Phytochemical Study and Antibacterial Activity Test of Extract, Fraction, and Subfraction of Harendong Bulu (Clidemia hirta (L.) D. Don) Leaves

• Main Author: Pramita Intani, Ulfa
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/45084
• Institution: Institut Teknologi Bandung

Melastomataceae is one of the plant families that was reported to contain antibacterial compounds. Harendong bulu [Clidemia hirta (L.) D. Don] is one of the species from Melastomataceae which has not been intensively studied for its antibacterial activity. Harendong bulu usually grows wild in forests and regarded as invasive plant with ability to interfere the growth of other plants. Traditionally, the harendong bulu leaves were used to treat wounds like infected wounds. Research studies showed that plant parts like roots, stems and leaves of harendong bulu mainly contributed to the antibacterial activity. This study was aimed to examine the phytochemical content of the leaves, to determine the antibacterial activity of extract, fraction, and subfraction of the leaves, as well as compounds responsible for the antibacterial activity. The study began with the preparation, characterization, and phytochemical screening of crude drug. The fresh leaves of harendong bulu were collected, dried, and ground into crude drug powder. The characterization of crude drug include of macroscopic and microscopic examination, determination of water content, total ash, water soluble ash, acid insoluble ash, soluble extract of water, soluble extract of ethanol, and loss on drying. Phytochemical screening showed positive presence of flavonoid, phenol, catechin tannin, gallic tannin, saponin, and steroid/triterpenoid. The crude drug was then extracted by the reflux method using solvents of increasing polarity which were n-hexane, ethyl acetate, and ethanol, respectively. The ethyl acetate extract was then fractionated by the vacuum liquid chromatography method using gradient elution composition with combination solvents of increasing polarity. Subfractionation was performed using classical column chromatography method with the gradient elution composition method using combination solvents of increasing polarity, and followed by subsequent subfractination using preparative thin layer chromatography. The antibacterial compound was then characterized using specific visualization reagents. The antibacterial activity test was then performed by both qualitative and quantitative tests whereby as for the qualitative antibacterial test, bioautography test was conducted, and the antibacterial activity was performed quantitatively by the microdilution test. The bioautography test was performed to determine the antibacterial compounds based on its chromatogram profile. The microdilution test was performed to determine the minimum inhibitory concentration of sample against bacteria. Result of microdilution test showed the same values for the minimum inhibitory concentration of ethyl acetate extract, fraction, and subfraction were 1024 µg/mL against Enterococcus faecalis and Staphylococcus aureus, and 2048 µg/mL against Propionibacterium acnes. Result of bioautography test showed the compound at Rf 0.74 gave inhibition zone on all three bacteria. Based on the characterization with specific visualization reagents, an antibacterial compound of Rf 0.74 was predicted as a flavonoid compound.