Judul: a-Glucosidase Inhibitory Activity of Purified Gandarusa by Column Chromatography
Abstrak: Gandarusa (Justicia gendarussa Burm. f.) merupakan herbal sumber daya lokal Indonesia yang berpotensi sebagai obat herbal antidiabetes. Penelitian ini bertujuan menentukan aktivitas inhibisi a-glukosidase dari senyawa yang terkandung pada fraksi hasil purifikasi ekstrak metanol gandarusa menggunakan kromatografi kolom. Simplisia gandarusa dimaserasi bertingkat dengan n-heksana, etil asetat, dan metanol. Ekstrak gandarusa difraksinasi dengan kromatografi kolom menggunakan pelarut optimal (etil asetat:n-heksana 4:6 v/v). Ekstrak kasar dan 8 fraksi hasil purifikasi dipekatkan kemudian ditentukan aktivitas antioksidannya dengan menggunakan KLT bioautografi dan aktivitas inhibisi a-glukosidasenya secara in vitro. Hasil penelitian menunjukkan bahwa purifikasi gandarusa menghasilkan fraksi kolom yang memiliki aktivitas antioksidan dan dapat menghambat a-glukosidase lebih baik dibandingkan ekstrak kasar tanamannya. Aktivitas inhibisi a-glukosidase tertinggi dimiliki oleh F2 (IC50 99,34 ppm), lebih tinggi dibandingkan dengan obat komersial akarbosa. Secara keseluruhan, fraksi gandarusa berpotensi untuk dikembangkan lebih lanjut sebagai obat herbal antidiabetes., Gandarusa (Justicia gendarussa Burm. f.) is a local Indonesian herbal resource with potential as an herbal antidiabetic remedy. This study aimed to determine the inhibitory activity of a-glucosidase from compounds present in the purified fractions of methanolic extract of gandarusa using column chromatography. Simplified gandarusa was extracted in stages with n-hexane, ethyl acetate, and methanol. The gandarusa extract was fractionated using column chromatography with an optimal solvent (ethyl acetate:n-hexane 4:6 v/v). The crude extract and eight purified fractions were then concentrated and evaluated for antioxidant activity using bioautographic thin-layer chromatography and in vitro a-glucosidase inhibitory activity. The results showed that the purification of gandarusa yielded a column fraction with antioxidant activity and better a-glucosidase inhibition compared to the crude extract of the plant. The highest inhibitory activity of a-glucosidase was found in F2 (IC50 99,34 ppm), which was higher than that of the commercial drug acarbose. Overall, the gandarusa fraction has potential for further development as an herbal antidiabetic remedy.
Keyword: a-glucosidase, antidiabetic, column chromatography, Justicia gendarussa

Judul: α-Glukosidase Inhibitory Activity of Methanol Extract and Fractionation of Aspergillus oryzae-fermented Gandarusa (Justicia gendarussa Burm. f)
Abstrak: Gandarusa dilaporkan mengandung senyawa metabolit sekunder yang dapat menghambat aktivitas α-glukosidase pada penderita diabetes melitus. Salah satu cara untuk meningkatkan produksi metabolit sekunder dengan metode Solid State Fermentation (SSF) menggunakan Aspergillus oryzae. Penelitian ini bertujuan menentukan aktivitas inhibisi α-glukosidase dari fraksi kromatografi kolom hasil fermentasi gandarusa oleh A. oryzae. Penelitian ini terdiri dari preparasi inokulum A. oryzae, fermentasi gandarusa metode SSF, optimasi pelarut purifikasi, pemisahan ekstrak metanol fermentasi gandarusa metode kromatografi kolom, dan pengujian aktivitas inhibisi α-glukosidase. Hasil penelitian didapatkan kombinasi pelarut etil asetat:n-heksana (4:6) sebagai pelarut optimum. Adapun purifikasi gandarusa memperoleh hasil pemurnian yang terbaik, dengan nilai aktivitas inhibisi α-glukosidase fermentasi gandarusa yang dipurifikasi memiliki nilai persentase lebih tinggi (fraksi 2: 54,91%) dibandingkan dengan tanpa purifikasi (ekstrak kasar: −26,36%). Sementara itu, nilai aktivitas α-glukosidase terhadap kontrol positif (akarbosa) sebesar 48,09%., Gandarusa has been reported to contain secondary metabolite compounds that can inhibit α-glukosidase activity in patients with diabetes mellitus. One way to increase the production of secondary metabolite compounds is the Solid State Fermentation (SSF) method using Aspergillus oryzae. This study aimed to determine the α-glukosidase inhibition activity of the column chromatography fraction of fermented gandarusa by A. oryzae. This research consisted of inoculum preparation of A. oryzae, fermentation of gandarusa using SSF method, purification solvent optimization, separation of methanol extract of gandarusa fermentation using column chromatography method, and α-glucosidase inhibition activity testing. The results showed that ethyl acetate:n-hexane (4:6) solvent combination was the optimum solvent. The purification of gandarusa obtained the best purification results, with the value of α-glukosidase inhibition activity of purified gandarusa fermentation having a higher percentage value (fraction 2: 54,91%) compared to without purification (crude extract: −26,36%). Meanwhile, the α-glukosidase activity value against the positive control (akarbosa) was 48,09%.
Keyword: α-glukosidase, Aspergillus oryzae, fermentation, gandarusa, column chromatography

Judul: Asymptotic Distribution of Estimator for the Intensity Function of a Doubly Periodic Poisson Process
Abstrak: In this manuscript, estimation of the intensity function of a doubly periodic Poisson process is discussed. It is assumed that only a single realization of the Poisson process is observed in a bounded window [0,n]. It is also assumed that the period of the intensity function is known. The rate of consistency and asymptotic normality of the estimator are formulated. Finally, a confidence interval for the local intensity function is also formulated.
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