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Juvenile hormone (JH) plays important roles in almost every aspect of insect development and reproduction. JHs are a group of acyclic sesquiterpenoids, and their farnesol backbone has been chemically modified to generate a homologous series of hormones in some insect lineages. JH III (methyl farnesoate, 10,11-epoxide) is the most common JH in insects, but Lepidoptera (butterflies and moths) and ‘higher’ Diptera (suborder: Brachycera; flies) have developed their own unique JHs. Although JH was first proposed in the hemipteran suborder Heteroptera (true bugs), the chemical identity of the heteropteran JH was only recently determined. Furthermore, recent studies revealed the presence of a novel JH, JH III skipped bisepoxide (JHSB3), in some heteropterans, but its taxonomic distribution remains largely unknown. In the present study, we investigated JHSB3 production in 31 heteropteran species, covering almost all heteropteran lineages, through ultra-performance liquid chromatography coupled with tandem mass spectrometry. We found that all of the focal species produced JHSB3, indicating that JHSB3 is widespread in heteropteran bugs and the evolutionary occurrence of JHSB3 ascends to the common ancestor of Heteroptera.

Background: Macroscopic identification has been widely used as a convenient method for herbal authentication and quality assessment. However, sensory evaluation heavily relied on personal experience and lacked enough evidence-based validations.Purpose: We aim to reveal the correlation between macroscopic characteristics and tissue-specific chemical composition of the root of Salvia miltiorrhiza (SMR), and then develop a rapid method for quality assessment.Methods: Thirty-two batches of SMR were collected and evaluated. The outer-surface color and diameter as the representative tissue features of SMR were selected as the macroscopic indexes. SMR were then divided into three parts along transverse section as outer bark, middle part and central part, to explore the spatial distribution of chemicals. Outer-surface color information was converted into RGB values, while the diameter data were expressed by mean distance, respectively. Thirteen major components including eight salvianolic acids and five tanshinones in each part were determined by liquid chromatography tandem mass spectrometry. Finally, several mathematical models were established and optimized to evaluate the correlation between outer-surface color, size and chemical distribution.Result: All five tanshinones mainly distributed in the outer bark while salvianolic acids were averagely existed among three parts. Correlational studies revealed that the surface color depth was significantly and positively correlated with tanshinone contents in the outer bark, while the size showed poor correlation in any chemicals. A color-oriented model was thus developed for the prediction of tanshinone contents in SMR, and a 9 × 9 standard color chart was created for easily use.Conclusion: This study contributes an alternative method for macroscopic features-based quality evaluation of herbs, and also complements some scientific data for traditional knowledge. [ABSTRACT FROM AUTHOR]

In this study, we aimed to establish a method for determination of multiple mycotoxins such as aflatoxins, ochratoxin A, and zearalenone in red pepper powder samples based on the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach for extraction and cleanup, with detection and quantification by high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in both positive- and negative-ion modes. The developed LC-MS/MS analytical method was compared with an enzyme-linked immunosorbent assay (ELISA) to improve the reliability of our developed method. The linearity, precision, and accuracy were validated for the LC-MS/MS methods. The results obtained with the LC-MS/MS were linear, with a correlation coefficient (R2) of >0.998. The limits of detection and quantification for mycotoxins were 0.07 to 0.71 μg/kg and 0.20 to 1.81 μg/kg, respectively. Intra- and interday precision tests (expressed as the relative standard deviation) for each analyte were 1.58 to 5.97% and 0.97 to 9.01%, respectively. Average recoveries were 85.70 to 94.99%. The validation results for the ELISA were linear (R2 > 0.995), and recoveries were 77.13 to 93.93%. Both analytical methods were applied to determine the presence of mycotoxins in commercial red pepper powder samples from South Korea. Four of the total 56 samples were contaminated with aflatoxins, and 6 samples were contaminated with ochratoxin A; these results were consistent for the two methods (P > 0.05). Therefore, our developed LC-MS/MS with QuEChERS approach for determination of multiple mycotoxins may be useful for controlling the quality and safety of red pepper powder. [ABSTRACT FROM AUTHOR]

Abstract: A sensitive and effective method for the simultaneous quantitative determination of pyrethrin residues in teas was developed and validated using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC–MS/MS). The six major constituents of the pyrethrins (pyrethrin I and II, jasmolin I and II, and cinerin I and II) were successfully separated and independently confirmed in a single run within approximately 5min. The multi-residue analysis of pyrethrins in teas involved simply extraction with acetonitrile, clean-up using a multilayer solid phase extraction cartridge, and subsequent separation by a hydrophilic end-capped Aquasil C18 columns with detection by tandem mass spectrometry using an electrospray ionization source in positive mode (ESI+). Recovery studies were carried out at three spiked levels (0.05, 0.1, 0.5mgkg−1). The overall average recoveries using this method in green teas and black teas at the three concentration levels ranged from 76.15% to 101.86% with relative standard deviations (RSDs) in the range of 2.71–12.93% (n =5) for all analytes. The limits of detections (LODs) were below 0.009mgkg−1, which were lower than the maximum residue limits (MRLs) of 0.5mgkg−1 in tea samples established by the European Union legislations in 2008, while the limits of quantification (LOQ) did not exceed 0.03mgkg−1. This study provides a theoretical basis for China to draw up MRLs for pyrethrins in teas. [ABSTRACT FROM AUTHOR]