Hypericum Chinense Research Articles

Biyouyanagin A, an Anti-HIV Agent from Hypericum chinense L. var. salicifolium

[structure: see text] A structurally unique hydrophobic compound, biyouyanagin A, was isolated from the MeOH extract of the leaves of Hypericum chinense L. var. salicifolium. The structure of biyouyanagin A was elucidated on the basis of spectroscopic evidence. Biyouyanagin A showed a significant activity against HIV and inhibited cytokine production.

Cytotoxic screening of medicinal and edible plants in Okinawa, Japan, and identification of the main toxic constituent of Rhodea japonica (Omoto).

The cytotoxic activity of ethanol extracts from 53 parts of 36 species of medicinal and edible plants cultivated in Okinawa was measured by using K562 human leukemia cells by a flow cytometric method. Two extracts from Rhodea japonica and Hypericum chinense were cytotoxic at a concentration of 10 microg/ml. The main cytotoxic constituent of Rhodea japonica was isolated and identified to be rhodexin A, which has been isolated as a cardetonic agent of the plant. The IC(50) value for rhodexin A against the growth of K562 cells was 19 nM, this activity being much stronger than that of ouabain (IC(50), 60 nM).

Synthesis and absolute configuration of (+)-hyperolactone B

The synthesis of (+)-hyperolactone B 2, isolated from Hypericum chinense L., was accomplished from ( S)-malic acid. This synthesis unambiguously established the absolute stereochemistry of hyperolactone B.

Spiro-lactones, hyperolactone A-D from Hypericum chinense

Novel spiro compounds, hyperolactones A-D were isolated from stems and leaves of Hypericum chinense. Hyperolactones have a common spiro-lactone structure with a 2-alkyl-or 2-aryl-9-methyl-9-vinyl-1,7-dioxaspiro [4.4] non-2-ene-4,6-dione skeleton.

New Cell Growth‐Inhibitory Cyclohexadienone Derivatives from Hypericum calycinum L.

AbstractThe crude petroleum‐ether extract of the aerial parts of Hypericum calycinum L. (Guttiferae) exhibited in vitro growth‐inhibitory activity against the Co‐115 human colon carcinoma cell line. Bioassay‐guided fractionation of this extract allowed the isolation of the cyclohexadienone derivatives 1–5, four of which are previously undescribed compounds. The structures of the known chinesin II (1) and of 2 (hypercalin A) were established by 1H‐ and 13C‐NMR spectroscopy and were confirmed by X‐ray analysis of their crystalline mixture which revealed the complete relative configuration of both compounds. The structure of 3 (hypercalin B) was elucidated by means of extensive 1D‐ and 2D‐NMR experiments, including DQ‐COSY, HETCOR and LR‐HETCOR. The structure of compound 4 (hypercalin C) was established by 1H‐ and 13C‐NMR spectroscopy and confirmed by X‐ray analysis to be the 3,5‐dihydroxy‐4‐{[(1R*,2S*, 5S*)‐2‐hydroxy‐2‐methyl‐5‐(1‐methylethenyl)cyclopentyl]methyl}‐6,6‐bis‐(3‐methylbut‐2‐enyl)‐2‐(2‐methylpropanoyl)cyclohexa‐2,4‐dien‐1‐one. The structures of the higher isomeric homologues 5a/5b were deduced by comparison of their UV, 1H‐, and 13C‐NMR spectra with those of 4. The isolated compounds appeared to be related to chinesin I and II previously isolated from Hypericum chinense L. and were responsible for the growth‐inhibitory activity of the extract against the Co‐115 human carcinoma cell line. Moreover, 1/2 and 3 showed molluscicidal activity against the schistosomiasis‐transmitting snail Biomphalaria glabrata.

Novel Spiro-Compound, Hyperolactone from Hypericum chinense L.

Abstract A novel metabolite spiro-compound, hyperolactone was isolated from stems and leaves of Hypericum chinense L. The structure was deduced by 2D-NMR experiment, chemical transformation and finaly by X-ray crystallography.

Antimicrobial Compounds, Chinesin I and II from Flowers of Hypericum chinense L.

Abstract Two new antimicrobial compounds against Gram-positive bacteria, chinesin I and II, were isolated from the flowers of Hypericum chinense L. The structures of chinesin I and II were elucidated on the basis of spectral and chemical evidences. Chinesin I is relatively active in the cytotoxicity test with Hela.