Proximate analysis of brown seaweed, Padina sp., antioxidant activity assessment of its methanolic extract and partial characterization of the isolated compounds

Date

10-2013

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Hidelisa P. Hernandez

Abstract

Proximate analysis of air-dried ground Padina sp. collected from Calatagan, Batangas was done to determine the chemical composition of the sample. Results showed that dried ground Padina sp. contained 65.14% moisture, 16.82% ash, 0.56% crude fat, 3.04% crude protein, 3.98% crude fiber and 10.47% carbohydrate. Fractionation of the methanolic extract yielded 15.88% aqueous fraction and 4.87% hexanes fraction based on mass of Padina sp. The least polar column chromatography eluates from the hexanes fraction after which compounds 1H, 2H and 3H were isolated. The isolated compounds were subjected to UV-Vis and 1H NMR spectroscopic analyses. Results showed that the compounds absorb mainly in the UV region. On the other hand, the 1H NMR spectra showed that 1H, 2H and 3H compounds may contain both aliphatic and aromatic groups. Antioxidant activity assays such as DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical-scavenging, hydrogen peroxide scavenging and hydroxyl radical-scavenging activity assays were performed on the crude methanolic extract. The effective concentration at 20% DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical-scavenging, 20% hydrogen peroxide-scavenging and 50% hydroxyl radical-scavenging activity of methanolic extract of dried ground Padina sp. were 0.74, 0.43 and 0.022 mg/mL, respectively. The values showed that the methanolic extract of Padina sp. is a potential source of antioxidants, but has lower antioxidant activity as compared to ascorbic acid.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2013 C42 /V47

Notes

source: ilib only (in process)

Document Type

Thesis

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