Essential oil composition of passiflora foetida L. (passifloraceae) flowers and chemical-biology study of the leaves extracts and isolated compound

Passiflora foetida is a climbing herb employed in ethno-medicine for the treatment of various ailments. The essential oil from flowers of P. foetida was obtained by hydrodistillation. The ethanol extract of the leaves was dissolved in water, then partitioned with n-hexane and n-butanol to obtain the various fractions; the fractions and isolated compound were subjected to in vitro antioxidant activity. Gas chromatography-mass spectrometry afforded the identification of forty-two constituents in the floral oil, dominated by β-caryophyllene (17.2%), cedrol (11.5%), and α-humulene (11.5%). The n-butanol fraction was the most active (70% inhibition and absorbance 0.401; 100 µg/mL) in the 2,2-diphenyl-1-picrylhydrazyl radicals and ferric reducing power assays, respectively. Chromatographic analysis facilitated the isolation of 8-C-β-d-glucosylapigenin (vitexin) from the butanol fraction of P. foetida. Vitexin demonstrated good antioxidant activities (75% inhibition and absorbance 0.424; 100 µg/mL) compared with ascorbic acid. The volatile metabolites of P. foetida flowers are reported for the first time.