Isolation and characterization of an antioxidant from oregano (Coleus amboinicus)

Date

3-1996

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Evamarie P. Capareda

Abstract

The ethyl acetate - soluble fraction from the methanol extract of oregano leaves inhibited lipid peroxidation by 37%. Column chromatography of this fraction on an Amberlite XAD-4 column yielded a fraction that inhibited lipid peroxidation by 45%, an antioxidant activity comparable to that of tocopherol. Reversed phase HPLC of this fraction on an ODS-5 Develosil column using 90:10 Me0H-F,t0Ac as solvent gave two peaks. The less polar component exhibited antioxidant activity of 5 9 °A which is comparable to that of butylated hydroxyanisole (BHA). 10 uL of the HPLC (peak 5 fraction gave 100% mortality after 24 hours in the brine shrimp lethality assay. The IR spectrum of this antioxidant and cytotoxic component (MSL) showed peaks indicative of a phenolic structure. This was supported by results of chemical test. UV-VLS spectroscopic analysis of MSL showed maximum wavelength of absorption at 216 ma and shoulder absorptions at 220, 276, 310, 400 and 662 nm. Statistical analysis of the assay data at 5% level of significance showed that there were significant effects on both antioxidative ability and cytotoxicity with respect to mature of extract or fraction. Also, there is a significant effect on the mortality of brine shrimp larvae due to time at the 5% level.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 1996 C4 L68

Document Type

Thesis

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