Photo: Elize Bezuidenhout / Unsplash
Harunganin - a xanthone with documented antibacterial and antimalarial activity. A priority class for anti-infective pipelines as antibiotic resistance drives renewed natural product interest.
Photo: Elize Bezuidenhout / Unsplash
Harungana madagascariensis is a small tree or shrub of Madagascar's dry deciduous and secondary forest, notable for its chemical latex defence system - a resinous exudate produced when bark is damaged, containing anthraquinones and xanthones unique to Madagascar populations. The compound harunganin, a polyhydroxy xanthone isolated from the bark and latex, has demonstrated antibacterial activity against gram-positive pathogens and in vitro antimalarial activity in published phytochemical studies.
Xanthones are a tricyclic compound class of growing pharmaceutical interest. Several xanthones are already in clinical development for antimicrobial, anti-inflammatory, and anti-proliferative applications. Madagascar's Hypericaceae represent an evolutionarily isolated population of this compound class - producing structural variants absent from the African and Asian relatives of Harungana.
The AMR context: Antibiotic resistance is driving renewed pharmaceutical industry interest in natural product-derived anti-infectives - a sector that had been largely abandoned in the 1990s. Xanthones from Madagascar's Hypericaceae represent a class of natural products that pharmaceutical companies have not systematically accessed at the genomic and paired-metabolomic level. Harunganin is the entry point; the biosynthetic gene cluster encoding it is the commercial target.