Novel malyngamide structural analogs: synthesis and biological evaluation
摘要:
In the course of our search for new anticancer agents, a series of novel malyngamide derivatives were synthesized by sharpless asymmetric epoxidation, followed by Julia-Kocinski olefination reactions as key reaction sequence. Anticancer activities of all these derivatives were screened against IMR-32, SF-295, SKNSH, HeLa, Colon-502713, SW-620, and Hop-62 cell lines for the first time.
Total synthesis of microginin, an angiotensin-converting enzyme inhibitory pentapeptide from the blue-green alga Microcystis aeruginosa
摘要:
Microginin, an angiotensin-converting enzyme inhibitory peptide isolated form the blue-green alga Microcystis aeruginosa, and its three diastereoisomers were efficiently synthesized, which unequivocally established the absolute stereostructure of microginin to be 1d.
Convergent Synthesis of Calcium-Dependent Antibiotic CDA3a and Analogues with Improved Antibacterial Activity via Late-Stage Serine Ligation
作者:Delin Chen、Kathy Hiu Laam Po、Pilar Blasco、Sheng Chen、Xuechen Li
DOI:10.1021/acs.orglett.0c01544
日期:2020.6.19
A convergent synthesis via the late-stage serine ligation of naturally occurring calcium-dependent antibiotic CDA3a and its analogues has been developed, which allowed us to readily synthesize the analogues with the variation on the lipid tail. Some analogues were found to show 100–500-fold higher antimicrobial activity than the natural compound CDA3a against drug resistant bacteria. This study will
Selective Generation of Free Radicals from Epoxides Using a Transition-Metal Radical. A Powerful New Tool for Organic Synthesis
作者:T. V. RajanBabu、William A. Nugent
DOI:10.1021/ja00082a021
日期:1994.2
halogens provides a route to functionalized cyclopentanes and other useful products. The radical initially formed from an epoxide can also be trapped by H-atom donors such as 1,4- cyclohexadiene or tert-butyl thiol, resulting in an overall reduction of the epoxide. In the absence of a H-atom donor or an olefin, this radical is trapped by Ti(", resulting in a fl-oxido-Ti organometallic species which undergoes
ANTI-BACTERIAL CALCIUM-DEPENDENT ANTIBIOTIC (CDA) ANALOGS AND METHODS OF TREATING BACTERIAL INFECTIONS
申请人:THE UNIVERSITY OF HONG KONG
公开号:US20210324009A1
公开(公告)日:2021-10-21
Provided herein are calcium-dependent antibiotics (CDAs), as a novel therapeutic target for treating bacterial infections. The present invention also relates to pharmaceutical compositions comprising such compounds, and to methods of use thereof for combating bacteria and treating bacterial infections.
the use of (R)-18 as the chiral building block to construct the γ-lactone-δ-lactam core 3 and cross-olefin metathesis as the key reaction to couple the latter with the allylicalcohol segment (R- or S-4). The efficient construction of the core 3 was realized by taking advantage of the inherent multiple reactivities of the chiral building block (R)-18. A highly diastereoselective one-pot transformation
Catalytic asymmetric epoxidation and kinetic resolution: modified procedures including in situ derivatization
作者:Yun Gao、Janice M. Klunder、Robert M. Hanson、Hiroko Masamune、Soo Y. Ko、K. Barry Sharpless
DOI:10.1021/ja00253a032
日期:1987.9
The use of 3A or 4A molecularsieves (zeolites) substantially increases the scope of the titanium(IV)-catalyzed asymmetricepoxidation of primary allylicalcohols. Whereas without molecularsievesepoxidations employing only 5 to 10 mol % Ti(O-i-Pr)/sub 4/ generally lead to low conversion or low enantioselectivity, in the presence of molecularsieves such reactions generally lead to high conversion