Capable source of those C-glycosides. We previously reported bifunctional C-glucosyl/C-arabinosyltransferases in Oryza sativa japonica and O. sativa indica, which influence the C-glycoside spectrum in various rice varieties. In this study, we proved the C-arabinosyl-transferring activity of rice C-glycosyltransferases (CGTs) on the mono-C-glucoside substrate nothofagin, followed by taking advantage of distinct CGTs and introducing heterologous UDP-pentose provide, to understand the production of eight different C-arabinosides/xylosides in recombinant E. coli. Fed-batch fermentation and precursor supplement maximized the titer of rice-originated C-arabinosides to 2010 mg/L in an E. coli chassis. The optimized final titer of schaftoside and apigenin di-C-arabinoside reached 19.87 and 113.16 mg/L, respectively. We demonstrate here the accomplishment of de novo bio-production of C-arabinosylated and C-xylosylated flavones by heterologous pathway reconstitution. These final results lay a foundation for further optimal manufacture of complex flavonoid compounds in microbial cell factories. Keyword phrases: De novo biosynthesis, C-Arabinoside flavone, C-Glycosyltransferase, Rice Introduction Flavone C-arabinosides are among the much less widespread classes of flavonoid glycosides occurring in nature. Despite of their mAChR1 Biological Activity rarity, lots of flavones bearing C-arabinosyls have been reported to show intriguing physiological activities. For example, schaftoside (apigenin 6-C-glucosyl-8-C-arabinoside, Sch) is present as a major component within the Chinese herb Desmodium styracifolium, possessing diverse bioactivities which includes antioxidant, anti-inflammatory (De Melo et al. 2005), antimelanogenic (Kim et al. 2018b) activities and inhibiting the formationCorrespondence: [email protected] Zhuo Chen and Yuwei Sun contributed equally to this operate 1 CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China Full list of author facts is readily available at the end of the articleof gallstones and kidney stones (Liu et al. 2017). Apart from, schaftoside was also reported as a feeding inhibitor and resistance aspect to brown planthopper (Stevenson et al. 1996). As an isomer of schaftoside, isoschaftoside (Isosch) was also identified to become an allelochemical against the development of Striga (Hooper et al. 2010). Carlinoside (luteolin 6-C-glucosyl-8-C-arabinoside) from Cajanus plants shows antihepatitic and bilirubin solubilization activity (Das et al. 2018). Not too long ago, each schaftoside and carlinoside had been identified as active components against COVID-19. In silico analysis regarded schaftoside as among the leading ten among 318 phytochemicals that had substantially reduced binding energy to Mpro (the Estrogen receptor list primary protease of SARSCoV-2) and ACE2 (angiotensinconverting enzyme two) as compared to the reference molecule PRD_002214 (Joshi et al. 2020). Molecular docking indicated carlinoside was the best candidate against MproThe Author(s) 2021. This article is licensed below a Inventive Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, provided that you give appropriate credit to the original author(s) and also the source, supply a link towards the Creative Commons licence, and indicate if modifications had been created. The images or other third party material in this write-up are included inside the article’s Inventive Commons licence,.