Telah dilakukan penelitian tentang skrining fitokimia dan uji aktivitas antioksidan dari daun nasi (Phrynium capitatum) dengan metode DPPH (1,1-difenil-2-pikrilhidrazil). Skrining fitokimia meliputi pengujian alkaloid, flavonoid, saponin, steroid, triterpenoid dan fenolik. Uji aktivitas antioksidan dilakukan dengan penambahan 2 mL larutan DPPH dengan 0,5 mL larutan ekstrak dengan konsentrasi masing-masing 1000, 750, 500 dan 250 µg/mL. Data yang diproleh kemudian digunakan untuk menghitung nilai IC50 dari ekstrak etanol daun nasi. Hasil pengujian menunjukan bahwa ekstrak etanol daun nasi mengandung senyawa alkaloid, flavonoid, saponin, steroid dan fenolik. Ekstrak etanol daun nasi memiliki aktivitas antioksidan trrtinggi pada konsentrasi 1000 µg/mL sebesar 65,77 % dan semakin menurun aktivitasnya dengan berkurangnya konsentrasi ekstrak, konsentrasi 750, 500 dan 250 µg/mL masing-masing sebesar 53,96 %, 43,8 % dan 19,58 % dengan nilai IC50 pada konsentrasi 701,78 µg/mL.A research on phytochemicals screening and antioxidant activity test of daun nasi (Phrynium capitatum) using DPPH (1,1-diphenyl-2-picrylhydrazyl) method had been conducted. Test for alkaloids, flavonoids, saponins, steroids, triterpenoids and phenolic were included in phytochemical screening. Antioxidant activity was tested through the addition of 2 mL DPPH solution into 0.5 mL of the extract having a concentration of 1000, 750, 500 and 250 µg/mL respectively. The data obtained was used to calculate the IC50 value for the ethanol extract of daun nasi. The results showed that the ethanol extract of daun nasi contains alkaloids, flavonoids, saponins, steroids and phenolic. Ethanol extract of daun nasi has the highest antioxidant activity of 65.77% at concentration of 1000 µg/mL. Its activity decreased with decreasing concentration of the extract, which were 53.96 %, 43.8 % and 19.58 % at concentration of 750, 500 and 250 µg/mL respectively. IC50 values was found at a concentration of 701.78 µg/mL.

ABSTRAK Telah dilakukan transesterifikasi minyak goreng bekas menggunakan katalis CaO/MCM-41 dari lumpur Lapindo dengan metode sonokimia. Pemisahan lumpur Lapindo dilakukan dengan metode refluks menggunakan HCl 6 M dan NaOH 6 M. Lumpur hasil refluks kemudian dianalisis dengan XRF dan digunakan sebagai sumber silika dalam sintesis MCM-41. MCM-41 disintesis dengan metode sonokimia selama 150 menit dan dianalisis menggunakan XRD, FT-IR, TEM, dan GSA. Katalis Ca diembankan pada MCM-41 menggunakan metode impregnasi basah dengan variasi pengembanan 1,15; 1,29; 2,39; dan 3,25% (b/b)

The MCM-41 was synthesized using CTAB as a template by sonochemical method and it was charactherized by FTIR, XRD, SAA, and TEM. Potasium was impregnated onto the MCM-41 using potasium acetate salt solution with K+ concentrations of 0.80, 1.35, 1.86, and 2.49 wt.% to produce K2O(1), K2O(2), K2O(3), and K2O(4)/MCM-41 catalysts. The K2O/MCM-41 catalysts were then analyzed by ICP and SAA. Acitivity of catalysts were evaluated in the transesterification reaction of used cooking oil at 50, 60, and 70°C for 120 min. The MCM-41 showed characteristic peaks of 2θ = 2-3°C. The TEM images showed ordered pore distribution with a hexagonal shape. The MCM-41 and K2O(4)/MCM-41 have spesific surface area of 1282.33 and 225.81 m2/g with pore diameter of 30.49 and 30.12 Å, respectively. The highest conversion of methyl ester was obtained from transesterification at 70°C using K2O(4)/MCM-41 catalyst and it was about 79.80 wt.%. Catalyst lifetime of the K2O(4)/MCM-41 for transesterification of used cooking oil was about 15.41 h.