[Chemical Constituents from Goodyera schlechtendaliana].

OBJECTIVE: To study the chemical constituents of Goodyera schlechtendaliana. METHODS: Compounds were isolated through various chromatographic techniques and identified by spectroscopic analysis and comparison with those in literature. RESULTS: Seven compounds were obtained from 95% ethanol extract. Their structures were identified as syringaldehyde (I), 5-hydroxymethylfurfural (II) , alloimperatorin (III), vanillic acid (IV), ferulic acid (V), glyceroyl monopalmitate (VI) and ß-sitosterol (VII). CONCLUSION: Compounds II- VII are reported from this genus and compounds I - VII are reported from this plant for the first time.

A new biphenanthrene with cytotoxic activity from Liparis nervosa (Thunb.) Lindl.

2,7,2'-Trihydroxy-3,4,4'7'-tetramethoxy-1,1'-biphenanthrene (1), a previously undescribed biphenanthrene, and five known phenanthrenes, i.e. 2,5-dihydroxy-4-methoxy-9,10-dihydroxyphenanthrene (2), 2,4-dihydroxy -7-methoxy-9,10-dihydroxyphenanthrene (3), 7-hydroxy-2-methoxy-phenanthrene-1,4-dione (4), 7-hydroxy-2-methoxy-9,10-dihydro-phenanthrene-1,4-dione (5), and 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,1'-biphenanthrene (6) were isolated from the whole plant (stems, leaves, roots and fruits) of Liparis nervosa (Thunb.) Lindl., which is a medicinal plant of the genus Liparis in the Orchidaceae family. The structures of isolates were identified using spectroscopic methods, including NMR and mass spectrometry. Additionally, the cytotoxic potency of all the isolates against human lung cancer A549 cell line was evaluated by an MTT assay. All the isolated compounds showed cytotoxic activities with IC50 values in the range of 10.20 ± 0.81 to 42.41 ± 2.34 µM. The obtained data highlight the importance of L. nervosa as a source of natural lead compounds for cancer therapy.

New biphenanthrenes with butyrylcholinesterase inhibitory activitiy from Cremastra appendiculata.

Encouraged by the in vitro potent inhibitory activity on butyrylcholinesterase (BChE) of 95% ethanol extract of Cremastra appendiculata (D. Don) Makino tubers, a further phytochemical investigation on C. appendiculata tubers was conducted, which led to the isolation of a pair of new biphenanthrene atropisomers, namely cremaphenanthrene F-G (1-2). Their structures were elucidated on the basis of extensive spectroscopic analyses and chemical method. It is the first time that biphenanthrene atropisomers have been isolated from the plant kingdom. Compound 1 showed potent BChE inhibitory effect with IC50 value of 14.62 ± 2.15 µM. Compound 2 exhibited weak BChE inhibitory effect with IC50 value of 79.56 ± 0.78 µM. Meanwhile, 1 and 2 were found to be inactive for acetylcholinesterase (AChE) inhibition. These findings suggested that compound 1 was a promising selective BChE inhibitor for AD prevention and treatment.

Goodyschle A, a new butenolide with significant BchE inhibitory activity from Goodyera schlechtendaliana.

Goodyschle A (1), a new butenolide, was isolated from the whole grass of Goodyera schlechtendaliana, an orchidaceous edible medicinal plant. The structure of the new compound was elucidated by 1 D and 2 D NMR experiments in addition to HRESIMS analyses. Compound 1 was evaluated for its bioactivities including cytotoxic activity against human gastric cancer (SGC-7901) and human hepatocellular carcinoma (HepG2) cell lines, inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and DPPH radical scavenging activity. As a result, compound 1 showed potent BChE inhibitory activity (IC50 value = 6.88 ± 1.63 µM), moderate DPPH radical scavenging activity (IC50 value = 16.25 ± 0.21 µM), and slight AChE inhibitory and cytotoxic activities. These findings suggest that compound 1 is worthy for further investigations in terms of its selective BChE inhibitory activity.

Bioactivity-Guided Isolation of Cytotoxic Phenanthrenes from Spiranthes sinensis.

Bioactivity-guided separation led to the isolation of six novel phenanthrenes, spiranthesphenanthrenes A-F (1-6), together with 19 known compounds, including seven phenanthrenes (7-13), one bibenzyl compound (14), five flavonoids (15-16 and 20-22), and six simple phenolic compounds (17-19 and 23-25), from the petroleum ether (PE) and ethyl acetate (EtOAc) extracts of Spiranthes sinensis (Pers.) Ames, an edible medicinal plant named "panlongshen" in Chinese that is popularly used in medicinal foods and herbal teas. The structures of the obtained compounds were identified on the basis of extensive NMR spectroscopy and HR-ESI-MS analyses. The cytotoxicities of the phenanthrenes (1-13), the bibenzyl compound (14) , and the flavonoids (15-16 and 20-22) toward SGC-7901, HepG2, and B16-F10 cell lines were examined in vitro. Compounds 1 and 7 exhibited moderate cytotoxic activities toward all of the selected cancer cell lines, and their IC50 values ranged from 19.0 ± 7.3 to 30.2 ± 5.6 µM. Spiranthesphenanthrene A (1) exhibited higher cytotoxic activity than the positive control cisplatin toward the B16-F10 cell line (IC50 = 19.0 ± 7.3 µM). A wound healing assay revealed the inhibition of the migration of B16-F10 cancer cells in a time- and dose-dependent pattern by treatment with 2.5, 5, and 10 µM solutions of compound 1 for 24 and 48 h, respectively. Western blots revealed that compound 1 obviously increased the level of the E-cadherin protein (an epithelial marker) and decreased the levels of the vimentin and N-cadherin proteins (mesenchymal markers). Furthermore, the level of the transcription factor Snail was also obviously decreased by compound 1 in a dose-dependent manner. Taken together, compound 1 inhibits the migration of B16-F10 cancer cells, which may be closely related to the inhibition of the epithelial-mesenchymal transition. Compound 1 represents a promising drug candidate for the prevention of tumor metastasis.

Bioactivity-guided isolation of biphenanthrenes from Liparis nervosa.

Three new biphenanthrenes, Liparisphenanthrenes A-C (1-3), along with three known ones were obtained from the ethanolic extract of Liparis nervosa (Orchidaceae) by bioactivity-guided fractionation. Their structures were elucidated on the basis of extensive spectroscopic analysis. All the compounds obtained were tested in vitro for cytotoxic activities against stomach (HGC-27) and colon (HT-29) cancer cell lines. 1, 4 and 5 showed potent cytotoxicities to HGC-27 cell line with IC50 values of 8.21-9.95µmol/L, and 1 and 5 also exhibited potent cytotoxic activities to HT-29 cell line with IC50 values of 8.53-9.27µmol/L.