Isolation and characterization of biologically active fractions from Orthosiphon aristatus (Blume) miq.

Date

4-2004

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Evamarie P. Capareda

Co-adviser

Florinia E. Merca

Committee Member

Jose Rene L. Micor

Abstract

Combination and in vacuo concentration of the dichloromethane (DCM), I DCM:Meol I and MeOH extracts from mature ground leaves of Orthosiphon aristatus, followed by gradient flash column chromatography of the concentrate. resulted in six fractions. These fractions were subjected to different biological assays, namely, paper disc diffusion assay (antibacterial and antifungal activity), seed germination inhibitor assay (allelopathy) and brine shrimp lethality assay (cytotoxicity). Three of the column fractions (F2, F3 and F4) were found to have antibacterial activity at 6 mg per ml DMSO against B. subtilis while only one fraction (F4) was active against S aureus. F5 was the most active in brine shrimp lethality assay, giving 100% mortality of brine shrimp larvae after 24 hours at a concentration of 10 mg per ml DMSO. This fraction also exhibited some inhibition of mustard seed germination but since the control (DMSO) also displayed inhibition of germination, the results were not definitive. Infrared spectroscopic analysis of F5 revealed the presence of strong O-H stretching that suggested the presence of alcoholic or phenolic compounds. The proton NMR and UV of F5 indicate that conjugated unsaturation could likewise be present in its components. An attempt to further fractionate FS by flash column chromatography resulted in parent decomposition and was no longer pursued.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2004 C4 G66

Document Type

Thesis

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