Inhibition of DNA topoisomerases I and II and cytotoxicity of compounds from Ulmus davidiana var. japonica.

Twenty five compounds including ten triterpenes (1-3, 5-11), six flavonoids (12-15, 24, 25), five lignans (17, 18, 21-23), two butenyl clohexnone glycosides (19-20), one fructofuranoside (16) and one fatty acid (4) were isolated from the roots of Ulmus davidiana var. japonica. The structures of those compounds were identified by comparing their physicochemical and spectral data with those of published in literatures. All the compounds were evaluated for DNA topoisomerase inhibitory activities and cytotoxicities. Among the purified compounds, 4 and 19 showed more potent inhibitory acitivities (IC(50): 39 and 19 µM, respectively) than camptothecin, as the positive control (IC(50): 46 µM) against topoisomerase I. Compounds, 4, 10, 12, 19, 24 and 25 showed strong inhibitory activities toward DNA topoisomerase II (IC(50): 0.1, 0.52, 0.47, 0.42, 0.17 µM and 17 nM, respectively), which were more potent than that of etoposide as positive control (IC(50): 20 µM). In A549 cell line, 5 and 6 showed cytotoxicities (IC(50): 4 µM and 3 µM, respectively, with IC(50) of camptothecin as positive control: 10.3 µM). In the HepG2 cell line, 3, 5 and 7 showed cytotoxicity (IC(50): 4, 3 and 4 µM, respectively, with IC(50) of camptothecin: 0.3 µM). Compounds 6, 12 and 23 showed cytotoxicities in the HT-29 cell line (IC(50): 19, 19 and 15 µM, respectively, with IC(50) of camptothecin: 2 µM).

[A new chemical component of Pueraria lobata (Willd.) Ohwi].

Pueraria lobata (Willd.) Ohwi. was extracted for two times with 70% ethanol and the 70% ethanol-extracts was condensed. Various column chromatography with AB-8 macroreticular resin, Toyopearl HW-40, pharmadex LH-20, and silica gel were employed for the isolation and purification of the 70% ethanol-extracts from Pueraria lobata (Willd.) Ohwi. Five compounds were isolated and their structures were identified by physiochemical properties and spectral analysis (UV, IR, MS, 1H NMR, 13C NMR, HMQC, HMBC, etc.): (4R)-3-[ 2-hydroxy-4-methoxyphenyl]-4-(4-beta-D-glucopyranosyloxybenzyl) but-2-en-4-olide (1), 4', 8-dimethoxyl-7-O-beta-D-glucopyranosyl isoflavone (2), eicosanoic acid (3), hexadecanoic acid (4), tetracosanoid acid-2,3-dihydroxypropyl ester (5). Compound 1 was a new compound, and compounds 2, 3, 4 were isolated from this plant for the first time.

Cytotoxic compounds of Schizolaena hystrix from the Madagascar rainforest.

Bioassay-guided fractionation of a crude ethanol extract from a Madagascar collection of Schizolaena hystrix afforded the two new long-chain compounds, 3 S-acetoxyeicosanoic acid ethyl ester ( 1) and 3 S-acetoxydoeicosanoic acid ( 2), and the known long-chain compound 3 S-acetoxyeicosanoic acid ( 3). In addition, the long-chain alcohol 1-hydroxydodecan-2-one ( 7), as well as the new flavonoid schizolaenone C ( 4) and the two known flavonoids diplacol ( 5) and 3'-prenylnaringenin ( 6) were isolated from a methanol extract of the same plant. Isolation and structure elucidation of the novel compounds and the cytotoxicities of all the isolates are reported.

[Study of supercritical-CO2 fluid extraction in extracting essential oils of Amomun tsao-ko].

Essential oils from Amomum tsao-ko are extracted by supercritical-CO2 fluid and the oils are analyzed by GC-MS. 1, 8-cineole, trans-geraniol eicosatrienoic acid methylester and d-nerolidol of them are the major constitutents, 12 constitutents of them are first obtained from the plant.

[Chemical constituents of Pedicularis muscicola Maxim].

It is one of the main components in an effective secret recipe for the treatment of snakebite in Mabian, an autonomaus county of the Yi nationality in Sichuan province. Four compounds have been isolated from the herb of Pedicularis muscicola. On the basis of spectrometric analysis and physico-chemical constants, they were identified as pediculariside, D-mannitol, arachidic acid and hentriacontane.