Unusual Isomeric Corniculatolides from Mangrove, Aegiceras corniculatum

Abstract

Four new isomeric macrolides of combretastatin D-2 congeners named isocorniculatolide A (1), 11-O-methylisocorniculatolide A (2), 11-O-methylcorniculatolide A (3), and 12-hydroxy-11-O-methylcorniculatolide A (4), and the known corniculatolide A (5), arjunolic acid, and maslinic acid were isolated from the CHCl(3) extract of the bark of Aegiceras corniculatum. The structures of the new compounds (1-4) were elucidated by a combination of spectroscopic analysis (1-5), chemical modifications, and single-crystal X-ray analysis (1).

Marine natural products

“…1023 Investigation of the chemistry of the bark of Aegiceras corniculatum (Nizampatnam coast, India) yielded corniculatolide macrolides 1265-1268. 1024 Four polyphenols excoecariphenol A-D 1269-1272, including two unusual thioglycosides, were reported from Excoecaria agallocha (China). 1025 Excoecariphenol D inhibited NS3-4A protease and exhibited anti-hepatitis C virus (HCV) activity in two assays.…”

Biotransformation of Artemisinin to 14-Hydroxydeoxyartemisinin: C-14 Hydroxylation by Aspergillus flavus

“…As part of our ongoing program on the isolation − and biotransformation , of bioactive compounds, we carried out biotransformation of artemisinin ( 1 ), which afforded four metabolites. They were identified as a new 14-hydroxydeoxyartemisinin ( 2 ) and three known metabolites ( 3 – 5 , Figure ).…”

12-Hydroxycorniculatolide a from the Mangrove Tree, Lumnitzera littorea

“…(δ C 34.1, 32.7, 28.8, 27.4) (Table 1). The NMR spectroscopic data of compound 1 (Figure 1) were similar to these of 12-hydroxy-11-O-methylcorniculatolide A (compound 3) [6], except for the lack of the resonance for the methoxy group in compound 1, which was also indicated from the m/z 14 difference in their MS molecular ion peaks. Moreover, the 13 C-NMR chemical shift of C-11 (δ C 133.4) in compound 3 changed to δ C 130.0 in compound 1.…”

“…Therefore, the structure of compound 1 was elucidated as 12-hydroxycorniculatolide A. The other three known compounds were identified as corniculatolide A (2) [6], 12-hydroxy-11-O-methylcorniculatolide A (3) [6] and 6,7-dimethoxycoumarin (4) [7] after comparisons were made with the published spectroscopic data. All compounds were screened against a panel of six Gram positive (Bacillus cereus, Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis and Streptrococcus mutans) and five Gram negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Vibro cholera and Shigella flexheri) bacteria (see SI).…”