Avaliação in vitro da actividade antifúngica de extractos de plantas kigelia africana, combretum molle e trichilia emetica para o controlo de fitopatógenos

Abstract

The demand for new antimicrobial agents, from plants, is intense due to the growing resistance of pathogenic microorganisms to antimicrobials already available in the market Marketplace. In addition, the long-term use of pesticides has a negative impact on the society and the environment due to the pollution caused by chemical residues. Compared to this problem, a current agriculture strategy, has been to seek alternative methods to the control of diseases and pests, which aim to cause less damage to the environment and human health. O objective of this work was to evaluate in vitro the effect of extracts from stem bark and roots of African Kigelia and Trichilia emetica as well as fractions of the powder extract of the leaves of Combretum molle on the development of phytopathogens in plants. The extracts were obtained by maceration using the solvents hexane, dichloromethane, acetate of ethyl and methanol according to the methodology described by Araújo et al. (2010) with some modification while the fractions were obtained using the solvents hexane, chloroform, n- butanol and 65% methanol according to the methodology described by Mavie (2007). The tests Phytochemicals for the identification of secondary metabolites were carried out according to the methodology described by Mouco et al., (2003) and Rezende et al., (2011). For the evaluation antifungal agents were used pure cultures of A.niger and C.gloeosporioides isolated from corn and cashew nuts, using disk diffusion and agar (well) drilling methods. Phytochemical tests carried out on extracts of Kigelia africana, revealed the presence of flavonoids, saponins, anthraquinones and triterpenoids / steroids. Phytochemical prospecting carried out on the extracts of Trichilia emetica revealed the presence of terpenes, flavonoids and tannins. For Combretum molle, the recognition tests of metabolite classes secondary ones revealed the presence of flavonoids, tannins, terpenes and saponins. The DCM, EtOAc and MeOH extracts from Kigelia africana inhibited the growth of microorganisms. The hexane extract of all plants did not exhibit antifungal activity. The aqueous, chloroform, butanolic and hydromethanolic fractions of Combretum molle inhibited the growth of microorganisms. The DCM and EtOAc extracts from Trichilia emetica showed activity against A. niger and the hexane and methanolic extracts were not active. The antifungal potential, partial or total, of plant extracts against phytopathogens, shows that the extracts of the plants under study can be a viable alternative for the control of plant diseases. Mais sobre o texto original É necessário fornecer o texto original para ver mais informações sobre a tradução Enviar feedback Painéis laterais