Sook Fun Pang

Microwave-Irradiation Induced Fast Simultaneous Extraction of Methoxylated and Hydroxylated Phenolic Compounds from Orthosiphon stamineus Leaves

A combined effect of microwave irradiation and solvent types on the phenolic compounds extraction from Orthosiphon stamineus leaves was studied. The effect of as extraction time, the microwave irradiation power and solid to solvent ratio on the extraction yield was studied. Aqueous solvent provides a broader range of polarity than the pure solvent, and hence enabled a simultaneous extraction of both methoxylated and hydroxylated phenolic compounds. It was found that the extraction time of 2 minutes, microwave irradiation power at 300W and 20:1 solvent to solid ratio yielded highest simultaneous extraction of polyphenols (i.e. rosmarinic acid 32.45 mg RA/g DW, sinensetin 261.15 μg Sin/g DW and eupatorin 2.27 mg Eup/g DW). Result from this work may serve as a useful guide to obtain higher yield of polyphenols from O. stamineus.

Assessment on Bioavailability of Flavonoids from Orthosiphon Stamineus During Spray Drying

This article presents findings of a microencapsulation study of flavonoids obtained from Orthosiphon stamineus leaves. The plant extract was obtained using ultrasonic-assisted extraction method. Protein and a polysaccharide derivative (maltodextrin) were used as the microencapsulation agent. Aqueous extract and dried powder were tested for their total flavonoids content by means of aluminum chloride colorimetric assay and detailed analysis of its polyphenol content by high-performance liquid chromatography. Morphology of the dried powder was analyzed by field emission scanning electron microscopy. Microencapsulation was found to use the least amount of protein (1.42 wt%) and has the highest total flavonoids retention (85.6 %) besides having the highest retention of the bioactive markers, sinensetin (81.8 %), and eupatorin (70.1 %). The formulation of 1:9 protein/maltodextrin ratio is also found to be more effective with 86.7 % total flavonoids retention compared other formulation, viz., 1:1 and 9:1.

Optimisation of Gallic Acid and Quercetin Extraction from Phyllanthus Niruri

This paper presents an optimization study of gallic acid and queretin extraction from Phyllanthis niruri by using response surface methodology. Gallic acid and quercetin was extracted with the aid of sonication and the polyphenols content was analyzed using Ultra Performance Liquid Chromatography (UPLC). The effect of extraction time, amplitude and ethanol concentration on the yield of gallic acid and quercetin were investigated. The optimum gallic acid yield (10.43 ± 0.28 mg GA/g DW) was found in ethanol concentration of 40.0%, extraction time of 15 minutes and amplitude of 86.85% after solving the regression equation. Meanwhile, the optimum condition to obtain the highest yield of quercetin (17.48 ± 0.21 mg Que/g DW) was found in ethanol concentration of 40.0%, extraction time of 15 minutes and amplitude of 75%. The findings in this work may serve as a useful guide to obtain highest extraction yield of gal lic acid and quercetin from Phyllanthus niruri.