Functional Characterization of a New Bifunctional Terpene Synthase LpNES1 from a Medicinal Plant Laggera pter odonta.

Laggera pterodonta, known in China as 'Choulingdan' for its stimulous odor, has long been used as traditional herbal medicine. The essential oil of L. pterodonta, which exhibits various pharmacological activities, is a rich resource of monoterpenes and sesquiterpenes. To date, however, the terpene synthases responsible for their production remain unknown. In present study, a new terpene synthase gene (LpNES1) was identified from L. pterodonta, transcript level of which was significantly upregulated in response to methyl jasmonate treatment. Recombinant LpNES1 could synthesize (E)-nerolidol and minor ß-farnesene from farnesyl diphosphate and linalool from geranyl diphosphate in vitro. Whereas, only sesquiterpenes including (E)-nerolidol and minor ß-farnesene were released when LpNES1 was reconstituted in yeast, even coexpressed with a geranyl diphosphate synthase (ERG20WW). Combined with subcellular localization experiment, the result indicated that the cytosol-targeted LpNES1 was responsible for (E)-nerolidol biosynthesis exclusively in L. pterodonta. Additionally, the expression level of LpNES1 gene was more prominent in floral buds than that in other tissues. LpNES1 characterized in present study not only lays the molecular foundation for sesquiterpene biosynthesis of L. pterodonta, but provides a key element for further biosynthesis of bioactive compound in microbes.

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.

Two new triterpenoids with antimicrobial activity from the leaves and twigs of Orophea yunnanensis.

Two new triterpenoids, 3-O-(4',5'-dihydroxybenzoyl)-lup-20(29)-en (1) and 3-O-(6'-desmethysyringyl)-13α-methyl-27-norolean-14-en-3ß-ol (2), were isolated from the leaves and twigs of Orophea yunnanensis. Their structures were identified by extensive spectroscopic experiments (NMR and MS) and comparison with literature data. Compounds 1 and 2 exhibited the moderate inhibitory activity against Sclerotinia sclerotiorum, Ceratocystis fimbriata and Verticillium dahliae Kleb with MIC values from 50 to 25 µg/mL, and also displayed the weak activity selectively against tested bacteria strains with MIC values from 100 to 50 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.

[Effect of Liangge San on lipopolysaccharide-induced nuclear factor kappa B activation in cultured mouse macrophages].

OBJECTIVE: To investigate the effect of Liangge San, a recipe of traditional Chinese herbal medicine, on lipopolysaccharide (LPS)-induced nuclear factor kB (NF-kB) activation in mouse macrophages cultured in vitro and explore the signal transduction mechanism of the detoxifying effect of Liangge San. METHODS: The mice were given oral administration of concentrated decoction of Liangge San to obtain the drug-containing serum. Macrophages from mouse abdominal cavity were collected, incubated and subsequently re-incubated with LPS and the prepared serum at different doses. Immunofluorescence method was adopted to examine the expression of NF-kB subunit p65 in the nuclei of the macrophages, and the fluorescence intensity of p65 expression was measured by laser scanning confocal microscope (LSCM). RESULTS: The fluorescence intensity of p65 expression in the nuclei of macrophages incubated with LPS for 1 h was significantly increased compared with that in the cells without LPS stimulation and Liangge San serum-treated cells. The fluorescence intensities were significantly decreased in cells treated with the inhibitor TLCK and different doses of Liangge San serum in comparison with those in LPS-stimulated cells. The fluorescence intensities were the lowest in cells treated with TLCK and high-dose Liangge San serum, and the cells treated with moderate and low doses of the serum both showed lower intensity compared with that of LPS-stimulated cells. p65 expression was similar between the macrophages incubated with LPS and those treated with serum that contained no Liangge San. CONCLUSIONS: Mouse serum containing Liangge San can inhibit LPS-induced p65 expression in mouse macrophages in a dose-dependent manner, which may be one of the signal transduction mechanisms of the detoxifying effect of Liangge San.