Changes in the contents of four active diterpenoids at different growth stages in Andrographis paniculata (Burm.f.) Nees (Chuanxinlian)

摘要

Background The therapeutic activities of Andrographis paniculata are attributed to four major active diterpenoids: andrographolide (AP₁), 14-deoxy-11,12-didehydroandrographolide (AP₃), neoandrographolide (AP₄), and 14-deoxyandrographolide (AP₆). This study aims to quantify the four active diterpenoids in various plant organs of A. paniculata at different growth stages in greenhouse and field experiments, with a developed HPLC-diode array detector (HPLC-DAD) method for simultaneous determination of these diterpenoids. Methods Plants were grown in greenhouse and in field conditions, harvested at different growth stages, and separated into different organs for determination of the four active diterpenoids by an HPLC-DAD method. Results The most abundant diterpenoid was AP₆ between seedling and vegetative stages in the greenhouse experiment (13.38 to 23.71 mg/g in 2006 and 10.67 to 24.54 mg/g in 2007). High levels of AP₆ were also detected in leaves at the transfer stage in the greenhouse experiment (36.05?±?0.69 mg/g) and field experiment (30.59?±?1.39 mg/g). The levels of AP₆ then decreased as plants matured. The highest content of AP₄ was in cotyledons (16.65?±?4.48 mg/g) at the transfer stage. The highest contents of AP₁ were detected in leaves at seed-forming stage in greenhouse experiment (24.72?±?1.89 mg/g) and vegetative stage in field experiment (43.16?±?0.92 mg/g). Flowers of A. paniculata contained high levels of AP₁ (21.42?±?3.74 mg/g). AP₃ and AP₄ were at low levels in leaves at all growth stages. Conclusion In A. paniculata, AP₆ was at the highest level in leaves at transfer stage in both greenhouse and field experiments. AP₁ was at the highest level in leaves at vegetative stage and seed-forming stage in field and greenhouse experiments, respectively. The contents of AP₃ and AP₄ in leaves were low at all growth stages.