Quantification of Fractions from Longan Seeds and Their Antimicrobial Activity

The efficacy of herbal drug is determined by qualit y of the original material because it affects bioavailability, safety, and equ ality of the product. In this study, simultaneous determination of four maker substances was established for the quality control of longan seed fractions by using high perf ormance liquid chromatography (HPLC). Extracted samples were analyzed with reverse-phase HPLC and eluted with a mixture of methanol and acetic acid aqueous solut ion, and then were detected at UV 270 nm by a Photo Diode Array Detector. Relative coefficients of variations of intra-day and inter-day analyses were less than 5%, and recovery studies of four marker standards were more than 90%. Thus, this method of simultaneous determination of four marker substances in longan s eed extract was reliably established. The sub-fraction of ethyl acetate extr act showed antimicrobial activity on several microorganisms, which could be 24 used as natural antimicrobial agents in skin care and human health.