Results 121 to 130 of about 118,548,268 (167)

The Biosynthesis of Acarbose and Validamycin

Chemical Record, 2001
AbstractThe studies reported here have established the biosynthetic origin of the mC7N units of acarbose and validamycin from sedo‐heptulose 7‐phosphate, and have identified 2‐epi‐5‐epi‐valiolone as the initial cyclization product. The deoxyhexose moiety of acarbose arises from glucose with deoxythymidyl‐diphospho‐4‐keto‐6‐deoxy‐D‐glucose (dTDP‐4‐keto ...
Taifo Mahmud, H G Floss, Heinz G Floss
exaly   +3 more sources

Separation and Preparation of Validamycin a and Validamycin B Using Anion-Exchange Resin

Chemical Engineering Communications, 2006
A method for the separation and preparation of validamycin A and validamycin B by anion-exchange resin is described. The two compounds, validamycin A and validamycin B, could be separated effectively in the 10 × 400 mm column with anion-exchange resin A600 under the optimized conditions: elution flow rate of 0.25 mL/min, added quantity of 0.7 g, bed ...
Yuanfeng Wu, Yu-Guo Zheng, Ya-Ping Xue
exaly   +2 more sources

Effects of Validamycin on Some Enzymatic Activities in Soil

Environmental Monitoring and Assessment, 2007
There have been few investigations of the possible effects of validamycin on the enzymatic activities in soil. The objective of this present work was to study the short-term influence of enzymatic activity in validamycin treated soils. The results showed that high dose of validamycin introduced into soil had an significant effect on soil enzymatic ...
Haifeng Qian
exaly   +3 more sources

The effect of validamycin A on tyrosinase: Inhibition kinetics and computational simulation

International Journal of Biological Macromolecules, 2013
In this study, we investigated validamycin A as a tyrosinase inhibitor based on its structural properties. We found that the reversible inhibition of tyrosinase by validamycin A occurred in a mixed-type manner with Ki=5.893±0.038mM, as determined by integrating kinetics studies and computational simulations. Time-interval tyrosinase studies showed that
Zhi-Jiang, Wang, Sunyoung, Ji, Yue-Xiu, Si, Jun-Mo, Yang, Guo-Ying, Qian, Jinhyuk, Lee, Shang-Jun, Yin   +6 more
openaire   +3 more sources

Total synthesis of (+)-validamycin B

Journal of the Chemical Society, Chemical Communications, 1987
The first complete synthesis of the antibiotic validamycin B as its dodeca-O-acetate is reported; coupling of the epoxide (6) and the partially protected valienamine derivative (14), followed by deprotection, gives the product (1b) which was identified by 1H n.m.r. spectroscopy.
Y, Miyamoto, S, Ogawa
openaire   +2 more sources

Synthetic studies on antibiotic validamycins. Part 11. Synthesis of validamycin A

Journal of the Chemical Society, Perkin Transactions 1, 1985
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
Seiichiro Ogawa, Taisuke Nose, Takao Ogawa, Tatsushi Toyokuni, Yoshikazu Iwasawa, Tetsuo Suami   +5 more
openaire   +1 more source

Structure of the antibiotic validamycin A

Journal of the Chemical Society, Chemical Communications, 1972
The chemical structure of validamycin A, a new water-soluble weakly basic antibiotic, was shown to be (1).
Satoshi Horii, Yukihiko Kameda
openaire   +1 more source