Chemical Constituents from Leaves of Myoporum bontioides and Their Bacteriostatic Activities

Abstract:

To study the chemical constituents in Myoporum bontioides A. Gray, thirteen compounds were isolated from the leaves of M. bontioides by various chromatography techniques. On the basis of spectral data, they were identified as prunasin (1), acteoside (2), 5,7-dihydroxyflavanone (3), anthemisol (4), (3R)- oct-1-en-3-ol-O-β-D-glucop-yranosyl-(1"→2")-O-β-D-glucopyranoside (5), 7-methoxyaromadenrin (6), 5,7-dihydroxy-2-(4-methoxyphenyl)-chroman-4-one (7), spainulenol (8), guaiol (9), (1S,2R,5S,6R)-2,6-bis(5- methoxy-3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (10), (1R,2S,5R,6S)-2-(4-hydroxy-3- methoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (11), demethylnobiletin (12) and 2-(3,4-dimethoxyphenyl)-5,6,7,8-tetra-methoxy-4H-chromen-4-one (13). Compounds 4, 5, and 7 - 11 were obtained from M. bontioides for the first time. The inhibitory activity against Staphyloccocus aureus and Escherichia coil were determined by the use of a 96 well plate assay. The results showed that 5,7-dihydroxyflavone (3) possessed modest level of antibacterial activity with MIC value of 62.50 μg mL^-1.

Key words:Myoporum bontioides A. Gray;Leaf;Chemical composition;Bacteriostatic activity