Judul: Penentuan Kuersetin dalam Bawang Dayak (Eleutherine palmifolia) dengan Kromatografi Cair Kinerja Tinggi
Abstrak: Eleutherine palmifolia known as bawang dayak or bawang sabrang is widely used as herbal medicine to treat various diseases, including diabetes, hypertension and lowering cholesterol. The objectives of this research are to determine content of quercetin in bawang dayak and to analyze the performance of determination method of quercetin in bawang dayak using high-performance liquid chromatography (HPLC). To ensure that HPLC method can be used for the intended purpose then the method has to be validated. Parameters determined on method validation were linearity, limit of detection, limit of quantification, and precision. The linearity in the concentrations of 0.5, 2.5, 10, and 20 mg/L showed correlation coefficient of 0.9992. The limit of detection was 0.0482 mg/L and the limit of quantification was 0.1460 mg/L. The precision of this method was 13.41%. The average concentration quercetin in bawang dayak was 0.2943%. The number of quercetin that is high enough make bawang dayak potential as a medicine.
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Judul: Kapasitas Antioksidan Bawang Dayak (Eleutherine palmifolia) dalam Bentuk Segar,Simplisia dan Keripik, pada Pelarut Nonpolar, Semipolar dan Polar
Abstrak: Bawang dayak (Eleutherine palmifolia) is a red bulb plant from Central Kalimantan, which has bioactive compounds such as phenols, flavonoids, alkaloids, glycosides and tannins. The existence of bioactive compounds become parameter of antioxidant activity of this red bulb. The study showed antioxidant capacity of bawang dayak in fresh form, simplisia (dried) form and chips form, which were extracted by the solvent hexane, ethyl acetate, methanol, ethanol and water. Antioxidant capacity was measured by DPPH method and rancimat method. Phytochemical screening was conducted to determine the bioactive compounds of bawang dayak in each form for every solvent. Based on DPPH method, bawang dayak in fresh form was extracted with ethyl acetate had the highest antioxidant capacity value that is 227.0% equal to 1.02 mg AEAC/mg extract. Simplisia form which was extracted with ethanol had antioxidant capacity value 51.8% equal to 0.21 mg AEAC/mg extract. Chips form was extracted with ethylacetate and ethanol had the highest antioxidant capacity values 57.5% and 46.5% which were equal to 0.24 mg AEAC/ mg extract and 0.18 mg AEAC/ mg extract. The induction time of ethylacetate fresh extract, ethanol simplisia extract and ethylacetate chip extract based on measurement with rancimat method, were 3.7 hours, 2.8 hours and 2.6 hours. All of extract had higher induction time than tocoferol. Besides, the measurement of phenolic content resulted that methanol fresh extract, ethanol simplisia extract and methanol chip extract had 4.29 mg GAE/100 mg extract, 3.52 mg GAE/ 100 mg extract and 3.38 mg GAE/100 mg extract. Vitamin C (ascorbic acid) on fresh bawang dayak was quite high, reaching 61.5mg/100gram, whereas vitamin C on simplicia and chip were decreased, respectively 41.0 mg/100 gram and 22.0 mg/100gram due to the heating process. The Ethylacetate fresh extract contains of alkaloid , phenolic, flavonoids, triterpenoids, steroids and glycosides compounds, while the ethanol simplscia extract and ethylacetate chip extract contains of alkaloids, saponins, tannins, phenolics, flavonoids, triterpenoids, steroids and glycosides compounds.
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Judul: Dynamics Model for Rural and Urban Economic Growth
Abstrak: Lewis theory of structural change has focused on mechanisms that allow countries to transform their domestic economic structure to a more modern economy. The proposed model deals with the mechanism of interaction between rural and urban Economic. This model is concerned with the process of labor transfer from rural to urban areas. This study aims to model the dynamics of economic growth in rural and urban areas, including determining the equilibrium solution and to carry out simulation of the model. The simulation results show that the transfer of labor from rural to urban areas will increase the rate of change of capital so that structural changes can be realized. In addition, increased propensity to save in rural areas will also accelerate structural change
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