Rapid Determination of Geniposide and Baicalin in Lanqin Oral Solution by Near-Infrared Spectroscopy with Chemometric Algorithms during Alcohol Precipitation.

The selection of key variables is an important step that improves the prediction performance of a near-infrared (NIR) real-time monitoring system. Combined with chemometrics, NIR spectroscopy was employed to construct high predictive accuracy, interpretable models for the rapid detection of the alcohol precipitation process of Lanqin oral solution (LOS). The variable combination population analysis-iteratively retaining informative variables (VCPA-IRIV) was innovatively introduced into the variable screening process of the model of geniposide and baicalin. Compared with the commonly used synergy interval partial least squares regression, competitive adaptive reweighted sampling, and random frog, VCPA-IRIV achieved the maximum compression of variable space. VCPA-IRIV-partial least squares regression (PLSR) only needs to use about 1% of the number of variables of the original data set to construct models with Rp values greater than 0.95 and RMSEP values less than 10%. With the advantages of simplicity and strong interpretability, the prediction ability of the PLSR models had been significantly improved simultaneously. The VCPA-IRIV-PLSR models met the requirements of rapid quality detection. The real-time detection system can help researchers to understand the quality rules of geniposide and baicalin in the alcohol precipitation process of LOS and provide a reference for the optimization of a LOS quality control system.

Identification of Antitumor Constituents in Toad Venom by Spectrum-Effect Relationship Analysis and Investigation on Its Pharmacologic Mechanism.

(1) Background: Toad venom (Bufonis Venenum, known as 'Chansu' in Chinese), the secretion of the ear-side gland and skin gland of Bufo gargarizans cantor or Duttaphrynus melanostictus Schneider, has been utilized to treat several diseases in China for thousands of years. However, due to the chemical variability of the components, systematic chemical composition and the key pharmacophores in toad venom have not yet fully understood. Besides, it contains a variety of effective compounds with different physiological activity and chemotypes, mainly including alkaloids, bufogenins, bufotoxins, and so on. The recent pharmacological researches have demonstrated that several bufogenins have remarkable pharmacological effects, such as anti-inflammatory, analgesic effects, and anti-tumor effects. Aim of the study: To identify the bioactive compounds and pharmacophores originating from toad venom based on analyzing spectrum-effect relationship by chemometrics and to explore the anti-cancer mechanism primarily. (2) Materials and methods: Fingerprint of the 21 batches of samples was established using HPLC (High Performance Liquid Chromatography). The anti-tumor activity of extracts were determined by in-vitro assays. Chemometric analysis was used to establish the spectrum-effect model and screen for active ingredients. Pharmacodynamic tests for the screened active compound monomers were conducted with in-vitro assays. Further anti-tumor mechanisms were investigated using western blot and flow cytometry. (3) Results: The established spectrum-effect model has satisfactory fitting effect and predicting accuracy. The inhibitory effect of major screened compounds on lung carcinoma cells A549 were validated in vitro, demonstrating that arenobufagin, telocinobufogenin, and cinobufotalin had significant anti-tumor effects. Through further investigation of the mechanism by western blotting and flow cytometry, we elucidated that arenobufagin induces apoptosis in A549 cells with the enhanced expression of cleaved PARP (poly (ADP-ribose) polymerase). These results may provide valuable information for further structural modification of bufadienolides to treat lung cancer and a method for discovery of anti-tumor active compounds. Conclusions: Our research offers a more scientific method for screening the principal ingredients dominating the pharmacodynamic function. These screened compounds (arenobufagin, etc.) were proven to induce apoptosis by overactivation of the PARP-pathway, which may be utilized to make BRCA (breast cancer susceptibility gene) mutant cancer cells more vulnerable to DNA damaging agents and kill them.

Chemical Profile and Multicomponent Quantitative Analysis for the Quality Evaluation of Toad Venom from Different Origins.

Toad venom (Chansu), a traditional Chinese medicine (TCM), has been widely used for treating various cancer. However, it is considerably difficult to evaluate the quality of Chansu due to its complex chemical compositions. Hence, finding the characteristic ingredients and developing a scientific and comprehensive quality evaluation method are essential for guaranteeing the safety and efficacy of Chansu. In this paper, the chemical composition database of Chansu was successfully established and HPLC-ESI-Q-TOF-MS/MS was applied for chemical profiling of the ingredients in Chansu. In total, 157 compounds were identified, including 22 amino acids, 8 alkaloids, 54 bufogenins, 63 bufotoxins, and 10 other compounds. Furthermore, HPLC fingerprints and quantitative analysis of its multicomponent were successfully developed to evaluate the quality consistency of Chansu from different origins. The results suggested that the HPLC fingerprint of Chansu could be divided into an amino acid and alkaloid region, as well as a bufogenins and bufotoxins region. The fingerprint profile of Chansu from different geographical origins were different, indicating that its quality was affected by the geographical factors. In addition, seven characteristic peaks were selected as the quantitative markers to evaluate the quality of the Chansu. The Kruskal-Wallis test illustrated that the contents of seven bufogenins in Chansu were significantly (p < 0.01) different among different origins. The total contents of the seven compounds ranged from 100.40 to 169.22 mg/g in 20 batches of Chansu samples. This study demonstrated that integrating HPLC-ESI-Q-TOF-MS/MS, HPLC fingerprints, and multicomponent quantitative analysis coupled with chemometrics was a comprehensive and reliable strategy for evaluation of Chansu in both qualitative and quantitative aspects. In addition, our study represented the most comprehensive characterization on the chemical compositions of Chansu, which could provide important reference information for the discovery of potential bioactive compounds.

[Correlative study of bufogenin constituents in venom of Bufo bufo gargarizans].

As known,simultaneous determination of various chemical indicators is one of the future trends in quality control of traditional Chinese medicines because of the extremely complex chemical compositions. This project is to screen the quality markers that can accurately control the quality of the Bufonis Venenum by exploring the intrinsic correlation of components. In this study,venom of Bufo bufo gargarizans from 17 different sources were used as research samples,and the contents of 7 bufogenin were determined by HPLC-DAD. Then,the data obtained were analyzed by Spearman correlation analysis and principal component analysis( PCA). In addition,a stepwise regression analysis was used to establish a predictive model for the contents of the seven bufogenin components( independent variable) and the total contents of the bufogenin( dependent variable). The results indicated that there is a significant positive correlation between the contents of telocinobufagin and cinobufotalin,and there is a significant positive correlation between the contents of bufalin,cinobufagin and resibufogenin. In contrast,the contents of telocinobufagin and cinobufotalin are negatively correlated with the contents of bufalin,cinobufagin and resibufogenin. However,the correlation between gamabufotalin and bufotalin and other components are not obvious. Furthermore,further study found that there is a correlation between the sum of the contents of bufalin,cinobufagin and telocinobufagin and the total contents of the bufogenin. In fact,the application of bufalin,cinobufagin and telocinobufagin as the quality control indicators of the Bufonis Venenum can better reflect the quality characteristics of the Bufonis Venenum compared with the previous quality control indicators. The conclusions will provide a reference for the revision of the quality standards of the Bufonis Venenum.

Optimization of extraction of linarin from Flos chrysanthemi indici by response surface methodology and artificial neural network.

The extraction of linarin from Flos chrysanthemi indici by ethanol was investigated. Two modeling techniques, response surface methodology and artificial neural network, were adopted to optimize the process parameters, such as, ethanol concentration, extraction period, extraction frequency, and solvent to material ratio. We showed that both methods provided good predictions, but artificial neural network provided a better and more accurate result. The optimum process parameters include, ethanol concentration of 74%, extraction period of 2 h, extraction three times, solvent to material ratio of 12 mL/g. The experiment yield of linarin was 90.5% that deviated less than 1.6% from that obtained by predicted result.

[Modeling of thermal degradation of linarin during concentration process].

Ganmaoling granule, with annual sale of over one billion yuan, is the first brand of domestic cold medicine sales. As the only traditonal Chinese medicine（TCM） quality control indicator of Ganmaoling granule, linarin is thermally unstable. Its content will be changed significantly during the production process, which would then affect the quality of the finished product. In this paper, the law of degradation of linarin was investigated. The experimental results showed that degradation reaction of linarin belongs to the first reaction characteristics. The effective methods to reduce the loss of linarin would be realized fortunately by strictly controlling the heating temperature or shortening the heating time.

[Study on balance of process of alcohol precipitation of ganmaoling granules].

Ganmaoling granule is the first brand of domestic cold medicine sales, but its preparation method and process control parameters are relatively rough. Therefore it is urgent to upgrade the technologies of large varieties of traditional Chinese medicine (TCM). This paper focused on the balance between the remove of impurity and the retention of linarin during the process of alcohol precipitation of Ganmaoling granules. The effects of four factors on the process were investigated via single factor experiments. The results showed that the precipitating period, the initial ethanol concentration and the final ethanol concentration had a great effect on retention of linarin while the initial density of the extract has not. Similarly, the initial ethanol concentration, the final ethanol concentration and the initial extract density have a great effect on the yield of dry extract while the time of alcohol precipitation has not. The parameters of alcohol precipitation of Ganmaoling granules were optimized as 16 h of precipitating period, 95% ethanol as the initial reagent, 70% of the final ethanol concentration, and 1.10 of the initial extract density.

[On-line monitoring of extraction of coldrine by near-infrared spectrum].

Extraction of the four Chinese herbals is the beginning step of the production process of coldrine granules and influences on drug quality significantly. In this paper, the on-line near infrared spectrum was collected during the extraction process of coldrine and then pre-processed by the first derivative. Partial least square regression (PLSR) model was developed for the quantity indicators of linarin, chlorogenic acid and solid content, according to results of both HPLC and weight-loss as reference methods. The correlation coefficient, root mean square error of cross-validation (RMSECV), root mean square error of calibration (RMSEC) and root mean square error of prediction (RMSEP) were used to optimize model parameters and confirm their performance. Correlation coefficients of three quality control indicator models reached more than 0.95.Values of RMSEC of linarin, chloroenic acid and solid content were 0.010 4, 0.009 34 and 0.055 5, respectively. And the values of RMSEP were 0.009 47, 0.142 and 0.008 42, respectively. The models, built on-line analyze data, revealed that the correlation coefficients of predicted values and measured values were greater than 0.97 and values of RSEP of linarin, chloroenic acid and solid content were 8.14%, 8.17% and 9.86%, respectively. The results showed that the NIR method could achieve the on-line detection and real-time monitoring of multi-indexes during the extraction process of coldrine. The technology could be used for drug quality control in the process of practical production, reducing the batch differences and ensuring pharmaceutical quality stability. In addition, it could provide real-time production data for subsequent product quality backtracking.

Quality Evaluation of Shexiang Tongxin Dropping Pill Based on HPLC Fingerprints Combined with HPLC-Q-TOF-MS/MS Method.

Shexiang Tongxin Dropping Pill (STP) is a composite formula of traditional Chinese medicine that is widely used for the treatment of cardiovascular diseases. It consists of seven medicinal extracts thereof or materials, including Bufonis venenum, synthetic Moschus, Panax ginseng, Bovis calculus artifactus, Bear bile powder, Salvia miltiorrhiza Bge and synthetic borneol. However, it is considerably difficult to evaluate the quality of STP due to its complex chemical compositions. This paper was designed to explore a comprehensive and systematic method combining fingerprints and chemical identification for quality assessment of STP samples. Twenty batches of STP samples were analyzed by high-performance liquid chromatography (HPLC) and high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry. Ten common peaks were detected by HPLC fingerprint similarity evaluation system. Meanwhile, 100 compounds belonging to 4 structural characteristics, including 23 bufadienolides, 36 organic acids, 34 saponins and 7 other types, were systematically identified as the basic components in STP. This study could be used for clarifying the multiple bioactive substances and developing a comprehensive quality evaluation method of STP.

Stereoselective Synthesis of Monofluoroalkenylphosphine Oxides via Photoinduced Decarboxylative Coupling of α-Fluoroacrylic Acids with P(O)H Compounds.

Herein, a practical and efficient method for synthesizing monofluoroalkenyl phosphine oxides via photoinduced decarboxylative/dehydrogenative coupling of α-fluoroacrylic acids with phosphine oxides and phosphonates has been developed. Various α-fluoroacrylic acids and P(O)H compounds containing relevant functional groups, including tetrafluorobenzene and pentafluorobenzene, were converted into corresponding products with excellent E-stereoselectivity in satisfactory yields. This method can be extended to achieve the synthesis of monofluoroalkenyl silanes under similar conditions.

A review of vibration energy harvesting in rail transportation field.

In this paper, we review, compare, and analyze previous studies on vibration energy harvesting and related technologies. First, the paper introduces the basic aspects of vibration energy acquisition in the railway environment, including vibration frequency, train speed, energy flow in the train, and vibration energy harvesting potential. Generally, the methods for scavenging vibration energy caused by passing trains can be divided into four categories: electromagnetic harvesters, piezoelectric harvesters, triboelectric harvesters, and hydraulic harvesters. The structure, output performance, merits, and disadvantages of different energy harvesting strategies are summarized and compared. The application of vibration energy harvesters is explained as supplying power to monitoring sensors on the line side and the vehicle side. Finally, the paper addresses the challenges and difficulties that have not been completely resolved in the current research literature, including system stability, durability, and economy. Some recommendations to fill these research gaps are put forward for further investigation.

Rapid monitoring approaches for concentration process of lanqin oral solution by near-infrared spectroscopy and chemometric models.

Qualitative and quantitative detection methods based on near-infrared spectroscopy (NIRs) have been proposed in the process analysis of traditional Chinese medicine in recent years. In this study, rapid monitoring methods were developed for quality control of concentration process of lanqin oral solution (LOS). Partial least squares regression (PLSR) method was adopted to construct quantitative models for epigoitrin, geniposide, baicalin, berberine hydrochloride and density. Simultaneously, the genetic algorithm joint extreme learning machine (GA-ELM) was first applied in qualitative analysis of NIRs to distinguish end point of concentration process. Results of PLSR models were satisfactory with the relative standard error of calibration valued at 3.80%, 3.75%, 3.79%, 11.5% and 1.22% for epigoitrin, geniposide, baicalin, berberine hydrochloride and density respectively, and the residual predictive deviation values were higher than 3. For qualitative analysis, the GA-ELM model obtained 100% prediction accuracy. The PLSR quantitative models and the end point discrimination model constructed by GA-ELM correspond with the requirements of practical applications. The results indicate that NIRs in combination with chemometrics has great potential in improving the efficiency in production.

Reduced graphene oxide-zinc oxide nanocomposite as dispersive solid-phase extraction sorbent for simultaneous enrichment and purification of multiple mycotoxins in Coptidis rhizoma (Huanglian) and analysis by liquid chromatography tandem mass spectrometry.

In the current study, a robust dispersive solid-phase extraction (dSPE) strategy using reduced graphene oxide-zinc oxide (rGO-ZnO) nanocomposite as the sorbent was proposed for separation, purification and enrichment of 12 mycotoxins in Coptidis rhizoma (Huanglian). The targeted mycotoxins included aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, aflatoxin M1, alternariol-methylether, mycophenolic acid, ochratoxin A, penitrem A, nivalenol, zearalenone and zearalanone. The rGO-ZnO nanocomposite was successfully synthesized through hydrothermal process by a modified Hummers method, and further characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FTIR spectroscopy, ultraviolet-visible spectroscopy and X-ray diffraction (XRD). Several key parameters affecting the performance of the dSPE approach were extensively investigated, and after optimization, acetonitrile/water/formic acid (80/19/1, v/v/v) as the extraction solution, 2% acetonitrile as the adsorption solution, 15 mg rGO-ZnO as the sorbent, n-hexane as the washing solution, and methanol/formic acid (99/1, v/v) as the desorption solution presented an excellent purification and enrichment efficiency. Under the optimal dSPE procedure followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), adequate linearity (R2 ≥ 0.991), high sensitivity (limit of quantification in the range of 0.09-0.41 µg kg-1), acceptable recovery (70.3-105.7%) and satisfactory precision (RSD 1.4-15.0%) were obtained. The analysis of 12 selected mycotoxins was also carried out in real Coptidis rhizoma (Huanglian) samples for applicability evaluation of the established method.

The impact of multiple climatic and geographic factors on the chemical defences of Asian toads (Bufo gargarizans Cantor).

Chemical defences are widespread in nature, yet we know little about whether and how climatic and geographic factors affect their evolution. In this study, we investigated the natural variation in the concentration and composition of the main bufogenin toxin in adult Asian toads (Bufo gargarizans Cantor) captured in twenty-two regions. Moreover, we explored the relative importance of eight climatic factors (average temperature, maximum temperature, minimum temperature, average relative humidity, 20-20 time precipitation, maximum continuous precipitation, maximum ground temperature, and minimum ground temperature) in regulating toxin production. We found that compared to toads captured from central and southwestern China, toads from eastern China secreted higher concentrations of cinobufagin (CBG) and resibufogenin (RBG) but lower concentrations of telocinobufagin (TBG) and cinobufotalin (CFL). All 8 climatic variables had significant effects on bufogenin production (ri>0.5), while the plastic response of bufogenin toxin to various climate factors was highly variable. The most important climatic driver of total bufogenin production was precipitation: the bufogenin concentration increased with increasing precipitation. This study indicated that the evolution of phenotypic plasticity in chemical defences may depend at least partly on the geographic variation of defensive toxins and their climatic context.

Linarin improves the dyskinesia recovery in Alzheimer's disease zebrafish by inhibiting the acetylcholinesterase activity.

BACKGROUND: Due to complex pathogenesis of Alzheimer's disease (AD), currently there is no effective disease-modifying treatment. Acetylcholinesterase (AChE) has introduced itself as an important target for AD therapy. Linarin as the representative active ingredient of flavonoid glycoside in Flos chrysanthemi indici has been found to have anti-acetylcholinesterase effect. AIMS: The present study intended to explore the potential effect of linarin for treatment of AD. MAIN METHODS: In this study, molecular docking simulation was used to evaluate whether linarin could dock with AChE and decipher the mechanism of linarin as an AChE inhibitor. After molecular docking simulation, AlCl3-induced Alzheimer's disease zebrafish model was established. Effects of linarin on treating AD zebrafish dyskinesia and AChE inhibition were compared with donepezil (DPZ) which was used as a positive control drug. KEY FINDINGS: Molecular docking simulation showed that linarin plays a critical role in AChE inhibition by binding AChE active sites. The experiments illustrated that the dyskinesia recovery rate of AD zebrafish could be significantly improved by linarin. The dyskinesia recovery and AChE inhibition rate were 88.0% and 74.5% respectively, while those of DPZ were 79.3% and 43.6%. SIGNIFICANCE: These findings provide evidences for supporting linarin to be developed into an AD drug by inhibiting the activity of AChE.