Judul: Isolation of Benzophenone Group from the Methanolic Extract of Mahkota Dewa [Phaleria macrocarpa (Scheff.) Boerl. Pulp
Abstrak: Traditionally, mahkota dewa plant [Phaleria macrocarpa (Scheff.) Boerl.] is used to treat various diseases in Indonesia, including cancer. In developing the mahkota dewa plant as material for cancer therapy, it requires for quality control that responsible for its activity. Quality control can be determined through marker compound. This study aimed to isolate marker compound benzophenone compound, from the methanol extract of mahkota dewa pulp. Isolation was done using column chromatography and preparative thin layer chromatography (TLC) guided by BSLT activity and benzophenone coloring reagent. Mahkota dewa pulp methanol extract was fractionated with silica gel. The fraction 4 column chromatography resulted had a LC50 value of 30.90 μg/ml. Based on TLC on fraction 4, fraction 4 consisted of benzophenone on Rf 0.37. Separation of fraction 4 using preparative TLC with eluent chloroform-methanol-water (70:20:2) yielded eight fractions. The benzophenone compound could be detected at fraction 45 with the Rf of value 0.37 and gave the LC50 value 899.28 μg/ml. Identification of fraction 45 by UV-Vis spectrometer showed UV absorption at 200 nm and 264 nm. IR spectra indicated that the fraction 45 has an aromatic compound and have the same pattern with phalerin.
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Judul: Isolasi Fraksi Flavonoid sebagai Inhibitor Enzim α-Glukosidase dari Buah Mahkota Dewa
Abstrak: Mahkota dewa (Phaleria macrocarpa) empirically recognized as anti-diabetic. This claim requires further analysis, one of it by enzymatic inhibition assay using α-glucosidase enzyme. This intestinal enzyme produce in the jejunum catalyzed the breakdown of glycogen to glucose which increased blood sugar level therefore, elevating the risk of diabetes. Efforts to inhibit this enzyme could decrease postprandial blood sugar level. The aim of experiment was to determine the most active flavonoid subgroup which inhibited α-glucosidase enzyme of fruit etanol extract from mahkota dewa initiated with liquid partition and was continued with flash chromatography partition. Fruit pericarp is macerated using 3 different solvents (water, ethanol 96%, and n-hexane). Dry extract was analyzed for its water content, ash content, phytochemical content, and inhibition activity of α-glucosidase enzyme using modified Kawaniski method. The most active isolate is analyzed further using flash chromatography. Fruit pericarp water concentration was 9,42%. Phytochemical compound of the extracts were alkaloids, flavonoids, tannins. saponins, steroids, but do not contain triterpenoids. Amyl alcohol fraction has the highest inhibition to α-glucosidase of 40,04%, for the ethyl acetate fraction only 25,26%, and glucobay as positive control was 97,45%. Further analysis with flash chromatography using solvent of the best resolution was chlorofom:methanol with ratio of 9:1 which showed that amyl alcohol fraction contain flavonoid from several classes of isoflavon, flavon, flavonol, and flavanon. This result showed that the flash chromatography partition has not succeeded to separate the subgroup of flavonoid which was active to inhibit α-glucosidase enzyme.
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Judul: Sistem Pakar Perencanaan Jalur Saluran Transmisi dan Dimensi Pondasi Strap Footing Untuk Tower Listrik Saluran Udara Tegangan Tinggi (SUTT)
Abstrak: Pusat-pusat pembangkit tenaga listrik terutama yang menggunakan tenaga air, biasanya terletak jauh dari pusat-pusat beban. Dengan demikian, tenaga listrik yang telah dibangkitkan harus disalurkan melalui saluran-saluran transmisi. Saluran-saluran ini membawa tenaga listrik dari pusat pembangkit ke pusat-pusat beban baik langsung maupun melalui gardu-gardu induk. Pada penelitian ini, saluran transmisi yang diteliti adalah Saluran Udara Tegangan Tinggi (SUTT) berdaya 150 Kv. Secara ideal jalur saluran transmisi untuk SUTT yang terdiri dari beberapa tower adalah sebuah garis lurus. Akan tetapi dalam aplikasi lapangannya tidak demikian. Bisa saja berupa titik-titik dengan lokasi yang tidak beraturan, karena disesuaikan dengan kondisi lapangan. Setelah titik-titik rencana jalur saluran transmisi lokasi tower dapat dibuat, hal lain yang perlu didisain adalah dimensi pondasi tower tersebut. Apabila kita salah memilih atau merencanakan pondasi, maka kesalahan tersebut mengakibatkan terjadinya kerusakan pada struktur bangunan lainnya. Pondasi yang dipakai adalah pondasi telapak kombinasi (strap footing) dengan perbaikan tanah menggunakan pondasi sumuran (bore pile).
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