Alpinia zerumbet: A Review of the Chemistry, Quantity, and Pharmacological Properties of Selected Kavalactones

Alpinia zerumbet or shell ginger is a ginger plant with diverse chemical constituents and medicinal and non-medicinal uses. Dihydro-5,6-dehydrokawain (DDK) and Dehydrokawain (DK) are two kavalactones (also known as kava pyrones or styrylpyrones) from A. zerumbet. Both DDK and DK have a carbonyl group at C2, a methoxy group at C4, and a double bond at C5 and C6. DK has a double bond at C7 and C8 that is absent in DDK. Quantity of DDK in A. zerumbet can be ranked as rhizome > leaf > flower > stem > seed. The pericarp and seed placenta of the fruit has higher quantity of DDK than the leaf. In most plant parts, the contents of DDK are higher than those of DK. Hispidin (HP) is synthesized from DK by hydrolysis. These three kavalactones from A. zerumbet have the most promising pharmacological properties that include insecticidal, fungicidal, antioxidant, inhibition of enzymes, inhibition of Advanced Glycation End-products (AGEs), inhibition of p21-activated kinase 1 (PAK1), inhibition of LIM domain kinase 1 (LIMK1), promotion of hair growth, anti-cancer, inhibition of melanogenesis, anti-inflammatory, anti-obesity, HIV-1 integrase inhibition, neuraminidase inhibition, osteogenic, anti-platelet aggregation, cytoprotective, anti-ulcerative, and singlet oxygen quenching activities. Some fields for further research are suggested. Sources of information in this review were from Google, Google Scholar, Science Direct, PubMed, J-Stage, China National Knowledge Infrastructure (CNKI), and PubChem.