Biologically Active Constituents from Plants of the Genus Xanthium

Herbaceous annual plants of the genus Xanthium are widely distributed throughout the world and have been employed medicinally for millennia. This contribution aims to provide a systematic overview of the diverse structural classes of Xanthium secondary metabolites, as well as their pharmacological potential. On searching in various reference databases with a combination of three keywords "Xanthium", "Phytochemistry", and "Pharmacology", relevant publications have been obtained subsequently. From the 1950s to the present, phytochemical investigations have focused mainly on 15 Xanthium species, from which 300 compounds have been isolated and structurally resolved, primarily using NMR spectroscopic methodology. Xanthium constituents represent several secondary metabolite types, including simple phenols, sulfur and nitrogen-containing compounds, lignans, sterols, flavonoids, quinones, coumarins, and fatty acids, with terpenoids being the most common of these. Among the 174 terpenoids characterized, xanthanolide sesquiterpenoids are abundant, and most of the compounds isolated containing sulfur were found to be new in Nature. The ethnomedical uses of Xanthium crude extracts are supported by the in vitro and in vivo effects of their constituents, such as cytotoxicity, antioxidant, antibacterial, antifungal, antidiabetes, and hepatoprotective activities. Toxicological results suggest that Xanthium plant extracts are generally safe for use. In the future, additional phytochemical investigations, along with further assessments of the biological profiles and mechanism of action studies of the components of Xanthium species, are to be expected.

Biologically Active Constituents from Plants of the Genus Desmos

The combination of traditional knowledge of medicinal plants with scientific rationale has yielded positive results in recent years. Bioactive compounds isolated from herbaceous plants have long been used as drugs that benefit human health, as well as providing useful compounds for drug development lead compound optimization. This chapter aims to provide a systematic overview of the structural types of Desmos secondary metabolites, along with their biological potential. Various chromatographic and spectroscopic methods have been utilized for isolating, purifying, and elucidating the structures of compounds from Desmos species. From 1982 to the present time, more than 200 metabolites have been isolated from members of this genus. Desmos spp. constituents include terpenoids, phytosterols, polyoxygenated cyclohexanes and cyclohexenes, oxepinones, fatty acids, with flavonoids, alkaloids, and miscellaneous phenols being the predominant compounds. The essential oils of Desmos species have also been investigated. Both crude plant extracts and isolated compounds from this genus have been evaluated for their biological activities. Desmos constituents have been found to exhibit cytotoxic, antimicrobial, antioxidative, anti-inflammatory, and aromatase and NFAT transcriptive inhibition effects.

Extraction, chemical characterization and biological activity determination of broccoli health promoting compounds

Broccoli (Brassica oleracea L. var. Italica) contains substantial amount of health-promoting compounds such as vitamins, glucosinolates, phenolic compounds, and dietary essential minerals; thus, it benefits health beyond providing just basic nutrition, and consumption of broccoli has been increasing over the years. This review gives an overview on the extraction and separation techniques, as well as the biological activity of some of the above mentioned compounds which have been published in the period January 2008 to January 2013. The work has been distributed according to the different families of health promoting compounds discussing the extraction procedures and the analytical techniques employed for their characterization. Finally, information about the different biological activities of these compounds has been also provided.