ABSTRACT
The essential oil of the leaves and spikes of Piper lenticellosum C. DC. (Piperaceae) was isolated by hydrodistillation and analyzed by GC/MS. A yield of 2.06 % was obtained. Twenty eight components were identified by comparison of their mass spectra with Wiley GC-MS library data and the retention indices (RI) calculated for every compound. The major constituents were piperitone (33.97 %), 1,8 cineole (11.92 %), limonene (11.07 %), safrole (8.18 %) and α-pinene (4.49 %). Antibacterial activity of the essential oil was evaluated against five important human pathogenic bacterial strains using the disk diffusion agar method. The results showed at moderate activity against Staphylococcus aureus ATCC (25923), Escherichia coli ATCC (25922) and Klebsiella pneumoniae ATCC (233357) with minimal inhibitory concentration (MIC) values of 100, 200 y 300 µL/mL, respectively. According to the literature consulted, this is the first report on chemical composition and antibacterial activity of the essential oil of Piper lenticelosum C. DC. from Ecuador.
ABSTRACT
The MeOH extract of Piper ecuadorense Sodiro, Piperaceae, was chosen for metabolite isolation and elucidation due to the strong antifungal activity exhibited, measured by means of the broth microdilution method. Two known flavonoids: pinostrobin (1) and pinocembrin (2) were isolated from 4.16 g. of dichloromethane extract by column chromatography, using a gradient of hexane/EtOAc. A total of 20 mg of 1 were obtained from the fraction eluted with hexane-EtOAc 95:5 v/v, and 100 mg of 2 were obtained from the fraction eluted with hexane-EtOAc 85:15 v/v. The MIC values of the MeOH extract was 31.25 µg/mL for Trichophyton mentagrophytes ATCC® 28185 and 62.5 µg/mL for Trichophyton rubrum ATCC® 28188. The MIC value of pinocembrin was 125 µg/mL for Trichophyton mentagrophytes ATCC® 28185 and Trichophyton rubrum ATCC® 28188. Pinostrobin in antifungal test was not active against fungi tested.
ABSTRACT
The essential oil of the species Clinopodium nubigenum (Kunth) Kuntze, Lamiaceae, was analyzed by GC-MS and GC-FID, taking into account the more recent literature. Among the seventy compounds identified, the majority are oxygenated monoterpenoids. The essential oil, tested for antimicrobial activity, resulted effective in vitro against Candida albicans. From the aqueous MeOH extract of the aerial parts of the plant two nonvolatile compounds, named schizonepetoside A and schizonepedoside C, have been isolated. They are rare glycosyl terpenoids, which were previously isolated from only one plant, but never found before in the genus Clinopodium.