Introduction: The Kecombrang plant (Etlingera elatior) is a plant that has natural antioxidant potential. The antioxidant activity of a plant depends on the amount of active compound extracted and the extraction method. This study aimed to determine the active compound with LC-MS/MS.
Methods: Vacum rotary evaporator, UV-Vis Shimadzu spectrophotometer, set of tools LCMS/MS ACQUITY UPLC®H-Class System (waters, USA). Kecombrang flowers (Etlingera elatior) were obtained from the Soka traditional village, Tabanan and determined at the LIPI-UPT Center for Plant Conservation of the Bali "Eka Karya" Botanical Garden” Bali.
Results: Kecombrang flowers (Etlingera elatior) reported that the higher the methanol concentration, the higher the total flavonoids and antioxidants level. Antioxidants were carried out to determine the capacity of the active compounds in the extract to scavenge free radicals. Based on the IC50 value obtained, the methanol extract of kecombrang flowers with a concentration of 99% had the highest antioxidant activity with an IC50 value of 86.59 mg/L and was classified as a strong antioxidant. Kecombrang flowers macerated with 70% methanol and 50% methanol had moderate antioxidant activity, as indicated by the IC50 values of 100.32 mg/L and 123.91 mg/L, respectively.
Conclusion: Antioxidant activity test of kecombrang flowers (Etlingera elatior) methanol extract with concentration variation 99%,70%, and 50% the best antioxidant value 99 % low concentration solvent has a high boiling point, so that it evaporates slowly, resulting in a higher extract yield.