OBJECTIVETo descript the equilibrium solubility of ginkgo flavonoid components in water and PBS of different pHs.

METHODThe HPLC method was adopted to determine the concentration of quercetin, kaempferol and isorhamnetin in ginkgo biloba extracts, and the equilibrium solubility of the three components in water and PBS of different pHs. Furthermore, the mass fraction weight coefficient method was adopted to express the integrated equilibrium solubility and oil-water distribution coefficient of ginkgo flavonoid components.

RESULTGinkgo flavonoid components were well dissoluble in water, with the maximum equilibrium solubility of 408.29 mg x L(-1) at pH 7.8. Therefore, it could be preliminarily predicted that ginkgo flavonoid components had higher application value, and could provide guiding basis for further development of preparations.

CONCLUSIONBy comparing the results of the direct addition method and the mass fraction weight coefficient method, we found that the mass fraction weight coefficient method was more scientific and reasonable. The tentative study could provide ideas to property characterization of traditional Chinese medicine components.

Flavonoids ; chemistry ; Ginkgo biloba ; chemistry ; Hydrogen-Ion Concentration ; Solubility

Ginkgo biloba has a very high medicinal value. The flavonol glycosides and terpene lactones contained in G. biloba extract (GBE) have such pharmacological effects as antioxidant, anti-platelet aggregation and memory improvement, enhancement of immune function. However, the ginkgolic acid (GA) contained in GBE is proved to be highly allergenic and cytotoxic, even minimal residual could also cause severe adverse effects. To minimize the potential safety hazards of ginkgo leaf preparations, this study focuses on GA's chemical structure, adverse effects, toxicity and genesis mechanism, desorption and attenuation in the hope of providing a new thought for studies on safety of Ginkgo biloba preparations.
Animals ; Ginkgo biloba ; chemistry ; Humans ; Salicylates ; adverse effects ; pharmacology ; toxicity

OBJECTIVETo establish the method for determination of the fingerprint of tablets of Ginkgo biloba L.

METHODSHPLC-DAD was used to determine the constituents in tablets. Diamonsil C18(200 mm x 4.6 mm, 5 microm) was used as analysis column and acetonitrile/KH(2)PO(4) as mobile phase with gradient elution. The column temperature was at 24 degree. The profile of chemical constituents in control sample and tablets obtained from the chromatograms were analyzed by similarity software.

RESULTThe method developed for components analysis of the standard extracts was linear within certain concentration (r>0.999). There was no difference between the fingerprints of 3 batches of products. The fingerprints of tablets and the extract showed a good similarity(>0.965).

CONCLUSIONThis method is accurate simple and can be used for the quality control of Ginkgo biloba L. preparations.

Chromatography, High Pressure Liquid ; Ginkgo biloba ; chemistry ; Tablets

Sustained-release tablet has become one of the hottest research spots in the area of sustained release preparations with its unique advantages. At present, a series of shortcomings were exited in the ordinary ginkgo preparations, which were used for the treatment of cardiovascular and cerebrovascular diseases. In order to avoid these shortcomings, ginkgo flavonoids matrix tablets were prepared in this paper. Furthermore, the amount and varieties of matrix material, adhesives and fillers were investigated. Meanwhile, the formulation was optimized by using the method of orthogonal design, and Zero-order, First-order, Higuchi, Ritger-peppas equation were used for the model fitting and mechanism discussing of drug release.
Chemistry, Pharmaceutical ; methods ; Flavonoids ; chemistry ; pharmacology ; Ginkgo biloba ; chemistry ; Kinetics ; Tablets ; chemistry

OBJECTIVETo prepare Ginkgo biloba extract multivariant-phospholipid complex(MGBP) and improve the vitro dissolution of ginkgo total flavonoids by adding another water-soluble carrier in phospholipid complex.

METHODMGBP was prepared using solvent evaporation method with Poloxamer-188 as the carrier and the multivariant complex was analyzed by DSC and X-diffraction technique. The physicochemical properties of the MGBP we also studied, including apparent oil-water distribution coefficients in different pH aqueous solution and its release in vitro.

RESULTThe in vitro dissolution of ginkgo total flavonoids was significantly increased while the apparent oil-water distribution coefficient was improved after been made into multivariant-phospholipid complex.

CONCLUSIONThe preparation technology of MGBP is simple and economic. MGBP can significantly increase the vitro dissolution of ginkgo total flavonoids and improve oil-water distribution coefficients, which can be the reference for the bioavailability in vivo in the further researches.

Ginkgo biloba ; chemistry ; Hydrogen-Ion Concentration ; Hydrophobic and Hydrophilic Interactions ; Phospholipids ; chemistry ; Water ; chemistry

A high-performance liquid chromatography method of pre-column derivatization with 1-phenyl-3-methyl-5 -pyrazolone (PMP) has been established for determination of 6 kinds of monosaccharides simultaneously. A special Agilent HC-C18 column (4. 6 mm x 250 mm, 5 microm), optimized for the separation of PMP derivatives, was used at ambient temperature of 40 degrees C. The PMP derivatives elution was performed with a mixture of 0.1 mol x L(-1) phosphate buffer (pH 6. 8) and acetonitrile in a ratio of 84: 16 at a flow rate of 1 mL x min(-1), and UV absorbance of the effluent was monitored at 245 nm. The results showed that the polysaccharides from exopleura of Ginkgo biloba were acidic heteropolysaccharides mainly containing mannose, rhamnose, D-galacturonic acid, glucose, galactose, arabinose, with the molar ratio of 0.032: 0.14: 0.296: 0.403:0.106: 0.046.
Ginkgo biloba ; chemistry ; Hydrolysis ; Monosaccharides ; analysis ; Plant Components, Aerial ; chemistry ; Polysaccharides ; chemistry

To provide a scientific evidence for the initial primary processing method, an ultra-high performance liquid chromatography combined with a triple quadrupole electrospray tandem mass spectrometry (UPLC-MS/MS) was used to analyze the contents variation of catechins, flavonoids, flavonoid glycosides, biflavones, terpene lactones and phenolic acids during the process of drying in the sun, in the shade, and baked with 35, 45, 60, 80 degrees C, respectively. The results show that drying in the 80 degrees C is conducive to the accumulation of catechins, flavonoid glycosides, terpene lactones, better than the effects of other procedures. Therefore, the fast drying at 80 degrees C is beneficial for the retention of various types of active ingredient of Ginkgo biloba, and this method could be applied as a preferably dry processing.
Chromatography, High Pressure Liquid ; Ginkgo biloba ; chemistry ; Plant Leaves ; chemistry ; Tandem Mass Spectrometry ; Technology, Pharmaceutical

OBJECTIVETo establish the technology for extraction of ginkgolides from Ginkgo Biloba with alcohol-water.

METHODThe parameters such as alcohol concentration, pH of extracting solution, ratio of dosage liquor, temperature and time, the extraction of ginkgolides from G. biloba was investigated, and its parameters were optimized.

RESULTThe optimized parameters were alcohol concentration 30%, extracting temperature 50 degrees C, extracting time 2 h, pH 5 solid-liquid ratio 1:15.

CONCLUSIONThis method has the merits of low cost and simple operation.

Ginkgo biloba ; chemistry ; Ginkgolides ; analysis ; isolation & purification ; Plant Extracts ; analysis ; isolation & purification ; Temperature

OBJECTIVETo investigate the differences of total flavonoid (TF) content and antifree radical activity between the-leaves of bamboo and Gingo biloba, as well as their seasonal changes.

METHODSpectrophotometery and Chemiluminescence methods were adopted to determine TF and half inhibiting concentration (IC50) on active oxygen free radicals of the leaves of bamboo, phyllostachys nigra (Lodd. ex. Lindl.) Munro, and Ginkgo biloba. Two kinds of leaves were picked in the same plot at the same time monthly.

RESULTThe TF of bamboo leaf varied in the range of 0.67%-1.71% (in dry basis of leaf, below as same) throughout a year, the minimum apparing in June and the maximum in July, then going down obviously, and remaining at a much high lever during November to next April. However, the TF of Ginkgo bilabo leaf varied in 1.48%-2.49% during whole growing period, early April to late November. It ascended with the growth of leaf, reaching the top during June and July, the going down slowly, and finally another peak appeared before defoliation. The average IC50 values on O2-. and .OH of bamboo leaf were at 11.0 micrograms.mL-1 and 5.3 mg.mL-1, and Ginkgo biloba at 19.0 micrograms.mL-1 and 3.6 mg.mL-1, respectively.

CONCLUSIONThe TF content and anti-free radical activity the bamboo leaf are comparable with the leaf of ginkgo biloba, which is a kind of potential resources for natural antioxidant and free radical scavenger.

Flavonoids ; analysis ; pharmacology ; Free Radical Scavengers ; pharmacology ; Ginkgo biloba ; chemistry ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry ; Poaceae ; chemistry ; Seasons

OBJECTIVETo prepare ginkgo biloba extract (GBE) sustained-release tablets and observe its in vitro release profile.

METHODGBE sustained-release tablets were prepared by direct compression method using sodium carboxymethylcellulose (CMC-Na) and hydroxypropyl methylcellulose HPMC) as matrix excipients. Based on the result of single-factor selecting experiment, the formulations and preparation process were optimized through orthogonal design, and release difference of tablets was evaluated with similarity factor (f2).

RESULTThe ratio of HPMC and CMC-Na, the viscosity of HPMC and the different types of the diluents had pronounced effect on the release of GBE sustained release tablets, although the hardness and weight difference of tablets did not show notable influences.

CONCLUSIONGBE sustained-release tablets that prepared by using the mixture of HPMC and CMC-Na display constant release profile in 12 h.

Delayed-Action Preparations ; chemistry ; Drug Compounding ; methods ; Drug Stability ; Ginkgo biloba ; chemistry ; Plant Extracts ; chemistry ; Tablets ; chemistry