Data/hora: 22/06/2024 01:30:12

Biblioteca(s): 	Embrapa Meio Ambiente.	
Data corrente: 	20/09/2012	
Data da última atualização: 	20/09/2012	
Autoria: 	QUEIROZ, S. C. do N. de; CANTRELL, C. L.; DUKE, S. O.; WEDGE, D. E.; NANDULA, V. K.; MORAES, R. M.; CERDEIRA, A. L.	
Afiliação: 	SONIA CLAUDIA DO N DE QUEIROZ, CNPMA; CHARLES L. CANTRELL, USDA-ARS; STEPHEN O. DUKE, USDA-ARS; DAVID E. EDGE, USDA-ARS; VIJAY K. NANDULA, USDA-ARS; RITA MARIA MORAES, UNIVERSITY OF MISSISSIPI; ANTONIO LUIZ CERDEIRA, CNPMA.	
Título: 	Bioassay-directed isolation and identification of phytotoxic and fungitoxic acetylenes from Conyza canadensis.	
Ano de publicação: 	2012	
Fonte/Imprenta: 	Journal of Agricultural and Food Chemistry, Washington, DC, v. 60, n. 23, p. 5893-5898, 2012.	
Idioma: 	Inglês	
Conteúdo: 	Abstract: Conyza canadensis (L.) Cronquist syn. (horseweed) is a problematic and invasive weed with reported allelopathic properties. To identify the phytotoxic constituents of the aerial parts, a systematic bioactivity-guided fractionation of the dichloromethane extract was performed. Three active enyne derivatives, (2Z,8Z)-matricaria acid methyl ester, (4Z,8Z)-matricaria lactone, and (4Z)-lachnophyllum lactone, were identified. The lactones inhibited growth of the monocot Agrostis stolonifera (bentgrass) and the dicot Lactuca sativa (lettuce) at 1 mg mL&#8722;1, while the (2Z,8Z)-matricaria acid methyl ester was less active. In a dose&#8722;response screening of the lactones for growth inhibitory activity against Lemna paucicostata, (4Z)-lachnophyllum lactone was the most active with an IC50 of 104 &#956;M, while the (4Z,8Z)-matricaria lactone was less active (IC50 of 220 &#956;M). In a fungal direct bioautography assay, the two lactones at 10 and 100 &#956;g/spot inhibited growth of the plant pathogenic fungi Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides. In a dose&#8722;response screening of the lactones against six different plant pathogenic fungi, (4Z,8Z)-matricaria lactone was more active than the commercial fungicide azoxystrobin on Col. acutatum, Col. fragariae, and Col. gloeosporioides at 30 &#956;M and about as active as the commercial fungicide captan against Col. gloeosporioides, while (4Z)-lachnophyllum lactone was less active.	
Palavras-Chave: 	Acetylenes; Horseweed.	
Thesagro: 	Alelopatia; Erva daninha; Fungicida; Herbicida; Toxidez.	
Thesaurus Nal: 	Alkynes; Allelopathy; Antifungal properties; Conyza canadensis; Fungicides; Herbicides; Phytotoxicity.	
Categoria do assunto: 	H Saúde e Patologia	
Registro original: 	Embrapa Meio Ambiente (CNPMA)	
Exemplares: 	CNPMA - (11303-1) - UPC - AP - DD -  -  -  - DIS