Objectives:The objectives of this research were to evaluate antioxidant activity from different polarities rice bran extract of three varieties of rice using two methods of antioxidant testing which were ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), and correlation of total phenolic, flavonoid and carotenoid content with their exhibitory concentration 50 (EC 50 ) of FRAP and inhibitory concentration 50 (IC 50 ) of DPPH antioxidant activities.Methods: Extraction was conducted by reflux using different polarity solvents. The extracts were evaporated using rotary evaporator. Determination of total phenolic, flavonoid and carotenoid content, antioxidant activities using FRAP and DPPH assays was performed by ultraviolet-visible spectrophotometry and its correlation with EC 50 of FRAP capacities and IC 50 of DPPH scavenging activities was analyzed by Pearson's method. Results:Ethanolic rice bran extract of black rice showed the lowest EC 50 of FRAP capacity 64.35 µg/ml and IC 50 of DPPH scavenging activity 23.92 µg/ml. The highest phenolic content, flavonoid content, and carotenoid content were also given by ethanolic rice bran extract of black rice. There was significantly negative correlation between total phenolic content and carotenoid content in rice bran extract of red rice and black rice with their IC 50 of DPPH. Conclusions:All of the rice bran extracts (except n-hexane rice bran extract of black rice and ethanolic rice bran extract of white rice) were very strong antioxidant by DPPH assay. Phenolic and carotenoid compounds in rice bran extracts of red rice and black rice were the major contributor in antioxidant activity by DPPH assay. Rice bran extracts of black rice had linear results by FRAP and DPPH assays.

The purpose of this research is to study the dominant chemical compounds of chicken bile extract. Chicken bile, which is usually disposed of as useless waste, is made a choice. The study began with material collection from native chicken farmers, Kluwut Village, Bulakambah sub-district, Brebes Regency, Central Java. The determination was carried out at Bandungense Herbarium School of Biological Science and Technology-ITB.  The choice of animals were native chickens. They belonged to the family Phylum: Chordata, Class: Aves, Nation: Galliformes, Tribe: Phasianidae, Surname: Gallus, Type: Gallus gallus Linn, The common name: native chicken (Indonesia), and domestic fowl in English. The bile portion was cut into small pieces and dried using a freeze dryer. The reflux method was then extracted using solvents with a different polarity, which are n-hexane, ethyl acetate, and ethanol. It gave out n-hexane extract, ethyl acetate extract, and ethanol extract. The extracts were evaporated using a rotary evaporator. The percentage of the obtained yield was n-hexane extract 7.63%, ethyl acetate extract 8.61%, and ethanol extract 34.91%. Selected ethyl acetate extract was fractionated by Vacuum Liquid Chromatography (VLC I)  and was monitored by a thin layer of Chromatography (TLC). Then fraction 5-6 was continued to sub fractionation by Classical Column Chromatography (CCC). Nuclear Magnetic Resonance (NMR) investigated isolate X and found that isolate X appeared to be cholesterol. From the second fractionation (VLC II), fraction 2-7 proceeded to the VLC III, and then subfraction 7 was evaluated using GC-MS. The dominant chemical compounds of subfraction 7 were oleic acid 38.72%, n-hexadecanoic acid (35.6%), octadecanoic acid (17.94%), palmitoleic acid (1.53%).

The aim of this research was to study the ethnopharmacognosy, antioxidant activity, and chemical content of chicken bile. In addition, a bioactivity-guided isolation was also performed to identify compounds in chicken bile having antioxidant activity. Extraction was carried out by reflux method. Each extract was tested for its antioxidant activity using DPPH and CUPRAC methods. Fractionation was performed on selected extract, namely ethyl acetate extract, using vacuum liquid chromatography and subfraction using preparative TLC method and classical column chromatography (CCC). Compound 1 was characterized and identified by NMR, compound 2 was characterized and identified by LC-MS/MS and NMR, subfraction 7 was characterized by GC-MS. The result of the antioxidant activity of ethanol extract of chicken bile using the DPPH method (IC 50: 46.64 g/mL), ethyl acetate extract (IC 50: 69.99 g/mL), n-hexane extract (IC 50: 71.65 g/mL, fraction 15-17 (IC 50: 88.77 g/mL) showed strong antioxidant, whereas by CUPRAC method all extracts (EC 50: 69.90, EC 50: 80.28, EC 50: 70.40) and fraction (EC 50: 64.53) are strong antioxidants. The result of identification of compound 1 by NMR was identified as cholesterol, identification of compound 2 by LC-MS/MS was (E)-hexadecyl-ferulate and subfraction 7 which was identified by GC-MS produced dominant compounds, namely oleic acid, n-hexadecanoic acid, octadecanoic acid and palmitoleic acid. In conclusion, extract, fraction 15-17 and subfraction of chicken bile have antioxidant activity where the active antioxidant compound is a phenol group compound, namely (E)-hexadecyl-ferulate. The other chemical constituents found in chicken bile are, oleic acid, n-hexadecanoic acid, octadecanoic acid, and palmitoleic acid.

Component in chicken bile may be similar to bear bile, which contains an immunostimulant agent ursodeoxycholic acid and related to antioxidant effect. The purposes of this study were to evaluate the antioxidant potential of chicken bile extract by the DPPH method, analyze the correlation between total phenolic and flavonoid content with IC50 of DPPH scavenging activities. Chicken bile was cut and dried using freeze dryer, then extracted by reflux using different polarity solvents. A rotary evaporator was used to concentrate the extracts. Calculation of total flavonoid and phenolic content, antioxidant potential using DPPH assay were carried out by UV-visible spectrophotometry, and Pearson’s method was used to analyze their correlation. IC50 of DPPH of ethanolic chicken bile extract was 46.64 µg/ml, while ethyl acetate and n-hexane extracts were 69.99 µg/ml and IC50 71.65 µg/ml, respectively. The highest phenolic content and flavonoid content were given by ethanolic chicken bile extract. The total phenolic and flavonoid content in chicken bile extracts had a significant and negative correlation with IC50 of DPPH. All chicken bile extracts are potential antioxidants by DPPH assay. Phenolic and flavonoid compounds in chicken bile extracts contributed together in antioxidant capacity by DPPH assay.

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