Production of flavonoids in organogenic cultures of Alpinia zerumbet.

Alpinia zerumbet plantlets were cultured in vitro in MS medium supplemented with growth regulators, including IAA, TDZ and BAP. Using high performance liquid chromatography (HPLC), the production of rutin, kaempferol-3-O-glucuronide, and kaempferol-3-O-rutinoside was evaluated, based on leaf hydroalcoholic extracts of three-month-old plantlets. The relative concentration of phenolics from the hydroalcoholic extracts of plantlets cultured in control medium reached 100% compared with plantlets treated with growth regulators and donor plants (80%). The in vitro rutin production was more pronounced than the other flavonoids. While no direct relation between the content of phenolic compounds and increased flavonoid production was observed, the combination of IAA + TDZ enhanced the production of rutin (83.2 microg/g dried leaves) and kaempferol-3-O-glucuronide (29 microg/g dried leaves), compared with growth regulators used alone. Overall, these findings suggest the value of in vitro cultivation as a means of enriching phenolic and flavonoid production in medicinal plants.