title: Dihydroisocoumarin from Xyris pterygoblephara active against dermatophyte fungi.
abstract: The ethanol extract from Xyris pteygoblephara aerial parts was evaluated against five microorganism strains, by the microdilution and agar diffusion methods. Extract fractionation led to the isolation of three compounds, whose structures were assigned by spectrometric data (1D and 2D NMR, IR, MS and UV) as (3R,4R)-(-)-6-methoxy-3,4-dihydro-3-n-pentil-4-acethoxy-1H-2-benzopyran-1-one (1), moronic acid and quercetin. The absolute configuration of 1 was defined by circular dichroism spectroscopy and comparison with data reported for other dihydroisocoumarins. Assay of 1 (100 microg/disc) by the agar diffusion method against clinical isolates of the dermatophytes Epidermophyton floccosum (inhibition zone, mm+/-s.d.: 4.5+/-0.8), Trichophyton mentagrophytes (4.8+/-0.4) and Trichophyton rubrum (10.2+/-0.8) revealed similar inhibition zones to the positive control amphotericin B (32 microg/disc; 5.0+/-0.2; 5.0+/-0.6 and 8.8+/-1.2, respectively). The result corroborates the ethnomedical use of Xyris species to treat dermatitis.
authors.affiliation: Faculty of Pharmacy, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil.
authors.forename: Keller Guilherme
authors.initials: KG
authors.lastname: Guimarães
authors.forename: José Dias
authors.initials: JD
authors.lastname: de Souza Filho
authors.forename: Thiago Rennó
authors.initials: TR
authors.lastname: Dos Mares-Guia
authors.forename: Fernão Castro
authors.initials: FC
authors.lastname: Braga
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology; D003883:Arthrodermataceae / Q000187:drug effects*; D002942:Circular Dichroism; D029624:Ferns / Q000737:chemistry*; D049934:Isocoumarins / Q000737:chemistry* / Q000494:pharmacology*; D015394:Molecular Structure
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D049934:Isocoumarins