Determination of seventeen main flavonoids and saponins in the medicinal plant Huang‐qi (Radix Astragali) by HPLC‐DAD‐ELSD

Abstract

A simple, rapid, and reliable method, namely high-performance liquid chromatography coupled with diode array and evaporative light scattering detectors (HPLC-DAD-ELSD), was developed to simultaneously determine twelve major flavonoids and five main saponins in different parts of the medicinal plant Huang-qi (Radix Astragali). The DAD wavelength was set at 280 nm for the UV detection of flavonoids, while the drift tube temperature was set at 105 degrees C and the nebulizing gas flow rate at 2.7 L/min for ELSD detection of saponins. The method was fully validated with respect to linearity (r2 >0.998), sensitivity, precision, and accuracy (recovery rate between 93.3 and 104.2%). The analytical results of different parts of the medicinal plant Huang-qi revealed that the levels of total flavonoids or saponins in individual parts can vary considerably and the concentration of each compound in different parts is also significantly different. The aerial parts (stems and leaves) contain even higher total contents of flavonoids (although of different kinds) than the commonly used roots of the plants. In addition, the concentration of total flavonoids and saponins in the extract of the fibrous roots was surprisingly highest among all parts of Astragalus species. All of these findings provide clear evidence and scientific support for utilization of different parts of the medicinal plant Huang-qi and also for reduction in waste of plant resources.

Extraction, separation, and detection methods for phenolic acids and flavonoids

“…These two types of detection provide limited selectivity and sensitivity. However, both of them have been successfully used: the HPLC -refractive index system in the quantification of (3,39 ,4,49,5,7-hexahydroxyflavan) in unripe banana pulp [160], and the HPLC -evaporative light scattering detection one in the determination of Ginkgo biloba and Radix Astragali flavonoids [161,162]. Table 4 gives an overview of relevant information on a selection of typical modern LC examples of sample preparation, separation, and detection conditions reported in the recent literature.…”

Anti-arthritic effect of astragaloside IV and its molecular mechanism

“…Accumulating evidence suggests that Astragalus membranaceus is one of the most widely used traditional Chinese tonic herbs presented either as a single herb or with other herbs in a complex prescription. It exerts many biological functions including anti-inflammatory and immunomodulating effects, and has long been used in traditional Chinese medicine to treat chronic autoimmune inflammatory diseases with less adverse effects [11][12][13][14] . The extracts from the astragalus root (Radix astragali) contain various saponins, polysaccharides, and flavonoids [11,15] .…”

Quality evaluation ofYanghuo Sanqitablet through a simultaneous determination of five major active flavonoids and three main saponins by HPLC-DAD-ELSD

“…In recent years, an on-line coupled HPLC-DAD-ELSD method has attracted ever-increasing attention and has been successfully applied to simultaneous quantification of multi-components in traditional Chinese herbal medicines and their preparations [14][15][16][17][18][19][20][21][22][23]. This method is potentially ideal for routine analysis and quality evaluation of YST since UV and ELSD signals contain complementary information for each other.…”