Phytochemical Constituents of Combretum Loefl. (Combretaceae)

Combretum is the largest and most widespread genus of Combretaceae. The genus comprises approximately 250 species distributed throughout the tropical regions mainly in Africa and Asia. With increasing chemical and pharmacological investigations, Combretum has shown its potential as a source of various secondary metabolites. Combretum extracts or isolates have shown in vitro bioactivitities such as antibacterial, antifungal, antihyperglycemic, cytotoxicity against various human tumor cell lines, anti-inflammatory, anti-snake, antimalarial and antioxidant effects. In vivo studies through various animal models have also shown promising results. However, chemical constituents and bioactivities of most species of this highly diversified genus have not been investigated. The molecular mechanism of bioactivities of Combretum isolates remains elusive. This review focuses on the chemistry of 261 compounds isolated and identified from 31 species of Combretum. The phytochemicals of interest are non-essential oil compounds belonging to the various structural groups such as terpenoids, flavonoids, phenanthrenes and stilbenoids.