Xiangzhong Huang

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The effects of different grazing intensities on in situ methane flux and the structure and diversity of the methanotrophic community are measured in the typical grassland of Inner Mongolia. Four grazing intensity sites founded in 1989, control (CK), low-intensity grazing (LG), middle-intensity grazing (MG) and heavy-intensity grazing (HG), were selected.(More)
Two new antimycin A analogues, antimycin B1 and B2 (1-2), were isolated from a spent broth of a marine-derived bacterium, Streptomyces lusitanus. The structures of 1 and 2 were established on the basis of spectroscopic analyses and chemical methods. The isolated compounds were tested for their anti-bacterial potency. Compound 1 was found to be inactive(More)
A novel 18-nor-clerodane diterpenoid named sagitone (1) was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis together with the five known diterpenoids columbin (2), palmatoside C (3), fibleucin (4), tinophylloloside (5) and epitinophylloloside (6). The structure of the new compound 1 was determined based on MS, IR,(More)
A novel lignan glysocide, namely sagitiside A (1), together with two known ones, (+)-lyoniresinol-2α-O-β-D-glucopyranoside (2) and (+)-5'-methoxyisolariciresinol 3α-O-β-D-glucopyranoside (3), was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis. The structure of the new compound (1) was determined based on MS, 1D(More)
Four new clerodane diterpenes, namely sagittatayunnanosides A-D (1-4), were isolated from the roots of Tinospora sagittata var. yunnanensis, together with two known compounds, tinospinoside C (5) and tinospinoside E (6). The structures of the four new compounds were well elucidated by extensive analyses of the MS, IR, and 1D and 2D NMR data. The cytotoxic(More)
Four new iridoid glycosides, 10-O-trans-p-coumaroylscandoside (1), 10-O-cis-p-coumaroylscandoside (2), 10-O-trans-p-coumaroyldesacetyl asperulosidic acid (3), and 10-O-cis-p-coumaroyldesacetyl asperulosidic acid (4), and two new grayanane diterpenoids, 14beta-O-(2S,3S-nilyl)-2alpha,3beta,5beta,6beta,16alpha-pentahydroxygrayanane (5) and(More)
Seven new steroidal glycosides, cynaforrosides K (1), L (2), M (3), N (4), and Q (7), based on a 13,14:14,15-disecopregnane-type aglycone, and cynaforrosides O (5) and P (6) with a 14,15-secopregnane-type aglycone, were isolated from the 95% ethanol extract of the roots of Cynanchum forrestii Schlechter. The structures of new compounds were determined on(More)
Eight new C-4-alkylated deoxybenzoins (1-8), three new diphenylethylenes (9-11), and five known diphenylethylenes were isolated from Arundina graminifolia. The structures of 1-11 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 9-11 are the first naturally occurring diphenylethylenes possessing a hydroxyethyl(More)
Nine new steroidal glycosides, cynaforrosides B, C, D, E, and F, based on a 13, 14: 14, 15-disecopregnane-type skeleton, cynaforrosides G, H, and I with a new aglycone named cynaforrogenin A, and cynaforroside J together with three known C21 steroidal glycosides cynatratoside A, hancoside and komaroside C were isolated from the ethanol extract of the roots(More)
OBJECTIVE To study the chemical constituents from the stems of Piper betle. METHODS Various chromatographic techniques were used to isolate and purify the constituents. The structures of these compounds were elucidated on the basis of spectral analysis. RESULTS Nine compounds were isolated from the petroleum ester and ethyl acetate soluble fractions of(More)