Study on organic acids in Ginkgo biloba extracts based on multivariate statistical analysis / 中草药

Objective: A method for simultaneous determination of nine active organic acids [shikimic acid, catechinic, (-)- epicatechin, gallic acid, protocatechuic acid, 6-hydroxykynurenic acid (6HKA), p-hydroxybenzoic acid (PHBA), hydroxycinnamic acid, and caffeic acid] in Ginkgo biloba extracts (GBEs) by HPLC wavelength switching method was established, and its quality was evaluated by statistical analysis. Methods: An Inertsil ODS-3 C18 column (250 mm×4.6 mm, 5 μm) was used with a column temperature of 40 ℃ and a mobile phase gradient of acetonitrile-0.4% phosphoric acid. The detection wavelengths were 220 nm [shikimic acid, catechinic, (-)-epicatechin], 254 nm (gallic acid, protocatechuic acid, 6HKA, PHBA), 310 nm (hydroxycinnamic acid, caffeic acid), respectively. Results: Remarkable differences were found among the nine compositions in different producing areas samples. The samples from different manufacturers showed significant difference in organic acid compounds. There were great difference of the contents of organic acid in various batches from different manufacturers. The data were processed through unsupervised principal component analysis (PCA), cluster analysis (CA), correlation, and regression analysis to compare the quality differences. Catechinic, gallic acid, protocatechuic acid, and 6HKA were recognized as characteristic chemical markers that contributed most to reflect the difference between samples, and there were internal relations among these compounds. Conclusion: The established method was simple, accurate, and reliable with good precision, repeatability and stability, which can be used for the simultaneous determination of nine organic acid compounds. Through multivariate statistical analysis, the Q-markers that may affect the difference of GBEs were better identified, which can lay the foundation for the comprehensive quality control of GBEs. Meanwhile, the extracting process of GBEs were not uniform. The stability of process parameter in the enterprise was prepared to be further enhanced.

Analysis of 25 inorganic elements in Ginkgo Folium preparations by ICP-MS / 中草药

Objective: To establish a method for simultaneous analysis on the 25 inorganic elements in Ginkgo Folium preparations. The inorganic elements in Ginkgo Folium among different preparation formulations were compared by inductively coupled plasma mass spectrometry (ICP-MS). Methods: The sample solutions were analyzed by ICP-MS after microwave digestion. The data were made from stacked lines of inorganic elements. Results: The determination results of 25 kinds of mineral elements all had a good linear relationship, r ≥ 0.950 0. The RSD values of the precision, stability, and repeatability all met the demands of quantitative analysis. The recovery was 91.35%-108.86% and RSD was 0.05%-4.45%. Twenty-five inorganic elements in Ginkgo Folium preparations were determined, and there were some correlations among the metal elements in it. The contents of Hg, Al, and Cr were abundant. So the content of heavy metals and harmful elements should be caused for concern. Conclusion: This experiment provides the evidence for the quality control and safety evaluation of Ginkgo Folium preparations.

Simultaneous determination of eleven flavonoid glycosides in ginkgo biloba leaves collected in different seasons by UPLC PDA method / 药学学报

A new UPLC method was developed for the simultaneous determination of eleven characteristic flavonoid glycosides in Ginkgo biloba leaves. The natural occurrence of flavonoid glycosides in Ginkgo biloba leaves within one vegetative season was investigated for the first time. The analysis was performed on an Agilent ZORBAX Eclipse Plus C18 column (50 mm x 4.6 mm, 1.8 microm), the mobile phase A was acetonitrile, the mobile phase B was 0.4% phosphate aqueous solution in a gradient elution at a flow rate of 0.6 mL x min(-1), the detection was carried out at 360 nm. The result showed that eleven flavonoid glycosides had good linearity with good average recovery, separately. The method was proved to be accurate, rapid and good reproducible for the quality evaluation of Ginkgo biloba leaves, and provide an easy and rapid means for the quantitative analysis of flavonoid glycosides and their content fluctuation with seasons.

Simultaneous determination of eleven flavonoid glycosides in Ginkgo biloba leaves and study on its fingerprint by ultra performance liquid chromatography method / 中国药学杂志

OBJECTIVE: To establish a UPLC fingerprint of Ginkgo biloba leaves and determine the contents of eleven flavonoid glycosides. METHODS: A UPLC method was established for the first time to simultaneously quantify the eleven major flavonoid glycosides in Ginkgo biloba leaves. The analysis was performed on an Agilent ZORBAX Eclipse Plus C18 column (4.6 mm × 50 mm, 1.8 μm), the mobile phase A was acetonitrile, the mobile phase B was 0.4% phosphoric acid, gradient elution was performed at the flow rate of 0.6 mL · min-1, and the detection was carried out at 360 nm. Similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine(2004 A) was used in data analysis. RESULTS: The UPLC fingerprint of Ginkgo biloba leaves was established. Total 21 peaks were selected as the characteristic common peaks and 11 of them were identified. There were some differences in the fingerprint chromatograms between 32 batches of Ginkgo biloba leaf samples. The validation result showed that the 11 flavonoid glycosides had good linearity and recoveries. CONCLUSION: The established UPLC method is simple, rapid, accurate, reliable, and sensitive, and can be applied to the identification and quality control of Ginkgo biloba leaves.

Chemical constituents of flavonoid glycosides in extract from Ginkgo biloba leaves used for injection / 中草药

Objective: To study the chemical constituents of flavonoid glycosides in the extract from Ginkgo biloba leaves used for injection. Methods: The constituents of flavonoid glycosides in the 70% ethanol extract from G. biloba leaves were isolated and purified by chromatography over silica gel, MCI, ODS, Sephadex LH-20 columns and RP-HPLC. The structures were identified on the basis of physicochemical properties and spectral data analyses. Results: Sixteen compounds were isolated and identified as 5, 7-dihydroxyl-4'-methoxylflavonol-3-O-rutinoside (1), quercetin-3-O-(2″, 6″-α-L-dirhamnopyranosyl)-β-D-glucoside (2), quercetin- 3-O-[2″-(6‴-p-coumaroyl)-β-D-glucopyranosyl] -α-L-rhamnopyranosyl-7-O-β-D-glucoside (3), isorhamnetin-3-O-(2″, 6″-α-L-dirhamnopyranosyl)-β-D-glucoside (4), rutin (5), luteolin-7-O-β-D-glucoside (6), quercetin-3-O-β-D-glucoside (7), quercetin- 3-O-(2″-β-D-glucopyranosyl)-α-L-rhamnoside (8), kaempferol-3-O-rutinoside (9), quercetin-3-O-α-L-rhamnoside (10), isorhamnetin-3-O-rutinoside (11), apigenin-7-O-β-D-glucoside (12), syringetin-3-O-rutinoside (13), kaempferol-3-O-(2″- β-D-glucopyranosyl)-α-L-rhamnoside (14), quercetin-3-O-α-L-rhamnopyranosyl-2″- (6‴-p-coumaroyl)-β-D-glucoside (15), and kaempferol-3-O-α-L-rhamnopyranosyl-2″- (6‴-p-coumaroyl)-β-D-glucoside (16). Conclusion: UPLC-PDA shows that all the compounds are flavonoid glycosides in the leaves of G. biloba and are marked in the extract and injection. Compound 1 is isolated from this plant for the first time, named flavonol glycoside K.

Simultaneous determination of eleven flavonoid glycosides in Ginkgo biloba extract by ultra performance liquid chromatography method / 中国药学杂志

OBJECTIVE: To establish an UPLC method for the determination of eleven flavonoid glycosides in Ginkgo biloba extract. METHODS: The analysis was performed on an Agilent ZORBAX Eclipse Plus C18 column(4.6 mm × 50 mm, 1.8 μm). Mobile phase A was acetonitrile, mobile phase B was 0.4% phosphoric acid, and gradient elution was carried out at a flow rate of 0.6 mL · min-1. The detection was carried out at 360 nm. RESULTS: The calibration curves of the eleven flavonoid glycosides had good linearinities with good recoveries. CONCLUSION: The method is simple, rapid, accurate, reliable, high sensitive, and can be used as the quantity control method of Ginkgo biloba extract.