ISOLATION, CYCLIC DIARYLHEPTANOID TRANSFORMATION, AND BIOACTIVITY ASSAY OF SECONDARY METABOLITES FROM STEMBARK OF MYRICA JAVANICA

• Main Author: Izdihar Fauziyyah, Jilan
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/68445
• Institution: Institut Teknologi Bandung

Myrica is a plant genus of the Myricaceae family which is spread in various regions of the world. This genus Myrica is also widely used as traditional medicines, including to treat fever, cough, throat infection and asthma. The medicinal properties of a plant depend on the content of its secondary metabolites. Based on literature, the main secondary metabolite of Myrica is cyclic diarylheptanoid. Cyclic diarylheptanoids are known to have various bioactivities, such as antioxidant, anticancer, anti-inflammatory, antibacterial, and antituberculosis activities. One of the Myrica species growing in Indonesia is Myrica javanica. The research on this species is very limited and studies on secondary metabolites of this species have not yet been reported. Based on that reason, the isolation of secondary metabolites from the stembark of M. javanica, chemical transformation on the main cyclic diarylheptanoid compound, and cytotoxic activity examination of the isolated compounds and transformation products against murine leukemia cells P-388 have also been carried out in this research.The research method used included three steps, including isolation of secondary metabolites, chemical transformation of the main diarylheptanoid cyclic isolated and bioactivity test of the isolated compounds and transformation products against murine leukemia P-388 cells. The isolation included the extraction process, i.e. maceration using acetone solvent, and then followed by separation and purification using Vacuum Liquid Chromatography (VLC) and Gravity Column Chromatography (GCC), as well as characterization of structure of isolated compounds using 1D NMR (1H-NMR and 13C-NMR) and 2D NMR (HSQC and HMBC). An optical rotation calculation was also carried out for compounds containing chiral carbon. The chemical transformation reaction conducted was a protection reaction on the phenol group with the prenyl and benzyl groups. The prenylation and benzylation reactions used 3,3-dimethylalyl bromide and benzyl chloride, respectively, under base conditions and acetone as solvent. The activity carried out was cytotoxic activity using the MTT assay method. In this research, three secondary metabolites were obtained from the stembark of M. javanica, consisting of two cyclic diarylheptanoid compounds (myricanol and myricanone) and one pentacyclic triterpenoid compound (taraxerol). Myricanol was a main compound of stembark M. javanica with the amount of 1.44 g from 85 g of dried stembark powder (1.68%). The three isolated compounds were first finding from M. javanica, however they have been obtain from other species in the same genus. In addition, two compounds were obtained from the transformation reactions of myricanol, i.e. MP compound from the prenylation reaction (20.1 mg, y.84.5%) and MB compound from the benzylation reaction (8.1 mg, y. 65%). MP compounds were identified as mono-O-prenylated myricanol, while MB compounds were mono-O-benzylated myricanol. Both reactions occurred at the same position, i.e. the OH group attached at A ring of myricanol. The prenylation and benzylation reactions of myricanol compounds were reported for the first time. The cytotoxic activity against murine leukemia P-388 cells of the four cyclic diarylheptanoid compounds, i.e. myricanol, myricanone, MP, and MB showed that MP and MB were active with IC50 values of 3.9 and 4,0 ?g/mL. Meanwhile, myricanol and myricanone were not active with IC50 values of 7,8 and 5.4 ?g g/mL, respectively. Thus, it can be stated that the prenylation and benzylation reactions on the myricanol can increase the cytotoxic activity of the compound twice.