Insecticidal Or Antifungal Activities And Their Ingredients Of Several Plants

The insecticidal or fungicidal activities of several plants were screened. The active ingredient of the highest toxic plant was isolated by activity direction.The structure of the ingredient was identified.1.The insecticidal activity of extracts from Actinidia chinensis and A. kolomikta against third instar larvae of the diamondback moth,Plutella xylostella(L.)was evaluated under laboratory conditions.The extracts of A. chinensis were prepared using six solvents,among which acetone was found best with mortality(62.22 to 79.55%after 24 h and 48 h of exposure)of P. xylostella.The LC₅₀values of the acetone extract from stems were 49.04 and 40.85 g·L^-1at 24 h and 48 h and from leaves were 74.07 and 67.28 g·L^-1, respectively.The acetone extract of stems was extracted by 3 solvents and the petroleum ether extract caused 71.3%mortality at 48 h.LC-MS analysis of PE extract from A.chinensis indicated that Hexadecanoic acid,Heptadecanoic acid,Phytol,9,12-Octadecadienoic acid(Z,Z),7,10,13-Hexadecatrienoic acid, and Octadecanoic acid were high abundance component.Root phloem of A.kolomikta was best among 5 parts of the plants,with 1.97 g·mL^-1of LC₅₀value2.Fungicidal activity of acetone extracts from 40 weeds against Phytophthora capsici,Pythium aphanidermatum,Fusarium oxysporium, Fusarium solani and Botrytis cinerea was screened in vitro.Fungitoxicity was calculated in terms of percentage mycelial inhibition.The results indicated that extracts of 10 weeds significantly reduced colony growth of at least 1 phytopathogic fungi.Extracts of Artemisia annua,Xanthium sibiricum possessed over 60%inhibition rate against all the 5 phytopathogic fungi tested. And Salvia plebeian inhibited 4 phytopathogic fungi.Eclipta prostrate was toxic to P.capsici P aphanidermatum and F.oxysporium.Lagopsis supine and Rehmannia glutinosa was toxic to 2 phytopathogic fungi.Descurainia sophia, Rumex dentatus,Plantago asiatica and Euphorbia helioscopia significantly inhibited mycelial growth of 1 phytopathogic fungi.3.Mycelial growth inhibition method was used to screen 9 Chinese traditional medicines against the above 5 phytopathogic fungi.The acetone extract of Acorus calamus L.was found best with inhibition rate of 88.56～100.00%against the 5 phytopathogic fungi tested.Three fungi were inhibited by Zanthoxylum bungeanum and Polygonum cuspidatum,respectively. Artemisia indica and Fructus carpesii possess bioactivity against 2 phytopathogic fungi.The EC₅₀value of A.calamus against P.capsic was 46.74 mg·L-1.The EC₅₀values of A.calamus crude acetone extract against F. solani,F.oxysporium and B.cinerea were 280.76,236.01 and 186.89 mg·L^-1, respectively,which shows that A.calamus was a promising fungicidal plant.4.Isolation and identification of the active ingredient from Acorus calamus was performed by activity direction.The petroleum ether extract was the toxicst against 4 phytopathogenic fungi among methanol,acetone and petroleum ether.Liquid-liquid extract was performed to its ethanol extracts and the highest activity partition of ethanol extract was also obtained by petroleum ether.200-300 mesh and H Silica gel were used to column chromatography for several times and the activity of all the partition was tested.Finally,Cis - asarone was isolated from PE extract and its structure was elucidated on the basis of UV,IR,MS,¹H-NMR,¹³C-NMR and 2D NMR (COSY,HSQC,HMBC)data.