Development of Analytical Methods for the Estimation of Alpinetin in Seeds of Amomum subulatum Roxb

The seeds of Amomum subulatum Roxb. is a well known drug in Ayurvedic system of medicine [1]. The seeds mainly contain essential oils, flavonoids and carbohydrates [2]. Alpinetin is a flavonoidal constituent that has recently been reported to posses vasorelaxant and anti-HIV effects [3–5]. In spite of valuable medicinal uses of this drug, there are few methods reported on its quality control [6]. Hence in the present investigations simple, accurate and reliable HPLC and HPTLC methods were developed to quantify alpinetin in amomum seeds for its quality control. RP-HPLC was performed on a C18 column with methanol and water as mobile phase in gradient elution at a flow rate of 1 mL min^-1. A sharp peak was obtained for alpinetin at a retention time of 5.7±0.02 minutes. Linear regression analysis showed good linear relationship between response and concentration in the range of 14–224µg mL^-1; the regression coefficient was 0.9998. A compact, well resolved peak of alpinetin with R_f value 0.48±0.02 was observed in thin layer chromatography using toluene, ethyl acetate and formic acid as solvent. Standard calibration curve revealed a good linear relationship with r² value of 0.993 between the peak area and concentration in the range of 20–200µg/spot. Both the methods were validated as per the ICH guidelines and the content of alpinetin was determined which was found in the range of 0.0098 to 0.012% w/w. Statistical analysis proved the methods are precise, reproducible, selective and accurate. Acknowledgment: Author(S) are thankful to CCRUM (AYUSH, ministry of health and family welfare, govt. of India) for financial assistance. Refences: [1] Anonymous (1999) The Ayurvedic Pharmacopoeia of India, Govt. of India, First edition, Part I, Vol. II, 158–159. [2] Shukla SH, Mistry HA (2010) Pharma Science Monitor, 1: 90–102. [3] Wang ZT, Lau CW (2001) Journal of Cardiovascular Pharmacology, 37: 596–606. [4] Tewtrakul S, Subhadhirasakul S (2003) HIV-1 protease inhibitory substances, 504–508. [5] Maridass M, Raju GK (2008) Ethnobotanical Leaflets, 12: 954–994. [6] Li Y, Chou G (2010) Zhongguo Zhong Yao Za Zhi, 35: 2091–2094.