Karakterisasi Kandungan Kimia Fraksi Etil Asetat Daun Kenikir (Cosmos caudatus K) dan Analisa Potensi Antioksidan Dengan Pendekatan In silico

Khrisna Pangeran, Dr. rer. nat. apt. Tatang Irianti, M.Sc. ; Dr. apt. Hari Purnomo, M.S.

2023 | Tesis | S2 Ilmu Farmasi

Antioksidan merupakan sebuah aktivitas menghambat reaksi oksidasi akibat paparan radikal bebas, pencarian senyawa antioksidan terus dikembangkan dari sumber bahan alam. Tujuan dari penelitian ini adalah penemuan desain molekul baru, dan mekanisme interaksi yang bertanggungjawab memiliki aktivitas antioksidan lebih potensial dari hasil isolasi fraksi etil asetat daun kenikir. 

Penelitian diawali dengan metode pemisahan senyawa dari ekstrak etanol dan fraksi etil asetat, kuantifikasi total fenolik dan flavonoid, uji aktivitas in vitro dengan DPPH, enzim tyrosinase, dan prediksi In silico. 

Hasil penelitian dihasilkan isolat E yang teramati noda tunggal dengan Rf 0,8. Senyawa memiliki penanda khas bernilai 1734,07 cm-1 dengan indikasi gerakan stretching vibration pada C-O. Memiliki panjang gelombang maksimum ± 216 nm, terindikasi nama senyawa diisooctyl pthalate dengan kelimpahan 49,75?n waktu retensi 27,20 menit. Hasil pengujian TPC dan TFC, fraksi air bernilai paling dominan dengan 0,430 mgGAE/g dan fraksi heksana senilai 0,056 mQE/g. Hasil uji DPPH, isolat E memiliki nilai IC50 sebesar 162,03 ppm dan %inhibisi 12,73%. Uji inhibisi tyrosinase substrat L-DOPA sebesar 77,51 ppm dibandingkan dengan asam kojic sebesar 16,48 ppm. Hasil telaah secara in silico, senyawa Diisooctyl Pthalate memiliki potensi antioksidan melalui jalur protein target  6ju9 dengan rerata skor docking -81,07 paling stabil. Hasil modifikasi menunjukkan peningkatan skor docking menjadi –100,11 berbeda nyata signifikan dibandingkan senyawa asli Diisooctyl pthalate (sig. 0,00<0>

Antioxidant is an activity that inhibits oxidation reactions due to exposure to free radicals, the search for antioxidant compounds continues to be developed from natural sources. The purpose of this study is the discovery of new molecular designs, and interaction mechanisms that are responsible for having more potential antioxidant activity from the isolation of ethyl acetate fraction of kenikir leaves. 

The research began with the method of separating compounds from ethanol extracts and ethyl acetate fractions, quantification of total phenolics and flavonoids, in vitro activity tests with DPPH, tyrosinase enzyme, and In silico prediction. 

The results of the study produced isolate E which observed in a single stain with Rf 0,80. The compound has a typical marker worth 1734.07 cm-1 with a stretching vibration movement on C-O. It has a maximum wavelength of ± 216 nm, with an abundance of 49.75% and a retention time of 27.20 minutes. TPC and TFC test results, the water fraction is the most dominant value with 0.430 mgGAE/g and hexane fraction as much as 0.056 mQE/g. Isolate E has an IC50 value of 162.03 ppm and %inhibition of 12.73% equal to DPPH. The tyrosinase inhibition test was resulting IC50 value at 77.51 ppm compared to kojic acid of 16.48 ppm. Diisooctyl Pthalate compound has antioxidant potential through 6ju9 target protein pathway with the most stable docking score of -81.07. The modification has better amino acid binding ability with a total of 10 linked amino acids and increased docking score value to -100.11, significantly different from the original Diisooctyl pthalate compound (sig. 0.00 <0>

Kata Kunci : Cosmos caudatum K, Antioksidan, Molecular Docking, In vitro, HKSA