86756-42-5Relevant academic research and scientific papers
Pseudoglycosyltransferase catalyzes nonglycosidic C-N coupling in validamycin a biosynthesis
Asamizu, Shumpei,Yang, Jongtae,Almabruk, Khaled H.,Mahmud, Taifo
, p. 12124 - 12135 (2011/10/09)
Glycosyltransferases are ubiquitous in nature. They catalyze a glycosidic bond formation between sugar donors and sugar or nonsugar acceptors to produce oligo/polysaccharides, glycoproteins, glycolipids, glycosylated natural products, and other sugar-containing entities. However, a trehalose 6-phosphate synthase-like protein has been found to catalyze an unprecedented nonglycosidic C-N bond formation in the biosynthesis of the aminocyclitol antibiotic validamycin A. This dedicated 'pseudoglycosyltransferase catalyzes a condensation between GDP-valienol and validamine 7-phosphate to give validoxylamine A 7′-phosphate with net retention of the 'anomeric configuration of the donor cyclitol in the product. The enzyme operates in sequence with a phosphatase, which dephosphorylates validoxylamine A 7′-phosphate to validoxylamine A.
Synthetic studies on antibiotic validamycins. Part 13. Total synthesis of (+)-validamycins A and E, and related compounds
Miyamoto, Yasunobu,Ogawa, Seiichiro
, p. 1013 - 1018 (2007/10/02)
(+)-Validoxylamine A (1) has been completely synthesized by deoxygenation of the validoxylamine B derivative (6) through formation of the aziridine, nucleophilic displacement with toluenethiol, reduction with Raney nickel, and deprotection. The validoxylamine A derivative (10) obtained was convertible, by glycosylation followed by deprotection, into validamycins A (2), E (3), and their analogues, which constitutes a total synthesis thereof.
Total Synthesis of (+)-Validoxylamine A
Ogawa, Seiichiro,Miyamoto, Yasunobu
, p. 889 - 890 (2007/10/02)
(+)-Validoxylamine A was synthesized by selective deoxygenation of (+)-validoxylamine B derivative, which was obtained by the coupling of the partially protected (+)-valienamine and (1R,2S,5R,7R,8R,9R,10R)-8,9-dibenzyloxy-5-phenyl-4,6,11-trioxatricyclo8.
Synthetic Studies on Antibiotic Validamycins. Part 11. Synthesis of Validamycin A
Ogawa, Seiichiro,Nose, Taisuke,Ogawa, Takao,Toyokuni, Tatsushi,Iwasawa, Yoshikazu,Suami, Tetsuo
, p. 2369 - 2374 (2007/10/02)
The antibiotic validamycin A (1a) has been synthesized for the first time (as its undeca-O-acetate) by glycosylation of the partially protected derivative (8) of the aglycone, validoxylamine A (2a), with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl chloride (11), followed by deprotection, thereby establishing the structure previously assigned.The totally O-acetylated derivative (19) of 7-deoxyvalidamycin A has been synthesized in a similar fashion.
A FORMAL TOTAL SYNTHESIS OF VALIDAMYCIN A
Ogawa, Seiichiro,Ogawa, Takao,Nose, Taisuke,Toyokuni, Tatsushi,Iwasawa, Yoshikazu,et al.
, p. 921 - 922 (2007/10/02)
Validamycin A has been prepared by a glycosidation of the partly blocked validoxylamine A, followed by deprotection.Since a racemic form of validoxylamine A has been totally synthesized, the synthesis of validamycin A is achieved by the present study.
