Studies on antioxidant activities of breviscapine in the cell-free system.

Breviscapine is a commercially produced plant extract from the Chinese herb Erigeron breviscapus. (Vant.) Hand.-Mazz., which contains 2 main flavonoids. It is widely used in clinic to treat ischemic diseases in which free radicals are considered to be the main causal factor. Our study is aimed to examine the antioxidant activity of this extract. The following assays were employed: 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, superoxide anion radical scavenging, nitric oxide radical scavenging, total anti-oxidative capacity, and antilipid peroxidation assays. Breviscapine was demonstrated to show an effective activity on scavenging DPPH, superoxide anion radicals and nitric oxide. The total antioxidative capacity of breviscapine (7.8 microg/ml to 250 microg/ml) was 1.22 to 6.74 FRAP value (x 10(-5) mmol). At the highest concentration of breviscapine, the inhibition extent of lipid peroxidation induced by Fe(2+) in rat liver homogenates was 38.5%. Because of the antioxidant activity, the present study is therefore designed to investigate the therapeutic potential of breviscapine for treatment of ischemic diseases.

[Chemical constituents from the seeds of Annona squamosa].

AIM: To study the antitumor active constituents of the seeds from Annona squamosa L. (Annonaceae). METHODS: Various chromatographic techniques were used to isolate and purify the constituents. Their physico-chemical properties and spectral data were determined to elucidate the structures. RESULTS: Eleven compounds were isolated and identified as annonaceous acetogenins: squamocenin (1), annotemoyin-2 (2), reticulatain-2 (3), squamocin-I (4), squamocin-B (5), squamocin (6), motrilin (7), squamostatin-D (8), squamostatin-E (9), cherimolin-1 (10), cherimolin-2 (11) from the ethyl alcohol extract of A. squamosa L. CONCLUSION: Squamocenin (1) is a new acetogenin. Annotemoyin-2 (2) and reticulatain-2 (3) were isolated from this plant for the first time.

[Two flavone glycosides from Chinese traditional medicine Amomum villosum].

OBJECTIVE: To study the water soluble constituents from Amomum villosum. METHOD: The constituents were separated and purified with chromatographic methods, identified by NMR, MS, UV and IR. RESULT: Two quercetin glycosides: quercitrin (quercetin-3-O-alpha-L-rhamnoside I) and isoquercitrin (quercetin-3-O-beta-D-glucoside II) were isolated and identified. CONCLUSION: I and II were isolated for the first time from A. villosum.

Diarylheptanoids from the rhizomes of Alpinia officinarum and their anticancer activity.

Two new diarylheptanoids (1, 2), together with two known analogs (3, 4), were isolated from the rhizomes of Alpinia officinarum. The new compounds were elucidated to be (5S)-5-hydroxy-7-(3, 4-dihydroxyphenyl)-1-phenyl-3-heptanone (1) and (5R)-5-hydroxy-7-(3-methoxy-4, 5-dihydroxyphenyl)-1-phenyl-3-heptanone (2) based on their spectral analysis. Compound 4 showed moderate cytotoxicity against human tumor cell lines, HepG2, MCF-7 and SF-268, while no significant effect were found for compounds 1-3.

Flavonol glycosides from Lysimachia capillipes.

Two new compounds, capilliposide I and capilliposide II, together with a known compound quercetin-3-O-(2,6-di-alpha-L-rhamnopyranosyl)-beta-D-galactopyranoside were isolated from the extracts of the whole herbs of Lysimachia capillipes. Their structures were established through their spectral data and chemical properties.

Murihexol, a linear acetogenin from Annona muricata.

Murihexol (1), a novel acetogenin, and three known ones, donhexocin (2), annonacin A and annonacin, have been isolated from the seeds of Annona muricata. Compound 1 is a C(35) acetogenin without any THF rings, with six hydroxyls in the long aliphatic chain. The hydroxyls of 1 and 2 are all located at C-4, C-10, C-15, C-16, C-19 and C-20, but their stereochemistries are different. The vicinal diol at C-15/C-16 in 1 is threo and C-19/C-20 has the erythro configuration; in 2 C-15/C-16 and C-19/C-20 all have the same threo configuration.