ENHANCEMENT AND OPTIMIZATION OF SINENSETIN EXTRACT FROM Orthosiphon stamineus USING SUPERCRTITICAL CARBON DIOXIDE EXTRACTION

Abstract

Sinensetin is a rare valuable flavonoid compound that contains 5 methoxy groups attached on the flavone backbone. This compound is abundantly established in citrus peel and can also be found in medicinal herb, 'misai kucing'. Scientifically, 'misai kucing' is known as Orthosiphon stamineus; mostly used to treat kidney stones by old folks. Orthosiphon stamineus was listed in National Key Economic Area (NKEA) as contributor towards the Malaysian Economic Growth. Thus, this study was conducted with objectives to determine suitable modifier for supercritical carbon dioxide (SC-CO 2 ) extraction and to optimize the SC-CO 2 extraction condition (pressure, temperature and average particle size) on the concentration of sinensetin. Water, methanol and acetone were used on the determination of modifier for SC-CO 2 extraction by using water bath extraction at 40 °C in 8 hours. The results showed that acetone gave the highest percentage of sinensetin extract of 0.11%. Therefore, acetone was used as a modifier to enhance the extraction of sinensetin. The concentration of sinensetin was increased and the highest percentage of sinensetin obtained was 6.99%. Response surface methodology (RSM) through Box-Behnken design via Design Expert Software was applied to optimize the SC-CO 2 conditions. The first-order polynomial was used to express the percentage of sinensetin with R 2 value of 0.542. The optimum SC-CO 2 operating condition was 30 MPa, 40 °C and 308.24 µm with sinensetin percentage of 4.35%. Hence, SC-CO 2 with small amount of modifier was the best method to extract sinensetin as compared to water bath extraction method. AbstrakSinensetin merupakan sebatian flavonoid yang jarang ditemui dan sangat berharga terdiri daripada 5 kumpulan metoksi yang terikat pada struktur flavone. Sebatian ini banyak dijumpai dalam kulit limau dan juga boleh didapati dalam herba 'misai kucing'. Secara saintifik, 'misai kucing' dikenali sebagai Orthosiphon stamineus; di mana 'misai kucing' digunakan untuk merawat batu karang oleh orang-orang tua. Orthosiphon stamineus telah disenaraikan dalam Kawasan Ekonomi Utama Negara (NKEA) sebagai penyumbang kepada pertumbuhan ekonomi negara. Oleh itu, kajian ini dijalankan dengan objektif untuk menentukan pelarut tambahan yang sesuai untuk pengekstrakan bendalir supergenting karbon dioksida (SC-CO 2 ) dan mengoptimumkan ISSN -2506 Ahmad Hazim et al: ENHANCEMENT AND OPTIMIZATION OF SINENSETIN EXTRACT FROMOrthosiphon stamineus USING SUPERCRTITICAL CARBON DIOXIDE EXTRACTION 868 pemboleh ubah SC-CO 2 (tekanan, suhu dan purata saiz zarah) terhadap kepekatan sinensetin. Air, metanol dan aseton telah digunakan untuk menentukan pelarut tambahan untuk pengekstrakan SC-CO 2 dengan menggunakan pengekstrakan rendaman air pada suhu 40 °C dalam masa 8 jam. Keputusan menunjukkan bahawa aseton memberikan peratusan sinensetin tertinggi sebanyak 0.11%. Oleh itu, aseton digunakan sebagai pelarut tambahan untuk meningkatkan pengekstrakan sinensetin dalam SC-CO 2 . Kepekatan sinensetin meningkat dan peratusan tertinggi sinen...