LIGNAN AND NEOLIGNAN DERIVATIVES FROM THE STEM BARK OF DEHAASIA CAESIA (LAURACEAE) AND THEIR CYTOTOXIC BIOACTIVITY

• Main Author: Rahmawati, Devi
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/85669
• Institution: Institut Teknologi Bandung

Dehaasia is a plant genus belonging to the Lauraceae family, consisting of 44 species. This genus has a high species diversity in Indonesia, particularly on the island of Sumatra. Locally, the genus Dehaasia is known as "forest cashew" or "pekan." The tree grows about 6?35 meters tall, with thin, white, smooth bark that is easy to peel off. Dehaasia has various uses; its wood is commonly used for building materials, and the plant can be used in ethnomedicine for treating microbial infections and boils. However, research on its secondary metabolites and bioactivity remains limited. Some species of Dehaasia are mainly reported to contain alkaloids, including benzylisoquinoline, bisbenzylisoquinoline, aporphine, bisaporphine, phenanthrene, and morphinan groups. Secondary metabolites from the genus Dehaasia have been reported to have diverse activities, such as antiplasmodial, antibacterial, cytotoxic, and antioxidant. One species of Dehaasia that grows in Indonesia and is found in the Bogor Botanical Gardens is Dehaasia caesia Blume, which is endemic to the island of Sumatra. The phytochemical study of this species has not been reported. Therefore, this study aimed to isolate secondary metabolites from the bark of Dehaasia caesia and test their cytotoxic bioactivity. The cytotoxic test against murine leukemia P-388 cells was chosen as the preliminary screening for the search for anticancer-lead-compounds recommended by the National Cancer Institute (NCI). The isolation method for secondary metabolites included extraction with acetone as a solvent. The acetone extract from the bark was separated and purified using various chromatography techniques, including vacuum liquid chromatography (VLC) and gravity column chromatography (GCC), resulting in pure compounds. The purity of the isolated compounds was tested using thin-layer chromatography (TLC). The structure of the compounds was analyzed using spectroscopic techniques, including 1D-NMR (1H NMR and 13C NMR) and 2D-NMR (HSQC and HMBC). Additionally,to determine the stereochemistry of the compounds, optical rotation and circular dichroism (CD) measurements were performed. The cytotoxicity of extract and isolated compounds were examined against murine leukemia P-388 cells using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. This research successfully obtained five compounds from the acetone extract of thebark of Dehaasia caesia, two of which were identified as neolignan derivatives, namely (-)-licarin B (54), 7S,8R-licarin A (55), and one lignan derivative, i.e. (-)-dihydroguaiaretic acid (56). The lignan and neolignan derivatives were previously isolated from several genera within the Lauraceae family, but this is the first isolation from Dehaasia. The cytotoxic test of the acetone extract from the bark of Dehaasia caesia and the isolated compounds against murine leukemia P-388 cells showed that the acetone extract from the bark of Dehaasia caesia and7S,8R- licarin A (55) were active with IC50 values of 5.6 ?g/mL and 3.9 ?g/mL, respectively. Meanwhile, (-)-licarin B (54) and (-)-dihydroguaiaretic acid (56) wereinactive, with IC50 values of 4.7 ?g/mL and 5.9 ?g/mL, respectively. The cytotoxic test against murine leukemia P-388 cells for (-)-licarin B (54) and (-)-dihydroguaiaretic acid (56) has not been previously reported.