure 5. Enamine stock trifunctional DEL-viable BBs, 1438 molecules in 8 classes ISSN 2308-8303 (Print) / 2518-1548 (Online) 8 Журнал органічної та фармацевтичної хімії 2023, 21 (1) or contain those as substructures, is given; the “unique scaffolds” column contains data on how many scaffolds are represented in the subclass; the ”unique molecules” shows exactly how many molecules contain “unique scaffolds”. To summarize the data obtained, we com- bined the results of our calculations into a sin- gle table (Table 4). The latter shows the inclu- sion of heterocyclization-derived scaffolds into the overall pool of bi- and tri-functional BBs, the stock (Enamine), as well as the virtual ones (Chemspace). The results of this analysis are not entirely expected: despite the fact that over the half of the core BBs chemotypes used in the heterocyclizations described in Table 1 remain in DEL-chemistry for a long time (functional al- dehydes, amines, etc.), their use in the reaction types outside “traditional” cross-couplings im- mediately provide more than 30 % of the scaffold diversity in the entire DELT chemical extra- space. For better visualizing the outline from Table 4, we constructed diagrams showing the contribu- tion of the heterocyclic scaffolds to bifunctional BBs space, both stock (Figure 8A) and virtual (Figure 8B). We did the same for stock and vir- tual trifunctional blocks (Figure 9A and 9B, re- spectively). 35366119 22184906 14301221 5627307 2829764 250154 237588 3029451 1187202 2929 28750 0 5000000 10000000 15000000 20000000 25000000 30000000 35000000 40000000 Amine_FG NHPG_FG ArX_FG Acid_FG Ester_FG Aldehyde_FG Nitro_FG Alkyne_FG Boronate_FG SO2X_FG Azide_FG Figure 6. Chemspace “tangible” virtual bifunctional DEL-viable BBs, 43 848 442 molecules in 11 classes 2505411 298722 1689153 2393330 167795 317919 784 27172 0 500000 1000000 1500000 2000000 2500000 3000000 ArX_(FG)2 Acid_(FG)2 NHPG_(FG)2 Amine_(FG)2 Ester_(FG)2 Nitro_(FG)2 Aldehyde_(FG)2 Alkyne_(FG)2 Figure 7. Chemspace “tangible” virtual trifunctional DEL-viable BBs, 3 119 488 molecules in 8 classes ISSN 2308-8303 (Print) / 2518-1548 (Online) 9 Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1) Table 1. Heterocyclization reactions on DNA from the first case study to 2020 # Reaction Scaffold/Code 1 2 3 Reaction type: 5-membered Aromatic Rings formation 1. [31] NH O Cu(II) cat., borate buffer NH O N N N Ar [B] = B(OH)2 or Bpin TMS N3 Ar[B] N H N N Scaf_01 2. [45] NH O O O R1 N R2 NH2 TMS N3 NH O O HN R2 N N N N R1 C N H N N N Scaf_02 3. [45] NH O O O NH O O N N OC N N PPh3 NH N R1 R1 CO2H O N N Scaf_03 4. [46] NH C N NH2OH R O NH O N O N R CO2H O N N Scaf_04 5. [47] N H N H NH2 S R1 O R2 Br N S R1 R2 S N Scaf_05 Reaction type: 6-membered Aromatic Rings formation 6. [32] N H O N N N N Me OH Cu(II) cat., bipyridine/TEMPO DMSO/H2O N H O N N Me OH N N Scaf_06 7. [32] N H O N N N N Me proline, DMSO/H2O N H O N N Me BocN O NBoc NHN N Scaf_07 8. [32] N H O N N N N Me DMSO/H2O N H O N N Me R R N N Scaf_08 Reaction type: Fused Aromatic Rings formation 9. [48] NH O O O HN O O C N Me Me Me N NH2 N N HN Me MeMe N N Scaf_09 ISSN 2308-8303 (Print) / 2518-1548 (Online) 10 Журнал органічної та фармацевтичної хімії 2023, 21 (1) 1 2 3 10. [49] N H O F NO2 N H O N N R2 R1 NH2 2. Reduction 1. 3. R2 O R1 N H N Scaf_10 Reaction type: Carbocyclic, 5 and 6-membered Non-Aromatic Rings formation 11. [50] O R Ar [Ir] blue LED array O R Ar + Scaf_11 12. [51] N O NH2 OR R1 R2 O N O NH R R2 O R1 1. 2. NH O O NH N H Scaf_12 13. [27] N H N O N H O N [Ru] N H Scaf_13 14. [49] NH2 Br O MeO R1 R2 N O R1 R2 + O N H Scaf_14 15. [49] N H O NH2 R2 OH O NH2 R1 N H O N NH R2 R1 O O 1. 2. O N H HN Scaf_15 16. [52] NH O Zr(DS)4, ACN/H2OO NH2 O2N O Cl O NH O O N O Ph 1. 2. O N H O Scaf_16 17. [52] NH O O Cl O Cl NH O O N Ph Zr(DS)4, ACN/H2O NH2 1. 2. O NH Scaf_17 18. [27] N H N O N H O N [Ru] O 1-3 O 1-3 O H N Scaf_18 O H N Scaf_19 ONH Scaf_20 Continuation of Table 1 ISSN 2308-8303 (Print) / 2518-1548 (Online) 11 Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1) Continuation of Table 1 1 2 3 Reaction type: Polycyclic Non-Aromatic Rings formation 19. [53] N H O S N O O R1R2 Pyrrolidine/BzOH DMSO/H O2 NH O S N O OH R1 R2 O S N Scaf_21 20. [54] N Ph X Me O HN NH O O O DIPEA dioxane/H2O N Ph X HN NH O O O X = CH Nor ON H O H N O NH Scaf_22 ON H O H NN O NH Scaf_23 21. [55] N Me O NH2 NH N Me O HN H N R OR HN N H Scaf_24 22. [56] N H O O H O H2N N Boc N H O O H N N Boc cat. H2O + N H HN Scaf_25 23. [51] O O O O O O N OHO O R H 1. 2. R NH2 OO NH N H O NH Scaf_26 24. [57] N H O O Me O N H O O ON Me H HMeNHOH NaOAc aq buffer OHN O Scaf_27 25. [58] N H O O H O N H H N R2R1 OH 3-4 [Au/AgSbF6] O N N O R1 R2 * * N H O 1-2+ aq. NH3/MeNH2 O NH N H Scaf_28 O N H NH Scaf_29 26. [49] N H O H N O NH2 R O N H O N NH O R O HN N H Scaf_30 Notes: 1. – DNA fragment (double-stranded), ds-DNA 2. – DNA fragment (single-stranded), ss-DNA 3. – ss-DNA fragment on a solid support ISSN 2308-8303 (Print) / 2518-1548 (Online) 12 Журнал органічної та фармацевтичної хімії 2023, 21 (1) Table 2. The impact of heterocyclization-derived scaffolds to the bifunctional BBs chemical space # Sub-class Scaffolds in ref Molecules in ref Unique scaffolds Unique molecules 1 Acid_Aldehyde 6 12 55 331 2 Acid_Alkyne 6 10 25 141 3 Acid_ArX 79 234 311 2440 4 Acid_Azide 13 24 21 71 5 Acid_Ester 23 71 95 521 6 Acid_Nboc 257 806 349 1919 7 Acid_Ncbz 10 28 23 84 8 Acid_NCS 0 0 2 7 9 Acid_Nfmoc 179 437 247 1509 10 Acid_Nitro 29 46 119 781 11 Aldehyde_ArX 20 54 92 820 12 Aldehyde_Azide 0 0 6 8 13 Aldehyde_Ester 11 37 68 368 14 Aldehyde_Nboc 53 115 86 262 15 Aldehyde_Nitro 7 11 46 222 16 Aldehyde_SO2X 0 0 4 12 17 Amino_Alkyne 23 63 59 430 18 Amino_ArX 177 422 577 3352 19 Amino_Azide 7 16 21 54 20 Amino_Ester 267 878 523 4047 21 ArX_AlkyneCH 2 4 18 108 22 ArX_ArX 57 168 232 1227 23 Azide_ArX 4 8 11 80 24 Azide_SO2X 0 0 3 17 25 Diamines_Nbn 67 131 75 205 26 Diamines_Nboc 302 807 469 1761 27 Diamines_Ncbz 11 18 19 46 28 Diamines_Nfmoc 3 7 9 11 29 Ester_Isocyanates 1 2 6 31 30 Ester_SO2X 9 29 43 372 31 Functional tetrazine 0 0 2 8 32 Functional_Boronates 21 40 90 562 33 Functional_BF3K 8 12 18 51 Table 3. The impact of heterocyclization-derived scaffolds to the trifunctional BBs chemical space # Sub-class Scaffolds in ref Molecules in ref Unique scaffolds Unique molecules 1 2 3 4 5 6 1 1,3,5-Trisfunctionalised_benzenes 12 15 20 257 2 Acid_Aldehyde_AlkyneCH 0 0 1 1 3 Acid_Aldehyde_ArX 1 3 6 23 4 Acid_Aldehyde_Nitro 0 0 1 4 5 Acid_ArX_Ester 0 0 5 16 6 Acid_ArX_Nitro 0 0 9 71 7 Acid_Ester_Nitro 0 0 2 5 8 Amino_ArX_ArX 3 10 35 172 9 Amino_ArX_Nitro 0 0 13 102 10 ArX_ArX_ArX 3 4 27 93 11 ArX_ArX_Carboxy 9 27 27 201 12 Azide_ArX_Carboxy 0 0 0 0 13 NbocAA_AlkyneCH 1 2 4 16 14 NbocAA_ArX 4 6 18 69 15 NbocAA_Ester 4 10 4 30 16 NbocAA_Nitro 0 0 1 4 ISSN 2308-8303 (Print) / 2518-1548 (Online) 13 Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1) 1 2 3 4 5 6 17 NbocArX_Amino 10 11 29 40 18 NbocEsterAA_Aldehyde 3 3 7 10 19 NbocEsterAA_Amino 23 41 24 57 20 NbocNCbzAA 2 2 4 8 21 NbocNfmocAA 21 34 23 75 22 NfmocAA_alkyneCH 1 1 3 7 23 NfmocAA_ArX 17 20 15 54 24 NfmocAA_Ester 1 4 5 27 25 NfmocAA_Nitro 0 0 1 3 Continuation of Table 3 Table 4. The overall quantity of bi- and tri-functional molecules containing the generated scaffolds (stock and virtual) # Scaffold (SMILES) Scaffold Structure/Code Bifunctional BBs Trifunctional BBs Stock Virtual Stock Virtual 1 2 3 4 5 6 7 1 C1CCNC1 N H Scaf_12 2078 7871461 109 485045 2 C1CCC1 Scaf_11 1104 5941890 27 312303 3 S1C=CN=C1 S N Scaf_05 648 1533087 15 75218 4 C1COCCN1 O NH Scaf_17 305 939622 3 51623 5 N1C=CN=N1 N H N N Scaf_01 175 660222 2 53908 6 C1=CC=NN=C1 N N Scaf_08 232 573015 33 52826 7 N1C=NC2=CC=CC=C12 N H N Scaf_10 69 175965 0 3524 8 O1C=NC=N1 O N N Scaf_04 39 156634 0 5888 9 N1C=NN=N1 N H N N N Scaf_02 29 103910 3 5056 10 C1NCC=C1 N H Scaf_13 21 57571 0 4304 11 C1=CN2C=CC=CC2=N1 N N Scaf_09 97 50346 5 1530 ISSN 2308-8303 (Print) / 2518-1548 (Online) 14 Журнал органічної та фармацевтичної хімії 2023, 21 (1) 1 2 3 4 5 6 7 12 O=C1NCCO1 O N H O Scaf_16 5 15795 0 756 13 O=C1CNCN1 O N H HN Scaf_15 5 4651 0 133 14 C1CC2=C(CN1)C=NN =C2 NHN N Scaf_07 0 2694 0 16 15 O=C1NCCC2=CC=CC =C12 O NH Scaf_26 2 274 0 5 16 O=C1NCC=C1 O N H Scaf_14 2 253 0 11 17 C1CC2=C(CN1)NC1=C C=CC=C21 HN N H Scaf_24 10 220 0 2 18 O=C1CC=CCN1 O H N Scaf_18 0 96 0 12 19 O=C1NCNC2=CC=CC =C12 O HN N H Scaf_30 0 11 0 0 20 C1CC2(CCCCO2)NN1 O N H NH Scaf_29 0 0 0 0 21 C1CC2CNC3=CC=CC =C3C2N1 N H HN Scaf_25 0 0 0 0 22 C1ONC2C1COC1=CC =CC=C21 OHN O Scaf_27 0 0 0 0 23 C1COC2(C1)CCNN2 O NH N H Scaf_28 0 0 0 0 24 C1COC2=C(C1)SC=N2 O S N Scaf_21 0 0 0 0 Continuation of Table 4 ISSN 2308-8303 (Print) / 2518-1548 (Online) 15 Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1) Continuation of Table 4 1 2 3 4 5 6 7 25 C1CCCC2=C(CC1)C =NN=C2 N N Scaf_06 0 0 0 0 26 O1C=NN=C1 O N N Scaf_03 0 0 0 0 27 O=C1CCC=CCN1 O H N Scaf_19 0 0 0 0 28 O=C1CCCC=CCN1 ONH Scaf_20 0 0 0 0 29 O=C1NC(=O)C2(CNC3=CC =CC=C3C2)C(=O)N1 ON H O H N O NH Scaf_22 0 0 0 0 30 O=C1NC(=O)C2(CNC3=NC =CC=C3C2)C(=O)N1 ON H O H NN O NH Scaf_23 0 0 0 0 2078 1104 648 305 232 175 97 69 Bifunctional BBs -(in stock, range 1) Scaf_12 Scaf_11 Scaf_05 Scaf_17 Scaf_08 Scaf_01 Scaf_09 Scaf_10 39 29 21 10 5 5 2 2 9 Scaf_04 Scaf_02 Scaf_13 Scaf_24 Scaf_16 Scaf_15 Scaf_26 Scaf_14 A 7871461 5941890 1533087 939622 660222 573015 175965 1409202 Bifunctional BBs (virtual, range 1) Scaf_12 Scaf_11 Scaf_05 Scaf_17 Scaf_01 Scaf_08 Scaf_10 156634 103910 57571 50346 15795 4651 269423140 Bifunctional BBs (virtual, range 2) Scaf_04 Scaf_02 Scaf_13 Scaf_09 Scaf_16 Scaf_15 Scaf_07 274 253 220 96 11107 Bifunctional BBs (virtual, range 3) Scaf_26 Scaf_14 Scaf_24 Scaf_18 Scaf_30 Bifunctional BBs - 2(in stock, range ) B 341 Figure 8. The visualized impact of the on-DNA heterocyclization reactions-derived scaffold to the existing chemical space of stock (A) and tangible virtual (B) bifunctional DEL-viable BBs ISSN 2308-8303 (Print) / 2518-1548 (Online) 16 Журнал органічної та фармацевтичної хімії 2023, 21 (1) ■ Conclusions We have analyzed both stock and virtual che- mical spaces of bi- and tri-functional DELT-viable building blocks using Enamine Ltd. stock collec- tion (ca. 30000 molecules) and Chemspace Ltd. tangible set (over 43 million structures) as case studies. Despite seeming variability within both groups (bi- and tri-functional BBs), the compounds with functions suitable for classic cross-coupling reactions, such as amide couplings or ArX – NHR2 couplings, namely acids, amines, protected amines and aryl halides, vastly outnumber other func- tional classes. The latter significantly limits both current and nearest-time potential chemical di- versity of the DNA-encoded libraries composed on the basis of these types of BBs, especially on the background of the huge size of such libra- ries: literally what we get is massive numbers of chemically homogeneous molecules, and it extre- mely complicates readout at the stages of the bio- logical testing. Considering the fact that in case of the cross-coupling approach to the DEL syn- thesis, the overwhelming majority of potentially useful transformations were already adapted for DNA-friendly conditions, one promising way to approach better diversity of DEL chemical spa- ce is to facilitate the synthesis of less common classes of bi- and tri-functional cores like those with sulfonyl halide, boronate, nitro- or aldehy- de FGs. However, recent advances in on-DNA heterocyclizations introduced some new chemo- types to the field. Surprisingly, adding 30 scaf- folds derived from 26 types of heterocyclizations, even with many of these scaffolds already being a part of the multifunctional cores space, has al- lowed to expand the general scaffold diversity of the chemical space observed by more than 30 %. This finding clearly indicates that adapting the existing and/or finding new heterocyclizations suitable for DNA-friendly conditions, which first and foremost could feed on the existing pool of BBs, is another very potent way to expand the scaffold diversity in DELs. ■ Acknowledgments The authors express their gratitude to Ena- mine Ltd. and Chemspace Ltd. for granting access to their data sets, and personally to Prof. And- rey A. Tolmachev for encouragement and compre- hensive support in preparing the manuscript. 109 33 27 15 5 3 3 2 8 Trifunctional BBs -(in stock)- Scaf_12 Scaf_08 Scaf_11 Scaf_05 Scaf_09 Scaf_17 Scaf_02 Scaf_01 A B 485045 312303 75218 53908 52826 51623 104449 Trifunctional BBs (virtual, range 1) Scaf_12 Scaf_11 Scaf_05 Scaf_01 Scaf_08 Scaf_17 5888 5056 4304 3524 1530 756 133 2419 Scaf_04 Scaf_02 Scaf_13 Scaf_10 Scaf_09 Scaf_16 Scaf_15 Trifunctional BBs 2(virtual, range ) 16 12 11 5 2 7 Scaf_07 Scaf_18 Scaf_14 Scaf_26 Scaf_24 Trifunctional BBs 3(virtual, range ) Figure 9. The visualized impact of the on-DNA heterocyclization reactions-derived scaffold to the existing chemical space of stock (A) and tangible virtual (B) trifunctional DEL-viable BBs ISSN 2308-8303 (Print) / 2518-1548 (Online) 17 Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1) ■ References 1. Brenner, S.; Lerner, R. A. Encoded combinatorial chemistry. 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Skopic, M. K.; Gotte, K.; Gramse, C.; Dieter, M.; Pospich, S.; Raunser, S.; Weberskirch, R.; Brunschweiger, A. Micellar Bronsted Acid Me- diated Synthesis of DNA-Tagged Heterocycles. J. Am. Chem. Soc. 2019, 141 (26), 10546 – 10555. https://doi.org/10.1021/jacs.9b05696. 57. Gerry, C. J.; Yang, Z.; Stasi, M.; Schreiber, S. L. DNA-Compatible [3+2] Nitrone-Olefin Cycloaddition Suitable for DEL Syntheses. Org. Lett. 2019, 21 (5), 1325 – 1330. https://doi.org/10.1021/acs.orglett.9b00017. ISSN 2308-8303 (Print) / 2518-1548 (Online) 19 Journal of Organic and Pharmaceutical Chemistry 2023, 21 (1) 58. Klika Skopic, M.; Willems, S.; Wagner, B.; Schieven, J.; Krause, N.; Brunschweiger, A. Exploration of a Au(I)-mediated three-component reaction for the synthesis of DNA-tagged highly substituted spiroheterocycles. Org. Biomol. Chem. 2017, 15 (40), 8648 – 8654. https:// doi.org/10.1039/c7ob02347b. Information about the authors: Oleksandr V. Oksiuta, Ph.D. Student of the Biologically Active Compounds Department, Institute of Organic Chemistry of the National Academy of Sciences of Ukraine; Data Scientist at Chemspace Ltd.; https://orcid.org/0000-0003-3049-0373. Alexander E. Pashenko, Ph.D. in Chemistry, Junior Researcher of the Department of Physicochemical Investigations, Institute of Organic Chemistry of the National Academy of Sciences of Ukraine; https://orcid.org/0000-0001-6157-0785. Radomyr V. Smalii, Ph.D. in Chemistry, Project Manager at Enamine Ltd.; https://orcid.org/0000-0003-0379-1138. Dmitriy M. Volochnyuk (corresponding author), Dr.Sci. in Chemistry, Professor of the Supramolecular Chemistry Department, Institute of High Technologies, Taras Shevchenko National University of Kyiv; Head of the Biologically Active Compounds Department, Institute of Organic Chemistry of the National Academy of Sciences of Ukraine; Senior Scientific Advisor, Enamine Ltd.; https://orcid.org/0000-0001-6519-1467; e-mail for correspondence: d.volochnyuk@gmail.com. Sergey V. Ryabukhin (corresponding author), Dr.Sci. in Chemistry, Professor, Head of the Supramolecular Chemistry Department, Institute of High Technologies, Taras Shevchenko National University of Kyiv; Senior Scientific Advisor, Enamine Ltd.; Senior Researcher of the Department of Physicochemical Investigations, Institute of Organic Chemistry of the National Academy of Sciences of Ukraine; https://orcid.org/0000-0003-4281-8268; e-mail for correspondence: s.v.ryabukhin@gmail.com.
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spelling oai:ojs.journals.uran.ua:article-2751332026-08-23T20:00:17Z Heterocyclization vs Coupling Reactions: A DNA-Encoded Libraries Case Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек Oksiuta, Oleksandr V. Pashenko, Alexander E. Smalii, Radomyr V. Volochnyuk, Dmitry M. Ryabukhin, Serhii V. DNA-encoded libraries technology orthogonal functional groups coupling reactions polyfunctional building blocks heterocyclizations chemoinformatics scaffold diversity технологія ДНК-кодованих бібліотек ортогональні функціональні групи реакції каплінгу поліфункціональні білдинг-блоки гетероциклізації хемоінформатика разноманітність молекулярних каркасів Aim. DNA-encoded libraries technologies (DELT) are gradually becoming an important part of standard drug discovery toolbox. DELT is looking to find its place between classic low-molecular-weight drug candidates on the one hand, and high-molecular-weight antibodies and peptides on the other hand. On its natural path to overcoming the “childhood diseases” typical for every novel technology, DELT has reached a point where the chemical diversity of DNA-encoded libraries (DELs) becomes an important factor to look out for. In this paper, we aim to take a closer look at the chemical diversity of DELs in their present state and find the ways to improve it.Results and discussion. We have identified the DEL-viable building blocks from the Enamine Ltd. stock collection, as well as from Chemspace Ltd. virtual collection, using the SMARTS set, which takes into account all the necessary structural restrictions. Using modern cheminformatics tools, such as Synt-On, we have analyzed the scaffold diversity of both stock and virtual core bi- and tri-functional building blocks (BBs) suitable for DNA-tolerant reactions. The identification of scaffolds from the most recently published on-DNA heterocyclization reactions and analysis of their inclusion into the existing BBs space have shown that novel DNA-tolerant heterocyclizations are extremely useful for expanding chemical diversity in DEL technologies.Conclusions. The analysis performed allowed us to recognize which functional groups should be prioritized as the most impactful when the new BBs are designed. It is also made clear that the development of new DNA-tolerant reactions, including heterocyclizations, have a significant potential to further expand DEL molecular diversity. Мета. Технології ДНК-кодованих бібліотек (DELT) поступово стають важливою частиною стандартного набору інструментів для пошуку нових лікарських субстанцій. Наразі DELT прагне знайти своє місце у просторі між класичними низькомолекулярними кандидатами у ліки з одного боку та високомолекулярними антитілами й пептидами з іншого. На своєму шляху до подолання «дитячих хвороб», характерних для кожної нової технології, DELT досягли того моменту, коли хімічна різноманітність ДНК-кодованих бібліотек (DEL) стає важливим фактором, на який варто звернути увагу. У цій статті ми прагнемо ближче розглянути хімічне різноманіття ДНК-кодованих бібліотек у їхньому поточному стані та знайти можливості для його покращення.Результати та їх обговорення. Ми визначили DEL-життєздатні будівельні блоки з наявної колекції Enamine Ltd., а також із віртуальної колекції Chemspace Ltd., використовуючи набір SMARTS, який враховує всі необхідні структурні обмеження. За допомогою таких сучасних інструментів хемоінформатики, як Synt-On, ми проаналізували різноманітність каркасів як уже синтезованих, так і віртуальних бі- та трифункціональних білдинг-блоків (BB), придатних для реакцій, у яких ДНК залишається інтактною. Ідентифікація молекулярних скафолдів, використовуваних у нещодавно опублікованих «on-DNA» реакціях гетероциклізації, та аналіз їх внесення до простору BB, який існує, засвідчили, що нові толерантні до ДНК гетероциклізації є надзвичайно корисними для розширення хімічної різноманітності в технологіях DEL.Висновки. Виконаний аналіз дозволив нам визначити, яким функціональним групам варто віддати пріоритет як найбільш впливовим у процесі дизайну нових BB. Також стало зрозуміло, що розвиток нових толерантних до ДНК реакцій, включаючи гетероциклізації, має значний потенціал для подальшого розширення молекулярного різноманіття DEL. National University of Pharmacy 2023-06-03 Article Article application/pdf https://ophcj.nuph.edu.ua/article/view/275133 10.24959/ophcj.23.275133 Journal of Organic and Pharmaceutical Chemistry; Vol. 21 No. 1 (2023); 3-19 Журнал органической и фармацевтической химии; Том 21 № 1 (2023); 3-19 Журнал органічної та фармацевтичної хімії; Том 21 № 1 (2023); 3-19 2518-1548 2308-8303 en https://ophcj.nuph.edu.ua/article/view/275133/273037 Copyright (c) 2023 Oleksandr V. Oksiuta, Alexander E. Pashenko, Radomyr V. Smalii, Dmitry M. Volochnyuk, Serhii V. Ryabukhin http://creativecommons.org/licenses/by/4.0
spellingShingle технологія ДНК-кодованих бібліотек
ортогональні функціональні групи
реакції каплінгу
поліфункціональні білдинг-блоки
гетероциклізації
хемоінформатика
разноманітність молекулярних каркасів
Oksiuta, Oleksandr V.
Pashenko, Alexander E.
Smalii, Radomyr V.
Volochnyuk, Dmitry M.
Ryabukhin, Serhii V.
Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек
title Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек
title_alt Heterocyclization vs Coupling Reactions: A DNA-Encoded Libraries Case
title_full Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек
title_fullStr Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек
title_full_unstemmed Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек
title_short Гетероциклізація або реакції каплінгу: випадок ДНК-кодованих бібліотек
title_sort гетероциклізація або реакції каплінгу: випадок днк-кодованих бібліотек
topic технологія ДНК-кодованих бібліотек
ортогональні функціональні групи
реакції каплінгу
поліфункціональні білдинг-блоки
гетероциклізації
хемоінформатика
разноманітність молекулярних каркасів
topic_facet DNA-encoded libraries technology
orthogonal functional groups
coupling reactions
polyfunctional building blocks
heterocyclizations
chemoinformatics
scaffold diversity
технологія ДНК-кодованих бібліотек
ортогональні функціональні групи
реакції каплінгу
поліфункціональні білдинг-блоки
гетероциклізації
хемоінформатика
разноманітність молекулярних каркасів
url https://ophcj.nuph.edu.ua/article/view/275133
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