Chemical characterization, antioxidant and antibacterial activities of six Agave species from Sinaloa, Mexico

Mexico has the greatest diversity of Agave species in the world and considering their uses in traditional medicine, these plants could be a rich source of bioactive compounds. In this research, we studied five wild Agave species from Sinaloa, Mexico (A. rzedowskiana, A. impressa, A. ornithobroma, A. schidigera and A. angustifolia) and one cultivated (A. tequilana). They were evaluated for antioxidant- and antibacterial activities and chemical composition. Statistical analysis consisted of a completely randomized design with one factor analysis of variance and the means were contrasted by the Tukey test (p <= 0.05). Agave tequilana showed the highest antibacterial activity with a Minimal Inhibitory Concentration (MIC) of 5 mg/mL, while A. rzedowskiana showed the highest antioxidant capacity by the DPPH method; both activities were higher than those reported for other Agave species. Agave ornithobroma had a higher content of the evaluated phytochemicals, mainly triterpenes and steroids. An activity based separation was carried out with the hexane extract of A. rzedowskiana; chromatographic separation and analysis by gas chromatography-mass spectrometry (GC-MS) showed 2-(3,4-dimethoxyphenil)-N-methylethanolamine, 9-octadecenoic acid and alpha-tocopherol (vitamin E) as the most abundant compounds. alpha-Tocopherol was clearly associated with the hexane extract antioxidant activity. This research showed a variety of phytochemicals in the studied Agave species and some of these species showed the highest antibacterial and antioxidant activities published up to date for this genus. (C) 2013 Elsevier B.V. All rights reserved.