SEMISINTESIS TURUNAN EURIKUMANON DARI EURIKUMANON AKAR PASAK BUMI (Eurycoma longifolia, Jack.), UJI AKTIVITAS ANTIPLASMODIUM DAN KAJIAN HUBUNGAN KUANTITATIF ANTARA STRUKTUR AKTIVITAS

Hanifah Yusuf, Dra. Apt., M.Kes, Prof. Dr. Mustofa, M.Kes., Apt

2014 | Disertasi | S3 Kedokteran Umum

Eurikumanon merupakan salah satu kuasinoid dengan kerangka struktur C20, hasil isolasi dari akar tumbuhan pasak bumi (Eurycoma longifolia, Jack.) yang termasuk familia Simarubaceae. Lima turunan ester eurikumanon telah disintesis dengan menggunakan starting material eurikumanon dari akar pasak bumi dan farmakofor asetil klorida, butiril klorida, valeril klorida, para-metoksibenzoil klorida dan suksinat anhidrida. Struktur hasil semisintesis yaitu eurikumanon triasetat, eurikumanon dibutirat, eurikumanon monovalerat, eurikumanon dimetoksibenzoat dan eurikumanon disuksinat ditentukan berdasarkan pada data spektra UV, IR, NMR dan MS. Ester eurikumanon tersebut dan eurikumanon sendiri diuji aktivitas antiplasmodialnya terhadap Plasmodium falciparum strain sensitif klorokuin 3D7 dengan metode Candle Jar. Aktivitas sitotoksiknya terhadap sel Vero diuji dengan metode MTT dan mekanisme kerjanya melalui penghambatan polimerisasi haem ditentukan dengan metode Bassilico et al. (1998). Aktivitas antiplasmodial, sitotoksik dan penghambatan polimerisasi haem dianalisis dengan metode regresi linear untuk menentukan nilai IC50. Prediksi untuk mendapatkan turunan eurikumanon baru yang lebih potensial dilakukan melalui analisis hubungan kuantitatif antara struktur aktivitas (HKSA) melalui perhitungan semiempirik metode Austin Model-1 (AM1) dan untuk mendapatkan persamaan terbaik dilakukan analisis regresi multilinear. Hasil uji aktivitas antiplasmodium menunjukkan bahwa eurikumanon dan turunannya memiliki nilai IC50 berturut-turut 0,0047 ± 0,0001; eurikumanon triasetat 23,13 ± 2,660;, eurikumanon dibutirat 7,20 ± 0,000; eurikumanon monovalerat 0,70 ± 0,074; eurikumanon dimetoksibenzoat 8,80 ± 0,005; eurikumanon disuksinat 5,23 ± 0,007 dan klorokuin 0,01 ± 0,004 μM. Aktivitas sitotoksiknya terhadap sel Vero diperoleh nilai IC50 berturut-turut: 609,89 ± 29,77; 1,74 ± 0,99; 219,29 ± 21,38; 92,40 ± 7,51; 132264,74 ± 31985,16; 12,75 ± 2,88 μg/mL. Aktivitas penghambatan polimerisasi haem oleh fraksi eurikumanon diperoleh nilai IC50 HPIA 12,31 ± 3,44 mg/mL dan klorokuin 3,61 ± 1,07 mg/mL. Hasil analisis HKSA terhadap eurikumanon dan turunannya, diperoleh hubungan yang bersifat linearistik antara aktivitas antiplasmodium dengan struktur elektroniknya yang dinyatakan dalam persamaan sebagai berikut: Log IC50 = – 3048,930 + 5137,957qC2 – 13799,126qC5 – 1537,764qC12 + 1556,313qC16 – 817,654qO29 + 4,654log P – 0,146VM + 0,270BM n = 6; nilai korelasi (r) = 0,982; standar kesalahan estimasi (SE) = 1,262; tingkat signifikansi = 95%; dengan Fhitung/Ftabel = 17,805 dan nilai PRESS = 1,593.

Eurycomanone is a C20 quassinoid found in pasak bumi roots plant (E. longifolia, Jack.) from family Simarubaceae. Five eurycomanone ester derivatives were synthesized by using starting material eurycomanone from pasak bumi roots and acetyl chloride, butiryl chloride, valeryl chloride, para-methoxybenzoyl chloride and succinic anhydride. The structure of semisynthesis products were determined as eurycomanone triacetate, eurycomanone dibutyrate, eurycomanone monovalerate, eurycomanone dimethoxybenzoate and eurycomanone disuccinate based on their spectroscopic data of UV, IR, NMR and MS. These compounds and eurycomanone itself were evaluated for their antiplasmodial activities against 3D7 chloroquine-sensitive strain of P. falciparum using Candle Jar method. Their cytotoxic activities on Vero cells were assayed using MTT method and their mechanism of action through inhibition of haem polymerization were also determined by Bassilico et al. (1998) method. The antiplasmodial, cytotoxic, and inhibition of haem polymerization activities were analyzed by linear regression method for determining their IC50 values. The prediction for finding new eurycomanone derivatives which are more potential, conducted through analysis of quantitative structure-activity relationship (QSAR) using semiempirical calculation with Austin Model-1 (AM1) method and the best equation gained by multilinear regression analysis. The result of antiplasmodial activity testing have been shown that eurycomanone have IC50 value 0,0047 ± 0,0001; eurycomanone triacetate 23,13 ± 2,660; eurycomanone dibutyrate 7,20 ± 0,000; eurycomanone monovalerate 0,70 ± 0,074; eurycomanone dimethoxybenzoate 8,80 ± 0,005; eurycomanone disuccinate 5,23 ± 0,007 nM and chloroquine diphosphate 0,01 ± 0,004 μM. The IC50 value on Vero cells are: 609,89 ± 29,77; 1,74 ± 0,99; 219,29 ± 21,38; 92,40 ± 7,51; 132264,74 ± 31985,16; 12,75 ± 2,88 μg/mL, respectively. The eurycomanone fraction were used for testing of haem polymerization inhibitory activity and the IC50 value of these fraction 12,31 ± 3,44 mg/mL and chloroquine diphosphate 3,61 ± 1,07 mg/mL. The result of QSAR analysis to eurycomanone and its derivatives was obtained the best QSAR equation model which has linearistic relationship between antiplasmodial activity to its electronic structure which can be expressed in the following equation: Log IC50 = – 3048,930 + 5137,957qC2 – 13799,126qC5 – 1537,764qC12 + 1556,313qC16 – 817,654qO29 + 4,654log P – 0,146VM + 0,270MW n = 6; correlation value (r) = 0,982, standard error of estimation (SE) = 1,262, 95% of significancy level with Fcalculation/Ftable = 17,805 and PRESS value = 1,593.

Kata Kunci : Eurycoma longifolia Jack, eurikumanon, ester eurikumanon, uji aktivitas antiplasmodium, sitotoksik, polimerisasi haem, analisis HKSA