Natural Products from Pholidota yunnanensis

Inhibitory activities on nitric oxide production of stilbenoids from Pholidota yunnanensis.[Pubmed: 24205813]

Three new stilbenoids, 1-(4'-hydroxybenzyl)-imbricatin, (E)-4'-hydroxy-2',3,3',5-tetramethoxystilbene, and (E)-3,4'-dihydroxy-2,6-bis(4-hydroxybenzyl)-2',3',5-trimethoxystilbene, together with 15 known stilbene derivatives, were isolated from Pholidota yunnanensis. Their structures were elucidated by spectroscopic methods and by comparison of their NMR data with those of related compounds. Furthermore, the inhibitory activities on nitric oxide (NO) production of the isolated compounds were examined in murine macrophages (RAW 264.7) activated by lipopolysaccharide. The cytotoxicity of 18 compounds was determined by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. Among the tested compounds, eight stilbenoids, including three dihydrophenanthrenes, three stilbenes, and one bibenzyl derivative showed inhibitory effects on NO production without cytotoxicity with IC₅₀ values ranging from 4.07 to 7.77 μM, as compared to MG-132, which was used as a positive control (IC₅₀ of 0.10 μM). One dihydrophenanthrene, phoyunnanin C, showed cytotoxic effects at the test concentrations.

A resveratrol analog, phoyunbene B, induces G2/M cell cycle arrest and apoptosis in HepG2 liver cancer cells.[Pubmed: 22326393]

Among the seven natural resveratrol analogs separated and identified from Pholidota yunnanensis R(OLFE), we found phoyunbene B (PYB, trans-3,4'-dihydroxy-2',3',5-trimethoxystilbene) was more effective in inhibiting the growth of HepG2 hepatocellular carcinoma cells than resveratrol. The inhibitory effect of PYB in HepG2 cells was due to its induction of G2/M cell cycle arrest and apoptosis. Induction of G2/M phase cell cycle arrest by PYB was associated with its up-regulation of Cyclin B1, while its induction of apoptosis was accompanied with its down-regulation of Bcl-2 and up-regulation of Bax. Our in vitro invasion/migration assays also showed that PYB could inhibit the invasion of hepatocellular carcinoma cells.

9, 10-Dihydrophenanthrene derivatives from Pholidota yunnanensis and scavenging activity on DPPH free radical.[Pubmed: 17454314]

Three new 9,10-dihydrophenanthrene derivatives named phoyunnanins A-C, together with six known 9,10-dihydrophenanthrene constituents, 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,1'-biphenanthrene (4), lusianthridin (5), eulophiol (6), 2,4,7-trihydroxy-9,10-dihydrophenanthrene (7) and imbricatin (8), were isolated from the 60% ethanolic extract of air-dried whole plant of Pholidota yunnanensis Rolfe. The structures of phoyunnanins A-C were established as 6-[2'-(3',3''-dihydroxy-5'-methoxybibenzy)]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (1), 6-[6'-(trans-3',3''-dihydroxy-5'-methoxystilbeny)]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (2) and 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,6'-biphenanthrene (3), respectively, on the basis of the spectroscopic analysis. All eight compounds (1-8) were found to show the DPPH free radical scavenging activity with EC(50) from 8.8 to 55.9 microM.

New stilbenoids from Pholidota yunnanensis and their inhibitory effects on nitric oxide production.[Pubmed: 16394543]

Six new stilbenoids, a (bibenzyldihydrophenanthrene) ether designated phoyunnanin D (1), a bis(dihydrophenanthrene) ether designated phoyunnanin E (2), and four stilbenes designated phoyunbene A-D (3-6), were isolated from the air-dried whole plant of Pholidota yunnanensis ROLFE. The new compounds were identified as 7-[2-(3-hydroxyphenethyl)-4-hydroxy-6-methoxyphenoxy]-4-hydroxy-2-methoxy-9,10-dihydrophenanthrene (1), 1-[(9,10-dihydro-4-hydroxy-2-methoxy-7-phenanthrenyl)oxy]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (2), trans-3,3'-dihydroxy-2',4',5-trimethoxystilbene (3), trans-3,4'-dihydroxy-2',3',5-trimethoxystilbene (4), trans-3,3'-dihydroxy-2',5-dimethoxystilbene (5), and trans-3-hydroxy-2',3',5-trimethoxystilbene (6) based on spectroscopic evidence. Furthermore, the inhibitory effects of compounds 1-6 on nitric oxide production in a murine macrophage-like cell line (RAW 264.7) activated by lipopolysaccharide and interferon-gamma were examined.

[Studies on chemical constituents of Pholidota yunnanensis].[Pubmed: 15709381]

To investigate the chemical constituents from Pholidota yunnanensis.

[Morphological and histological identification of Pholidota yunnanensis].[Pubmed: 12567953]

The article reports the characters and microscopical characteristics of herba of Pholidota yunnanensis. The results can supply basis for the identification of the medicinal material.