Headspace volatiles of the leaves and flowers of malvaviscus arboreus cav. (malvaceae)

Abstract

Malvaviscus arboreus Cav., commonly known as Sleeping Hibiscus, is a plant species that belongs to the family Malvaceae with ornamental, culinary, and ethnomedical importance. This medicinal herb was reported to exhibit noteworthy antioxidant, cytotoxic, hepatoprotective, and anti-infective activities attributed to the presence of a variety of phytochemicals. In this work, the volatile compositions of the leaves and flowers of M. arboreus were studied and compared for the first time using the headspace gas chromatography-mass spectrometry (GC–MS) technique. Overall, 39 components were identified, comprising 36 from the leaves and 11 from the flowers, with an evident greater contribution of oxygenated compounds (89.54% in leaves and 89.35% in flowers) to their total volatiles. Phenolic ethers (41.64%) and ketones (21.57%) were the major chemical groups emitted by the flowers, while ketones (27.40%) and carboxylic acids (18.16%) dominated the volatile blends of the leaves. Anethole (32.32%), methyl isobutenyl ketone (19.18%), and methyl chavicol (9.32%) were the most abundant floral volatiles, whereas acetic acid (18.16%) was the major constituent given off by the leaves, followed by 2-cyclohexenone (9.60%) and anethole (7.39%). Additionally, from a biosynthetic point of view, the floral volatiles of M. arboreus showed the prevalence of phenylpropanoids/benzenoids (41.64%); however, fatty acid derivatives (54.30%) predominated among those produced by the leaves. The obtained results revealed noteworthy qualitative and quantitative variations in M. arboreus leaves and flowers' headspace volatiles that would help complement our phytochemical knowledge on this limitedly studied plant.