Identification of bioactive diterpenoid lactones using nuclear magnetic resonance from Andrographis paniculata

Abstract

Background: Andrographis paniculata (AP) (Burm. F) Nees, belongs to the family Acanthaceae, it is also known as a highly bitter plant. In South East Asia this plant is commonly used for cold, cough and respiratory tract infections. Andrographolide (ANG), 14-deoxy-11, 12-didehydroandrographolide (DDA) are the major bioactive diterpenoid lactone compounds of the plant shown vasorelaxant effect, anticancer, anti-inflammatory, and to treat variety of diseases which is well-documented. Materials and Methods: The high-performance liquid chromatography (HPLC) and 1H-NMR analysis of AP chloroform extract (APCE) revealed the presence of ANG, 14-deoxyandrographolide (DA), and DDA. The main advantage of 1H-NMR is simple, rapid and successfully applied to quantify the active diterpenoids and an alternative to HPLC method to check the presence of various bioactive compounds and its presence in the active raw materials of AP. Results: The results revealed that most active bioactive compounds such as ANG, DA, and DDA are present in the APCE portion of the AP. The chemical shifts of various groups confirmed through 1H-NMR that all the three ANG, DA, and DDA has potent vasorelaxant effect and majority of these compounds are present in the APCE portion and not in the methanol or aqueous fractions. The 1H-NMR study confirmed that diterpenoids such as ANG, DA, and DDA from APCE has vasorelaxant effect on the animal study.