Ringkasan Disertasi, Judul : Potensi Senyawa Metabolit Sekunder Kulit Batang Melochia umbellata (Houtt) Stapf var. degrabrata K (Malvaceae) Sebagai Antimikroba

Abstract

The Potential of Secondary Metabolites Compound from Stem Bark M. umbellate (Houtt) Stapf var. Degrabrata K (Malvaceae) as antimicrobial (Supervised by Nunuk Hariani Soekamto, Hanapi Usman and Ahyar Ahmad).The purpose of this study to isolate and to determine chemical compounds of n-hexane and chloroform extract of the stem bark M. umbellate (Houtt) Stapf var. Degrabrata K (Malvaceae), which includes to determine the bioactivity of extracts and isolated compounds toxicity against A. salina larvae shrimp, to test antibacterial and antifungal activity of the extracts and isolated compounds, to study the relationship of molecular structure of compounds isolated from the bark of the properties and bioactivity to propose biogenesis pathway isolates compounds of M. umbellate (Houtt) Stapf var. Degrabrata K. Isolation and purification were done through several stages of bark sample preparation, extraction by maceration to use methanol solvent, the partition of methanol extract with n-hexane, chloroform and ethyl acetate solvent. Fractionation of the extract of n-hexane and chloroform by vacuum column chromatography technique, the eluent mixture of hexane and ethyl acetate gradient, followed by column chromatography press and gravity column chromatography to obtain pure compound, isolate pure compounds obtained purity determined by thin layer chromatography (TLC) three eluent systems and melting point determination. The molecular structure was determined by analyzing the spectral data of UV-Vis, IR, 1H NMR, 13C-NMR, 2D-NMR includes DEPT, HMQC, HMBC, and COSY. Isolated from the stem bark of M. umbellate (Houtt) Stapf var. K. Degrabrata gained 3 compounds, namely compound 3β-acetyl-12-oleanen-28-oats, stigmasterol (stigmast-5,22-dien-3-β-ol) and stigmasteron (stigmast-5,22-dien-on). Test results of bioactivity against n-hexane extract, chloroform, ethyl acetate and methanol are all active against A. salina Leach shrimp larvae with LC50 values in a row: 407.38, 460.79, 405.58, 408.79 µg / mL, whereas compounds 1, 2 and 3 are less active (low toxic) with LC50 values are respectively: 361.93; 548.48 and 410.81 µg / mL. The results of antibacterial and antifungal bioactivity test the n-hexane extract, methanol and compound 1 gave the highest inhibition against B. subtilis bacteria and fungi C. albicans with inhibition zone diameter of > 14 mm, ethyl acetate extract and compound 3 are active against S. aureus bacteria and the fungus A. niger with inhibition zone diameter of > 14 mm. while chloroform extracts and compounds 2 showed weak inhibition against the growth of bacteria and fungi test.