Two new quinolinone glycoalkaloids from <i>Chrysanthemum indicum</i> L. and their antimicrobial activity

Phytochemical investigation of Chrysanthemum indicum L. yielded two new quinolinone glycoalkaloids named as Chrysanthemumsides A-B (1-2). The structures of the new compounds were elucidated by analysis of their 1D- and 2D-NMR, HRESIMS and ECD calculations. Compounds 1-4 were evaluated for antimicrobial activity against the Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans, and the data showed that compound 2 had significant antimicrobial effects (MIC 3.9 to 7.8 μg/mL).</p

In Situ Oral Metabolism Analysis of Astringent Compounds in Tea by Paper Spray Mass Spectrometry, Electrospray Mass Spectrometry, Turbidimetry, and Sensory Evaluation

The phenolic compounds (PCs) are the primary components responsible for the astringency of tea infusions, and this astringency is intricately linked to the in situ oral metabolism of PCs in saliva. Initially, a total of 54 PCs were identified in tea infusions by electrospray mass spectrometry (ESI-MS). Subsequently, an in vivo metabolism analysis of PCs during varying drinking times and oral locations was conducted by both paper spray mass spectrometry (PS-MS) and sensory evaluation. The metabolism of PCs within oral saliva was a prolonged process, the residual PCs were distributed across diverse oral regions after drinking tea infusion, and the higher residual PC content reflected the stronger astringency intensity. Furthermore, an in vitro metabolism analysis of PCs under varied reaction temperatures and durations was performed by ESI-MS and turbidimetry. As the reaction time extended, more PCs in tea was interacting with saliva. Moreover, the higher temperatures facilitated this interaction between PCs and saliva. Therefore, this investigation establishes a foundation for further elucidating the mechanisms underlying astringency formation

Plant Uptake and Metabolism of 2,4-Dibromophenol in Carrot: In Vitro Enzymatic Direct Conjugation

Plants can extensively uptake organic contaminants from soil and subsequently transform them into various products. Those compounds containing hydroxyl may undergo direct conjugation with endogenous biomolecules in plants, and potentially be preserved as conjugates, thus enabling overlooked risk via consumptions of food crops. In this study, we evaluated the uptake and metabolism of 2,4-dibromophenol (DBP) by both carrot cells and whole plant. DBP was completely removed from cell cultures with a half-life of 10.8 h. Four saccharide conjugates, three amino acid conjugates, and one phase I metabolite were identified via ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry analysis. The dibromophenol glucopyranoside (glucose conjugate) was quantitated by synthesized standard and accounted for 9.3% of the initial spiked DBP at the end of incubation. The activity of glycosyltransferase was positively related to the production of 2,4-dibromophenol glucopyranoside (<i>p</i> = 0.02, <i>R</i>² = 0.86), implying the role of enzymatic catalysis involved in phase II metabolism

New discovery of a late Middle Pleistocene mammalian fauna in Ganxian Cave, Southern China

This report describes fossils recovered from Ganxian Cave in 2008 and 2018 by the Natural History Museum and Anthropology Museum of Guangxi. The cave sedimentary fill yielded rich mammalian fossils consisting mainly of isolated teeth of medium- to large-sized mammals (Primates, Proboscidea, Perissodactyla, Carnivora, Rodentia, Artiodactyla) of typical ‘Ailuropoda-Stegodon’ fauna, (e.g. Stegodon orientalis, Ailuropoda baconi, Pongo weidenreichi, Tapirus sinensis, Megatapirus augustus, Crocuta ultima), and more numerous extant species belonging to 28 taxa in total. The biochronological age of the fauna agreed with the age estimates obtained using Uranium–series and coupled ESR/U-series dating. Collectively, these results indicate a Ganxian fossil age range of 168.9 ± 2.4 ka to 362 ± 78 ka and establish Ganxian Cave as one of the most precisely dated Middle Pleistocene fossil sites in southern China. Comparison of Ganxian fauna with Pleistocene fossil records of the well-documented faunas of southern China and southeast Asia indicates that the Asian elephant (Elephas maximus) probably first appeared in Ganxian Cave. Paleoenvironmental reconstruction-based analysis of the large mammalian fossil assemblage from Ganxian Cave indicates that during the late Middle Pleistocene, the habitat consisted mainly of forests with some open areas and the climate was warm and humid.</p

Phylogenetic clone analysis of 24 tigecycline-resistant isolates

<p>. These isolates were divided into 9 clonal groups (group A to I).</p

Relationship between <i>acrB</i> expression levels and tigecycline MICs.

<p>Relationship between <i>acrB</i> expression levels and tigecycline MICs.</p

Tigecycline MIC distribution for 215 KPC-producing <i>K</i>. <i>pneumoniae</i> clinical isolates.

<p>Tigecycline MIC distribution for 215 KPC-producing <i>K</i>. <i>pneumoniae</i> clinical isolates.</p

Newborn cell migration and differentiation in the developing HVC.

<p>A and B: Migration of BrdU-labeled cells along vimentin-immunoreactive radial glia fibers in the male (A) and female (B) after culture for seven days <i>in vitro</i> (7 DIV). C: Comparison of the number of BrdU-labeled cells along radial glia fibers per mm² within the developing HVC between the two sexes. D and E: Cells double-labeled with BrdU and Hu in the developing HVC of male (D) and female (E). F: Comparison of the number of cells double-labeled with BrdU and Hu per mm² within the developing HVC between the two sexes. ** indicates <i>P</i><0.001. Scale bar = 100 µm (A and B), and 50 µm (D, E and two inserts in A, B).</p

Distribution of VEGF-positive cells in the HVC.

<p>A–H: VEGF-positive cells at 15 post-hatching days (P15, A–D) or at adulthood (E–H). I: Comparison of the number of VEGF-positive cells in the developing HVC between the two sexes at P15 and adult. Scale bar = 200 µm (A and B), 500 µm (E, F), and 100 µm (C, D, G, H).</p

Summary of the assumed action routes of estradiol/testosterone on cell proliferation, migration and differentiation in adult (right) and juvenile (left) HVC.

<p>The action routes in adult HVC are discussed in a previous report (Louissaint et al., 2002). Note that there are substantial differences in the resources (shown by dashed brown arrows) of BDNF (from endothelial cells or not) and estradiol/testosterone (from capillary or from autonomous synthesis in local brain), and their actions during sexual differentiation of song control nucleus (shown by green arrows) between adult and juvenile birds. Curved arrows indicate some proliferating cells. Abbreviations: AR, androgen receptor; ER, estrogen receptor; Hu, Hu protein; VEGF, vascular endothelial growth factor; BDNF, brain-derived neurotrophic factor.</p