The enzyme encoded by Myrmecia incisa, a green microalga, phospholipase A2 gene preferentially hydrolyzes arachidonic acid at the sn-2 position of phosphatidylcholine.

The enzyme phospholipase A2 (PLA2) plays a crucial role in acyl remodeling of phospholipids via the Lands' cycle, and consequently alters fatty acid compositions in triacylglycerol (TAG). In this study, a full-length cDNA sequence coding Myrmecia incisa phospholipase A2 (MiPLA2) was cloned using the technique of rapid amplification of cDNA ends. Comparison of the 1082-bp cDNA with its corresponding cloned DNA sequence revealed that MiPLA2 contained 3 introns. Mature MiPLA2 (mMiPLA2) had a conserved Ca2+-binding loop and a catalytic site motif that has been recognized in plant secretory PLA2 (sPLA2) proteins. Correspondingly, phylogenetic analysis illustrated that MiPLA2 was clustered within GroupXIA of plant sPLA2 proteins. To ascertain the function of MiPLA2, the cDNA coding for mMiPLA2 was subcloned into the vector pET-32a to facilitate the production of recombinant mMiPLA2 in Escherichia coli. Recombinant mMiPLA2 was purified and used for the in vitro enzyme reaction. Thin-layer chromatography profiles of the catalytic products generated by recombinant mMiPLA2 indicated a specificity for cleaving sn-2 acyl chains from phospholipids, thereby functionally characterizing MiPLA2. Although recombinant mMiPLA2 displayed a strong preference for phosphatidylethanolamine, it preferentially hydrolyzes arachidonic acid (ArA) at the sn-2 position of phosphatidylcholine. Results from the fused expression of p1300-sp-EGFP-mMiPLA2 illustrated that MiPLA2 was localized in the intercellular space of onion epidermis. Furthermore, the positive correlation between MiPLA2 transcription and free ArA levels were established. Consequently, the role of mMiPLA2 in the biosynthesis of ArA-rich TAG was elucidated. This study helps to understand how M. incisa preferentially uses ArA to synthesize TAG.

Automated identification of pesticide mixtures via machine learning analysis of TLC-SERS spectra.

Identification of components in pesticide mixtures has been a major challenge in spectral analysis. In this paper, we assembled monolayer Ag nanoparticles on Thin-layer chromatography (TLC) plates to prepare TLC-Ag substrates with mixture separation and surface-enhanced Raman scattering (SERS) detection. Spectral scans were performed along the longitudinal direction of the TLC-Ag substrate to generate SERS spectra of all target analytes on the TLC plate. Convolutional neural network classification and spectral angle similarity machine learning algorithms were used to identify pesticide information from the TLC-SERS spectra. It was shown that the proposed automated spectral analysis method successfully classified five categories, including four pesticides (thiram, triadimefon, benzimidazole, thiamethoxam) as well as a blank TLC-Ag data control. The location of each pesticide on the TLC plate was determined by the intersection of the information curves of the two algorithms with 100 % accuracy. Therefore, this method is expected to help regulators understand the residues of mixed pesticides in agricultural products and reduce the potential risk of agricultural products to human health and the environment.

Marine Bacillus haynesii chitinase: Purification, characterization and antifungal potential for sustainable chitin bioconversion.

The development of chitinase tailored for the bioconversion of chitin to chitin oligosaccharides has attracted significant attention due to its potential to alleviate environmental pollution associated with chemical conversion processes. In this present investigation, we purified extracellular chitinase derived from marine Bacillus haynesii to homogeneity and subsequently characterized it. The molecular weight of BhChi was approximately 35 kDa. BhChi displayed its peak catalytic activity at pH 6.0, with an optimal temperature of 37 °C. It exhibited stability across a pH range of 6.0-9.0. In addition, BhChi showed activation in the presence of Mn2+ with the improved activity of 105 U mL-1. Ca2+ and Fe2+ metal ions did not have any significant impact on enzyme activity. Under the optimized enzymatic conditions, there was a notable enhancement in catalytic activity on colloidal chitin with Km of 0.01 mg mL-1 and Vmax of 5.75 mmol min-1. Kcat and catalytic efficiency were measured at 1.91 s-1 and 191 mL mg-1 s-1, respectively. The product profiling of BhChi using thin layer chromatography and Mass spectrometric techniques hinted an exochitinase mode of action with chitobiose and N-Acetyl glucosamine as the products. This study represents the first report on an exochitinase from Bacillus haynesii. Furthermore, the chitinase showcased promising antifungal properties against key pathogens, Fusarium oxysporum and Penicillium chrysogenum, reinforcing its potential as a potent biocontrol agent.

Improvement on Quality Standard of Yuanhu Zhitong Oral Liquid / 中国实验方剂学杂志

ObjectiveTo improve the quality standard of Yuanhu Zhitong oral liquid in order to strengthen the quality control of this oral liquid. MethodThin layer chromatography（TLC） was used for the qualitative identification of Corydalis Rhizoma and Angelicae Dahuricae Radix in Yuanhu Zhitong oral liquid by taking tetrahydropalmatine， corydaline reference substances and Corydalis Rhizoma reference medicinal materials as reference， and cyclohexane-trichloromethane-methanol（5∶3∶0.5） as developing solvent， Corydalis Rhizoma was identified using GF254 glass thin layer plate under ultraviolet light（365 nm）. And taking petroleum ether（60-90 ℃） -ether-formic acid（10∶10∶1） as developing solvent， Angelicae Dahuricae Radix was identified using a silica gel G TLC plate under ultraviolet light（305 nm）. High performance liquid chromatography（HPLC） was performed on a Waters XSelect HSS T3 column（4.6 mm×250 mm， 5 μm） with acetonitrile（A）-0.1% glacial acetic acid solution（adjusted pH to 6.1 by triethylamine）（B） as the mobile phase for gradient elution（0-10 min， 20%-30%A； 10-25 min， 30%-40%A； 25-40 min， 40%-50%A； 40-60 min， 50%-60%A）， the detection wavelength was set at 280 nm， then the fingerprint of Yuanhu Zhitong oral liquid was established， and the contents of tetrahydropalmatine and corydaline were determined. ResultIn the thin layer chromatograms， the corresponding spots of Yuanhu Zhitong oral liquid， the reference substances and reference medicinal materials were clear， with good separation and strong specificity. A total of 12 common peaks were identified in 10 batches of Yuanhu Zhitong oral liquid samples， and the peaks of berberine hydrochloride， dehydrocorydaline， glaucine， tetrahydropalmatine and corydaline. The similarities between the 10 batches of samples and the control fingerprint were all >0.90. The results of determination showed that the concentrations of corydaline and tetrahydropalmatine had good linearity with paek area in the range of 0.038 6-0.193 0， 0.034 0-0.170 0 g·L-1， respectively. The methodological investigation was qualified， and the contents of corydaline and tetrahydropalmatine in 10 batches of Yuanhu Zhitong oral liquid samples were 0.077 5-0.142 9、0.126 1-0.178 2 g·L-1， respectively. ConclusionThe established TLC， fingerprint and determination are simple， specific and reproducible， which can be used to improve the quality control standard of Yuanhu Zhitong oral liquid.

Simultaneous analysis of the of levamisole with triclabendazole in pharmaceuticals through developing TLC and HPLC-PDA chromatographic techniques and their greenness assessment using GAPI and AGREE methods.

Two simple and rapid chromatographic methods were developed and validated for the analysis of levamisole and triclabendazole simultaneously in pure and pharmaceutical products. The first method is thin-layer chromatography (TLC) with densitometry, and the second method is high-performance liquid chromatography with PDA detection (HPLC-PDA). A Hypersil BDS C18 column with dimensions of 4.6 × 150 mm and a particle size of 5 µm was used in the HPLC-PDA method. An isocratic condition was used to carry out the separation, and the mobile phase was made up of acetonitrile and a 0.03 M potassium dihydrogen phosphate buffer in double-distilled water. The ratio of the mobile phase preparation was 70:30 (v/v), and the flow rate was 1 mL/min. A wavelength of 215 nm was employed for analyte detection. Precoated silica gel 60 F254 aluminium plates were used for the TLC method's separation. Mobile phase was made of ethyl acetate, hexane, methanol, and ammonia (69:15:15:1) for the separation. The detection wavelength selected was 215 nm. According to the International Council for Harmonization (ICH) guidelines, the proposed methods were validated and it was found that the two chromatographic methods are accurate, precise, and linear for both compounds in the range of 3.75-37.5 and 6-60 mg/L for the HPLC method for levamisole and triclabendazole, respectively and in the range of 2-14 µg/spot for the TLC method. The developed methods greenness profile was assessed using AGREE and ComplexGAPI tools.

Comparison of TLC, HPLC, and direct-infusion ESI-MS methods for the identification and quantification of diacylglycerol molecular species.

Diacylglycerols (DAGs) are anabolic precursors to membrane lipid and storage triacylglycerol biosynthesis, metabolic intermediates of lipid catabolism, and potent cellular signaling molecules. The different DAG molecular species that accumulate over development or in different tissues reflect the changing aspects of cellular lipid metabolism. Consequently, an accurate determination of DAG molecular species in biological samples is essential to understand various metabolic processes and their diagnostic relevance. However, quantification of DAG molecular species in various biological samples represents a challenging task because of their low abundance, hydrophobicity, and instability. This chapter describes the most common chromatographic (TLC and HPLC) and mass spectrometry (MS) methods used to analyze DAG molecular species. In addition, we directly compared the three methods using DAG obtained by phospholipase C hydrolysis of phosphatidylcholine purified from a Nicotiana benthamiana leaf extract. We conclude that each method identified similar major molecular species, however, the exact levels of those varied mainly due to sensitivity of the technique, differences in sample preparation, and processing. This chapter provides three different methods to analyze DAG molecular species, and the discussion of the benefits and challenges of each technique will aid in choosing the right method for your analysis.

A method for the rapid determination of pesticides coupling thin-layer chromatography and enzyme inhibition principles.

Herein, we developed a method coupling TLC and enzyme inhibition principles to rapidly detect OPs (dichlorvos, paraoxon and parathion). After the removal of the organic solvent from the samples using TLC and paper-based chips, the enzyme was added to the detection system. The results showed that the current method effectively reduced the effects of solvents on enzyme behavior. Moreover, the pigments could be successfully retained on TLC with 40% ddH2O/ACN solution (v/v) as a developing solvent. Additionally, the detection limits (LODs) were 0.002 µg/mL for dichlorvos, 0.006 µg/mL for paraoxon, and 0.003 µg/mL for parathion. Finally, the method was applied to spiked cabbage, cucumber, and spinach and showed good average recoveries ranging between 70.22% and 119.79%. These results showed that this paper-based chip had high sensitivity, precleaning, and elimination of organic solvent properties. Furthermore, it provides a valuable idea for sample pretreatment and rapid determination of pesticide residues in food.

[Advances in thin layer chromatography coupled with mass spectrometry technology].

Thin layer chromatography (TLC) is a very useful liquid chromatography approach. The simple device, convenient operation, versatility, high throughput capabilities, low cost, and simple sample pretreatments make it widely employed in various fields. In recent years, TLC-MS has become one of the most prominent trends for this technology as developments of modern analytical technology and comprehensive application of different approaches. With the development and upgrading of medicine, food, and scientific instrument industries, it is believed that TLC-MS technology should play a better role and obtain an opportunity for development. This study reviewed TLC-MS interface technologies (most of which are in recent 10 years) based on more than 150 studies and classified these TLC-MS technologies as three strategies. The first is indirect coupling using commercially available interface instruments. The second is TLC-in-site detection directly with special MS ion source devices like fast-atom-bombardment desorption ionization, matrix-assisted laser desorption ionization, surface-assisted laser desorption ionization, electrospray-assisted laser desorption ionization, laser-induced acoustic desorption/electrospray ionization, electrostatic-spray ionization, easy ambient sonic-spray ionization, desorption sonic spray ionization, ionization using "desorption/ionization resource", ionization using "molecular ionization-desorption analysis source", multiwavelength laser desorption ionization, ionization using flowing afterglow-atmospheric pressure glow discharge, ionization low-temperature plasma probe, desorption/ionization induced using neutral clusters, ionization using inductively coupled plasma and so on. These MS analyses are performed after TLC development, thus, the relative position of the chromatographic bands on TLCs is invariable, and this analysis can be regarded as static detection, though flexible travel stages or conveyor belts can be introduced to move TLC plates. The third strategy is to monitor TLC run using MS in real-time just as the monitor employed in HPLC, in which the chromatographic bands are still moving. This strategy is generally run on forced-flow TLC techniques and is less examined. The typical coupling technologies (especially appeared in recent ten years) are summarized and briefly described in this study. TLC-MS has greatly enhanced the research efficiency of bioactive substances for food and drugs due to the widespread usage of TLC-bioautography technology. Nowadays, the main bottleneck in the development of TLC-MS is the design and commercialization of "plug and play" components. The high-throughput and real-time monitoring TLC-MS technology with flexible scanning functions is also expected. Furthermore, the comparative studies of different kinds of desorbing-ionizing technologies are also application problems for further discussion.

Identification of Dalbergiae Odoriferae Lignum and Its Counterfeits by 1H-NMR Combined with Multivariate Statistical Analysis / 中国实验方剂学杂志

ObjectiveTo establish the identification method of Dalbergiae Odoriferae Lignum（DOL） and its counterfeits by nuclear magnetic resonance hydrogen spectrum（1H-NMR） combined with multivariate statistical analysis. Method1H-NMR spectra of DOL and its counterfeits were obtained by NMR， and the full composition information was established and transformed into a data matrix， and the detection conditions were as follows：taking dimethyl sulfoxide-d6（DMSO-d6） containing 0.03% tetramethylsilane（TMS） as the solvent， the constant temperature at 298 K（1 K=-272.15 ℃）， pulse interval of 1.00 s， spectrum width of 12 019.23 Hz， the scanning number of 16 times， and the sampling time of 1.08 s. Similarity examination and hierarchical cluster analysis（HCA） were performed on the data matrix of DOL and its counterfeits， and orthogonal partial least squares-discriminant analysis（OPLS-DA） was used to analyze the data matrix and identify the differential components between them. In the established OPLS-DA category variable value model， the category variable value of DOL was set as 1， and the category variable value of the counterfeits was set as 0， and the threshold was set as ±0.3， in order to identify the commercially available DOL. The OPLS-DA score plot was used to determine the types of counterfeits in commercially available DOL， and it was verified by thin layer chromatography（TLC）. ResultThe results of similarity analysis and HCA showed that there was a significant difference between DOL and its counterfeits. OPLS-DA found that the differential component between DOL and its counterfeits was trans-nerolidol. The established category variable value model could successfully identify the authenticity of the commercially available DOL. The results of the OPLS-DA score plot showed that there were heartwood of Dalbergia pinnata and D. cochinchinensis in the commercially available DOL， and were consistent with the TLC verification results. ConclusionThere is a phenomenon that heartwood of D. pinnata and D. cochinchinensis are sold as DOL in the market. 1H-NMR combined with multivariate statistical analysis can effectively distinguish DOL and its counterfeits， which can provide a reference for the identification of them.

Establishment of Specific Chromatogram and Thin-layer Identification Method for Kaixinsan / 中国实验方剂学杂志

ObjectiveTo establish the specific chromatogram and thin layer chromatography（TLC） identification method of Kaixinsan（KXS） samples， in order to clarify the key quality attributes and provide reference for the quality evaluation of KXS. MethodHigh performance liquid chromatography（HPLC） specific chromatogram of KXS was developed with YMC Hydrosphere C18 column（4.6 mm×250 mm， 5 μm）， the mobile phase was acetonitrile（A）-0.2% formic acid aqueous solution（B） for gradient elution（0-15 min， 2%-20%A； 15-25 min， 20%-25%A； 25-30 min， 25%-30%A； 30-45 min， 30%-31%A； 45-50 min， 31%-44%A； 50-65 min， 44%-45%A； 65-73 min， 45%-75%A； 73-95 min， 75%-100%A； 95-105 min， 100%A； 105-105.1 min， 100%-2%A； 105.1-120 min， 2%A）， the detection wavelength was 320 nm. Ultra high performance liquid chromatography-linear ion trap-electrostatic field orbitrap mass spectrometry（UHPLC-LTQ-Orbitrap MS） was used to identify the chemical components of KXS with electrospray ionization（ESI）， negative ion mode and scanning range of m/z 50-2 000. TLC identification methods for Poria and Ginseng Radix et Rhizoma in KXS were established. ResultThere were 11 common peaks in the specific chromatogram of KXS， attributed to Polygalae Radix， Poria and Acori Tatarinowii Rhizoma. Taking peak 9（α-asarone） as the reference peak， the relative standard deviations of the retention times of 15 batches of KXS samples were<0.2%. A total of 34 compounds were identified by UHPLC-LTQ-Orbitrap MS， including terpenoids， phenylpropanoids， oligosaccharides and ketones. The established TLC had good separation and was rapid， reliable， simple， feasible， suitable for the identification of Poria and Ginseng Radix et Rhizoma in KXS. ConclusionThe specific chromatogram and TLC of KXS are stable and reproducible. The material basis of KXS is basically clarified by MS， which can provide a reference for the development and quality control of KXS.

Establishment of Specific Chromatogram and TLC Identification for Qingxin Lianziyin / 中国实验方剂学杂志

ObjectiveTo establish the specific chromatogram and thin layer chromatography（TLC） of Qingxin Lianziyin（QXLZY） benchmark samples， in order to clarify the key quality attributes and provide a reference for the quality evaluation of QXLZY. MethodHigh performance liquid chromatography（HPLC） specific chromatogram of QXLZY benchmark samples was developed by using a YMC Hydrosphere C18 column（4.6 mm×250 mm， 5 μm） with the mobile phase of acetonitrile（A）-0.2% formic acid aqueous solution（B） for gradient elution（0-10 min， 5%-20%A； 10-20 min， 20%A； 20-25 min， 20%-24%A； 25-40 min， 24%-30%A； 40-55 min， 30%-50%A； 55-65 min， 50%-100%A； 65-75 min， 100%A； 75-75.1 min， 100%-5%A； 75.1-90 min， 5%A）， and the detection wavelength was 360 nm. Ultra-high performance liquid chromatography-linear ion trap/orbitrap mass spectrometry（UHPLC-LTQ-Orbitrap MS） with electrospray ionization（ESI） was used to identify the components of QXLZY benchmark samples by accurate relative molecular weight and multilevel MS fragment ion information， the detection conditions were positive and negative ion modes and data dependency scanning mode. TLC identification methods for Ophiopogonis Radix， Lycii Cortex， Nelumbinis Semen， Poria， Astragali Radix and Ginseng Radix et Rhizoma in QXLZY were established. ResultA total of 15 characteristic peaks were identified from Glycyrrhizae Radix et Rhizoma， Plantaginis Semen and Scutellariae Radix， and the relative standard deviations of the retention times of 15 characteristic peaks in 15 batches of QXLZY benchmark samples were≤3% with peak 8（baicalin） as the reference peak. A total of 100 compounds， including flavonoids， organic acids， saponins， amino acids and others， were identified in the benchmark samples by UHPLC-LTQ-Orbitrap MS. The established TLC had good separation and was suitable for the identification of Ophiopogonis Radix， Lycii Cortex， Nelumbinis Semen， Poria， Astragali Radix and Ginseng Radix et Rhizoma in QXLZY. ConclusionThe material basis of QXLZY benchmark samples is basically determined by MS designation and source attribution. The established specific chromatogram and TLC of QXLZY are simple， stable and reproducible， which can provide a reference for the development and quality control of QXLZY.

Thin-layer chromatography on silver nitrate-impregnated silica gel for analysis of homemade tetrahydrocannabinol mixtures.

PURPOSE: Various forms of cannabidiol (CBD)-containing products are sold in Japan. CBD is easily converted to mixtures of ∆9-tetrahydrocannabinol (∆9-THC) and its isomer, ∆8-THC, using household chemicals like diluted hydrochloric acid. This ease of production increases concerns regarding production of homemade THC mixtures. It is difficult to separate ∆9-THC, ∆8-THC, and CBD using thin-layer chromatography (TLC) on conventional silica gel. The selectivity of TLC on silver nitrate-impregnated silica gel (AgNO3-silica gel) differs from that of conventional silica gel. This study thus aimed to evaluate the separation ability of AgNO3-silica gel TLC. METHODS: To evaluate potential separation ability, standards of five THC isomers (∆9-THC, ∆8-THC, a pair of diastereomers of ∆10-THC, and ∆6a,10a-THC), CBD, CBN, and ∆9-THCA were analyzed by 10% AgNO3-silica gel TLC (developed using toluene, system A) and silica gel TLC [developed using n-hexane/diethyl ether (8:2, v/v), system B]. Then, mock homemade THC mixtures, prepared by heating crystalline CBD in acidic ethanol, were analyzed using systems A and B. RESULTS: System A showed clear separation between the five THC isomers and between ∆9-THC, ∆8-THC, CBD, and their by-products in the mock homemade THC mixture. However, system B did not separate some combinations of THC isomers and gave a single group-like spot to the THC mixture. CONCLUSION: AgNO3-silica gel TLC shows high separation ability between THC isomers and among ∆9-THC, ∆8-THC, and CBD. It will thus be useful for analyzing homemade THC mixtures.

Simplified Enzymatic Synthesis of 2-Keto-3-Deoxy-D-Gluconate from D-Gluconate Using the Gluconate Dehydratase from Thermoproteus tenax.

Many research areas, e.g., basic research but also applied fields of biotechnology, biomedicine, and diagnostics often suffer from the unavailability of metabolic compounds. This is mostly due to missing easy and efficient synthesis procedures. We herein describe the biocatalytic/enzymatic production of 2-keto-3-deoxy-D-gluconate, an intermediate of central metabolic pathways in all three domains of life and also of bacterial polysaccharides, lipopolysaccharides, and cell wall components. The method is based on the gluconate dehydratase from the hyperthermophilic crenarchaeon Thermoproteus tenax, which can be easily recombinantly overproduced in Escherichia coli and-due to its intrinsic thermostability-rapidly be purified by two precipitation steps. The enzyme completely converts D-gluconate to solely stereochemically pure KDG, taking benefits from the enol-keto-tautomerism of the primary reaction product. The final product can then easily be separated from the protein by ultrafiltration. The simple one-step procedure, which is suitable at least for the lab-scale/gram-scale production of KDG, replaces lengthy multi-step reactions and is easily scalable. This approach also illustrates the great application potential of Archaea with their unusual metabolic pathways and enzymes for the synthesis of added value products.

4-Hydroxybenzoic Acid as an Antiviral Product from Alkaline Autoxidation of Catechinic Acid: A Fact to Be Reviewed.

The dark brown mixture resulting from the autooxidation of catechinic acid (CA) (AOCA) has been reported to possess antiviral activity against Herpes Simplex Virus 1 and 2 (HSV-1 and HSV-2). Unfortunately, the constituents of AOCA were not separated or identified and the compound(s) responsible for AOCA's antiviral activity remained unknown until recently. Colorless 4-hydroxy benzoic acid (4-HBA) has been reported as the main constituent (75%) of AOCA, and as being responsible for its antiviral activity. The findings seemed not to be reliable because of the existence in the literature of very different findings, because of the high concentration that was attributed to the supposed 4-HBA in the dark mixture, and because of the absence of essential analytical experiments to confirm 4-HBA in AOCA. Particularly, the AOCA chromatograms highlighting a peak attributable to 4-HBA, using commercial 4-HBA as a standard, is missing, as well as investigations concerning the antiviral activity of marketed 4-HBA. Therefore, in this study, to verify the exactness of the recent reports, we prepared CA from catechin and AOCA from CA, and the absence of 4-HBA in the mixture was first established by thin-layer chromatography (TLC), and then was confirmed by UHPLC­MS/MS, UV­Vis, and ATR­FTIR analyses. For further confirmation, the ATR­FTIR spectral data were processed by principal components analysis (PCA), which unequivocally established strong structural differences between 4-HBA and AOCA. Finally, while the antiviral effects of AOCA against HSV-2 were confirmed, a commercial sample of 4-HBA was completely inactive.

Generating an EMS Mutant Population and Rapid Mutant Screening by Thin-Layer Chromatography Enables the Studies of Monoterpenoid Indole Alkaloids Biosynthesis in Catharanthus Roseus.

Decades of research on the medicinal plant Catharanthus roseus have led to the complete elucidation of the 29-step pathway for the biosynthesis of the anticancer drug vinblastine from geraniol and tryptophan precursors. Several approaches have been used to identify the enzymes involved in this iconic and remarkably complex pathway. This chapter describes the use of the classic ethyl methanesulfonate (EMS) mutagenesis to create a selfed M2 mutant population, which can be rapidly screened to select mutants with altered monoterpenoid indole alkaloid (MIA) biosynthesis with a simple, high-throughput thin-layer chromatography (TLC)-based screening strategy. This TLC-based MIA screening has led to the discovery and characterization of three enzymes responsible for vinblastine biosynthesis.

Functional cotton fabric-based TLC-SERS matrix for rapid and sensitive detection of mixed dyes.

A facile cotton fabric with a built-in TLC-SERS structure was fabricated to demonstrate an integrated TLC separation and SERS identification of mixed dyes. The soft and flexible SERS fabric was firstly fabricated using a simple method in which gold nanoparticles were in-situ synthesized on cotton fabrics by heating. ß-CD was then grafted onto cotton fabric through crosslinking with citric acid in presence of sodium hypophosphite monohydrate via esterification reaction. The adsorption and TLC development performance of ß-CD grafted fabrics were comprehensively investigated with two organic dyes, one anionic dye and one nonionic dye. Besides, the recyclable adsorption and separation performance were tested to evaluate its sustainable application prospects. It displayed less adsorption capacity loss and reusable separation performance after several cycles than the pristine cotton fabrics. Finally, two sets of mixed dyes were successfully separated on the TLC fabrics and then identified via on-site SERS according to their different migration distance. The developed TLC-SERS fabric shows the advantage of quick, easy to handle, low-cost, sensitive, and could be exploited in on-site study of synthetic dyes in art objects, textile and packaging products or forensic applications.

Development and Validation of Analytical Methods for Radiochemical Purity of 177Lu-PSMA-1.

Prostate Specific Membrane Antigen (PSMA) is a highly relevant target in nuclear medicine due to its overexpression in prostate cancer. The 68Ga/177Lu-PSMA-1 combination is a theranostic agent for the detection and treatment of tumors overexpressing the PSMA target. Specifically, 177Lu-PSMA-1 is used in the treatment of castration-resistant prostate cancer that is ineffective or intolerant to the latest generation of chemotherapy and/or hormone therapy. This radiopharmaceutical is manufactured in a radiopharmaceutical synthesizing unit and must pass a quality control where the radiochemical purity (RCP) is assessed prior to release of the batch. RCP evaluation is performed by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Since there is no monograph for 177Lu-PSMA-1 in the European Pharmacopoeia, we validate the analytical methods according to the EANM recommendations adapted from ICH Q2. Specificity, linearity, accuracy, precision, intermediate precision, limit of quantification (LOQ) and robustness were described for HPLC and TLC in this study. The results obtained demonstrated the robustness and reliability of the HPLC and TLC analytical methods for the evaluation of the RCP of 177Lu-PSMA-1.

Discussion on Pharmacopoeia Standard and Drug Site of Amomi Fructus Based on Quality Investigation of Commercial Samples / 中国实验方剂学杂志

ObjectiveTo investigate the quality of Amomi Fructus in the market， and to compare the difference between the seed mass and shell， so as to provide a basis for standardizing the usage of Amomi Fructus. MethodThe properties， thin layer identification， moisture， the content of bornyl acetate were determined by the methods in the 2020 edition of Chinese Pharmacopoeia， and the ash and extract content were determined according to the collection method of the 2020 edition of Chinese Pharmacopoeia. ResultAmong the 17 batches of samples， except the content of bornyl acetate in 2 batches of Amomum longiligulare， 2 batches of A. longiligulare and A. villosum mixture was lower than the standard， the quality of other samples all met the standard of the 2020 edition of Chinese Pharmacopoeia， but there were two specifications with shell and without shell. The husk rate， volatile oil， extract and bornyl acetate contents of the seed mass and shell were tested. It was found that the content of volatile oil in three kinds of Amomi Fructus seed mass was 1.8-5.3 times that of the corresponding shell， and the content of bornyl acetate in the seed mass was 8.8-62.1 times that of the corresponding shell， but there was little difference in the extract content. ConclusionBased on the above research， it is considered that the content of bornyl acetate in A. longiligulare contained in the 2020 edition of Chinese Pharmacopoeia remains to be discussed. It is tentatively determined that the total ash content of Amomi Fructus should not be more than 10.0%， and the extract content should not be less than 15.0%. At the same time， it is suggested that when Amomi Fructus is used as medicine， the dosage of Amomi Fructus should be calculated according to the removal rate of 20%-30% of shell， and it should be crushed regardless of whether it is used in shell or not.

Improvement on Quality Standard of Belladonnae Herba / 中国实验方剂学杂志

ObjectiveTo improve the current standard of Belladonnae Herba in the 2020 edition of Chinese Pharmacopoeia. MethodTaking hyoscyamine sulfate， atropine sulfate and scopoletin as reference substances， and ethyl acetate-methanol-concentrated ammonia（17∶4∶2）as developing solvent， thin layer chromatography （TLC） was applied in the qualitative identification of Belladonnae Herba. The moisture， total ash and ethanol-soluble extract of Belladonnae Herba were determined based on the general principles in the 2020 edition of Chinese Pharmacopoeia （volume Ⅳ）. The contents of hyoscyamine sulfate and scopolamine hydrobromide were analyzed by high performance liquid chromatography （HPLC） with mobile phase of acetonitrile-54 mmol·L-1 phosphate buffer solution （14∶86）， flow rate of 1.0 mL·min-1 and detection wavelength at 210 nm. ResultThe spots in the TLC were clear with good separation and specificity. Hyoscyamine sulfate and scopolamine hydrobromide showed a good linearity with peak area in the range of 0.024 7-0.789 6 g·L-1 （r=0.999 9） and 0.003 9-0.124 0 g·L-1 （r=0.999 9）， the average recoveries of these two ingredients were 100.29% （RSD 1.6%） and 99.04% （RSD 1.4%）， respectively. The limits for moisture， total ash in Belladonnae Herba should be less than 13.0% and the limit for the ethanol-soluble extract should be more than 10.0%. Due to the low content and wide variation of scopolamine hydrobromide， the content of hyoscyamine sulfate should not be less than 0.098%. ConclusionThe established method is simple， specific and reproducible， which can be used to improve the quality control standard of Belladonnae Herba.

Establishment of Quality Standard for Benchmark Samples of Liangditang / 中国实验方剂学杂志

ObjectiveTo establish the quality standard of Liangditang benchmark samples. MethodUltra performance liquid chromatography-quadrupole time-of-flight mass spectrometry （UPLC-QTOF-MS） was used to qualitatively analyze the chemical composition of Liangditang on the basis of molecular and fragment ion peak information with cracking law. The mobile phase was methanol （A）-0.05% phosphate aqueous solution （B） for gradient elution （0-10 min， 5%-23.5%A； 10-20 min， 23.5%A； 20-58 min， 23.5%-63%A； 58-60 min， 63%-90%A）， the flow rate was 0.8 mL·min-1， and the detection wavelength was 254 nm. Electrospray ionization was employed under positive ion mode， the detection range was m/z 100-1 700. Key quality attributes and sources were determined by comparing with single medicine and reference substances. Through mass transfer analysis of multiple batches from decoction pieces to benchmark samples， high performance liquid chromatography （HPLC） for determining the contents of index components and HPLC detection of characteristic maps were established. Through the determination of 15 batches of benchmark samples， the content range of the index components and the common peaks of the characteristic map were determined. Thin layer chromatography （TLC） was applied to the identification of 5 medicines in the formula. Moisture and dry extract yield of the benchmark samples were determined by drying method. ResultA total of 27 compounds were inferred from the benchmark samples of Liangditang， among which 9 compounds were confirmed by comparison with the control， including catalpol， harpagide， gallic acid， albiflorin， paeoniflorin， verbascoside， angoroside C， cinnamic acid and harpagoside. A method for determining the characteristic maps of the benchmark samples were established and 13 peaks were assigned， and the characteristic peaks were mainly derived from wine-processed products of Rehmanniae Radix， Scrophulariae Radix and wine-processed products of Paeoniae Radix Alba. The similarity between the characteristic map of 15 batches of benchmark samples and the control characteristic map was >0.9. Methods for the determination of paeoniflorin， harpagoside， L-hydroxyproline and glycine were established， and the contents of these four components in 15 batches of benchmark samples were within ±30% of the corresponding mean value， and the transfer rate of decoction pieces to the benchmark samples was stable and controllable. TLC was established to identify 5 prescription drugs （except Ejiao） with two kinds of test solutions， and the results showed that the method had good specificity. The average dry extract yield was 48.06%， and the average moisture was 5.58%， which were within the range of ±10% and ±30% of their mean values， respectively. ConclusionThe quality standard of Liangditang benchmark samples was as follows：the similarity between the benchmark samples and the control characteristic map is >0.9， the contents of paeoniflorin， harpagoside， L-hydroxyproline and glycine are 217-403， 24-46， 634-1 178， 1 253-2 328 mg per dose， the dry extract yield is 43.0%-53.0%， the moisture is 4.0%-7.0%， under the set detection conditions， the benchmark samples have corresponding characteristic spots by comparing with the control herbs of 5 medicines. This quality standard is stable and reliable， which fills the gap in the quality control of Liangditang， and can provide a reference for the establishment of the quality standard of Liangditang granules.