Determination and content changes of total flavonoids and three flavonoid aglycones in Crotalaria ferruginea Grah.

Rutin, quercetin, genistein and kaempferol were used as reference substances. Their contents were determinated in Crotalaria ferruginea Grah. Ultraviolet spectrophotometry was used to determine absorbance of rutin at 500 nm wavelength.Thus total flavonoids were inspected.The contents of quercetin, genistein and kaempferol were determined by HPLC from C.ferruginea. The results were as follows: In the growing season(from March to August), the contents of the 4 components were all low, but in the dormancy(October to the following February), the contents of the four components gradually increased. The contents in the following February was the highest. The contents in the samples from different growth years increasd with the growth period. In the plants which had grown from 1 to 6 years, the contents of the three flavonoid aglycones increased with increasing age. In the plants which had grown from 6 to 9 years, the contents had a linear ascending tendency. After the plant grew more than 9 years, the contents increased slower. In the samples from diffenert growth years, the content of flavonoids was also increased with increasing age. But the difference was that in the whole process, the content of flavonoids had a curved change. The content of 5-year old plant was the lowest(13.42 mg/g), and 10-year old plant was the highest(25.10 mg/g), the average annual increase was 1.168 mg/g. The results showed that the hightest contents of total flavonoids, quercetin, genistein and kaempferol were in C.ferruginea from Linshui Chang′an of Sichuan Province. The contents of total flavonoids and quercetin in C.ferruginea from Binjiang and Kunming of Yunnan Province had little difference and they were less than those of Chang′an. Only the contents of genistein and kaempferol in C.ferruginea from Binjiang were more than in Kunming. The lowest contents of total flavonoids, quercetin, genistein and kaempferol were in C.ferruginea from Leishan County, Guizhou Province.