Search

A novel compound, 13,13-dimethyl,12-(16-hydroxy,16,16-dimethyl)-propanol-∆11,12-hydrogenated pyranyl-7,8[benzo]-4′-methoxyisoflavone (1), together with two known insect secondary metabolites 2 and 3, was isolated from the 70% methanol extract of Periplaneta americana cockroaches. The structures of the isolated compounds were established by NMR spectroscopic and HR-ESI-MS analysis. Their antibacterial activities were determined by Kirby-Bauer disc diffusion antibiotic susceptibility testing. The results indicated that both isoflavone compounds 1 and 2 showed significant inhibitory effects against the Gram-positive bacterium B. subtilis with minimum inhibitory concentrations (MIC) values of 15 μg/mL.

Three new compounds were isolated from the adult insect of Allomyrina dichotoma L. for the first time. A new skeleton compound is named as Allomyrinanoid A ( 1 ) originated from the familiar norbornane derivatives and two new compounds of purine alkaloid are named as adenine-9-methylaldehyde oxime B ( 2 ) and 6- N -methyleneimine-adenine-9-methylaldehyde oxime B ( 3 ). The compounds ( 2 ) and ( 3 ) are the tautomers of imine–enamine and creatively separated form the solvent using column chromatography method. The structures of all isolated compounds were established by spectroscopic methods including analyses of their 1D, 2D NMR and HRESI-MS data, and confirmed by comparison of the literature data. These new components displayed antibacterial activities against both Gram-positive and Gram-negative strain.

Three new compounds were isolated from the adult insect of Allomyrina dichotoma L. for the first time. A new skeleton compound is named as Allomyrinanoid A ( 1 ) originated from the familiar norbornane derivatives and two new compounds of purine alkaloid are named as adenine-9-methylaldehyde oxime B ( 2 ) and 6- N -methyleneimine-adenine-9-methylaldehyde oxime B ( 3 ). The compounds ( 2 ) and ( 3 ) are the tautomers of imine–enamine and creatively separated form the solvent using column chromatography method. The structures of all isolated compounds were established by spectroscopic methods including analyses of their 1D, 2D NMR and HRESI-MS data, and confirmed by comparison of the literature data. These new components displayed antibacterial activities against both Gram-positive and Gram-negative strain.

The present study was to isolate oligostilbenoids with anti-MRSA activity from the seed cake of Paeonia in Luoyang, China. In the screening program for natural bioactive compounds that enhance the expression of a minimal inhibitory concentration (MIC) value of the tested compounds against Methicillin-resistant staphylococcus aureus, and the exploration of their structure-activity relationship. The MIC of the purified molecule Gnetin H was 0.059mg/mL and Trans-?-viniferin was 0.118mg/mL. Activity-guided fractionation of the seed cake of Paeonia EtOAc extract led to the isolation of three oligostilbenoids (1-3), and revealed the antibacterial activity of stilbenoids associated with the structure of phenol polymerization degree.