Thesis (M.Sc.)--Chulalongkorn University, 2007

In this work, sugarcane (Saccharum officinarum L.) bagasse was extracted by sequential solvent extraction, liquid-liquid extraction and single CH2Cl2 extraction process. The extracts were tested for antioxidant, tyrosinase inhibition and UV-screening activities. The best process to obtain extract with good antioxidant, tyrosinase inhibition and UV-absorption activities from sugarcane bagasse is CH2Cl2 sequential solvent extraction. The high-yielded extracts with good activities were subjected for further isolation by chromatographic techniques and 4-hydroxybenzaldehyde, syringic acid, 3,5-dimethyl-4-hydroxybenzaldehyde, 4-hydroxy-3-methoxycinnamic acid, 3’,5’-dimethoxy-4’-hydroxy acetophenone and undecane-4,6-dione could be identified. Free radical scavenging activity of sugarcane extract is partly contributed from the presence of syringic acid, 3,5-dimethyl-4-hydroxybenzaldehyde and 4-hydroxy-3-methoxycinnamic acid. While tyrosinase inhibition activity is partly contributed by the presence of syringic acid, 4-hydroxybenzaldehyde and undecane-4,6-dione.