Five new polyphenolic derivatives with antimicrobial activities from the root barks of Periploca sepium.

Five new polyphenolic derivatives, sepiumols A-E (1-5), were isolated from the root barks of Periploca sepium. Their structures were elucidated by interpretation of NMR spectroscopic and mass spectrometric data. Compounds 1, 3 and 5 were found to exhibit significant antifungal activity, particularly for 3 with the remarkable activity against Gibberella saubinetii and Alternaria longipes with MIC values of 1.56 and 3.13 µg/mL (ketoconazole: 0.78 µg/mL), respectively. In addition, compounds 1, 3 and 5 also displayed significant antibacterial activity against methicillin-resistant Staphylococcus aureu with MIC values of 12.50-25 µg/mL (ciprofloxacin: 0.78 µg/mL).

Three new biphenyls from the twigs of Garcinia tetralata and their anti-tobacco mosaic virus activity.

Phytochemical investigations on the ethanol extract of the twigs of Garcinia tetralata resulted in the isolation of three new biphenyls, tetralatabiphenyls A-C (1-3), along with three known biphenyl derivatives (4-6). Structural elucidations of 1-3 were performed by spectroscopic methods such as 1D and 2D NMR spectra, in addition to high-resolution mass spectra. Compounds 1-6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compound 3 showed high anti-TMV activity with inhibition rate of 31.1%. Compounds 1, 2, and 4-6 also showed modest anti-TMV activities with inhibition rates in the range of 18.9-24.5%, respectively.

Xanthones from the herb of Swertia elata and their anti-TMV activity.

Two new xanthones (1-2), together with four known ones (3-6), were isolated from whole herb of Swertia elata. Their structures were elucidated by spectroscopic methods including extensive 1D- and 2D-NMR techniques. Their anti-tobacco mosaic virus (anti-TMV) activity test revealed that 1-6 showed weak anti-TMV activities with inhibition rate in the range of 15.2-28.8% at the concentration of 20 µM.