Determination of six C-Glycoside flavones and antitumor activity of water-soluble total flavonoids from Isodon lophanthoides var. gerardianus / 中国中药杂志

This research established an HPLC method for determination of six C-Glycoside flavones of warer-soluble total flavonoids from Isodon lophanthoides var. gerardianus (Benth.) H. Hara, and studied the antitumor activity of the warer-soluble total flavonoids. The HPLC system consisted of Kromasil 100-5 C18 (4.6 mm x 250 mm, 5 microm) column and a solution system of methanol, acetonitrile and 0.5% formic acid gradient elution at a flow rate of 0. 8 mL x min(-1) and the wavelength of detector was at 334 nm. The column temperature was 25 degrees C. The antitumor activity of water-soluble flavonoids was assayed using HepG2 cell as the tested cell. The linear ranges of vicenin II, vicenin III, isoschaftoside, schaftoside, vitexin, 6, 8-di-C-a-L-arabinosylapigenin were 0.25-2.53, 0.12-1.20, 0.37-3.69, 0.16-1.63, 0.19-1.92, 0.14-1.42 microg, respectively. The average recoveries (n = 6) were 99.6% (RSD 0.87%), 100.2% (RSD 2.0%), 99.6% (RSD 1.8%), 97.9% (RSD 1.5%), 98.8% (RSD 1.2%), 98.6% (RSD 1.2%), respectively. After exposure in 24, 48, 72 h, the total flavonoids showed inhibitory effect on the proliferation of HepG2 cells with IC50 as the evaluation index, the IC50 values of 1.89, 1.71, 1.51 g x L(-1), respectively. The method is quick, simple and accurate with good re- producibility, and can be used for determination of vicenin II, vicenin III, isoschaftoside, schaftoside, vitexin, 6, 8-di-C-a-L-arabino- sylapigenin in the warer-soluble total flavonoids from L lophanthoides var. gerardianus. The warer-soluble total flavonoids from L lophanthoides have inhibitory effect on the proliferation of HepG2 cells.

Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L.) system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice-rice-ryegrass (Lolium multiflorum L.) (R-R-Ry), rice-rice-Chinese milk vetch (Astragalus sinicus L.) (R-R-Mv), rice-rice-rape (Brassica napus L.) (R-R-Ra) and rice-rice with winter fallow (R-R-Fa). The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (P<0.05) than in the R-R-Fa system during the early and late rice season. The ß-glucosidase activities reached peak values at the tillering stage after residue application, and alkaline phosphatase activities reached peak values at the booting stage after residue application, respectively, the activities of ß-glucosidase and alkaline phosphatase gradually decreased after this. Arylsulfatase activities reached peak values at the maturity stage. Arylamidase activities reached peak values at the maturity stage. The numbers of aerobic bacteria, actinomycete and fungus of residue treatments were significantly higher (P<0.05) than that the R-R-Ra system. However, the number of anaerobic bacteria under the R-R-Ry and R-R-Mv systems was significantly lower (P<0.05) than that under the R-R-Fa system during early rice and late rice growth stage. Thus, incorporation of winter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality.

Water-soluble constituents from Isodon lophanthoides var. gerardianus and their antitumor activities / 中草药

Objective: To investigate the water-soluble constituents of Isodon lophanthoides var. gerardianus. Methods: Compouds were isolated and purified by D-101, Sephadex LH-20, and ODS column chromatographies. The chemical structures were elucidated on the basis of spectral data and physicochemical properties. Results: Twelve compounds were isolated and identified as vitexin II (1), vicenin III (2), isoschaftoside (3), schaftoside (4), vitexin (5), 6, 8-di-C-α-L-arabinosylapigenin (6), apigenin-7-O-glucuronide (7), apigenin 6-C-β-L-arabin-osyl-8-C-α-L-arabinopyranoside (8), apigenin 6-C-β-D-xylopyranosyl-8-C-α-L-arabinopyranoside (9), caffeic acid (10), rosmarinic (11), and rutin (12). Conclusion: Compounds 1-9 are separated from I. lophanthoides var. gerardianus for the first time, and constituents of the water-soluble parts of I. lophanthoides var. gerardianus are studied systematically for the first time. Compounds 1, 6, and 11 exert antiproliferative effects on HepG2 cells.