Kaempferia diterpenoids and flavonoids: an overview on phytochemistry, biosynthesis, synthesis, pharmacology, and pharmacokinetics

Kaempferia species have contained various crucial ethnobotanical features, and are being used as traditional folk medicines in some Southeast Asia. This review tends to highlight important information (phytochemistry, biosynthesis, synthesis, pharmacology, and pharmacokinetics) of Kaempferia principal phytochemical classes diterpenoids and flavonoids. The electronic sources, e.g., Google Scholar, Sci-Finder, and Web of Science, and the most meaningful keywords "Kaempferia", "diterpenoids", and "flavonoids" have been more often utilized for searching the literature. More than 190 phytochemicals type diterpenoids (153 compounds) and flavonoids (42 compounds) have been separated from Kaempferia species. Isopiramanes and flavones are representative compounds. Kaempferia diterpenoids and flavonoids established great attention due to their pharmacological values such as antioxidative, anti-inflammatory, antimicrobial, antiviral, and antimalarial activities, especially anticancer. They also protected against harms to the neuron, skin, and liver. Pharmacokinetic studies revealed that metabolism of Kaempferia flavonoids might be related to the transformation of hydroxyl groups. Advances in chromatographic separations to obtain huge amounts of Kaempferia isolated compounds are expected. Future in vivo and clinical investigations on the components of Kaempferia should be carried out to provide accurate dosage and normative recommendations.