Flavonoids Microwave Assisted Extraction Polyphenols Torbangun Leaves Torbangun leaves (Coleus ambonicus, L.) contain polyphenol compounds, flavonoids and antioxidant compounds that can be obtained by extraction methods. However, with the conventional extraction method it has the disadvantage of long extraction time and requires a lot of solvents. Therefore, this study discusses the use of microwave assisted extraction (MAE) method to extract the leaves of Torbangun. This study uses two treatment factors on MAE i.e. power variations (100, 180 and 300 Watts) and extraction time (1, 2 and 3 minutes). This study aims to analyze the effect of MAE on the content of polyphenol compounds and flavonoids in the extraction process of Torbangun leaf. The results showed that the highest total phenol (4196.59 mg GAE/g extract) was found in the treatment of 300 watt of power with extraction time of 3-minutes with IC50 value of 9.89 mg/ml. The highest total flavonoid value was 300 watt of power with 1-minute extraction time which was 4.54 mg QE/g DW.

Torbangun (Coleus amboinicus L) leaf is one of the herbs from Indonesia that has been reported to have many bioactive compounds for human health. These phytochemicals are predominantly incorporated into phenolics, such as flavonoids. An extraction process is needed to obtain all the valuable compounds, and conventional solvent extraction, such as heating and maceration, could be easily applied because of its simplicity. However, this method requires high energy, a longer extraction time, and a large amount of solvent. To overcome these limitations, in this study, microwave-assisted extraction (MAE) was utilized to extract phenolic compounds, including flavonoids from torbangun leaves. Three factors (solvent to feed ratio, microwave power, and extraction time) were evaluated to affect the three responses (extract volume, TPC, and TFC). The extraction process optimization was carried out to get a higher response. The Box-Behnken experiment design and Response Surface Methodology (RSM) determined the optimal operating condition.The result shows 30 ml/g of solvent to feed ratio, 300 W of microwave power, and 4.6 minutes of extraction time as the optimum condition. Applying those conditions, the extract is expected to reach 10.13 ml of extract volume, 9.17 mg GAE/ ml extract of total phenolic, and 3.62 mg QE/ ml extract of total flavonoid. In sum, MAE was useful for extracting phenolic compounds from torbangun leaves and could be an alternative method due to its high efficiency.