Antifungal activity of the extracts and neolignans from Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck

Abstract

Extratos de folhas de Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck (Piperaceae), uma planta medicinal utilizada no Brasil para tratar doenças infecciosas, foram testados para a atividade antifúngica sobre as leveduras Candida albicans, C. krusei, C. parapsilosis e C. tropicalis. O extrato em acetato de etila apresentou boa atividade contra C. albicans com uma CIM de 125 μg mL-1 , moderada atividade contra C. krusei e C. parapsilosis (CIM de 500 μg mL-1) e foi inativo contra C. tropicalis (CMI> 1000 μg mL-1). Com base nestes resultados, o extrato em acetato de etila foi fracionado em nove frações em cromatografia de coluna de sílica gel. As frações hexano e clorofórmio mostraram variados níveis de atividade antifúngica contra as leveduras testadas. Posterior separação da fração hexânica em cromatografia de coluna resultou nas substâncias puras eupomatenóide-6, eupomatenóide-5, eupomatenóide-3 e conocarpano. A elucidação estrutural das substâncias foi baseada em dados espectrais (RMN de 1 H e de 13 C, HSQC, HMBC, gNOE, IV e EM). O conocarpano foi a única substância isolada, com atividade contra as leveduras. As propriedades antifúngicas do extrato de P. regnellii demonstraram preliminar validação científica do uso da planta na medicina popular. Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck (Piperaceae) is a medicinal plant traditionally used in Brazil to treat infectious diseases. The extracts obtained from the leaves of P. regnellii were investigated for their antifungal activities against the yeasts Candida albicans, C. krusei, C. parapsilosis, and C. tropicalis. The EtOAc extract presented a significant activity against Candida albicans with MIC at 125 μg mL-1 , and a moderate activity against both C. krusei and C. parapsilosis with MIC at 500 μg mL-1. Candida tropicalis was not inhibited by this extract at concentrations as high as 1000 μg mL-1. Based on these findings, the EtOAc extract was fractionated by silica gel column chromatography into nine fractions. The hexane and CHCl 3 fractions showed varied levels of antifungal activity against all test yeasts. Further column chromatography separation of the hexane fraction afforded the pure compounds eupomatenoid-6, eupomatenoid-5, eupomatenoid-3 and conocarpan. The structure of the compounds was based on spectral data (1 H and 13 C NMR, HSQC, HMBC, gNOE, IR and MS). Conocarpan was the only active compound on the yeasts. The antifungal property of P. regnellii extract provides preliminary scientific validation for the traditional medicinal use of this plant.

Antifungal activity of extracts of some plants used in Brazilian traditional medicine against the pathogenic fungusParacoccidioides brasiliensis

“…Pessini et al (2005) showed that the EtOAc extract of P. regnellii presented significant activity against C. albicans and moderate activity against both C. krusei and C. parapsilosis. The compounds eupomatenoid-6, eupomatenoid-5, eupomatenoid-3, and conocarpan were isolated, but only the latter was active against the yeasts (Pessini et al, 2005).…”

“…Pessini et al (2005) showed that the EtOAc extract of P. regnellii presented significant activity against C. albicans and moderate activity against both C. krusei and C. parapsilosis. The compounds eupomatenoid-6, eupomatenoid-5, eupomatenoid-3, and conocarpan were isolated, but only the latter was active against the yeasts (Pessini et al, 2005). Constantin et al (2001) analyzed the essential oil obtained by hydrodistillation of leaves of P. regnellii by GC-MS and found that it was active against Staphylococcus aureus and C. albicans.…”

Antifungal Activity of Dihydrobenzofuran Neolignans

“…Table 1 1 >1000 >1000 >1000 >1000 >1000 1000 2 >1000 >1000 >1000 >1000 >1000 >1000 3 >1000 >1000 >1000 >1000 >1000 1000 4 >1000 >1000 >1000 >1000 >1000 1000 5 >1000 >1000 >1000 >1000 >1000 >1000 6 >1000 >1000 >1000 >1000 >1000 >1000 7 >1000 >1000 >1000 >1000 >1000 >1000 8 >1000 >1000 >1000 >1000 >1000 >1000 According to the literature, MIC values lower than 100μg/mL, between 500 and 1000μg/mL, and higher than 1000μg/mL correspond to promising, moderate and weak activities, respectively, whereas MIC values higher than 1000μg/mL denotes inactivity. 21 Based on these criteria, compounds 3, 4 and 7 displayed weak activity against T. mentagrophytes, whereas all the other tested compounds were inactive against the other selected dermatophytes.…”

“…18 DBNs have been also reported to display interesting antifungal activities. [19][20][21][22] Thus, as part of our ongoing project on the biological activities of dihydrobenzofuran neolignans, in this paper we investigate the antifungal activity of eight synthetic DBN against selected dermatophytes.…”

Chemical Analysis of Essential Oil and Hydrolates of Leaves, Inflorescences and Stems of Piper chimonanthifolium Kunth

“…3 Piper aduncum L., known as fake jaborandi , is reported in folk medicine as diuretic, wound healing and antihemorrhagic, 4 Piper regnellii (Micah) C. DC has antifungal activity 5 and Piper hispidinervum C. DC. is used in the manufacture of fixative for fragrances and as natural insecticides.…”