Chemical constituents from roots of Pieris formosa and their bioactivity / 中国中药杂志

By the means of chromatographic methods and spectroscopic evidences, 7 diterpenoids were isolated and identified from the roots of Pieris formosa. These known compounds are elucidated as secorhodomollolide C(1), pierisoid B (2), secorhodomollolide B (3), secorhodomollolide A (4), pierisformotoxin G (5), pierisformotoxin B (6) and pierisformotoxin A (7). Compounds 3, 4 were obtained from this plant for the first time. The analgesic activities of compounds 1-7 were evaluated using an acetic acidinduced writhing test in mice. Compounds 3, 4, 6, and 7 exhibited significant analgesic activity at 5 mg·kg;⁻ (ip) compared to vehicle-injected mice (<0.05). The writhe inhibition rates of compounds 3, 4, 6 and 7 at 5 mg·kg⁻¹ (ip) were 41.3%, 39.4%, 38.6% and 37.5%, respectively.

Biological activity of Dolichos biflorus L. trypsin inhibitor against lepidopteran insect pests.

Protease inhibitors confer resistance in plants against insect pests by inhibiting larval gut proteases. Cultivars of Dolichos biflorus were screened for their inhibitory activity against midgut proteases of Pieris brassicae larvae. Seed extracts of developing and germinating seeds of HPK4 cultivar inhibited larval gut proteases of Spodoptera littoralis efficiently. Neonate larvae of P. brassicae fed on cabbage leaf discs coated with 0.025-2.50 mg protein (seed extract) resulted in 10-80% larval mortality and significantly reduced leaf area eaten and faecal matter as compared to control. The treated larvae had 40% less soluble proteins per mg faecal matter and there was similar decline in midgut proteases of treated larvae (@ 2.5 mg protein) compared to untreated ones after 5 days. The LC50 and LT50 value was calculated to be 1.05 mg/leaf disc and 4.8 days (2.5 mg protein), respectively for neonate larvae of P. brassicae. Significant reduction in egg hatching (75%) was observed in egg mass treated with 5.3 mg of crude inhibitor protein of mature seeds. This could be due to the inhibition of proteases involved in the hydrolysis of egg chorion proteins. The studies demonstrated the insecticidal activity of D. biflorus seed extracts.

Phenolic glucosides from the leaves of Pieris japonica / 药学学报

The aim of the study is to investigate chemical constituents of the leaves of Pieris japonica. The isolation and purification of the constituents were performed by various chromatography and spectral analysis. Three new phenolic glucosides, erythro-syringoylglycerol 4-O-β-D-glucoside (1),1-(2-β-D-glucopyranoxyl-4-methoxyl-6-hydroxyphenyl)-3-hydroxyl-1-propanone (3),erythro-1-(4-hydroxyl-3-methoxyphenyl)-2-[4-(3-β-D-glucopyranoxypropyl)-2,6-dimethoxyphenoxy]-1,3-propanediol (4), along with five known phenolic glucosides, syringoylglycerol 8-O-β-D-glucoside (2), magnolenin C (5), syringaresinol mono-β-D-glucoside (6), 3-(4-hydroxyl-3-methyphenyl)-1-propanol-1-O-β-D-glucoside (7) and 3,5-dimethoxyl-4-hydroxybenzyl alcohol 4-O-β-D-glucoside (8) were isolated and identified from the plant leaves. Compounds 1 and 2 inhibited significantly (P<0.01) the proliferation of murine T and B cells at concentration of 1×10-6 mol·L-1, in vitro.

Bioactivity of several podophyllotoxin analogues / 医学研究生学报

Objective: The bioactivity of four podophyllotoxin analogues were tested against 3rd instar larvae of Culex pipiens pallens and 5 h instar larvae of Pieris rapae L.Methods:WHO bioassay and leaf-dlpping method. Results: ①Deoxypodophyllotoxin and ?-apopicropodophyllotoxin exhibited toxicity(against) Culex pipiens pallens,and their LC_(50) were 0.001 48 and 0.001 68 g/L,respectively.②All the four podophyllotoxin analogues displayed inhibitory effect on the growth and development against Culex pipiens pallens,their pupation rates were delayed comparing with control.③Deoxypodophyllotoxin,?-apopicropodophyllotoxin and Podophyllotoxin exhibited toxicity against Pieris rapae L,the LC_(50) 96 h after treatment were 0.045 4?0.078 2 and 0.159 7 g/L,respectively.④All the four podophyllotoxin analogues showed antifeedant activity against Pieris rapae L,their AFC_(50)were 0.016 1,0.018 7,0.039 4 and(0.273 9) g /L,respectively.⑤All four podophyllotoxin analogues displayed inhibitory effect on the growth and development against Pieris rapae L,but the extent of each compound were very different. Conclusion: Based on the data obtained in this investigation,it is possible that the dissimilarity in the structure of the analogues leads to their different bioactivity.