Authors:Jian Cui, Yongde Yue, Feng Tang, and Jin Wang
For the purpose of qualitative and quantitative analysis of flavonoids from eight species of Indocalamus, Indocalamus latifolius (Keng) McClure, I. herklotsii McClure, I. decorus Q. H. Dai, I. barbatus McClure, I. sinicus (Hance) Nakai, I. longiauritus Hand.—Mazz, I. guangdongensis H. R. Zhao et Y. L. Yang, I. pedalis (Keng) Keng f., a simple, efficient, accurate and low-cost method was constructed. Six flavonoids, vitexin, isovitexin, orientin, isoorientin, quercetin and tricin, were selected as marker flavonoids. The multistage development was performed in Automated Multiple Development (AMD2) and solvents in different ratios were used as mobile phase. The developed plates were scanned by TLC Scanner3. The components separated well and RF values of the six marker flavonoids were 0.22, 0.31, 0.38, 0.45, 0.57, and 0.88, respectively. The method was validated for precision, accuracy, selectivity and repeatability, which were expressed as coefficient of variation (CV [%]). The concentrations and kinds of flavonoids were significantly different in these six species of Indocalamus. The concentration of total flavonoids in the dry leaves was in the range of 0.11–0.40%, and the decreasing order of concentration was I. barbatus, I. sinicus, I. longiauritus, I. guangdongensis, I. decorus, I. pedalis, I. latifolius, I. herklotsii; the concentration of total flavonoids in I. barbatus was the maximum among these eight species of Indocalamus, and they would be more useful in extracting natural bamboo flavonoids.
Authors:Jia Sun, Yongde Yue, Feng Tang, and Xuefeng Guo
Flavonoids are the main functional compounds in a bamboo leaf extract. Because of their activity flavonoids are widely used in many of health products, cosmetics, and food supplements. A simple high-performance thin-layer chromatographic (HPTLC) method has been established for simultaneous quantification of vitexin, isovitexin, orientin, and isoorientin in the leaves of three different bamboo species:
Mazel ex H. de Lehaie,
McClure, and Pleioblastus yixingensis S. L. Chen et S. Y. Chen. The method was validated for precision (expressed as the coefficient of variation, CV [%]), accuracy, sensitivity, and selectivity. Instrumental precision was found to be 0.37, 0.52, 0.39, 0.13, and 0.84% and the repeatability of the method 0.98, 0.91, 1.02, 1.04 and 0.87% for isovitexin, rutin, orientin, isoorientin, and vitexin, respectively. The accuracy of the method was determined by measurement of recovery at three different concentrations. Average recovery was 99.54% for isovitexin, 99.31% for orientin, and 100.55% for isoorientin from P. pubescens; 98.97% for orientin, 99.00% for isovitexin, and 99.58% for vitexin from
; and 98.86% for orientin, 100.04% for isoorientin, and 99.63% for vitexin in
. In the fraction extracted from bamboo leaves known as Flavone Gruff the flavonoid content was 6.44% (
) for orientin, 3.45% for isovitexin, and 6.58% for isoorientin in
; 7.82% for orientin, 2.82% for isovitexin, and 13.7% for vitexin in
; and 4.92% for orientin, 3.50% for isoorientin, and 22.5% for vitexin in
. Although the presence of rutin was confirmed in the bamboo leaves investigated, it could not be quantified because of its low concentration. The proposed HPTLC method was found to be simple, precise, selective, sensitive, and accurate for routine quality control of the leaves of different bamboo species and formulations containing bamboo-leaf flavonoids.