SINTESIS ANALOG KURKUMIN MONOKETON BERBAHAN DASAR SINAMALDEHIDA DAN UJI AKTIVITASNYA SEBAGAI INHIBITOR ENZIM ALFA-GLUKOSIDASE

YUNIA MARDIANIS, Dr. Chairil Anwar; Dr. Winarto Haryadi, M.Si.

2016 | Tesis | S2 Ilmu Kimia

Telah dilakukan sintesis analog kurkumin monoketon sebagai senyawa target yang berbahan dasar sinamaldehida dan uji aktivitasnya sebagai inhibitor enzim alfa-glukosidase. Tahap sintesis melibatkan reaksi kondensasi aldol silang Claisen-Schmidt dengan variasi keton sehingga dihasilkan senyawa analog kurkumin monoketon. Pengujian aktivitas antidiabetes senyawa analog kurkumin dilakukan melalui inhibisi enzim alfa-glukosidase yang diisolasi dari beras lapuk (Oryza sativa). Tahapan awal penelitian ini yaitu analog kurkumin disintesis dengan mereaksikan sinamaldehid dan monoketon berupa aseton (analog kurkumin A [(1E,3E,6E,8E)-1,9-difenil-1,3,6,8-nanotetraen-5-on]), siklopentanon (analog kurkumin B [(2E,5E)-2,5-bis((E)-3-fenilalilidin) siklopentanon]), dan sikloheksanon (analog kurkumin C [(2E,6E)-2,6-bis((E)-3-fenilalilidin) sikloheksanon]) dalam pelarut etanol. Sintesis tersebut dilakukan dalam kondisi basa KOH dengan pengadukan pada suhu 52 °C selama 50 menit. Seluruh senyawa hasil sintesis dianalisis strukturnya menggunakan FTIR, direct inlet-MS, 1H- dan 13C-NMR. Tahap selanjutnya analog kurkumin hasil sintesis diuji aktivitasnya sebagai inhibitor enzim alfa-glukosidase. Hasil penelitian menunjukkan bahwa analog kurkumin monoketon hasil sintesis diperoleh rendemen berurutan sebesar 85,57; 72,15; dan 82,97%. Hasil berupa padatan berwana kuning dengan titik leleh berurutan sebesar 116,60-122,40; 196,20-200,10; dan 142,30-148,10 °C. Hasil uji inhibisi terhadap enzim alfa-glukosidase mengindikasi bahwa analog kurkumin B memiliki aktivitas tertinggi dan cukup berpotensi untuk menginhibisi enzim alfa-glukosidase dengan persentase inhibisi sebesar 70,71%.

The synthesis of curcumin analogues monoketone as target compounds from cinnamaldehyde and inhibition assay against aplha-glucosidase enzyme had been performed. The stepwise of synthesis was performed by aldol condensation Claisen-Schmidt reaction and used ketones variation to give curcumin analogues monoketone. The antidiabetic activity of curcumin analogues was carried out by inhibition test against alpha-glucosidase enzyme of mildwed rice (Oryza sativa). The first step of synthesis was started by reacting cinnamaldehyde and monoketones such as acetone (curcumin analog A [(1E,3E,6E,8E)-1,9-diphenyl-1,3,6,8-nanotetraen-5-one]), cyclopentanone (curcumin analog B [(2E,5E)-2,5-bis((E)-3-phenylallylidene) cyclopentanone], and cyclohexanone (curcumin analog C [(2E,6E)-2,6-bis[(E)-3-phenylallylidene] cyclohexanone]) in etanol as solvent. The synthesis was carried out in base condition (KOH) by stirring at 52 °C for 50 minutes. The stuctures of all products were identified by using FTIR, direct inlet-MS, 1H- and 13C-NMR. Futhermore, the activity of curcumin analogues was tested against with aplha-glucosidase enzyme inhibition. The results show that the curcumin analogues (A-C) were yielded in 85.57; 72.15; and 82.97%, respectively as yellow solid. The melting point of curcumin analogues (A-C) were at 116.60-122.40; 196.20-200.10; and 142.30-148.10 °C, respectively. The inhibition against alpha-glucosidase enzyme indicated that the curcumin analog B was potential to inhibit alpha-glucosidase enzyme with the highest activity by giving inhibtion percentage of about 70.71% at 2.5 mM.

Kata Kunci : analog kurkumin monoketon, sinamaldehida, enzim alfa-glukosidase, antidiabetik