[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-41131-en":3,"doc-seo-41131-105":30,"detail-sidebar-cat-0-en-105":95},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":21,"is_downloadable":21,"audit_status":21,"page_count":22,"language":23,"language_code":24,"site_id":25,"html_lang":24,"table_of_contents":26,"faqs":27,"seo_title":13,"seo_description":14,"update_tm":28,"read_time":29},41131,7971461741311,"Ophelia","https://ap-avatar.wpscdn.com/avatar/74000253aff267980c6?x-image-process=image/resize,m_fixed,w_180,h_180&k=1779345379180704826",8,"Research & Report","Prebiotic Photochemical Coproduction of Purine Ribo-and Deoxyribonucleosides","The hypothesis that early life began with a mixed nucleic acid system containing both RNA and DNA has gained support from findings that multiple RNA and DNA subunits can be co-produced in a shared reaction network. A unified prebiotically plausible synthesis of the missing purine ribonucleosides and pyrimidine deoxyribonucleosides remained unclear. This study presents a stereoselective, furanosyl-selective photochemical route producing adenosine, inosine, and corresponding deoxynucleosides from thioanhydroadenosine via sulfi te in alkaline solution, supported by mechanistic radical recombination that forms the ribo C2′–O bond.","[pubs.acs.org/JACS](pubs.acs.org/JACS)  Communication   \nPrebiotic Photochemical Coproduction of Purine Ribo-and Deoxyribonucleosides  \nJianfeng Xu,* Nicholas J. Green, David A. Russell, Ziwei Liu, and John D. Sutherland *  \n Cite This: J. Am. Chem. Soc. 2021, 143, 14482−14486  \nRead Online  \nACCESS  \n Metrics & More  \n Article Recommendations  \n*sı   \nSupporting Information  \nDownloaded via 104.28.2 18.132 on August 28, 2024 at 17:34:03 (UTC) .  \nSee [https://pubs.acs.org/sharingguidelines](https://pubs.acs.org/sharingguidelines) for options on how to legitimately share published articles.  \nABSTRACT: The hypothesis that life on Earth may have started with a heterogeneous nucleic acid genetic system including both RNA and DNA has attracted broad interest. The recent finding that two RNA subunits (cytidine, C, and uridine, U) and two DNA subunits (deoxyadenosine, dA, and deoxyinosine, dI) can be coproduced in the same reaction network, compatible with a consistent geological scenario, supports this theory. However, a prebiotically plausible synthesis of the missing units (purine ribonucleosides and pyrimidine deoxyribonucleosides) in a unified reaction network remains elusive. Herein, we disclose a strictly stereoselective and furanosyl-selective synthesis of purine ribonucleosides (adenosine, A, and inosine, I) and purine deoxynucleosides (dA and dI), alongside one another, via a key photochemical reaction of thioanhydroadenosine with sulfite in alkaline solution (pH 8−10). Mechanistic studies suggest an unexpected recombination of sulfite and nucleoside alkyl radicals underpins the formation of the ribo C2′−O bond. The coproduction of A, I, dA, and dI from a common intermediate, and under conditions likely to have prevailed in at least some primordial locales, is suggestive of the potential coexistence of RNA and DNA building blocks at the dawn of life.  \nThe composition of Earth’s first genetic polymer has long  \nbeen the subject of intense research. 1−3 Contrary to the common “RNA world” hypothesis, the “R/DNA world” theory posits that the first genetic system might have comprised both RNA and DNA nucleotides.4−6 This scenario potentially circumvents the postulated “genetic takeover” of homogeneous DNA from RNA as the genetic information carrier in the RNA world,7 replacing it with a divergence of RNA and DNA subcomponents into more specialized roles. Recent developments in the prebiotic synthesis of purine deoxyribonucleosides (dA 1 and dI 2)8,9 from ribo-aminooxazoline (RAO 3, Scheme 1), a common intermediate in the synthesis of pyrimidine ribonucleosides (C 4 and U 5),10 support the notion that RNA and DNA building blocks could have coexisted before life’s emergence. However, existing prebiotic syntheses of purine ribonucleosides 11−14 depend on chemically and enantiomerically pure sugar starting materials unlikely to have existed on primordial Earth (e.g., ribose) 15 or produce low yields of biologically relevant nucleosides among a plethora of undesirable isomers and congeners. Hence, a robust, stereoselective and furanosyl-selective synthesis of purine ribonucleosides remains an attractive goal of prebiotic synthesis. Because of its properties as a conglomerate, RAO 3, which crystallizes enantiopure from solutions of minimally enantioenriched carbohydrates, 16, 17 is of interest as a common precursor to nucleosides.  \nPreviously, we described a potentially prebiotic synthesis of deoxyadenosine 1 via photochemical reduction of thioanhydroadenosine 6 with sodium bisufite or hydrogen sulfide at pH 7. Thioanhydroadenosine 6 was furnished by tethered glycosylation with anhydropyrimidines 7, derived fromenantiopure RAO 3.9 Our synthesis of dA 1 was ultimately completely selective for the canonical stereochemistry, regiochemistry, and furanosyl isomer of dA and thus  \nScheme 1. Synthesis of Purine Deoxyribonucleosides and Pyrimidine Ribonucleosides in a Unified Reaction Networka  \naRAO is a common precursor in previous works9, 10 an","cbCaihjFNntmDfsH","https://ap.wps.com/l/cbCaihjFNntmDfsH","pdf",1103500,2,1,5,"English","en",105,"# Abstract\n## Prebiotic RNA/DNA coexistence\n## Challenge in synthesizing missing nucleosides\n## New stereoselective photochemical synthesis\n## Mechanistic interpretation and implications","[{\"question\":\"What main problem does the study address about prebiotic nucleoside synthesis?\",\"answer\":\"A prebiotically plausible, unified reaction network for producing the missing purine ribonucleosides and pyrimidine deoxyribonucleosides had remained unresolved.\"},{\"question\":\"Which compounds are synthesized in this photochemical approach?\",\"answer\":\"The work reports stereoselective and furanosyl-selective synthesis of purine ribonucleosides (adenosine and inosine) and purine deoxynucleosides (dA and dI).\"},{\"question\":\"What key reaction and conditions enable the coproduction?\",\"answer\":\"A photochemical reaction of thioanhydroadenosine with sulfite in alkaline solution (pH 8–10) drives the formation of the nucleosides in a shared pathway.\"},{\"question\":\"How do mechanistic studies explain formation of the ribo C2′–O bond?\",\"answer\":\"Mechanistic results indicate an unexpected recombination of sulfite and nucleoside alkyl radicals underpins formation of the ribo C2′–O bond.\"}]",1783319115,13,{"code":4,"msg":31,"data":32},"ok",{"site_id":25,"language":24,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":90,"head_meta":92,"extra_data":94,"updated_unix":28},"prebiotic-photochemical-coproduction-of-purine-ribo-and-deoxyribonucleosides","",{"@graph":36,"@context":89},[37,53,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,47,50],{"item":41,"name":42,"@type":43,"position":21},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":20},"https://docshare.wps.com/document/","Document",{"item":48,"name":12,"@type":43,"position":49},"https://docshare.wps.com/document/research-report/",3,{"item":51,"name":13,"@type":43,"position":52},"https://docshare.wps.com/document/prebiotic-photochemical-coproduction-of-purine-ribo-and-deoxyribonucleosides/41131/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":24,"description":14,"dateModified":61,"datePublished":62,"encodingFormat":60,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":41,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-13","2026-07-06",true,{"@type":65,"interactionType":66,"userInteractionCount":20},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81,85],{"name":72,"@type":73,"acceptedAnswer":74},"What main problem does the study address about prebiotic nucleoside synthesis?","Question",{"text":75,"@type":76},"A prebiotically plausible, unified reaction network for producing the missing purine ribonucleosides and pyrimidine deoxyribonucleosides had remained unresolved.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"Which compounds are synthesized in this photochemical approach?",{"text":80,"@type":76},"The work reports stereoselective and furanosyl-selective synthesis of purine ribonucleosides (adenosine and inosine) and purine deoxynucleosides (dA and dI).",{"name":82,"@type":73,"acceptedAnswer":83},"What key reaction and conditions enable the coproduction?",{"text":84,"@type":76},"A photochemical reaction of thioanhydroadenosine with sulfite in alkaline solution (pH 8–10) drives the formation of the nucleosides in a shared pathway.",{"name":86,"@type":73,"acceptedAnswer":87},"How do mechanistic studies explain formation of the ribo C2′–O bond?",{"text":88,"@type":76},"Mechanistic results indicate an unexpected recombination of sulfite and nucleoside alkyl radicals underpins formation of the ribo C2′–O bond.","https://schema.org",{"og:url":51,"og:type":91,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":93,"canonical":51},"index,follow",{"doc_id":7,"site_id":25},{"code":4,"msg":5,"data":96},[97,101,105,109,113,118,123,126,131,134,138],{"id":21,"doc_module":4,"doc_module_name":46,"category_name":98,"show_sort_weight":99,"slug":100},"Story & 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