Paper Title
Chlorogenic Acid Content in Lonicera Japonica Flowering Bud by Quantitative Thin-Layer Chromatography

Abstract
Lonicera japonica Thunb. or Japanese honeysuckle has been widely used in traditional medicine to treat many ailments. Chlorogenic acid is a main active compound in this plant. Dried L. japonica flowering buds were purchased from 15 various herbal drugstores throughout Thailand. Chlorogenic acid contents were quantitatively analysed by TLC‑densitometry with winCATS software compared to TLC-image analysis with ImageJ software. The mobile phase for TLC development consisted of ethyl acetate : formic acid : acetic acid : water (10:1.1:1.1:2.6). Chlorogenic acid content was found to be 2.24±0.50 and 2.09±0.44 g/100 g of crude drug by TLC‑densitometry and TLC-image analysis respectively. There was not statistically significantly difference between these methods. Consequently, TLC-image analysis could be used as an alternative method in place of TLC-densitometry. Index Terms - Chlorogenic acid, Lonicera japonica, quantitative analysis, thin-layer chromatography