Simultaneous Determination of Gallic Acid and Quercetin in Leaf Extract of <i>Madhuca</i> <i>longifolia</i> from Myanmar by HPLC-DAD: Method Development and Validation

Madhuca longifolia (J.Koenig ex L.) Macbr. belongs to the Sapotaceae family. This research work focused on the determination of gallic acid and quercetin in an aqueous leaf extract of M. longilolia . The development and validation of the analytical method using HPLC-DAD have been performed. The validated method was applied to determine both compounds in the leaves of M . longifolia . Optimized HPLC conditions were developed and validated for specificity, linearity, sensitivity, precision and accuracy. The linearity ranges and linear regression value were 3.125 to 100 μg/mL with r 2 =1 for gallic acid and 0.78 to 50 μg/mL with r 2 =0.9999 for quercetin, respectively. The LOD and LOQ were 0.24 and 0.73 μg/mL for gallic acid and 0.21 and 0.63 μg/mL for quercetin. Intra and inter-day precision were in the range of 0.18 to 1.76. The recovery percentage were 103.86% to 104.98% for gallic acid and 100.10% to 102.97% for quercetin. The concentration ranges of gallic acid and quercetin in the extracts were 207.95 to 405.79 mg/100 g and 7.31 to 20.56 mg/100 g, respectively. The developed HPLC method was considered to be accurate, precise and reliable for the determination of gallic acid and quercetin in M. longifolia aqueous leaf extract. This may be the first-time report for HPLC-DAD method development for the determination of bioactive phenolic compounds in Madhuca longifolia from Myanmar.