DIVERSITY OF RESVERATROL OLIGOMERS FROM HOPEA AND RELATED PLANTS OF DIPTEROCARPACEAE FROM INDONESIA

• Main Author: Sahidin
• Format: Dissertations
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/9195
• Institution: Institut Teknologi Bandung

ABSTRACT: <br /> <br /> <br /> Hopea is one of the main genera of Dipterocarpaceae consisting of four subgenera and about 100 species. According to literature search, only eight species have been reported so far on their chemical contents. Based on structural examination on the resveratrol oligomers as the main chemical constituents of the genus, Hopea tends to produce modified resveratrol dimers. To elaborate more on this phytochemical trend, which is biogenetically expected to proceed further, more phytochemical studies are required on some other species. Furthermore, some reports also showed that a number of resveratrol oligomers exhibit strong cytotoxic effects by inhibition mechanism via apoptosis. However, these studies were limited to the unmodified resveratrol oligomers. Therefore, keeping in mind that the Hopea produces modified oligomers, cytotoxic properties of the isolated oligomers are also worth to investigated. Based on these issues, this study has been carried out on the phytochemistry and biological activities of the resveratrol oligomers from stem bark of three species of Hopea, namely H dryobalanoides, H. gregaria, and H mengarawan. In addition, the same study has also been conducted to one of Shorea species, S. assamica, growing endemically with H gregaria. <br /> <br /> <br /> Samples of Hopea dryobalanoides and H mengarawan were collected from the Experimental Garden of Jasinga, Bogor, whereas of H gregaria and S. assamica, both are the endemic plants of South East Sulawesi, were obtained from the forest of Pohara, Kendari. Isolation of the secondary metabolites involved a number of laboratory works, including extraction, fractionation, and purification, using various chromatographic techniques. The molecular structures of the isolated compounds were determined based on spectroscopic data, including UV, IR, 1-D and 2-D NMR, and mass spectra. Biological activities of the isolated compounds were evaluated against brine shrimps Anemia salina for toxicity evaluation and against murine leukemia P-388 cells for cytotoxic properties. <br /> <br /> <br /> From this study three new natural compounds of the modified type of resveratrol dimers, i.e. diptoindonesin D (1), diptoindonesin F (2), and diptoindonesin G (3), together with twelve resveratrol derivatives have been isolated from the four plant