دانلود رایگان مقاله لاتین گلیکوزیلاسیون رجیوسلکتیو هیدروکسیل الکل از سایت الزویر
عنوان فارسی مقاله:
گلیکوزیلاسیون رجیوسلکتیو هیدروکسیل الکلی triterpenoids protostane واسطه شده زیست دگرگونی قارچی
عنوان انگلیسی مقاله:
Highly regioselective glucosylation of alcoholic hydroxyls of protostane triterpenoids mediated by fungal biotransformation
سال انتشار : 2017
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مقدمه انگلیسی مقاله:
1. Introduction
Protostane triterpenoids belong to a group of tetracyclic triterpenes that exhibit unique structural characteristics [1]. To date, a number of protostanes have been obtained from natural sources, especially the genus Alisma of the Alismataceae family [1]. In our previous chemical investigations, we isolated several vital protostanes from Alisma orientale, which is a traditional medicine widely distributed throughout China, Japan, North America, and Europe [2]. Bioassays have also demonstrated that protostane triterpenoids have potential inhibitory effects on vascular contraction [3], immunosuppression [4], and HBV [5]. However, it is noteworthy that no natural or artificial protostane glycosides have been obtained. Therefore, to the best of our knowledge, chemical and biological investigations of protostane glycosides have not been reported in the literature. To prepare the synthetic glycosides, chemical glycosylation has been conducted and displayed weaknesses, such as relatively low yield of the final glycosides, glycosyl activation, and multiple steps of protection/ deprotection to control regio- and stereo-selectivity [6–8]. Compared with chemical glycosylation, biotransformed glycosylation has been thought to be an efficient and environmentally friendly method. Ye et al. conducted the glucosylation of cinobufagin, cardioactive C-24 steroids using suspensions of cells of Catharanthus roseus [9]. Compared with the glucosylation of alcoholic hydroxyls, more investigations have been conducted on the phenolic hydroxyls. Glucosides of the phenolic hydroxyls of taxifolin by cultured cells of Nicotiana tabacum and Catharanthus roseus have been prepared by Shimoda et al. [10] Cunninghamella echinulata AS 3.3400 and Rhizopus japonicus ZW-4 were also used to glucosylate the phenolic compounds magnolol and honokiol [11]. Xie et al. explored a new glycosyltransferase (UGT73AE1) from Carthamus tinctorius, which could catalyze glycosylation of phenolic hydroxyls [12]. In brief, biotransformation has been shown to catalyze the glycosylation of natural compounds efficiently. However, most of these investigations were related to the glycosylation of phenolic hydroxyls. It is still worthwhile to explore a highly efficient transformational method to catalyze the glycosylation of alcoholic hydroxyls of natural compounds selectively. Based on biotransformation studies of various natural compounds [13–16], we conducted the biotransformed glucosylation of alcoholic hydroxyls in the structures of protostanes with regioselective characteristics.
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کلمات کلیدی:
Jungui Dai - Citations - ResearchGate https://www.researchgate.net/profile/Jungui_Dai/citations Highly regioselective glucosylation of alcoholic hydroxyls of protostane triterpenoids ... Article: Glucosylation of cinobufagin by cultured suspension cells of ... [PDF]Regioselective Benzoylation of Diols and Carbohydrates by Catalytic ... www.mdpi.com/1420-3049/21/5/641/pdf by Y Lu - 2016 - Cited by 1 - Related articles May 17, 2016 - regioselectivities in the benzoylation of hydroxyl groups with an excess amount of alcohol [33]. ... method showed good regioselectivity for the primary hydroxyl group in ... The carbonylimidazole derivatives are a class of highly acylation ..... of a Palladium-Catalyzed O-Glycosylation through an Inner-Sphere ... Pyrethroids: From Chrysanthemum to Modern Industrial Insecticide https://books.google.com/books?isbn=3642273467 Noritada Matsuo, Tatsuya Mori - 2012 - Science The highly conserved residues of glutamic acid and histidine are considered to be ... The 14 proteins showed the regioselective glucosylation of the hydroxyl ... either acid or alcohol moieties are considered to be similarly glucosylated by these ... Carbohydrate Chemistry Volume 41: - Page 140 - Google Books Result https://books.google.com/books?isbn=1782621210 Amelia Pilar Rauter, Thisbe K Lindhorst, Yves Queneau - 2015 - Reference ... 4 h serendipitously regioselective to leave the C1 hydroxyl group (alcohol 28) available for the glycosylation as it was used in Scheme 7.27a Up ... 36a reacted in a highly a-stereoselective (a/b 20:1) manner with donor 55, its peracetylated ... Current Organic Chemistry - Jul 1999 - Page 382 - Google Books Result https://books.google.com/books?id=0HO-3M534nEC Vol. 3, No. 4 - Magazine Enantiotopic group-selective hydrolysis of highly oxygenated six-membered allylic ... primary alcohol, which served as the glycosyl acceptor for galactosylation. ... In this glycosylation reaction so far, the migration of the acetyl group from the ... Regioselective protection-deprotection of hydroxyl groups of carbohydrates have ... The Organic Chemistry of Sugars - Page 182 - Google Books Result https://books.google.com/books?isbn=1420027956 Daniel E. Levy, Péter Fügedi - 2005 - Science ... and syntheses of large and highly complex structures, some even exceeding ... its anomeric hydroxyl to some of the alcoholic hydroxyl groups of the acceptor, ... of the various glycosylation methods, protecting groups and reaction conditions. ... having only the primary hydroxyl free, was obtained from 1 by regioselective ...
