Chemical Composition and Antimicrobial Activity of the Essential Oil from Piper carpunya Ruiz & Pav. ("Guaviduca") Leaves

The essential oil (EO) obtained from dried leaves of Piper carpunya Ruiz & Pav. ("Guaviduca") was isolated by hydrodistillation and characterized by GC-MS. The EO yield was 1.22% (v/w) from 180 g of dried leaves after 3 h of hydrodistillation, corresponding to 2.20 mL of oil. The refractive index and relative density were 1.49 and 0.95, respectively. GC-MS analysis identified compounds accounting for 97.52% of the total chromatographic area, with piperitone (40.35%) as the major constituent, followed by methyl eugenol (8.98%), sylvestrene (6.76%), d-limonene (6.30%), and 1,8-cineole/eucalyptol (6.29%). Antimicrobial activity was evaluated by disk diffusion using the pure EO against selected bacterial ATCC strains and clinical isolates of Candida. The EO showed limited antibacterial activity, with inhibition halos ranging from 6 to 10 mm against Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, and Enterococcus faecalis ATCC 29212. In contrast, marked antifungal activity was observed against two clinical isolates of Candida albicans, Candida tropicalis, and Candida glabrata, with inhibition halos ranging from 34 to 42 mm. These results indicate that the EO of Piper carpunya displays predominantly antifungal rather than antibacterial activity under the conditions tested.