PENGHAMBATAN SENYAWA METABOLIT SEKUNDER DAUN KELOR (Moringa oleifera) TERHADAP AKTIVITAS ENZIM ALFA-GLUKOSIDASE YANG DIISOLASI DARI BERAS LAPUK

ATIKA PUTRI ADENIA, Dr. Endang Astuti, M.Si; Dr. Chairil Anwar

2016 | Skripsi | S1 KIMIA

Penelitian penghambatan senyawa metabolit sekunder daun Moringa oleifera untuk menghambat aktivitas enzim alfa-glukosidase dan penentuan tipe inhibitor telah dilakukan. Penelitian diawali dengan ekstraksi metabolit sekunder dengan metode maserasi menggunakan pelarut n-heksana dan etanol selama 3x8 jam. Kandungan metabolit sekunder pada ekstrak n-heksana (EH) dan ekstrak etanol (EE) dianalisis secara kualitatif melalui uji fitokimia menggunakan uji warna. Enzim alfa-glukosidase diperoleh melalui isolasi dari beras lapuk dan pemurnian parsial dengan fraksinasi ammonium sulfat dan dialisis. Enzim alfa-glukosidase hasil pemurnian diuji aktivitas dan ditentukan kinetika reaksi enzimatisnya berupa nilai Vmaks yaitu kecepatan maksmimum enzim yang tidak dapat bertambah lagi dengan penambahan konsentrasi substrat dan nilai KM yaitu konsentrasi substrat untuk mencapai setengah nilai Vmaks. Metabolit sekunder daun Moringa oleifera diuji aktivitas penghambatannya terhadap enzim alfa-glukosidase dengan menentukan persentase inhibisi serta tipe inhbitornya. Hasil penelitian menunjukkan rendemen EH 1,94 % mengandung flavonoid dan alkaloid, sedangkan EE 5,14 % mengandung flavonoid, alkaloid, terpenoid, dan tanin. Aktivitas enzim alfa-glukosidase setelah pemurnian parsial meningkat dari 0,019 U/mL menjadi 0,044 U/mL dengan KM 9,919 mM dan Vmaks 0,706 mmol/menit. Nilai % inhibisi enzim alfa-glukosidase tertinggi diakibatkan oleh penambahan EE konsentrasi 25,00 mg/L sebesar 44,27 % dan kontrol positif quersetin konsentrasi 50,00 mg/L sebesar 35,42 %. Hasil tersebut menyatakan bahwa EE dan quersetin berpotensi menghambat aktivitas enzim alfa-glukosidase dengan tipe inhibitor unkompetitif.

Research of alpha-glucosidase inhibiting activity and inhibition type of secondary metabolites from Moringa oleifera have been done. Firstly, Moringa oleifera leaves were extractd using n-hexane and ethanol for 3x8 hours. Phytochemical analysis revealed the presence of secondary metabolites in n-hexane extract (EH) and ethanol extract (EE) qualitatively by varying color. The alpha-glucosidase was obtained by isolation from rotten rice and partial purification using ammoniuim sulfate fractination and dialysis. Then, activity of alpha-glucosidase and reaction kinetic consist of Vmaks and KM were determined. Vmaks is the maximal velocity when increasing the substrate concentration indefinitely does not increase the rate of an enzyme-catalyzed reaction, while KM is the substrate concentration that gives the enzyme a half of its Vmaks. The percent of inhibition from secondary metabolites of Moringa oleifera leaf was determined through inhibitory assay. Inhibition type of secondary metabolites was investigated. The results showed that 1.94 % EH yield contains flavonoid and alkaloid, while 5.14 % EE contains flavonoid, alkaloid, terpenoids, and tannin. Increasing of alpha-glucosidase activity from 0.019 U/mL to 0.044 U/mL is caused by partial purified of crude extract enzyme with the kinetic parameters KM 9.919 mM and Vmaks 0.706 mmol/menit. The highest % inhibition value of alpha-glucosidase caused by EE with concentrate of 25.00 mg/L in the amount of 44.27 % and quercetin as positive control concentrate of 50.00 mg/L in the amount of 35.42 %. Therefore, EE might be potential as uncompetitive inhibitors in inhibiting activity of alpha-glucosidase.

Kata Kunci : Moringa oleifera, enzim alfa-glukosidase, inhibitor