One single amino Acid for estimation the content of total free amino acids in qingkailing injection using high-performance liquid chromatography-diode array detection

Validation of a Simple HPLC-Based Method for Lysine Quantification for Ruminant Nutrition

Robust and selective quantification methods are required to better analyze feed supplementation effectiveness with specific amino acids. In this work, a reversed-phase high-performance liquid chromatography method with fluorescence detection is proposed and validated for lysine quantification, one of the most limiting amino acids in ruminant nutrition and essential towards milk production. To assess and widen method applicability, different matrices were considered: namely Li₂CO₃ buffer (the chosen standard reaction buffer), phosphate buffer solution (to mimic media in cellular studies), and rumen inoculum. The method was validated for all three matrices and found to be selective, accurate (92% ± 2%), and precise at both the inter- and intra-day levels in concentrations up to 225 µM, with detection and quantification limits lower than 1.24 and 4.14 µM, respectively. Sample stability was evaluated when stored at room temperature, 4 °C, and -20 °C, showing consistency for up to 48 h regardless of the matrix. Finally, the developed method was applied in the quantification of lysine on real samples. The results presented indicate that the proposed method can be applied towards free lysine quantification in ruminant feeding studies and potentially be of great benefit to dairy cow nutrition supplementation and optimization.

RP-HPLC-DAD determination of free amino acids in cocoa samples during fermentation and roasting

Amino acids (AA) composition in cocoa beans can predict the synthesis of compounds which affect cocoa flavor. Thus, their determination is of great interest for the community implied in the commercialization and production of cocoa. In consequence, in this work, the analysis of AA produced during cocoa beans fermentation and roasting was carried out. A high-performance liquid chromatographic method with DAD detection at 254 nm was optimized and validated for their selective determination in six varieties of cocoa beans with different genotypes, all of them grown in Venezuela. AA were extracted by defatted milled cocoa powder ultrasonication using purified water at 70 ºC. Then, they were derivatized with phenyl isothiocyanate, and their derivatives were separated, using a reversed-phase column with gradient elution, achieving a satisfactory resolution among the peaks (greater than 1.0) in less than 29 min. 110 cocoa samples were analyzed. Results showed a significant content of free AA, ranging from 3.87 to 5.97 g/kg in absence of fermentation with a predominance of acidic AA. Moreover, there is a progressive increase in the AA content while fermentation process occurs, with a predominance of hydrophobic AA such as alanine, valine, isoleucine, leucine, phenylalanine, and tyrosine. On the other hand, all cocoa types showed a partial degradation of free AA during the roasting step, especially the hydrophobic ones.

Pharmacokinetic-Pharmacodynamic Modeling to Study the Antipyretic Effect of Qingkailing Injection on Pyrexia Model Rats

Qingkailing injection (QKLI) is a modern Chinese medicine preparation derived from a well-known classical formulation, An-Gong-Niu-Huang Wan. Although the clinical efficacy of QKLI has been well defined, its severe adverse drug reactions (ADRs) were extensively increased. Through thorough attempts to reduce ADR rates, it was realized that the effect-based rational use plays the key role in clinical practices. Hence, the pharmacokinetic-pharmacodynamic (PK-PD) model was introduced in the present study, aiming to link the pharmacokinetic profiles with the therapeutic outcomes of QKLI, and subsequently to provide valuable guidelines for the rational use of QKLI in clinical settings. The PK properties of the six dominant ingredients in QKLI were compared between the normal treated group (NTG) and the pyrexia model group (MTG). Rectal temperatures were measured in parallel with blood sampling for NTG, MTG, model control group (MCG), and normal control group (NCG). Baicalin and geniposide exhibited appropriate PK parameters, and were selected as the PK markers to map the antipyretic effect of QKLI. Then, a PK-PD model was constructed upon the bacalin and geniposide plasma concentrations vs. the rectal temperature variation values, by a two-compartment PK model with a Sigmoid Emax PD model to explain the time delay between the drug plasma concentration of PK markers and the antipyretic effect after a single dose administration of QKLI. The findings obtained would provide fundamental information to propose a more reasonable dosage regimen and improve the level of individualized drug therapy in clinical settings.

Aroma improvement by repeated freeze-thaw treatment during Tuber melanosporum fermentation

The aroma attributes of sulfurous, mushroom and earthy are the most important characteristics of the aroma of Tuber melanosporum. However, these three aroma attributes are absent in the T. melanosporum fermentation system. To improve the quality of the aroma, repeated freeze-thaw treatment (RFTT) was adopted to affect the interplay of volatile organic compounds (VOCs). Using RFTT, not only was the score on the hedonic scale of the aroma increased from the “liked slightly” to the “liked moderately” grade, but the aroma attributes of sulfurous, mushroom and earthy could also be smelled in the T. melanosporum fermentation system for the first time. A total of 29 VOCs were identified, and 9 compounds were identified as the key discriminative volatiles affected by RFTT. Amino acid analysis revealed that methionine, valine, serine, phenylalanine, isoleucine and threonine were the key substrates associated with the biosynthesis of the 9 key discriminative VOCs. This study noted that amino acid metabolism played an important role in the regulation of the aroma of the T. melanosporum fermentation system.

Detecting drug-herbal interaction using a spontaneous reporting system database: an example with benzylpenicillin and qingkailing injection

PURPOSE

The study aims to quantify anaphylaxis signal for combined exposure of benzylpenicilin and qingkailing injection (QI) compared with individual exposure of the two drugs and the background risk based on all other exposures in SRS database.

METHODS

Data used in this study were collected during 2003-2014 from China Guangdong Provincial Center of ADR Monitoring. We studied the suspected ADR reports using a case/non-case design. The cases were defined as the reactions coded by WHO-preferred terms of anaphylactic shock or anaphylactoid reaction. Reporting odds ratios (RORs) were used as a measure of disproportionality and were adjusted for age and gender to reduce confounding effects. An observed-to-expected ratio Ω was also used for interaction detection.

RESULTS

The crude RORs (95 % CIs) for anaphylaxis in patients who used only benzylpenicillin or QI and those who used the two drugs concomitantly compared with patients who used neither of the two drugs were 2.50 (2.34-2.68), 1.59 (1.46-1.73), and 6.22 (3.34-11.58), respectively. The adjusted RORs (95 % CIs) were 2.48 (2.31-2.65), 1.54 (1.41-1.67), and 6.01 (3.22-11.20), respectively, after being adjusted for age and gender. The measured Ω, Ω0, Ω025, and Ω975 was 1.03, 1.09, 0.14, and 1.71, respectively.

CONCLUSIONS

Case reports in the database are suggestive of a safety signal which indicates that an interaction between benzylpenicillin and QI resulting in excess risk of anaphylaxis may occur. SRS databases have a potential for signaling unknown drug-herbal interactions. More effort is needed to expand this potential.

Large-scale qualitative and quantitative characterization of components in Shenfu injection by integrating hydrophilic interaction chromatography, reversed phase liquid chromatography, and tandem mass spectrometry

It is of great importance to clarify in depth the chemical composition, including qualitative and quantitative aspects, of traditional Chinese medicine (TCM) injection that contains a great number of hydrophilic and hydrophobic ingredients to guarantee its safe medication in clinic. Column-switching hydrophilic interaction liquid chromatography-reversed phase liquid chromatography coupled with tandem mass spectrometry (HILIC-RPLC-MS/MS) has been revealed to be advantageous at simultaneous measurement of compounds covering a broad polarity range. Previous studies have profiled the hydrophobic components, mainly aconite alkaloids and ginsenosides, in Shenfu Injection (SFI); however, the hydrophilic substances haven't been taken into account. In the present study, we aim to holistically characterize the hydrophilic constituents and to simultaneously quantitate both hydrophilic and hydrophobic components in SFI. A strategy integrating predefined multiple reaction monitoring, step-wise multiple ion monitoring, and enhanced product ion scans was proposed to universally screen the hydrophilic substances using a hybrid triple quadrupole-linear ion trap mass spectrometer. Structural identification was carried out by comparing with authentic compounds, analyzing MS(2) spectra, and referring to accessible databases (e.g., MassBank, METLIN and HMDB). A total of 157 hydrophilic compounds were detected from SFI, and 154 ones were identified as amino acids, nucleosides, organic acid, carbohydrates, etc. A column-switching HILIC-RPLC-MS/MS system was developed and validated for simultaneously quantitative analysis of 40 primary hydrophilic and hydrophobic ingredients in SFI, including eleven amino acids, nine nucleosides, nine aconite alkaloids, and eleven ginsenosides. Taken together, the findings obtained could provide meaningful information for comprehensively understanding the chemical composition and offer a reliable approach for the quality control of SFI.

Quantitative profiling of polar metabolites in herbal medicine injections for multivariate statistical evaluation based on independence principal component analysis

Botanical primary metabolites extensively exist in herbal medicine injections (HMIs), but often were ignored to control. With the limitation of bias towards hydrophilic substances, the primary metabolites with strong polarity, such as saccharides, amino acids and organic acids, are usually difficult to detect by the routinely applied reversed-phase chromatographic fingerprint technology. In this study, a proton nuclear magnetic resonance (1H NMR) profiling method was developed for efficient identification and quantification of small polar molecules, mostly primary metabolites in HMIs. A commonly used medicine, Danhong injection (DHI), was employed as a model. With the developed method, 23 primary metabolites together with 7 polyphenolic acids were simultaneously identified, of which 13 metabolites with fully separated proton signals were quantified and employed for further multivariate quality control assay. The quantitative 1H NMR method was validated with good linearity, precision, repeatability, stability and accuracy. Based on independence principal component analysis (IPCA), the contents of 13 metabolites were characterized and dimensionally reduced into the first two independence principal components (IPCs). IPC1 and IPC2 were then used to calculate the upper control limits (with 99% confidence ellipsoids) of χ2 and Hotelling T2 control charts. Through the constructed upper control limits, the proposed method was successfully applied to 36 batches of DHI to examine the out-of control sample with the perturbed levels of succinate, malonate, glucose, fructose, salvianic acid and protocatechuic aldehyde. The integrated strategy has provided a reliable approach to identify and quantify multiple polar metabolites of DHI in one fingerprinting spectrum, and it has also assisted in the establishment of IPCA models for the multivariate statistical evaluation of HMIs.