The retro-aldol reaction at residue 8 of R106-1 produced a chemical handle, in the form of a sarcosine residue, that was amenable to classical aldol alkylation conditions. In vitro assay of several new hydroxylated analogs have shown that L isomers exhibit more potent antifungal activity than D isomers. However, all analogs exhibited a significant decrease in activity against Cryptococcus neoformans. By contrast, structural modifications of R 106 were tolerated by some Candida spp., but the potency of activity was diminished as compared to that of the natural product R106-1. The full structure-activity relationship of the new R106 analogs has provided important information about the steric and electronic requirements of binding to target receptors. Furthermore, comparison of the structural differences between R106-1 and other derivatives, suggested that the potential for hydrogen bonding (at residue 8) was a key structural feature that was required to maintain activity against Cryptococcus neoformans.
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http://dx.doi.org/10.7164/antibiotics.49.386 | DOI Listing |
Food Chem Toxicol
November 2022
Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Universidad Complutense de Madrid, 28040, Madrid, Spain.
Most of the studies on doxycycline (DOX) and florfenicol (FF) remain focused on the improvement of antimicrobial activity and antimicrobial spectrum, and there is no relevant report on whether there is interaction between the two drugs after the combination. This research study evaluated the effect of DOX on FF metabolism in vitro and its mechanisms. The findings of this study showed that DOX inhibits FF metabolism in two ways.
View Article and Find Full Text PDFLife Sci
May 2022
Faculty of Pharmaceutical Sciences, Dep. of Clinical Analysis (University of São Paulo), Av. Prof Lineu Prestes, 580, Cidade Universitária, 05508-000 São Paulo, SP, Brazil.
Introduction: Ischemia-Reperfusion (I/R) damage is one of the major challenges in cardiothoracic surgeries and in a pathological manner, is identified by exacerbated damage signals resulted from blood supply restriction and subsequent flow restoration and re‑oxygenation. I/R damage includes cellular dysfunction and death, impairing tissue and organ function. Inflammation and oxidative stress are known to underlie either ischemia or reperfusion, leaded by HIF, TNF-α, NF-κB, IL-6 and ROS formation.
View Article and Find Full Text PDFInt J Food Microbiol
November 2007
Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, PR China.
Aureobasidin A (AbA), an antifungal cyclic depsipeptide antibiotic produced by Aureobasidium pullulans R106, has previously been shown to be effective against a wide range of fungi and protozoa. Here we report the inhibitory effects of AbA on spore germination, germ tuber elongation and hyphal growth of five pathogenic fungi including Penicillium digitatum, P. italicum, P.
View Article and Find Full Text PDFJ Pept Res
May 1999
Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Takatsuki, Japan.
A structural feature of aureobasidins, cyclic depsipeptide antibiotics produced by Aureobasidium pullulans R106, is the N-methylation of four out of seven amide bonds. In order to investigate possible relationship between the molecular conformation and the amide N-methylation, aureobasidin A (AbA), which exhibits the potent antifungal activity, was subjected to X-ray crystal analysis. The crystal, recrystallized from ether (orthorhombic, space group P2(1)2(1)2(1), a = 21.
View Article and Find Full Text PDFJ Antibiot (Tokyo)
April 1996
Infectious Disease Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, USA.
The retro-aldol reaction at residue 8 of R106-1 produced a chemical handle, in the form of a sarcosine residue, that was amenable to classical aldol alkylation conditions. In vitro assay of several new hydroxylated analogs have shown that L isomers exhibit more potent antifungal activity than D isomers. However, all analogs exhibited a significant decrease in activity against Cryptococcus neoformans.
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