BIFLAVONOIDS FROM LEAVES AND TWIGS OF INDONESIAN AGATHIS ROBUSTA (ARAUCARIACEAE) AND ITS BIOACTIVITY AS AN ANTICANCER

• Main Author: Utami Cahyaning Rahayu, Dyah
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34376
• Institution: Institut Teknologi Bandung

Cancer (malignant tumor) is one of the diseases with the second highest mortality rate in the world beside heart disease. Up to know, the research on cancer drugs particularly cancer drugs obtained from natural resources (terestial plants or marine organisms), grows rapidly since the good bioactive compounds for curing cancer are limited and had side effects. One of the natural compound types which have been known to have anticancer activity is biflavonoids or flavone dimers. This compounds are composed of two monomer units of flavonoids, such as apigenin or naringenin, which are joined through oxidative coupling reaction. This reaction can produce several biflavonoid skeletons, such as agathisflavone (A), amentoflavone (B), cupressuflavone (C), robustaflavone (D), and hinokiflavone (E) having differences in bond linkage of two monomers, either through C-C or C-O-C bond. Previous researches have been reported that biflavonoids have high activity against several cancer cells, including lung carcinoma cells NCI-H460 and renal carcinoma cells RXF-393. In addition, these compounds have also been known to have various activities, such as anti-HIV, anti-malarial, antidepressant, antiepileptic, antituberculosis, antiimflamatory, antiherpes, antiinfluenza, hepatitis B virus replication inhibitor, and beta secretase (BACE-1) enzyme inhibitor as an anti-Alzheimer's. One of Indonesian plants which have known to have biflavonoids is Agathis (Araucariaceae). This genus is often found as evergreen tree distributing in Australia and Indomalaya, such as Indonesia (Kalimantan and Irian Jaya), Papua New Guinea, and New Caledonia. A. robusta is one of five species from Agathis genus which grows well in Indonesia, especially in Java and Kalimantan Island. This species has a high economic value for its wood and resin which can be used for industrial purposes, such as paper and furniture industries. Moreover, this species also has ecological function as the city lungs. However, there are no recent studies have been reported on secondary metabolites, especially biflavonoids, from Indonesian A. robusta. Even though biflavonoids have been known to have anticancer activities, but the activities on HUVEC (Human Umbilical Vein Endothelial Cells) proliferation and murine leukemia cells P-388 have not reported yet. Therefore, this research has been conducted to isolate biflavonoid from leaves and twigs of Indonesian A. robusta using extraction methods and various chromatographic techniques, such as vacuum liquid chromatography, radial chromatography, gravity column chromatography with silica gel and Sephadex LH-20 as a stationary phase. Furthermore, the extracts and secondary metabolites isolated were also examined on antiangiogenesis as HUVEC (Human Umbilical Vein Endothelial Cells) proliferation inhibitor and cytotoxic activity against murine leukemia P-388 cells. Fourteen compounds which are nine biflavonoid compounds have been successfully obtained from the acetone extract of A. robusta leaves and twigs. All compounds were elucidated according their spectroscopic data, including IR, UV- Vis, NMR (1H, 13C, NOESY, HSQC, and HMBC), MS, and CD Spectra as 7,7“- di-O-methylagathisflavone (11); 4“‘,7,7“-tri-O-methylagathisflavone (12); kayaflavone (13); 4‘,4“‘,7,7“-tetra-O-methylamentoflavone (14); 7,7“-di-O- methylcupressuflavone (15); 4‘,4“‘,7,7“-tetra-O- methylcupressuflavone (16); 7“ - mono-O-methylrobustaflavone (17); 4‘,7“-di-O-methylrobustaflavone (18), and imbrikataflavone (19). The preliminary HUVEC proliferation assay of acetone extract of the leaves and twigs of A. robusta showed weak activity with IC50 values were 35.0 and 29.0 µ g/mL, respectively. Then, four biflavonoid compounds have also been assayed on HUVEC proliferation and indicated that compound (17) and (15) were active with IC50 values were 2.1 and 3.3 µ g/mL, respectively; compound (14) showed weak activity with IC50 value was 73.0 µ g/mL; and compound (16) was not active on HUVEC proliferation with IC50 values more than 100.0 µ g/mL. Furthermore, the preliminary assay of acetone extract of A. robusta leaves on cytotoxic against murine leukemia P-388 cells showed inactive with IC50 value was 46.0 µ g/mL. Interestingly, the acetone extract of A. robusta twigs was active with IC50 value of 17.6 µ g/mL. Five biflavonoid compounds have also been examined their cytotoxicity against murine leukemia P-388 cells. Compound (17) was very active with IC50 values less than 0.1 µ g/mL. In addition, compound (15) showed active activity with IC50 value was 1.8 µ g/mL. Three other compounds, (19), (16), and (14) and were inactive with IC50 values 44.5, 70.5, and > 100.0 µ g/mL. Thus, it can be suggested that the compound (15) and (17) are potential to be the lead compounds for anticancer.