Fang Deng

Objectives: The quality of 30 batches of the Tibetan Dracocephali tangutici Herba was evaluated using HPLC fingerprinting and DNA sequences.Methods: Botanical identification of 30 batches of D. tangutici herba was conducted using the DNA barcoding approach, specifically analyzing the ITS and rbcL sequences. HPLC fingerprints of Tibetan Dracocephali tangutici Herba were established. The quality of 30 batches of D. tangutici herba was comprehensively evaluated using principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS‐DA), and entropy weighting method (EWM) combined with grey relation analysis (GRA).Results: The botanical provenance of all 30 batches of herbs was proven to be Dracocephali tangutici Maxim. using DNA barcoding techniques, namely, ITS sequence and rbcL sequence testing. A total of 17 common peaks were chosen from the HPLC fingerprinting analysis. Among these, three peaks were recognized by comparing them with three reference standards: chlorogenic acid, cryptochlorogenic acid, and salvianolic acid B. The similarity scores of the 30 batches of D. tangutici herba varied between 0.846 and 0.991. The 30 batches of samples were categorized into two groups using PCA. The findings from OPLS‐DA indicated that chlorogenic acid and four flavonoids could be the crucial components for evaluating the quality of D. tangutici herba. Additionally, the combined evaluation results of EWM and GRA suggested that the quality of the 30 batches of samples varied significantly.Conclusion: The results of this study can provide a reference basis for the development of quality standards for D. tangutici herba in Tibet.

Introduction: Citri Sarcodactylis Fructus has the effects of relieving cough, removing phlegm, and reducing asthma, but little is known about the metabolic and distribution of its chemical constituents in vivo. Therefore, it is necessary to study the metabolism of Citri Sarcodactylis Fructus in vivo.Objective: We aimed to (1) analyze the distribution of prototype compounds and metabolites of the chemical constituents of Citri Sarcodactylis Fructus in rat and (2) infer the metabolites and metabolic pathways of the chemical constituents.Materials and methods: A C₁₈ column (3 × 100 mm, 2.6 μm) was used. The mobile phase was water containing 0.1% formic acid (eluent A) and acetonitrile containing 0.1% formic acid (eluent B) at a discharge rate of 0.3 mL/min. Mass spectra of biological samples were collected in electrospray ionization (ESI) positive ion mode in the m/z 100–1500 scan range. The obtained biological samples were then subjected to chemical analysis, including plasma, urine, feces, and heart, liver, spleen, lungs, kidneys, stomach, and small intestine tissues. Prototype compounds and metabolites were identified.Results: In all, 40 prototype compounds and 78 metabolites, including 26 phase I metabolites and 52 phase II metabolites, were identified using UHPLC–Q/Orbitrap HRMS. Eight possible metabolic pathways (reduction, hydrolysis, dehydration, methylation, hydroxylation, sulfation, glucuronidation, and demethylation) were proposed. The prototype compounds were predominantly distributed in lung tissues. The metabolites were mainly distributed in plasma and kidney tissues.Conclusion: We systematically investigated the metabolites of Citri Sarcodactylis Fructus in vivo. We suggest metabolic pathways that might be relevant for further metabolic studies and screening of active ingredients of Citrus Sarcodactylis Fructus in vivo.

Based on the structures of natural products streptochlorin and pimprinine derived from marine or soil microorganisms, a series of streptochlorin derivatives containing the nitrile group were designed and synthesized through acylation and oxidative annulation. Evaluation for antifungal activity showed that compound 3a could be regarded as the most promising candidate—it demonstrated over 85% growth inhibition against Botrytis cinerea, Gibberella zeae, and Colletotrichum lagenarium, as well as a broad antifungal spectrum in primary screening at the concentration of 50 μg/mL. The SAR study revealed that non-substituent or alkyl substituent at the 2-position of oxazole ring were favorable for antifungal activity, while aryl and monosubstituted aryl were detrimental to activity. Molecular docking models indicated that 3a formed hydrogen bonds and hydrophobic interactions with Leucyl-tRNA Synthetase, offering a perspective for the possible mechanism of action for antifungal activity of the target compounds.

Pimprinine and streptochlorin are indole alkaloids derived from marine or soil microorganisms. In our previous study, they were promising lead compounds due to their potent bioactivity in preventing many phytopathogens, but further structural modifications are required to improve their antifungal activity. In this study, pimprinine and streptochlorin were used as parent structures with the combination strategy of their structural features. Three series of target compounds were designed and synthesized. Subsequent evaluation for antifungal activity against six common phytopathogenic fungi showed that some of thee compounds possessed excellent effects, and this is highlighted by compounds 4a and 5a, displaying 99.9% growth inhibition against Gibberella zeae and Alternaria Leaf Spot under 50 μg/mL, respectively. EC₅₀ values indicated that compounds 4a, 5a, 8c, and 8d were even more active than Azoxystrobin and Boscalid. SAR analysis revealed the relationship between 5-(3′-indolyl)oxazole scaffold and antifungal activity, which provides useful insight into the development of new target molecules. Molecular docking models indicate that compound 4a binds with leucyl-tRNA synthetase in a similar mode as AN2690, offering a perspective on the mode of action for the study of its antifungal activity. These results suggest that compounds 4a and 5a could be regarded as novel and promising antifungal agents against phytopathogens due to their valuable potency.

Citrus, a raw material widely used in food and medicine, is susceptible to fungal infection and its metabolites during growth, transportation, and storage. Thus, monitoring the residual levels of various mycotoxins in Citrus traditional Chinese medicines and related products is crucial. This study described a simple, reliable, and sensitive method for simultaneous identification and quantification of 30 mycotoxins in Citrus products. The method is based on modified quick, easy, cheap, effective, rugged, and safe extraction and purification followed by ultra‐high‐performance liquid chromatography–quadrupole/orbitrap high‐resolution mass spectrometry. The limit of detection ranged from 0.10 to 1.50 μg/kg, and the quantification ranged from 0.25 to 5.00 μg/kg. The recoveries at three spiked levels were 64.90–99.72% and the relative standard deviation was less than 12%. The method was applied to 55 Citrus samples. The detection rates of tentoxin and mycophenolic acid were the highest, reaching 22.7% and with concentration ranges of 0.33–1.03 and 0.57–2.09 μg/kg, respectively. All contamination levels were below the maximum residue limits recommended by the European Commission and China. These results could be used to establish guidelines for screening mycotoxins in Citrus products and the limits of acceptable levels.

Introduction: Citri Sarcodactylis Fructus (CSF) is widely used as a food ingredient and a traditional Chinese medicine. In China, CSF is cultivated in many places, including Sichuan, Guangdong, Zhejiang, and Fujian provinces. The types and chemical contents of CSF from different origins may vary greatly due to the difference in climate and environmental conditions. Therefore, comparing the chemical composition of CSF from various places is vital.Objective: To rapidly select potential characteristic compounds for differentiating CSF from different origins.Material and methods: Thirty‐one batches of CSF samples from different regions were analysed using ultra‐performance liquid chromatography with hybrid quadrupole‐orbitrap high‐resolution mass spectrometry. Thereafter, chemometric methods, including principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS‐DA), were employed to find differential metabolites among the CSF samples from various origins.Results: PCA revealed 77.9% of the total variance and divided all CSF samples into three categories corresponding to their origins. OPLS‐DA displayed better discrimination of CSF from different sources, with R²X, R²Y, and Q² of 0.801, 0.985, and 0.849, respectively. Finally, 203 differential metabolites were obtained from CSF from different origins using the variable importance in projection of the OPLS‐DA model, 30 of which were identified, and five coumarin compounds were selected as marker compounds discriminating CSF from different origins.Conclusion: This work provides a practical strategy for classifying CSF from different origins and offers a research foundation for the quality control of CSF.