ANTIFUNGAL POTENTIAL OF EXTRACTS AND FRACTIONS OF Randia nitida LEAVES ON SOYBEAN PATHOGENS AND THEIR PHYTOCHEMISTRY

Abstract

-This study aimed to evaluate the antifungal activity of methanol extract and fractions of leaves of Randia nitida (Kunth) DC on Colletotrichum truncatum (Schw.) Andrus & Moore, Rhizoctonia solani Kühn and Sclerotinia sclerotiorum (Lib.) De Bary and perform chemical and antioxidant activity tests. Crude methanol extract (EBM) and fractions (hexane = FHX, dichloromethane = FDM and ethyl acetate = FAE) underwent classical phytochemical analysis and determination of total phenols, flavonoids and antioxidant activity. Samples were individually incorporated into PDA culture mediums (potato-dextrose-agar) at concentrations of 10, 20, 40, 80 and 160 µg mL -1 of extract or fraction. Mycelial growth was evaluated when control reached the edge of the plate. Phytochemical results indicated that flavonoids, steroids and triterpenoids are the major chemical constituents in both EBM and fractions. Total phenols, flavonoids and antioxidant activity were higher for FAE and EBM, followed by FDM and FHX; however, the latter showed higher content of steroids and triterpenoids compared to the other fractions. For C. truncatum, R. solani and S. sclerotiorum, the most efficient fractions were respectively FAE, FDM and FHX, all of them in the highest concentration (160 µg mL -1). The highest inhibition rate was observed against S. sclerotiorum, reaching 93.75%. We concluded that all fractions have antifungal activity on the plant pathogens, being FHX the most active against S. sclerotiorum, which might have been due to the presence of steroids and triterpenes.Keywords: Alternative control. Sclerotinia sclerotiorum. Rhizoctonia solani. Colletotrichum truncatum. Secondary metabolites. DPPH. foram submetidas a análise fitoquímica clássica e determinado os fenóis totais, flavonoides e atividade antioxidante. As amostras foram incorporadas, individualmente, ao meio de cultura BDA (batata-dextrose-ágar) nas concentrações de: 10, 20, 40, 80 e 160 µg mL -1 de extrato ou fração. O crescimento micelial foi avaliado quando a testemunha alcançou a borda da placa. Os resultados fitoquímicos indicaram que os flavonoides, esteroides e triterpenos são os constituintes químicos majoritários no EBM e nas frações . O teor de fenóis totais, flavonoides e a atividade antioxidante foi maior para a fração FAE e extrato EBM, seguido da fração FDM e da FHX, contudo a fração hexânica apresentou maior conteúdo de esteroides e triterpenos em relação as demais frações . Para os três fungos, as frações eficientes foram as frações FAE, FDM e FHX, respectivamente, todas na maior concentração estudada (160 µg mL -1 ). A maior porcentagem de inibição foi observada frente ao patógeno S. sclerotiorum, chegando a 93,75%. Conclui-se que todas as frações apresentam atividade antifúngica sobre os fitopatógenos e a fração FHX foi a mais ativa frente a Sclerotinia sclerotiorum, provavelmente pela presença de esteroides e triterpenos. POTENCIAL ANTIFÚNGICO DE EXTRATOS E FRAÇÕES DE Palavras

Green Synthesis of Silver Nanoparticles Using Randia aculeata L. Cell Culture Extracts, Characterization, and Evaluation of Antibacterial and Antiproliferative Activity

“…In studies carried out in methanolic extracts of Randia nitida leaves, 524.5 mg GAE/g DW of total phenolic and 178.5 mg QE/g DW of flavonoid content were reported [ 61 ]. These values are slightly higher than those for R. aculeata in our study.…”

Phytochemical composition and biological activities of the plants of the genus Randia

“…Methanolic extract of leaves and its fractions show antifungal activity against Colletotrichum truncatum, Rhizoctonia solani, and Sclerotinia sclerotiorum. This activity may be related to their main flavonoid, steroid, and triterpene components (Cruz-Silva et al 2016).…”

The Impacts of Asparagus Extract Fractions on Growth and Fumonisins Biosynthesis in Fusarium Proliferatum

“…Many solvents of different polarities including methanol, ethanol, acetone, diethyl ether, water or their mixtures, should be used for extracting bioactive compounds from plants, applying the rule-a solvent will properly dissolve the solute of similar polarity [42]. Da Cruz-Silva et al [43] conducted research on Randia nitida extracts and their fractions concerning their influence on Colletotrichum truncatum, Rhizoctonia solani and Sclerotinia sclerotiorum growth. The leaves extract was subjected to fractionation using methanol, n-hexane, dichloromethane and ethyl acetate, proving that each of them differed in terms of content of compound groups as well as their quantities.…”

“…For example, methanolic fraction contained phenolic compounds, tannins, flavonoids, coumarins, triterpenes, steroids and alkaloids, while n-hexane fraction contained only triterpenes and steroids. Methanolic and ethyl acetate fractions contained the same groups of compounds, but in ethyl acetate fraction, lower amounts of tannins, triterpenes and steroids were detected [43]. Sales et al [44] applied the extracts, along with acetate, butanol, dichloromethane, n-hexane and ethanolic fractions of extracts of 60 plants against two pineapple pathogens: Fusarium guttiforme and Chalara paradoxa.…”