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Two previously undescribed dihydrophenanthrene derivatives (1 and 2) were isolated along with twelve known analogues from the whole plant of Dendrobium terminale. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis. The NMR data of known phenanthrene derivatives (7 and 9) were revised by 2D NMR. The isolated compounds were evaluated for cytotoxicity against three kinds of tumor cell lines (sw1990, HCT-116, and HepG2). Especially compounds 11 and 14 showed stronger antitumor effects, and the structure-activity relationship of these compounds was discussed. [ABSTRACT FROM AUTHOR]

Two new sesquiterpenoids, dendroaduoid A (1) and dendroaduol (2), together with four known sesquiterpenoids were isolated from the stems of Dendrobium aduncum. Their structures were identified by HR‐ESI‐MS and NMR experiments, and the complete assignments of 1H and 13C NMR data for two new sesquiterpenoids were obtained by the aid of HSQC, HMBC, 1H‐1H COSY, NOESY, and ECD techniques. The cytotoxic effects of the isolated compounds on four tumor cell lines (HCT‐116, HepG2, A549, and SW1990) were evaluated using MTT assay. Otherwise, the inhibitory activity of these six sesquiterpenoids on glycosidase was also evaluated. [ABSTRACT FROM AUTHOR]

Six dendrobine-type alkaloids were isolated from the tubes of Dendrobium nobile by silica gel, Sephadex LH-20 gel column chromatography, and preparative HPLC. Compound 1 is a new alkaloid containing a pair of amide tautomers, whereas compound 2 is a new dendrobine-type alkaloid. By using spectroscopic techniques including 1 D and 2 D NMR, the structures of compounds 1‒6 were identified as N-methoxylcarbonyldendrobine (1), dendronboic acid (2), dendrobine (3), 6-hydroxyldendrobine (4), dendrobine N-oxide (5), and denrine (6). The cytotoxic effects of the isolated compounds on two human tumour cell lines (HCT-116 and SW1990) were evaluated using MTT assay. [ABSTRACT FROM AUTHOR]

A new dibenzocyclooctdiene (1), and a new eupodienone (2) type lignans were isolated along with five known analogues from the whole plant of Gymnotheca involucrata Pei. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis. Bioassay results showed that compounds 1 and 2 exhibited no antimicrobial activity against four Gram-positive bacterial strains and four Gram-negative bacteria at the concentration of 1 mg/mL. [ABSTRACT FROM AUTHOR]

In this study, seven bibenzyl compounds were isolated from the stem of Dendrobium nobile by silica gel, MCI column chromatographic and preparative HPLC technology. By using spectroscopic techniques including NMR and MS, these compounds were identified as 4,α-dihydroxy-3,5,3’-trimethoxybibenzyl (1), 4,5-dihydroxy-3,3’,α-trimethoxybibenzyl (2), 4,4’-dihydroxy-3,5,3’-trimethoxybibenzyl (3), 4,5-dihydroxy-3,3’-dimethoxybibenzyl(4), 4,3’-dihydroxy-3,5-dimethoxybibenzyl (5), 5,4’-dihydroxy-3,3’-dimethoxybibenzyl (6) and 5,3’-dihydroxy-3-methoxybibenzyl (7). Compound 1 is a new compound and compound 4 was isolated from this plant for the first time.

To study the chemical constituents of Clematoclethra scandens subsp. actinidioides, chromatographic methods such as silica gel and MCI column chromatographic technology, and preparative HPLC were used and sixteen compounds were isolated from the aerial parts of this plant. By using spectroscopic techniques including 1H, 13C-NMR, HMBC and ESI-MS, these compounds were identified as betulinic acid (1), ursolic acid (2), oleanic acid (3), corosolic acid (4), 3beta-(trans-p-coumaroyloxy)-2alpha, 23-dihydroxyurs-12-en-28-oic acid (5), 3beta-(trans-p-coumaroyloxy)-2alpha, 23-dihydroxyurs-12, 20 (30)-dien-28-oic acid (6), 2alpha, 3alpha, 23-trihydroxyurs-12, 20 (30)-dien-28-oic acid (7), 2alpha, 3alpha, 23-trihydroxyurs-12-en-28-oic acid (8), asiatic acid (9), 2alpha, 3alpha, 24-tri-hydroxyurs-12-en-28-oic acid (10), 2alpha, 3beta, 23-trihydroxyurs-12, 20 (30)-dien-28-oic acid (11), 2alpha, 3beta, 19alpha, 24-tetrahydroxyurs-12-en-28-oic acid (12), 2alpha, 3alpha, 19alpha, 24-tetrahydroxyurs-12-en-28-oic acid (13), 2alpha, 3beta, 23, 24-tetrahydroxyurs-12-en-28-oic acid (14), 2alpha, 3alpha, 19alpha, 23, 24-pentahydroxyurs-12-en-28-oic acid (15) and daucosterol (16). Among them, compounds 3-6, 11-12, 14 and 15 were isolated from this endemic plant for the first time.