Over the past few decades, complementary medicine therapy using medicinal plants have been developed in healthcare. Phytochemical studies about medicinal plants have been conducted to verify their potency as medicinal remedies in modern therapeutics. Dipterocarpus littoralis commonly known as Meranti Jawa in Indonesia is traditionally used to treat diseases such as diarrhea, diabetic and malaria. This study aimed to isolate bioactive compounds from D. littoralis using bioguided fractionation method. The bioactivity measured were antioxidant, antidiabetic, and antiplasmodial activity. Alpha-glucosidase and alpha-amylase assays were applied to estimate the in vitro antidiabetic activity of D. littoralis. The antioxidant activities were determined by using the free radical scavenging assays 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2-2 00 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Analysis of total flavonoid and phenolic contents were expressed as Quercetin Equivalent (QE) and Gallic Acid Equivalent (GAE), respectively. The in vitro antiplasmodial activity test of methanol extract of D. littoralis was also conducted against Plasmodium falciparum strain 3D7. Purification of the ethyl acetate fraction of the methanol extract of D. littoralis resulted in an oligostilbenes namely α-viniferin (1). The structure of the α-viniferin was characterized by comprehensive spectral analysis including IR, 1D and 2D NMR, and in comparison with the literature data. Compound 1 showed an alpha-glucosidase and alpha-amylase inhibitory activity with IC 50 values of 256.17 and 212.79 μg/mL, respectively. The in vitro antiplasmodial activity test against Plasmodium falciparum strain 3D7 at a concentration of 100 μg/mL revealed a strong antiplasmodial inhibitory activity with IC 50 value of 2.76 μg/mL. Our findings indicated that α-viniferin (1) which is isolated from D. littoralis extract could be regarded as potential antidiabetic and antiplasmodial resources in the future.

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Background:Medicinal plants derived natural product such as alkaloids, flavonoids and terpenes. The traditional uses claim that medicinal plants of NTT are potential folk medicine but very little research has been conducted on these plants. Objective: The present study is directed towards evaluating naturally effective antioxidant of twenty-four traditional medicinal plants collected from Kupang, East Nusa Tenggara (NTT) using in vitro models. Method: The antioxidant activities were determined by using the free radical scavenging assays 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2-2"-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Analysis of total flavonoid and phenolic contents were expressed as Quercetin Equivalent (QE) and Gallic Acid Equivalent (GAE), respectively. Statistical methods are used in data analysis include mean or standard deviation, and regression analysis. Result: Methanol extract of Sterculia quadrifida R. Br. root exhibited the highest DPPH radical scavenging activity with IC 50 value of 3.11μg/mL, followed by Schleichera oleosa and Euphorbia hirta L. extracts with IC 50 values of 10.05 and 10.09 μg/mL, respectively. Methanol extract of S. quadrifida also showed highest ABTS radical scavenging activity with IC 50 value of 7.29 μg/mL, followed by Eugenia jambolana Lam. and Lamea grandus with IC 50 value of 9.15 and 12.29 μg/mL, respectively. S. quadrifida extract showed high flavonoid and phenolic content with 661.85 mg of GAE and 116.84 mg of QE per 100 g of extracts. Conclusion: The present study gives scientific evidences that twenty four samples of NTT plants have high free radical scavenging capacity. Strong radical scavenging activity of these plants especially S. quadrifida could be considered as a potential source of natural antioxidants.

The Steam-Electric Power Station (PLTU) is one of the initiatives to meet the nation's current electricity requirements. The use of fuel for steam power plant is still dominated by fossil fuels such as coal. Even though domestic energy needs are met, steam power plant turns out to be a contributor to gas emissions that cause global warming, as well as a by-product in the form of fly ash which can cause environmental and ecosystem problems. Fly ash contains silica oxide (SiO2) and aluminum oxide (Al2O3) compounds which can be used as raw materials for synthesizing aluminosilicate-based materials such as geopolymers and zeolites. This study tested the characteristics and composition of chemical compounds in fly ash from Pulang Pisau's power plant, Central Kalimantan. Characterization using X-Ray Diffraction (XRD) showed that peaks of quartz material dominated fly ash from Pulang Pisau's power plant at 2θ=20.82°;26.61° and mullite minerals at 2θ= 31. 2°;33.1°; 35.4°;39.2°;59.8°. The results of the chemical compound composition were tested using the ASTM-D3682-12 standard. Fly ash has a composition of 29.00% SiO2, 9.98% Al2O3, 13.75% Fe2O3, and 28.37% CaO. Fly ash from Pulang Pisau's power plant is classified as type C fly ash, which can potentially be used as a source of aluminosilicate-based material synthesis.