Phenolic phytochemicals in "Calamansi" (Citrus madurensis loureiro) fruit: profile, antioxidant activity and angiogenic potential assessment

Date

10-2005

Degree

Bachelor of Science in Agricultural Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Evelyn B. Rodriguez

Co-adviser

Maxima E. Flavier

Committee Member

Dolores P. Buquiran

Abstract

The study focused on the determination of the phenolic compounds present in "calamansi" (Citrus madurensis loureiro) and on the evaluation of their antioxidant and angiogenic activities. A profile of the phenolic compounds present in the extracts was determined using a descending two-dimensional paper chromatography technique. Among the major components identified using UV-Vis spectrophotometry and descending one-dimensional paper chromatography were vitexin. hesperitin and naringenin. occurring predominantly in their glycosidic forms. Using the Folin-ciocalteau method. the highest total phenolic content among the three phenolic extracts of "calantansi" was estimated in the MAW extract (1308.00 mg GAE/ kg fresh sample; 1090.00 mg CE/ kg fresh sample). The acid-hydrolyzed extract ranked second (453.60 mg GAE/ kg fresh sample; 379.20 mg CFJ kg fresh sample). and the base-hydrolyzed extract showed the lowest values (149.00 mg GAE/ kg fresh sample; 125.00 mg CE/ kg fresh sample). The antioxidant activity of the phenolic (MAW) extract was assessed by the determination of inhibition of TBARS formation in lecithin liposome and DNA oxidation. Highest TBARS inhibitions were obtained at the highest concentration (20 ppm) in lipid reaction medium for BHT (81.09 %). quercetin (72.06 %) and the phenolic extract 162.94 col. A decreasing pattern of inhibition of TBARS formation was given by ascorbic acid (50.49 !. at 5 ppm to 40.20 % at 20 ppm) and hesperidin (41.67 % at 5ppm to 35.29 % at 20 ppm). In DNA reaction medium. highest TBARS inhibition was exhibited by quercetin (46.97 t011owed by the phenolic extract (43.94 %) and BHT 142.93 "oat 20 ppm. Similar decreasing behavior of inhibition of TBARS formation as in the lipid medium were given by ascorbic acid (33.33 % at 5 ppm to 0.00 % at 8 ppm) and hesperidin (36.36 % at 5 ppm to 23.64 % at 8 ppm) in the DNA medium. The radical scavenging efficiency was also determined using the DPPH assay and the highest free radical scavenging (FRS) activities were obtained at the highest concentration (300 ppm) that was used for all the samples. Quercetin gave the highest FRS activity (92.4%). followed by BHT 177.01°o) and hesperidin (24.81 %). The phenolic extract ranked the lowest with 10.15 % FRS activity. Potential anti-angiogenic activities were also evaluated using the Duck-Embryo assay. Thinning and reduction of blood vessels in a concentration-dependent manner, was shown by the phenolic extract, ascorbic acid and hesperidin-treated duck embryos in comparison with the untreated duck embryo wherein normal diameter and formation of blood vessels were observed. The anti-angiogenic potential was shown to generally increase at increasing concentrations and was observed to start at varying concentrations; for ascorbic acid (800 ppm) and the phenolic extract (1200 ppm).

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2005 A13 G66

Document Type

Thesis

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