Thermal fixation technologies affect phenolic profile, ginkgolides, bilobalide, product quality, and ginkgolic acids in Ginkgo biloba leaf tea.

Ginkgo biloba leaves (GBLs) contain high phytoconstituents, but ginkgolic acids (GAs, the main toxic compound in GBLs) have limited its applications. Processing Ginkgo biloba dark tea (GBDT) using fixation technology could decrease the toxic compounds; retain flavonoids, ginkgolides, and bilobalide; and improve the product quality. For the first time, various thermal fixations (hot air fixation [HAF], iron pot fixation [IPF], and boiled water fixation [BWF]) followed by rolling, fermentation, and drying were applied to produce GBDT. A comprehensive analysis of the toxicants (GAs), main bioactive compounds (ginkgolides and bilobalide, flavonoids, antioxidants, and phenolic profiles), and product qualities (moisture content, reducing sugar [RS], free amino acids [FAAs], enzyme activity, color properties, antioxidant capacity, etc.) were evaluated. The results revealed that thermal fixations BWF and HAF significantly reduced the GA contents (41.1%-34.6%). Most terpene lactones showed significant differences in control, IPF, and HAF. The HAF had lower total flavonoid content (TFC) than BWF and IPF. The control group (unfixated) had the highest toxic components (GA), terpene trilactones, and TFC compared with various fixations. Adding different fixations to rolling, fermentation, and drying had various impacts on GBDT, and principal component analysis supported the results. Among four thermal fixations, HAF yielded the best results in RS, FAA, total phenolic content, and antioxidant activities, while IPF had the highest TFC. BWF had the lowest content for GA. In conclusion, HAF (6) was chosen as the best technique for producing GBDT since it preserved GBDT's bioactive components while lowering its toxic components.

Discovery of unreported ginkgolides of anti-PAF activity using characteristic ion and neutral loss recognition strategy in Ginkgo biloba L.

Ginkgolides are the most important bioactive components of Ginkgo biloba L, of which ginkgolide B has been successfully developed and marketed as a drug. The reported ginkgolides are very rare and exhibit a complex matrix due to the chemodiversity of Ginkgo biloba L. Herein, the global profile of characteristic ion and neutral loss recognition strategy were used for to discover eight undescribed ginkgolides, very rare cyclohexane ginkgolides R-V, ginkgolides D-F, and eight known ginkgolides. These ginkgolides were target isolated and identified using high-resolution mass spectrometry, nuclear magnetic resonance spectroscopy, and X-ray crystallography. The undescribed and known ginkgolides exhibited antiplatelet aggregation activities. In particular, compounds U and D had IC50 values of 2.20 ± 0.15 and 6.50 ± 0.87 µM, respectively. This study has enriched the known structural diversity of ginkgolides and extended the application of mass spectrometry to the global profiling of natural products present in Ginkgo biloba L. Moreover, it could help chemists rapidly discover unreported compounds from a complex matrix.

Polymer Optical Waveguide Grating-Based Biosensor to Detect Effective Drug Concentrations of Ginkgolide A for Inhibition of PMVEC Apoptosis.

In this work, we successfully developed a fluorinated cross-linked polymer Bragg waveguide grating-based optical biosensor to detect effective drug concentrations of ginkgolide A for the inhibition of pulmonary microvascular endothelial cell (PMVEC) apoptosis. Fluorinated photosensitive polymer SU-8 (FSU-8) as the sensing core layer and polymethyl methacrylate (PMMA) as the sensing window cladding were synthesized. The effective drug concentration range (5-10 µg/mL) of ginkgolide A for inhibition of PMVEC apoptosis was analyzed and obtained by pharmacological studies. The structure of the device was optimized to be designed and fabricated by direct UV writing technology. The properties of the biosensor were simulated with various refractive indices of different drug concentrations. The actual sensitivity of the biosensor was measured as 1606.2 nm/RIU. The resolution and detection limit were characterized as 0.05 nm and 3 × 10-5 RIU, respectively. The technique is suitable for safe and accurate detection of effective organic drug dosages of Chinese herbal ingredients.

A novel method for ginkgolide biosynthesis elucidation based on MeJA induction and differential metabolomics.

Ginkgolides from Ginkgo Biloba have significantly therapeutic effect to cardiovascular and cerebrovascular diseases. However, the biosynthetic pathway of ginkgolides has not been fully elucidated until now. As ginkgolides are synthesized in the ginkgo roots, the accumulation of ginkgolides intermediate metabolites varies greatly between roots and leaves. As Methyl jasmonate (MeJA) can effectively enhance the biosynthesis of ginkgolides, a novel method based on MeJA induction and differential metabolomics was used to screen the differentially intermediate metabolites among ginkgo leaves, roots and roots-MJ-3. Two differential intermediate metabolites (dehydroabietadienal and 1, 2, 3, 4, 4a, 9, 10, 10a-Octahydro-6-hydroxy-7-isopropyl-1, 4a-dimethyl-1-phenanthrenemethanol) were identified in ginkgo roots by UPLC-QTOF-MS. Then, a new ginkgolides biosynthetic pathway was proposed based on differential metabolomics. This study provides a novel method for the elucidation of nature product precursor and is helpful to promote the clarification of ginkgolides biosynthetic pathway.

Hedychium coronarium Rhizomes: Promising Antidiabetic and Natural Inhibitor of α-Amylase and α-Glucosidase.

Hedychium coronarium Koen., commonly known as ginger lily, is considered an endemic medicinal plant. In the present study, the antidiabetic action of its rhizomes was investigated by α-amylase and α-glucosidase inhibition assay, and the active compounds were identified through bioactivity guided isolation technique. Among the six different extracts, the EA extract has shown highest inhibition, and the subfractions from active EA extract were separated by silica gel column chromatography. The subfraction showing highest inhibition was investigated for its chemical composition by high-resolution liquid chromatography-mass spectroscopy (HRLC-MS/MS). The fatty acids such as suberic acid and terpenes such as triparanol, ginkgolide C, and swietenine were found to be the major compounds in the subfractions. The present work revealed that H. coronarium rhizome extract and its active constituent could be used as a natural inhibitor of these two carbohydrate-metabolizing enzymes and may play a key role in the management of diabetes.

Chemical analysis, pharmacological activity and process optimization of the proportion of bilobalide and ginkgolides in Ginkgo biloba extract.

Variations on the efficacy of commercial Ginkgo biloba preparations have been reported, although all the products follow the same standards. Terpene trilactones (TTLs), including bilobalide (BB) and ginkgolides, are one of the main active components in G. biloba extract and have been received the most attention due to their chemical uniqueness and their importance for quality control. A plenty of studies demonstrated that BB and ginkgolides display differential activities on various biological processes. However, the influence of different ratios of BB and ginkgolides on the efficacy of TTLs has not been detected yet. The aims of this study were: (1) to test whether different ratios of BB and ginkgolides existed in commercial G. biloba preparations; (2) to detect the influence of different ratios of BB and ginkgolides on the in vivo efficacy of TTLs; and (3) to optimize the extraction process of G. biloba to approach the better BB and ginkgolides ratio with the maximum in vivo effects. First, the content and proportion of BB and ginkgolides in various G. biloba preparations were quantified by HPLC-MS analysis. As the results, an obvious fluctuation in the proportion of BB and ginkgolides was observed in the preparations from different commercial suppliers. The ratio was ranged from 0.3 to 0.8. Second, a zebrafish thrombosis model was used to evaluate the antithrombotic effects of different ratios of BB and ginkgolides. The result showed that the proportion of BB and ginkgolides at 1:2 produced the maximum antithrombotic effects. Third, the extraction process of G. biloba was optimized using a design space technique aiming to approach the best BB and ginkgolides ratio obtained from zebrafish experiment. The extraction process was modeled based on the results of Box-Behnken designed experiments. Design space was then calculated using a probability-based method. Within this design space, G. biloba extraction process can be guaranteed to achieve the better BB and ginkgolides ratio with high assurance. Normal operation space for G. biloba extraction process was recommended as ethanol concentration of 50% to 70%, liquid-to-solid ratio of 5.6 mL/g to 7.3 mL/g, and extraction time of 2.2 h to 3.0 h. This work not only suggest that the proportion of BB and ginkgolides should be used as a quality control index in ginkgo preparations besides the content of TTLs, but also provide a way to approach it with the extraction process parameters controlled in the normal operation ranges.

Applying risk management to analytical methods for the desorbing process of ginkgo diterpene lactone meglumine injection.

Analysis errors can occur in the desorbing process of ginkgo diterpene lactone meglumine injection (GDMI) by a conventional analysis method, due to several factors, such as easily crystallized samples, solvent volatility, time-consuming sample pre-processing, fixed method, and offline analysis. Based on risk management, near-infrared (NIR) and mid-infrared (MIR) spectroscopy techniques were introduced to solve the above problems with the advantage of timely analysis and non-destructive nature towards samples. The objective of the present study was to identify the feasibility of using NIR or MIR spectroscopy techniques to increase the analysis accuracy of samples from the desorbing process of GDMI. Quantitative models of NIR and MIR were established based on partial least square method and the performances were calculated. Compared to NIR model, MIR model showed greater accuracy and applicability for the analysis of the GDMI desorbing solutions. The relative errors of the concentrations of Ginkgolide A (GA) and Ginkgolide B (GB) were 2.40% and 2.89%, respectively, which were less than 5.00%. The research demonstrated the potential of the MIR spectroscopy technique for the rapid and non-destructive quantitative analysis of the concentrations of GA and GB.

Ginkgo biloba Food Supplements on the European Market - Adulteration Patterns Revealed by Quality Control of Selected Samples.

The aim of this study was to prove whether Ginkgo biloba food supplements on the European market comply with pharmaceutical quality, and whether their composition satisfies the European Pharmacopoeia criteria. Medicinal products containing a standardised Ginkgo leaf extract are used for the improvement of cognitive impairment and quality of life in mild dementia. Further, Ginkgonis folium is used for the treatment of peripheral circulation disorders. Pharmacopoeial Ginkgo dry extract contains 22.0 - 27.0% flavonoids and 5.4 - 6.6% terpene lactones (ginkgolides, bilobalide). In addition to its widespread use as an herbal medicine (herbal medicinal product), the same extract can be an ingredient in food supplements. The content of active secondary metabolites was quantified in a number of European food supplements containing Ginkgo dry extract or Ginkgo leaf. Flavonoids were quantified using a modified pharmacopoeial HPLC-UV method, and terpene lactones (ginkgolides A, B, C, and bilobalide) using LC-MS/MS. Some Ginkgo leaf supplement samples were also analysed by microscopy. The quality of food supplements on the European market is dubious. In this paper, we present selected examples of several methods of adulteration and falsification, including higher/lower doses of Ginkgo dry extract or Ginkgo leaf than declared and the addition of undeclared extraneous materials. These examples reveal several patterns in the manufacturing of adulterated products.

New urea-modified paper substrate for enhanced analytical performance of negative ion mode paper spray mass spectrometry.

Electrospray ionization mass spectrometry (ESI-MS) analysis in the negative ion mode is adversely affected by ionization suppression caused by electrical discharge and the presence of salts. Paper spray mass spectrometry (PS-MS) also suffers from the above phenomenon, being built on principles similar to those of ESI. Herein, we report the use of a paper substrate modified by 1-[3-(trimethoxysilyl)propyl]urea to improve the sensitivity of quantitative PS-MS analysis in the negative ion mode. The obtained results demonstrated that the urea modified paper substrate can effectively bind anions and highly polar compounds in the sample solution, decreasing competitive ionization in the negative ion mode of PS-MS and significantly reducing the signal intensity of Cl- adducts. In addition, the analyte responses were also significantly improved owing to the decreased electrical discharge observed for the less polar surface to decrease electrical discharge. Compared to non-modified PS-MS, urea-modified PS-MS exhibits a much higher sensitivity, showing 2-109 times improved signal-to-noise ratio (S/N). In real sample analysis, the limits of detection (LODs) of salicylic acid in urine and terpene lactones in Ginkgo biloba extract (EGb) were improved 10-fold and 2-40-fold, respectively, compared to that of non-modified PS-MS.

Hydrogen/deuterium exchange, a unique and effective method for MS fragmentation behavior elucidation of ginkgolides and its application to systematic research in Ginkgo biloba.

Ginkgolides, the main active constituents of Ginkgo biloba, possess significant selectively inhibition on platelet-activating factor and pancreatic lipase and attract wide attention in pharmacological research area. In our study, an effective hydrogen/deuterium (H/D) exchange method was developed by exchanging the α-Hs of lactone groups in ginkgolides with Ds, which was very useful for the elucidation of the fragmentation patterns of ginkgolides in Quadrupole Time-of-flight Mass Spectrometry (Q-TOF-MS), especially in accurately distinguishing the type and position of substituent in framework of ginkgolides. Then, a systematic research strategy for qualitative and quantitative analysis of ginkgolides, based on H/D exchange, tandem solid-phase extraction and LC-Q-TOF-MS, was developed, which was successfully applied in each medicinal part of G. biloba, which indicated that ginkgolide B was the most abundant ginkgolide in the seeds of G. biloba (60.6µg/g). This research was the successful application of H/D exchange in natural products, and proved that H/D exchange is a potential method for analysis research of complex TCMs active constituents.

Pharmacokinetics and tissue distribution of ginkgolide A, ginkgolide B, and ginkgolide K after intravenous infusion of ginkgo diterpene lactones in a rat model.

Ginkgo diterpene lactones are compounds that are extracted from the Ginkgo biloba leaf and possess pharmacologic activities with neuroprotective effects. To address the poor bioavailability of ginkgo diterpene lactones, ginkgo diterpene lactone meglumine injection (GDLI) was formulated and is commercially available. In this study, a simple, sensitive and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for assessing the total amount and the amount of the prototype forms of ginkgolides A (GA), B (GB) and K (GK) in rat plasma and tissues. This method was used to calculate the concentrations of the hydrolysed carboxylic forms and assess the pharmacokinetics of the ginkgolides after intravenous (i.v.) GDLI administration in rats. Generally, all three ginkgolide forms showed dose-dependent plasma concentrations, and no obvious differences in pharmacokinetic parameters, i.e., area under the curve (AUC) of plasma concentration versus time and half-life, were observed after GDLI administration on 7 consecutive days. These ginkgolides primarily existed in the carboxylic form in the plasma, and the systemic concentrations of the carboxylic forms of GA and GB were 11- to 17- and 3- to 4-fold higher than those of their prototype forms, respectively. In contrast, dramatically increased levels of the GA and GB prototype lactones were detected in the liver and heart. GA, GB, and GK were extensively distributed in various organs/tissues; the highest levels were found in the kidneys, liver, and intestine, and the lowest levels were found in the brain. These data suggest that ginkgolides have difficulty crossing the blood-brain barrier and that their targets for protecting against cerebral ischaemia are located outside the central system.

Characterizations of the hydrolyzed products of ginkgolide A and ginkgolide B by liquid chromatography coupled with mass spectrometry.

Ginkgolides are diterpenoid trilactones responsible for the neuromodulatory properties of Ginkgo biloba extracts. They are to be hydrolyzed in aqueous solutions as mixed carboxylate forms potentially including three monocarboxylates, three dicarboxylates and one tricarboxylate. Characterizations of the hydrolyzed products are challenging because there is no way to prepare them individually. In this work, the major hydrolyzed products of ginkgolide A (GA) and ginkgolide B (GB) including all three monocarboxyaltes have been produced in buffers and subjected to liquid chromatography coupled with triple quadrupole MS and LTQ Orbitrap MS analysis. With the comparative analysis of the trilactone of GA and GB, it was highlighted a unique charge-driven fragmentation pathway of twice neutral losses of CO on the lactone-C. The monocarboxylates were accordingly identified based on the construction of their fragmentation pathways cross-linked with those of the trilactone. In brief, the lactone-C hydrolyzed product is characteristic of the absence of product ions between [M-H](-) and [M-H-C2H2O3](-) (m/z 351 for GA and m/z 367 for GB). The featured fragmentation pathway of the lactone-F hydrolyzed product is the cleavage of ring-A, yielding a fragment (m/z 295 for GA and m/z 309 for GB) followed with twice (GA) or triple (GB) neutral losses of CO. The most characteristic fragment of the lactone-E hydrolyzed product is [M-H-H2O-CO2-2CO](-) (m/z 307 for GA and m/z 323 for GB) in contrast to the other two monocarboxylates. The knowledge gained in this work was of special uses to investigate the biological fates and the corresponding pharmacological mechanisms of ginkgolides.

[Determination of five kinds of trace ginkgolic acids in diterpene ginkgolides meglumine injection materials by LC-MS/MS].

To develop a LC-MS/MS method for the determination of five kinds of trace ginkgolic acids in diterpene ginkgolides meglumine injection materials, the column was Agilent ZORBAX Eclipse plus C18 (3.0 mm x 50 mm, 1.8 µm), and the mobile phase consisted of methanol-water (containing 0.2% formic acid) (95:5) at a flow rate of 0.5 mL · min(-1). The multiple reaction ion monitoring (MRM) with an ESI interface in the negative ion mode was selected. The results showed that the linear ranges of five kinds of ginkgolic acids were in the range of 0.2-36.0 µg · L(-1) (r ≥ 0.999 5). The lowest limit of quantification (LOQ) of ginkgo acid C13: 0, C15:1, C17:2, C15:0 and C17:1 were 0.18, 0.18, 0.21, 0.10 and 0.20 µg · L(-1), respectively. The average recovery was between 73.28% and 87.56%, and the average content of total ginkgolic acids in three batches of samples was in the range of 0.023-0.028 µg · g(-1), which was much lower than 2 µg · g(-1) prescribed in drug registration standards. This method is simple and rapid with high sensitivity, which can be used for the determination of five kinds of trace ginkgolic acids in diterpene ginkgolides meglumine injection materials.

Pharmacokinetics and tissue distribution study of ginkgolide L in rats by ultra-high performance liquid chromatography coupled with tandem mass spectrometry.

An ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) approach was developed and validated for the determination of ginkgolide L (GL) in rat plasma and tissues using diazepam as internal standard (IS). Detection was performed on a triple quadrupole MS system using multiple reaction monitoring (MRM) mode in positive mode. Sample preparation was carried out through a liquid-liquid extraction with ethyl acetate. The chromatographic separation was achieved by using an Agilent ZORBAX SB-Aq column with a mobile phase of 0.5% aqueous formic acid (A) and methanol (B). The monitored transitions were set at m/z 391.14→271.10 for GL and m/z 285.08→193.10 for IS, respectively. The validated method was successfully applied to the pharmacokinetic and tissue distribution study of GL in rats after intravenous administration. Good linearity was found between 2.5-2000ng/mL (r>0.996) for plasma samples, and calibration curves were also linear for other tissue samples over a wide range. The results indicated that GL has linear pharmacokinetic properties after intravenous administration at three doses. GL could distribute to tissues quickly and the major distribution tissue of GL in rats was liver. This was the first report of pharmacokinetic and tissue distribution data for GL.

Accurate analysis of ginkgolides and their hydrolyzed metabolites by analytical supercritical fluid chromatography hybrid tandem mass spectrometry.

Hydrolysis plays an important role in the metabolic transformations of lactones. Analysis of lactones and their hydrolyzed metabolites in biological samples is challenging, because unexpected hydrolysis or reversed dehydration may occur depending on the test environments. In this work, a supercritical fluid chromatography hybrid triple-quadrupole mass spectrometry (SFC-QQQ MS) method has been proposed for simultaneous analysis of ginkgolides and hydrolyzed metabolites. The SFC utilizes carbon dioxide as the mobile phase, avoiding hydrolysis of ginkgolides that always happens during reversed phase liquid chromatographic detection. Compared with normal phase liquid chromatography, the SFC provides good resolutions especially for ginkgolide with similar structures. This SFC-QQQ MS method was validated in linearity, precision, accuracy, and stability for ginkgolides and metabolites. Then this method was successfully applied to pharmacokinetic study of 3 ginkgolides and their 6 hydrolyzed metabolites after intravenous administration of total ginkgolide extract. Ginkgolides and metabolites showed different clear rates and excluded in 2-4h. The developed SFC-QQQ MS method allows accurate determination of ginkgolides and metabolites with high resolutions, and can be extended to analysis of other water-unstable compounds.

Pharmacokinetic studies of ginkgolide K in rat plasma and tissues after intravenous administration using ultra-high performance liquid chromatography-tandem mass spectrometry.

Ginkgolide K (GK), a derivative compound of ginkgolide B, has been recently isolated from the leaves of Ginkgo biloba. It is a powerful natural platelet activate factor (PAF) antagonist, and also has obvious protect effects for cerebral ischemia. However, no reports have been described for the pharmacokinetic study of GK. In this study, a simple, sensitive and reliable ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed for the determination of GK in rat plasma and tissues. Biological samples were pretreated by an efficient liquid-liquid extraction with ethyl acetate. The chromatographic separation was achieved on an Agilent ZORBAX SB-Aq column (4.6 mm × 50 mm, 1.8 µm) with a mobile phase of 0.5% aqueous formic acid (A)-menthol (B). Quantitation was carried out on a triple quadruple mass spectrometry using positive electrospray ionization in multiple reaction monitoring mode. Diazepam was used as internal standard (IS). The ion transitions monitored were set at m/z 407.10 → 389.20 and m/z 285.08 → 193.10 for GK and IS, respectively. The developed method was fully validated and successfully applied to the pharmacokinetics and tissue distribution study of GK after intravenous administration. The current results have indicated that pharmacokinetic parameters of GK vary in a dose-dependent manner with rapid elimination in 4h. The major distribution tissues of GK in rats were liver and kidney. This study would provide critical information to promote the future study of GK.

[Study on limit detection of flavones in diterpene ginkgolides meglumine injection materials by LC-MS and HPLC-DAD].

Limit test of flavones in diterpene ginkgolides meglumine injection materials by UV-Vis and HPLC-DAD method was studied in this essay. The HPLC-DAD method has lower LOD (about 1% of the UV-Vis), that is, the sensitivity is higher than UV-Vis method. Through the analysis of the kinds of flavonoids ingredients in the samples by LC-MS, the three compounds with highest contents are kaempferol, quercetin and isorhamnetin. Kaempferol, quercetin and isorhamnetin were chosen as reference compounds for HPLC analysis, and the HPLC separation analysis was carried on an Agilent Eclipse plus C18 column (4.6 mm x 250 mm, 5 µm) with methanol and water containing 0.4% phosphoric acid (50: 50) as mobile phase, and the flow rate was 1.0 mL x min(-1). The detection wavelength was set at 360 nm. This method has good specificity, precision and reproducibility. The LODs of quercetin, kaempferide and isorhamnetin were 27.6, 22.3, 29.5 µg x L(-1). The average recovery was 87.9% (RSD 3.3%), 91.7% (RSD 3.1%), 88.3 (RSD 1.3%) for quercetin, kaempferide and isorhamnetin, respectively. Based on the 10 batches of sample results and sensitivity of different HPLC, the content of total flavonoids ingredients of diterpene ginkgolides meglumine injection materials was limited no more than 2 x 10(-5). This method is simple, quick and has good maneuverability, and could be used to the limit test of flavonoids in the diterpene ginkgolides meglumine injection materials.

UPLC-PDA-TOF/MS coupled with multivariate statistical analysis to rapidly analyze and evaluate Ginkgo biloba leaves from different origin.

In the present study, an ultra performance liquid chromatography coupled with photodiode array detector and time-of-flight mass spectrometry (UPLC-PDA-TOF/MS) was proposed and validated for rapidly analyzing and evaluating Ginkgo biloba leaves from different origins by using multivariate statistical analysis. Batches of these kinds of G. biloba leaves were subjected to UPLC-PDA-TOF/MS analysis, the datasets of retention time (RT)-m/z pairs, ion intensities and sample codes were further processed with orthogonal partial least squared discriminant analysis (OPLS-DA) to holistically compare the difference between these G. biloba leaves, and to generate an S-plot. Those compounds correlated to the points at the two ends of S were regarded as the most differentiating components. By comparing the mass/UV spectra and retention times with those of reference compounds and/or tentatively assigned by matching empirical molecular formulae with those of the known compounds published in the literatures, these differentiating components were finally characterized as kaempferol 3-O-[2-O-(6-O-p-hydroxy-trans-cinnamoyl)-ß-D-glucosyl)-α-L-rhamnoside], kaempferol 3-O-[2-O,6-O-bis(α-L-rhamnosyl)-ß-D-glucoside], ginkgolide C, kaempferol 3-O-[2-O-(ß-D-glucosyl)-α-L-rhamnoside], and bilobetin. These compounds would be the potential chemical markers for the two kinds of leaves. The results suggested that this newly established approach could be used to rapidly evaluate the quality of herbs from different origin, and to provide good strategy for further rectify and standardize the herb market.

Electrocardiographic profile of guinea pig heart submitted to Ginkgo biloba extract and its terpenoids / Perfil eletrocardiográfico do coração de cobaia submetido ao extrato de Ginkgo biloba e seus terpenóides

Electrocardiographic effects produced by Ginkgo biloba extract (EGb) and by ginkgolides A (GA) and B (GB), and bilobalide (BB) were investigated in guinea pig heart mounted in Langendorff apparatus (Tyrode, 34 ± 0.1 ºC, 95% O2, 5% CO2). Electrocardiographic parameters were evaluated in the conditions: 1) control with Tyrode and DMSO, 2) EGb (n=4), GA (n=5), GB (n=5) or BB (n=6), and 3) washout. The results showed that 0.1 and 1.0 mg/ml of EGb do not change the electrocardiographic parameters. However, 10 mg/ml of EGb increased the PR interval (PRi) at 21% (p<0.001). This increase was also observed for 50 mM GA (20%, p<0.001) and 70 mM BB (13%, p<0.001), which indicates Ca2+ channel block. However, the 50 mM GB reduced the PRi at 11 % (p<0.001). The GA (23%, p<0.001), GB (16%, p<0.001), and BB (40%, p<0.001) reduced the QT interval (QTi), which suggests the activation of the potassium channel. However, EGb increased QTi (6%, p<0.001). The EGb (28%, p<0.05) and GB (13%, p<0.05) reduced the heart rate. Atrioventricular (AV) block was observed with EGb, GA, and BB. We can conclude that EGb and its terpenoids alter the ECG parameters inducing AV block, which indicates possible arrhythmogenic potential.

Os efeitos eletrocardiográficos produzidos pelo extrato de Ginkgo biloba (EGb) e gingkolídeos A (GA) e B (GB), e bilobalide (BB) foram investigados em coração de cobaia montado sistema de Langendorff (Tyrode, 34 ± 0.1 ºC, 95% O2, 5% CO2). Os parâmetros do ECG foram avaliados nas condições: 1) Tyrode e DMSO, 2) EGb (n=4), GA (n=5), GB (n=5) ou BB (n=6) diluídos em DMSO e 3) washout. Os resultados demonstram que 0,1 e 1,0 mg/mL de EGb não alteraram os parâmetros eletrocardiográficos. Entretanto, 10 mg/ml de EGb aumentaram o intervalo PR (PRi) em 21% (p<0.001). Esse aumento também foi observado com GA a 50µM (20%, p<0,001) e BB a 70 mM (13%, p<0,001) indicando bloqueio de canais de cálcio. Por outro lado, GB reduziu o PRi (11%, p<0,001). O intervalo QT (QTi) foi reduzido por GA (23%, p<0,001), GB (16%, p<0,001) e BB (40%, p < 0.001) sugerindo uma ativação de canais de potássio. Entretanto, EGb aumentou o QTi (6%, p<0.001). A frequência cardíaca foi reduzida por EGb (28%, p<0.05) e GB (13%, p<0.05). Bloqueios átrio-ventriculares (BAV) foram observados com EGb, GA e BB. Podemos concluir que EGb e os terpenos alteram parâmetros eletrocardiográficos induzindo BAV e demonstrando possível potencial arritmogênico.

[Microfluidic evaporative light scattering detector coupled with capillary liquid chromatography and its application to Ginkgo biloba extract analysis].

A novel separation system of microfluidic evaporative light scattering detector (microELSD) coupled with capillary liquid chromatography (cLC) was built and applied to the separation and detection of herbal medicine Ginkgo biloba extract and its disperse tablet formulation. Compared with the traditional HPLC, this microELSD-cLC system consumed much less sample and solvent. Some key parameters were optimized. It was found that the higher the evaporization temperature of the drift tube, the higher S/N could be achieved. The mobile phase A was 0.05% (v/v) trifluoroacetic acid (TFA), and the mobile phase B was methanol containing 0.05% (v/v) TFA. The optimized gradient conditions were as follows: 0-10 min, 5% B - 25% B; 10-25 min, 25% B - 38% B; 25-35 min, 38% B; 35-40 min, 38% B - 42% B; 40-55 min, 42% B - 50% B. The complex herbal medicine Ginkgo biloba extract and its disperse tablet formulation were successfully separated. Four main therapeutic components (bilobalide and ginkgolide A, B, C) were finally separated and determined, which were terpene lactones with pretty weak UV absorption. The RSDs of the detected terpene lactones from different manufacturers were all no more than 2.42%, which proved this platform's good analysis repeatability. The results showed the applicability of the platform to the analysis of complex traditional Chinese medicines.