Benzyl glucosinolate and benzyl isothiocyanate in papaya (Carica papaya) seeds : level, angionic potential, and antiradical activity

Date

4-2007

Degree

Bachelor of Science in Agricultural Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Evelyn B. Rodriguez

Abstract

The occurrence, level, angiogenic potential and antiradical activity of benzyl glucosinolate in papaya (Carica papaya) seeds were determined.

The amount of benzyl glucosinolate in papaya in papaya seeds, indirectly determined as benzyl thiourea derivative, was found to be 0.392 mg/g ± 0.006 dried seeds.

Benzyl glucosinolate and its breakdown product, benzyl isothiocyanate, were isolated, purified and characterized. The purified benzyl glucosinolate exhibited a melting point range of 187 - 189 °C and a maximum UV absorption at 248.5 nm. On the other hand, the isolated benzyl isothiocyanate showed a boiling point range of 239 - 241 `'C and UV absorption peaks at 203, 247 and 272 nm. The IR spectrum of benzyl glucosinolate showed an , 0-H stretch at 3300 - 3400 cm-1,; spz C-H stretch at 2950 cm-1,: aromatic C=C stretch at 1590 cm-1 and 1400 cm-1,; S=0 stretch at 1350 cm-1, and 1000 cm-1, S03- stretch at 1050 cm-1,: and S-0 stretch at 650 cm-1. The benzyl isothiocyanate, on the other hand showed bands at 3100, 2100 and 1650 cm-1, corresponding to aromatic C-H stretch, -N=C=S stretch and aromatic C=C stretch, respectively.

Whole and autolyzed glucosinolate extracts were prepared from papaya seeds. The whole or intact extract was obtained by inactivating the endogenous myrosinase enzyme. TLC analysis of the whole glucosinolate extract showed three spots, one of which had an Ri identical to that of isolated benzyl glucosinolate. The autolyzed glucosinolate extract also gave three spots, with one spot having an RI identical to that of the isolated benzyl isothiocyanate.

The antiradical activity of benzyl glucosinolate, benzyl isothiocyanate, whole extract, autolyzed extract and quercetin at various concentrations (50 ppm, 100, ppm, 200 ppm, 300 ppm and 500 ppm) was evaluated using the DPPH assay. Quercetin was the most efficient DPPH inhibitor with 95.6 % inhibition at 500 ppm. At the 500 ppm, the autolyzed and the whole glucosinolate extract inhibited the DPPH radical by 71.1 % and 66.7, respectively. On the other hand, the isolated benzyl glucosinolate and benzyl isothiocyanate gave a lower percent inhibition of 35.6 % and 22.2 %, respectively at 500 ppm.

The angiogenic potential of benzyl glucosinolate, benzyl isothiocyanate, whole glucosinolate extract, autolyzed glucosinolate extract and quercetin were assessed al various concentrations (50 ppm, 100 ppm, 400 ppm and 800 ppm) in PBS using the duck embryo assay. It was found that benzyl glucosinolate, benzyl

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2007 A13 P53

Document Type

Thesis

This document is currently not available here.

Share

COinS