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The dermatophytes are filamentous fungi that cause cutaneous fungal infections because they use keratin as a nutrient source. For this study the antidermatophyte activity of the extracts and derivates from leaves of Piper regnellii was analyzed. From the dichloromethane extract (EBD) neolignans such as eupomatenoid-3 and eupomatenoid-5 were obtained, and it was submitted to fractionation to remove the green residue, designated as the chloroform fraction (FF). Extracts, chloroform fraction and compounds were tested against Trichophyton rubrum ATCC 28189 to determine the minimum inhibitory concentration (MIC). The chloroform fraction was incorporated to nail lacquer that was analyzed by photoacoustic spectroscopy, in vitro assay and scanning electronic microscopy. For antifungal activity in solid medium the dichloromethane extract and chloroform fraction were used. The compounds eupomatenoid-3 and eupomatenoid-5 were less active than the dichloromethane extract against T. rubrum. EBD and FF showed moderate activity in hyphal growth inhibition in solid medium and EBD did not link to ergosterol. Nail lacquer containing the chloroform fraction showed good penetration through the nail as determined by photoacoustic spectroscopy. From in vitro studies it was observed that nail lacquer concentrations above 20 mg/mL prevented the growth of fungi, but concentrations up to 2.5 inhibited the growth. Scanning electronic microscopy was used to confirm the in vitro nail lacquer activity results. The specie P. regnellii showed great antifungal activity against T. rubrum, and nail lacquer containing its chloroform fraction has great potential to treat onychomycosis caused by these microorganisms. [ABSTRACT FROM AUTHOR]

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 of the leaves from P. regnellii were investigated for their antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA). The ethyl acetate extract presented a good activity against MRSA, with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of 16 μg/mL. Based on this finding, the ethyl acetate extract was fractionated by silica gel column chromatography into nine fractions. The hexane fraction was active against MRSA (MIC at 4 μg/mL). Further column chromatography separation of the hexane fraction afforded the pure compound eupomatenoid-5. The structure of the compound was established by spectral data (1H and 13C NMR HSQC, HMBC, gNOE, IR and MS). Eupomatenoid-5 was the only compound active on the bacterium. The antibacterial property of P. regnellii extract provides preliminary scientific validation for the traditional medicinal use of this plant. The active compound eupomatenoid-5 should be further studied in animal models to verify in vivo efficacy and toxicity. [ABSTRACT FROM AUTHOR]