A label-free and signal-amplifiable fluorescent biosensor based on aptamer-conjugated gold nanoparticles and hybridization chain reaction for determination of carcinoembryonic antigen.

The sensitive detection of cancer biomarkers is crucial for early accurate diagnostics and therapy of cancer patients. Carcinoembryonic antigen (CEA) is a tumor-associated antigen derived from colon cancer and embryonic tissues. In this study, we have developed a label-free fluorescence biosensing platform for the quantification of CEA with the "turn-on" signal output. This platform employs a label-free strategy that incorporates an aptamer-modified gold nanoparticle (Apt@AuNP) probe for the recognition of CEA, in combination with hybridization chain reaction (HCR) amplification. In the presence of target CEA, Apt@AuNPs selectively capture CEA, resulting in a reduction of subsequent complementary chains (CP) binding on Apt@AuNPs. The remaining CP, acting as the initiator sequence for HCR, triggers the HCR, leading to the formation of abundant G-quadruplex structures. By employing Thioflavin T (ThT) for the formation of G-quadruplex/ThT complexes, the biosensor exhibits a significant enhancement of the fluorescence signal. Under optimized conditions, the biosensor platform demonstrates a limit of detection of 0.03 nM and a linear range from 0.1 to 2.5 nM. Additionally, the specificity investigation reveals the high selectivity of this fluorescent biosensor. Finally, the performance of this method has been validated by successfully detecting CEA in real-life samples, highlighting its potential for clinical applications.

Quorum Sensing Enhances Direct Interspecies Electron Transfer in Anaerobic Methane Production.

Direct interspecies electron transfer (DIET) provides an innovative way to achieve efficient methanogenesis, and this study proposes a new approach to upregulate the DIET pathway by enhancing quorum sensing (QS). Based on long-term reactor performance, QS enhancement achieved more vigorous methanogenesis with 98.7% COD removal efficiency. In the control system, methanogenesis failure occurred at the accumulated acetate of 7420 mg of COD/L and lowered pH of 6.04, and a much lower COD removal of 41.9% was observed. The more significant DIET in QS-enhancing system was supported by higher expression of conductive pili and the c-Cyts cytochrome secretion-related genes, resulting in 12.7- and 10.3-fold improvements. Moreover, QS enhancement also improved the energy production capability, with the increase of F-type and V/A-type ATPase expression by 6.3- and 4.2-fold, and this effect probably provided more energy for nanowires and c-Cyts cytochrome secretion. From the perspective of community structure, QS enhancement increased the abundance of Methanosaeta and Geobacter from 54.3 and 17.6% in the control to 63.0 and 33.8%, respectively. Furthermore, the expression of genes involved in carbon dioxide reduction and alcohol dehydrogenation increased by 0.6- and 7.1-fold, respectively. Taken together, this study indicates the positive effects of QS chemicals to stimulate DIET and advances the understanding of the DIET methanogenesis involved in environments such as anaerobic digesters and sediments.

Authentication of Asini Corii Colla and Taurus Corii Colla based on UPLC-MS/MS and the discovery of antioxidant peptides associated with the PI3K-AKT pathway.

Asini Corii Colla (ACC) and Taurus Corii Colla (TCC) are well-known for their high nutritional value, especially for medicinal purposes. However, the aforementioned are also potential candidates for adulteration because of their low yield and high price. A UPLC-MS/MS approach based on the specific peptide was proposed to detect adulterated gelatin with possible mixed animal species. To explore the antioxidant activity, the peptides were separated to evaluate their effect on ·OH radical and DPPH· scavenging activity, together with PI3K-AKT pathway activation. The results showed that the peptides had excellent DPPH· and ·OH radical scavenging effects, and could alleviate H2O2-induced oxidative stress by promoting the phosphorylation of PI3K and AKT. According to the results of MALDI-TOF/MS, the shared mass-to-charge ratio (m/z) 1466, 1744 and 2382 may serve as a material basis for the antioxidant activity of both ACC and TCC, and contribute to their traditional tonic effects.

Multi-constituents variation in medicinal crops processing: Investigation of nine cycles of steam-sun drying as the processing method for the rhizome of Polygonatum cyrtonema.

The rhizome of Polygonatum cyrtonema (Polygonati Rhizoma) is widely consumed as medicine-homology-food in Asia for its tonic effect, which can be enhanced by traditional steam-sun drying for nine cycles. However, the multi-constituents variation in this process was unclear, and the necessity of nine cycles should be further discussed. In this study, the multiple constituents, including saccharides, amino acids, nucleosides and bases, lipids, saponins, homoisoflavones and cinnamamides, in P. cyrtonema treated with sun drying, heated air drying, each cycle of steam-heated air drying, infrared drying and microwave drying were compared. The results showed that the content of total saccharides increased in samples from one to four cycles of steam-heated air drying (365.0-945.6 mg/g) and decreased from four to nine (945.6-288.0 mg/g). The content of fructose increased in samples from one to six cycles (29.9-234.7 mg/g) and decreased from six to nine (234.7-177.7 mg/g). The abundance of most phospholipids and free fatty acids increased continuously from one to nine cycles while most of the amino acids, nucleosides and bases showed continuous declining trend. Principal component analysis showed that the samples treated with one to four cycles were wider in distance than four to nine, indicating the chemical composition tending to be stable after fourth steaming. If taking total saccharides, fructose, and phospholipids as the major quality indicator, four cycles of steam-heated air drying processing should be the ideal postharvest processing method to obtain better taste, flavor and functionality. Samples treated with heated-air drying and infrared drying were far in distance from steaming ones by hierarchical cluster analysis, which means these processing methods were not suitable to replace the traditional steam-sun drying process. Collectively, the above results will not only provide novel processing methods that will obtain the high active ingredients for P. cyrtonema, but also shed light on the optimization of processing technology for the industrial production of medicinal crops which need nine cycles of steam-sun drying processing.

MOF derived double-carbon layers boosted the lithium/sodium storage performance of SnO2nanoparticles.

Tin oxide (SnO2) was considered as a promising alternative to commonly used graphite anode in energy storage devices thanks to its superior specific capacity. However, its electrochemical property was severely limited due to the inherent poor conductivity and drastic volume variation during the charging/discharging process. To overcome this disadvantage, we grew Sn-MOF directly on graphene oxide (GO) layers to synthesize a double carbon conductive network-encapsulated SnO2nanoparticles (SnO2/C/rGO) via a facile solvothermal method. During the process, Sn-MOF skeleton transformed into porous carbon shells, in which nanosized SnO2particles (~8nm) were embedded, while GO template was reduced to highly conductive rGO layer tightly wrapping the SnO2/C particles. This double-carbon structure endowed SnO2/C/rGO anode with enhanced specific capacity and rate property both in lithium ion batteries (LIB) and sodium ion batteries (SIB). The SnO2/C/rGO anode showed a highly reversible specific capacity of 1038.3 mAh g-1at 100 mA g-1, and maintained a stable capacity of 720.2 mAh g-1(70.1%) under 500 mA g-1after 150 cycles in LIBs. Similarly, highly reversible capacity of 350.7 mAh g-1(81.1%) under 100 mA g-1after 150 cycles was also achieved in SIBs. This work provided a promising strategy in improving the electrochemical properties of SnO2nanoparticles (NPs), as well as other potential anode materials suffering from huge volume change and poor conductivity.

MOF-derived porous carbon nanofibers wrapping Sn nanoparticles as flexible anodes for lithium/sodium ion batteries.

Facile synthesis of flexible electrodes with high reversible capacity plays a key role in meeting the ever-increasing demand for flexible batteries. Herein, we incorporated Sn-based metal-organic framework (Sn-MOF) templates into crosslinked one-dimensional carbon nanofibers (CNFs) using an electrospinning strategy and obtained a hierarchical porous film (Sn@C@CNF) after a carbothermal reduction reaction. Merits of this modification strategy and its mechanism in improving the electrochemical performance of Sn nanoparticles (NPs) were revealed. Electrospun CNFs substrate ensured a highly conductive skeleton and excellent mechanical toughness, making Sn@C@CNF a self-supported binder-free electrode. Serving as a self-sacrificing template, Sn-MOF provided Sn NPs and derived into porous structures on CNFs after pyrolysis. The hierarchical porous structure of the carbon substrate was beneficial to enhancing the Li+/Na+ storage of the active materials, and the carbon wrappings derived from polyacrylonitrile (PAN) nanofibers and the MOF skeleton could jointly accommodate the violent volume variation during cycling, enabling Sn@C@CNF to have excellent cycle stability. The Sn@C@CNF anode exhibited a stable discharge specific capacity of 610.8 mAh g-1 under 200 mA g-1 for 180 cycles in lithium ion batteries (LIBs) and 360.5 mAh g-1 under 100 mA g-1 after 100 cycles in sodium ion batteries (SIBs). As a flexible electrode, Sn@C@CNF demonstrated a stable electromechanical response to repeated 'bending-releasing' cycles and excellent electrochemical performance when assembled in a soft-pack half-LIB. This strategy provided promising candidates of active materials and fabrication methods for advanced flexible batteries.

Comparative analysis of nucleosides, nucleobases, and amino acids in different parts of Angelicae Sinensis Radix by ultra high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry.

A rapid and sensitive ultra high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry method was established and employed to determine 21 nucleosides, nucleobases, and amino acids in 60 samples from different parts of Angelicae Sinensis Radix. The established methods were validated by good linearity (r2  > 0.9937), limits of detection (0.12-77.75 ng/mL), limits of quantitation (0.31-272.13 ng/mL), intra- and interday precisions (RSD ≤ 4.84%, RSD ≤ 6.26%), stability (RSD ≤ 5.92%), repeatability (RSD ≤ 7.14%), recovery (91.4-103.4%), and matrix effects (0.92-1.03). Chemical comparative analysis revealed that the content of total analytes in four parts of Angelicae Sinensis Radix were different, and exhibited the order: Head (14.89 mg/g) > Body (10.15 mg/g) > All (8.22 mg/g) > Tail (6.23 mg/g). Principal component analysis showed that the samples could be classified into four groups in accord with four different parts of Angelicae Sinensis Radix. The results could provide a scientific basis and reference for the quality control of Angelicae Sinensis Radix, and may be conducive to further research on the pharmacological activities of Angelicae Sinensis Radix.

[Modern drying processing method for Angelicae Sinensis Radix based on multi-bioactive constituents].

To provide a scientific basis for the selection and optimization of the modern drying processing method for Angelicae Sinensis Radix (ASR). Three phenolic acids (esters), 6 phthalides were determined by using UPLC-PDA while polysaccharides were determined by UV-Vis spectrophotometry. Then the effects of drying methods on the inner qualities of ASR were evaluated through principle components analysis (PCA) combined with the appearance properties after drying. Results showed that the contents of chlorogenic acid and ferulic acid in samples obtained with controlled temperature and humidity drying (CTHD), medium and shortwave infrared drying (MSID) and microwave vacuum drying (MVD) methods were significantly higher than those with primary drying processing(PDP) method and the fresh samples. Multivariate statistical analysis showed that samples processed with CTHD had more similar general chemical properties with those processed with PDP, suggesting that CTHD was appropriate for the modern primary drying processing of ASR. With samples processed with traditional PDP method as reference, the CTHD method was further optimized in the processing parameters for ASR by orthogonal experiment design. Considering the consumption of drying power and time and other parameters, the modern drying parameters for the primary drying processing of ASR were finally optimized as follows: controlled temperature and humidity drying at 40-45 ℃, relative humidity below 25% and target moisture content about 50% in the first stage of drying process, tempering for 12-24 h, and then drying under the conditions of temperature at 50-60 ℃, relative humidity below 20% and fan frequency at 30-40 Hz in the second stage. The study provided the scientific evidence for the selection of appropriate drying method and suitable parameters for the modern primary drying processing of ASR, as well as the beneficial exploration and practice on the formation of technical standard of primary drying processing for roots and rhizomes types herbal medicines.

Comparative analysis of 15 chemical constituents in Scutellaria baicalensis stem-leaf from different regions in China by ultra-high performance liquid chromatography with triple quadrupole tandem mass spectrometry.

Scutellaria baicalensis is a traditional Chinese herbal medicine containing multiple components, which has been extensively used in clinics to treat epidemic febrile disease and hyperactivity cough. To get a deeper understanding about Scutellaria baicalensis stem-leaf resources, we analyzed 15 chemical constituents in 35 batches of Scutellaria baicalensis stem-leaf from eight regions in China. A rapid, simple, and sensitive method using ultra-high performance liquid chromatography coupled with triple quadrupole electrospray tandem mass spectrometry has been developed for the first time to simultaneously determine 15 chemical constituents (including phenolic acids and flavonoids) in Scutellaria baicalensis stem-leaf. Sufficient separation of 15 target constituents was achieved on a Waters Acquity UPLC BEH C18 (2.1 mm × 100 mm, 1.7 µm) column within 14 min under the optimized chromatographic conditions. The established method was validated and showed good linearity, precision, repeatability, stability, and recovery and was successfully applied for the simultaneous determination of the 15 chemical constituents in these samples. Hierarchical clustering analysis and principal components analysis were performed to estimate and classify these samples based on the contents of the 15 chemical constituents. This study provided theoretical basis and scientific evidence for the development and utilization of Scutellaria baicalensis stem-leaf resources.

UHPLC-TQ-MS Coupled with Multivariate Statistical Analysis to Characterize Nucleosides, Nucleobases and Amino Acids in Angelicae Sinensis Radix Obtained by Different Drying Methods.

To explore the nutrients in roots of Angelica sinensis (Angelicae Sinensis Radix, ASR), a medicinal and edible plant, and evaluate its nutritional value, a rapid and reliable UHPLC-TQ-MS method was established and used to determine the potential nutritional compounds, including nucleosides, nucleobases and amino acids, in 50 batches of ASR samples obtained using two drying methods. The results showed that ASR is a healthy food rich in nucleosides, nucleobases and amino acids, especially arginine. The total average content of nucleosides and nucleobases in all ASR samples was 3.94 mg/g, while that of amino acids reached as high as 61.79 mg/g. Principle component analysis showed that chemical profile differences exist between the two groups of ASR samples prepared using different drying methods, and the contents of nutritional compounds in samples dried with the tempering-intermittent drying processing method (TIDM) were generally higher than those dried using the traditional solar processing method. The above results suggest that ASR should be considered an ideal healthy food and TIDM could be a suitable drying method for ASR when taking nucleosides, nucleobases and amino acids as the major consideration for their known human health benefits.

[Optimization of drying process for Scrophulariae Radix by multivariate statistical analysis].

To establish the suitable modern drying processing parameters for Scrophulariae Radix (SR). With reference to the traditional drying processing method of SR and the characteristics of modern drying equipment, the drying process for SR was simulated as the following three stages: temperature-controlled drying-tempering-temperature-controlled drying. Eighteen batches of SR samples were obtained by the drying methods after the orthogonal design experiment with seven factors namely temperature, wind speed, and target moisture for the first stage, tempering time and temperature, as well as temperature and wind speed for the second stage. UPLC-TQ-MS was applied for determination of nine target compounds including catalpol, harpagide, verbascoside, ferulic acid, angroside-C, aucubin, harpagoside, cinnamic acid and ursolic acid in those dried samples and another 19 batches of SR samples collected from genuine producing area. Principal Component Analysis (PCA) was performed, and total energy consumption was also taken into consideration for analysis and evaluation. Results showed that the optimal drying processing method for SR was as follows: drying temperature of 60 ℃, drying wind speed of 50 Hz, and 50% for target moisture in the first stage; 24 h for tempering time and temperature of 20 ℃ in the second stage; drying temperature of 60 ℃, and drying wind speed of 30 Hz in the third stage. The medicinal materials with optimized modern drying processing method were extremely similar to those collected from genuine producing area in the aspect of both external properties and target compounds, and they were in line with the 2015 version of "Chinese Pharmacopoeia" requirements. In addition, they could help to shorten the drying time and increase the efficiency of primary processing, and thus promote the normalization and standardization of primary drying processing for SR.

[Establishment of quality standard for Corni Fructus based on the multiple bioactive constituents].

This study is to establish the methods for determination of iridoid glycosides and triterpenic acids in Corni Fructus and provide technical support for the quality control of Corni Fructus. Morroniside, loganin and sweroside were determined by HPLC-UV method with acetonitrile and 0.1% formic acid as the mobile phase, and the detective wavelength was set at 240 nm. Oleanolic acid and ursolic acid were determined by HPLC-ELSD method with methanol-0.5% ammonium acetate (87:13) as the mobile phase. The results showed that the linear ranges of morroniside, loganin and sweroside were 5.335-213.4 mg · L(-1) (r = 0.9999), 5.515-220.6 mg · L(-1) (r = 1.0000), 1.992-79.68 mg · L(-1) (r = 1.0000), respectively. The average recoveries of the above three iridoid glycosides were 98.49%-99.28% with RSDs of recoveries being less than 2%. The linear ranges of oleanolic acid and ursolic acid were 7.74-154.8 mg · L(-1) (r = 0.9964), 10.82-216.4 mg · L(-1) (r = 0.9996), respectively. The average recoveries of the above two triterpenic acids were 98.11%-99.27% with RSDs of recoveries being less than 3%. The method established in this research is simple, rapid and reliable, and can be used for quality control of Corni Fructus. Furthermore, the research provided experimental data for the improvement of present quality standard of Corni Fructus, which has important significance to guarantee its quality and clinical curative effect.

[Weibull distribution for modeling drying of Angelicae Sinensis Radix and its application in moisture dynamics].

To establish the water dynamics model for drying process of Angelicae Sinensis Radix, the Weibull distribution model was applied to study the moisture ratio variation curves, and compared the drying rate and drying activation energy with the drying methods of temperature controllable air drying, infrared drying under different temperatures (50, 60, 70 degrees C). The Weibull distribution model could well describe the drying curves, for the moisture ratio vs. drying time profiled of the model showed high correlation (R2 = 0. 994-0. 999). The result proved that the drying process of Angelicae Sinensis Radix belonged to falling-rate drying period. For the drying process, the scale parameter (a) was related to the drying temperature, and decreased as the temperature increases. The shape parameter (ß) for the same drying method, drying temperature had little impact on the shape parameter. The moisture diffusion coefficient increase along with temperature increasing from 0.425 x 10(-9) m2 x s(-1) to 2.260 x 10(-9) m2 x s(-1). The activation energy for moisture diffusion was 68.82, 29.60 kJ x mol(-1) by temperature controllable air drying and infrared drying, respectively. Therefore, the Weibull distribution model can be used to predict the moisture removal of Angelicae Sinensis Radix in the drying process, which is great significance for the drying process of prediction, control and process optimization. The results provide the technical basis for the use of modern drying technology for industrial drying of Angelicae Sinensis Radix.

[Effect of drying methods on monoterpenes, phenolic acids and flavonoids in Mentha haplocalyx].

To provide a scientific basis for the selection of the appropriate drying method for Mentha Haplocalyx Herba (MHH), determine 2 monoterpenes, 4 phenolic acids and 5 flavonoids in MHH by GC-MS and UPLC-TQ-MS methods, and investigate the effects of the drying methods on the changes in contents of these analytes. The qualities of products obtained with different drying methods were evaluated by the multivariate statistical method of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Results showed that the drying methods had the greatest impact on menthol, caffeic acid, and rosemary acid, which were followed by chlorogenic acid and diosmetin-7-O-glucoside. The contents in these analytes processed with hot-air-drying method were higher than those with microwave-drying and infrared-drying methods at the same temperatures. The contents in these analytes processed under low temperature (40-45 °C) were higher than those under higher temperature (60-70 °C). Above all, the contents in phenolic acids processed with microwave fixation (exposed under microwave at 100 °C for several minutes) were obviously higher than those of not being processed, showing an inhibition of some enzymes in samples after fixation. The TOPSIS evaluation showed that the variable temperature drying method of 'Hot-Air 45-60 °C' was the most suitable approach for the primary drying processing of MHH. The results could provide the scientific basis for the selection of appropriate drying method for MHH, and helpful reference for the primary drying proces of herbs containing volatile chemical components.

Hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HILIC-UPLC-TQ-MS/MS) in multiple-reaction monitoring (MRM) for the determination of nucleobases and nucleosides in ginkgo seeds.

In this study, a rapid, simple and sensitive analytical method was developed for the quantitative determination of 20 nucleosides and nucleobases in functional foods at trace levels using hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HILIC-UPLC-TQ-MS/MS) in multiple-reaction monitoring (MRM) mode. Under optimised chromatographic conditions, good separation of 20 target compounds was achieved using a Waters Acquity UPLC BEH Amide column and gradient elution in 11min. The limits of detection (LODs) and quantification (LOQs) were between 0.02-42.54ng/mL and 0.05-98.18ng/mL for the 20 analytes, respectively. This is the first report about simultaneous analysis of nucleosides and nucleobases in functional foods using this method, which afforded good linearity, precision, repeatability and accuracy. The method developed was successfully applied to quantify target compounds in batches of ginkgo seeds. The method potentially could be used to determine polar and trace-level nucleosides and nucleobases in ginkgo seeds.

Direct determination of underivatized amino acids from Ginkgo biloba leaves by using hydrophilic interaction ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry.

Ginkgo biloba leaf extract has been widely used in dietary supplements and more recently in some foods and beverages. In addition to the well-known flavonol glycosides and terpene lactones, G. biloba leaves are also rich in amino acids. To determine the content of free amino acids, a reliable method has been established by using hydrophilic interaction ultra-HPLC coupled with ESI-MS. 20 free amino acids were simultaneously determined without derivatization in 12 min. The proposed method was fully validated in terms of linearity, sensitivity, repeatability, as well as recovery. Furthermore, the principal component analysis was applied to different G. biloba leaves collected in November (after fruit harvest season), which revealed that the samples from different production areas exhibited regional disparity in different clusters in accordance with their various hydrophilic interaction chromatograms coupled with mass profiles. The established approach could be helpful for evaluation of the potential values as dietary supplements and the quality control of G. biloba leaves, which might also be utilized for the investigation of other medicinal herbs containing amino acids.

Analysis of herb-herb interaction when decocting together by using ultra-high-performance liquid chromatography-tandem mass spectrometry and fuzzy chemical identification strategy with poly-proportion design.

A novel and generally applicable approach was established for the herb-herb interaction analysis when decocting together by using ultra-high-performance liquid chromatography coupled with a triple quadrupole electrospray tandem mass spectrometer and fuzzy chemical identification with poly-proportion design. A simple programme was originally developed for the rapid identification and classification of herbal constituents on the basis of the establishment of herbal constituent databases, recognition of the reference compound peaks, selection of the diagnostic ions or fragmentation pathways, classification of chemical groups and formation of group networks. In this study, the exact structures of the chemical constituents did not need to be determined, and only the constituents attributed to different groups were further considered for quantitative analysis. Such a novel approach was successfully applied to kansui-licorice interaction analysis when decocting together. A total of 26 constituents from kansui and 45 constituents from licorice were classified into different chemical groups, and they were further quantitatively analyzed on the basis of semi-symmetric proportion design. The results showed that kansui could significantly promote the concentration of most triterpenoid saponins, phenylpropanoids and their glycosides (the constituents from licorice) in solution when co-decocting, and licorice could clearly promote the concentration of most diterpenes and triterpenes (the constituents from kansui) in solution, potentially explaining the incompatibility of kansui and licorice. Overall, the presently developed strategy should be useful for the interaction analysis for complex mixtures containing various complicated constituents, such as herbal, environmental, agricultural and biological samples.

Simultaneous quantification of flavonol glycosides, terpene lactones, biflavones, proanthocyanidins, and ginkgolic acids in Ginkgo biloba leaves from fruit cultivars by ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry.

On the basis of liquid chromatography coupled with triple quadrupole mass spectrometry working in multiple reaction monitoring mode, an analytical method has been established to simultaneously determine flavonol glycosides, terpene lactones, biflavones, proanthocyanidins, and ginkgolic acids in Ginkgo biloba leaves. Chromatographic separation was carried out on an Acquity BEH C18 column (100 mm × 2.1 mm, 1.7 µ m) with gradient elution of acetonitrile and 0.10% formic acid (v/v) at a flow rate of 0.4 mL/min, and column temperature 30°C. The developed method was validated in terms of linearity, accuracy, precision, stability, and sensitivity. The optimized method was successfully applied to analyze twenty-two G. biloba leaf samples of fruit cultivars collected from different places in China. Furthermore, hierarchical clustering analysis (HCA) was performed to evaluate and classify the samples according to the contents of the twenty-four chemical constituents. All of the results demonstrated that the developed method was useful for the overall evaluation of the quality of G. biloba leaves, and this study was also helpful for the comprehensive utilization and development of G. biloba resources.

Hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry for highly rapid and sensitive analysis of underivatized amino acids in functional foods.

This work presented a new analytical methodology based on hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry in multiple-reaction monitoring mode for analysis of 24 underivatized free amino acids (FAAs) in functional foods. The proposed method was first reported and validated by assessing the matrix effects, linearity, limit of detections and limit of quantifications, precision, repeatability, stability and recovery of all target compounds, and it was used to determine the nutritional substances of FAAs in ginkgo seeds and further elucidate the nutritional value of this functional food. The result showed that ginkgo seed turned out to be a good source of FAAs with high levels of several essential FAAs and to have a good nutritional value. Furthermore, the principal component analysis was performed to classify the ginkgo seed samples on the basis of 24 FAAs. As a result, the samples could be mainly clustered into three groups, which were similar to areas classification. Overall, the presented method would be useful for the investigation of amino acids in edible plants and agricultural products.

Two new nonacosanetriols from Ginkgo biloba sarcotesta.

Two new fatty alcohols named as (7S,8R,11S)-nonacosanetriol (1) and (10R,12R,15S)-nonacosanetriol (2), along with eight known compounds including ginkgolic acid (3), hydroginkgolic acid (4), sciadopitysin (5), ginkgetin (6), isoginkgetin (7), ginkgolide A (8), ginkgolide B (9) and ginkgolide C (10) have been isolated from the petroleum ether extract of Ginkgo biloba sarcotesta. Their structures were elucidated by means of chemical and extensive spectroscopic analysis. The absolute stereochemistry of compounds 1 and 2 was elucidated on the spectroscopic analysis of the R- and S-MTPA esters. Compounds 1 and 2 exhibited slight activity of antithrombin and moderate activity of antiplatelet aggregation in vitro. This was the first report regarding the anticoagulative activities of biflavonoids in G. biloba, and isoginkgetin (7) showed significant antithrombin and antiplatelet aggregation activity.