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 hopane-type triterpenoids from the aerial part of Adiantum capillus-veneris and their antimicrobial activities.

Three new hopane-type triterpenoids (1-3), fern-7(8)-en-19α, 28-diol (1), pteron-14-ene-7α,19α,28-triol (2) and 3ß,4α,25-trihydroxyfilican (3), were isolated from the aerial parts of Adiantum capillus-veneris. Their structures were determined by NMR spectroscopic and mass spectrometric data. Compounds 2 and 3 exhibited remarkable antifungal activity against Helminthosporium maydis and Alternaria alternata with MIC values of 12.5-3.125 µg/mL, and compound 3 also against Verticillium dahliae Kleb with an MIC value of 3.125 µg/mL. In addition, compounds 1-3 also displayed weak antibacterial activity against Micrococcus lysodeikticus, Bacterium paratyphosum B and Pseudomonas aeruginosa with an MIC value of 100 µg/mL.

Three new phenanthrenes with antimicrobial activities from the aerial parts of Juncus effusus.

Three new phenanthrenes (1-3), designated as 2-methoxy-1,6-dimethyl-5-vinyl-9, 10-dihydrophenanthren-7-ol, 1,6-dimethyl-4,5-dihydropyrene-2,7-diol and 1-(3,7- dihydroxy-2,8-dimethyl-9,10-dihydrophenanthren-1-yl)ethanone, were isolated from the aerial parts of Juncus effusus. Their structures were determined by extensive spectroscopic experiments (NMR and MS) and comparing with those related known compounds. The antifungal and antibacterial activities of 1-3 were evaluated. Compound 1 showed remarkable antifungal activities against six agricultural pathogenic fungi (Rhizoctonia solani, Verticillium dahliae Kleb, Sclerotinia sclerotiorum, Gibberella saubinetii, Bipolaris zeicola, and Phytophthora parasitica) with minimum inhibitory concentration (MIC) values ranging from 3.125 to 12.5 µg/mL, and also displayed significant antibacterial activities against two human pathogenic bacteria (Bacterium paratyphosum B and Micrococcus lysodeikticus) with MIC values of 12.5 and 25 µg/mL, respectively.

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.