Metabolic and Molecular Insights Into Nicotiana benthamiana Trichome Exudates: An Ammunition Depot for Plant Resistance Against Insect Pests.

Nicotiana benthamiana, a widely acknowledged laboratory model plant for molecular studies, exhibits lethality to certain insect pests and can serve as a dead-end trap plant for pest control in the field. However, the underlying mechanism of N. benthamiana's resistance against insects remains unknown. Here, we elucidate that the lethal effect of N. benthamiana on the whitefly Bemisia tabaci arises from the toxic glandular trichome exudates. By comparing the metabolite profiles of trichome exudates, we found that 51 metabolites, including five O-acyl sugars (O-AS) with medium-chain acyl moieties, were highly accumulated in N. benthamiana. Silencing of two O-AS biosynthesis genes, branched-chain keto acid dehydrogenase (BCKD) and Isopropyl malate synthase-C (IPMS-C), significantly reduced the O-AS levels in N. benthamiana and its resistance against whiteflies. Additionally, we demonstrated that the higher expression levels of BCKD and IPMS-C in the trichomes of N. benthamiana contribute to O-AS synthesis and consequently enhance whitefly resistance. Furthermore, overexpression of NbBCKD and NbIPMS-C genes in the cultivated tobacco Nicotiana tabacum enhanced its resistance to whiteflies. Our study revealed the metabolic and molecular mechanisms underlying the lethal effect of N. benthamiana on whiteflies and presents a promising avenue for improving whitefly resistance.

Unlocking the Siderophore Biosynthesis Pathway and Its Biological Functions in the Fungal Insect Pathogen Beauveria bassiana.

Siderophores are small molecule iron chelators. The entomopathogenic fungus Beauveria bassiana produces a plethora of siderophores under iron-limiting conditions. In this study, a siderophore biosynthesis pathway, akin to the general pathway observed in filamentous fungi, was revealed in B. bassiana. Among the siderophore biosynthesis genes (SID), BbSidA was required for the production of most siderophores, and the SidC and SidD biosynthesis gene clusters were indispensable for the production of ferricrocin and fusarinine C, respectively. Biosynthesis genes play various roles in siderophore production, vegetative growth, stress resistance, development, and virulence, in which BbSidA plays the most important role. Accordingly, B. bassiana employs a cocktail of siderophores for iron metabolism, which is essential for fungal physiology and host interactions. This study provides the initial network for the genetic modification of siderophore biosynthesis, which not only aims to improve the efficacy of biocontrol agents but also ensures the efficient production of siderophores.

New metabolites from the marine-derived bacterium Pseudomonas sp. ZZ820R.

Six previously undescribed compounds, named monaxanthones A and B, monaphenol A, monathioamide A, monaprenylindole A, and monavalerolactone A, were isolated from the culture of a marine-sourced bacterium Pseudomonas sp. ZZ820R in rice medium. Their structures were elucidated based on the HRESIMS data, NMR and MS-MS spectroscopic analyses, optical rotation and ECD calculations. Monathioamide A is an unprecedented sulfur-contained compound and monavalerolactone A represents the first example of this type of natural products. Monaprenylindole A showed antibacterial activity against methicillin-resistant Staphylococcus aureus.

Bioactive Penicipyrrodiether A, an Adduct of GKK1032 Analogue and Phenol A Derivative, from a Marine-Sourced Fungus Penicillium sp. ZZ380.

Penicipyrrodiether A, an adduct of GKK1032 analogue and phenol A derivative, was isolated from a culture of marine-associated fungus Penicillium sp. ZZ380 and represents the first example of this type of fungal metabolite. Its structure was elucidated by extensive spectroscopic analyses, including 1D- and 2D-NMR, HRESIMS, MS/MS, and electronic circular dichroism calculation as well as single-crystal X-ray diffraction. Penicipyrrodiether A showed antibacterial activity in inhibiting the growth of methicillin-resistant Staphylococcus aureus with a MIC value of 5.0 µg/mL. Its plausible pathway for biosynthesis has been proposed.

[Identification of phenylpropanoids in ciwujia injection by HPLC-MS].

There are reports about the chemical compounds of Ciwujia herbs, but with no study report about the chemical material basis of Ciwujia injection (CWJI). In this study, LC-MS(n) and LC-Q-TOF-MS techniques were adopted for a qualitative analysis on phenylpropanoids in CWJI. The Ultmate XB-C18 column (4.6 mm x 250 mm, 5 microm) was adopted and eluted with the mobile phase of 0.5% formic acid-water and acetonitrile, with the flow rate at 0.8 mL x min(-1) and the column temperature at 20 degrees C. Based on the data of high-resolution and multi-stage MS, control products and literatures, altogether 54 phenylpropanoids were identified in Ciwujia Injection, including 34 phenylpropanoids, 16 ligans and 4 coumarins. Among them, 28 were reported for the first time in Ciwujia, and 14 compound structures were identified in comparison with the control products. The method established in this study could be used to simply and rapidly identify phenylpropanoids in CWJI. The findings provide scientific data for defining the chemical material basis of CWJI.

Divergent kinetic and thermodynamic hydration of a porous Cu(II) coordination polymer with exclusive CO2 sorption selectivity.

Selective adsorption and separation of CO2 are of great importance for different target applications. Metal-organic frameworks (MOFs) represent a promising class of porous materials for this purpose. Here we present a unique MOF material, [Cu(tba)2]n (tba = 4-(1H-1,2,4-triazol-1-yl)benzoate), which shows high CO2 adsorption selectivity over CH4/H2/O2/Ar/N2 gases (with IAST selectivity of 41-68 at 273 K and 33-51 at 293 K). By using a critical point dryer, the CO2 molecules can be well sealed in the 1D channels of [Cu(tba)2]n to allow a single-crystal X-ray analysis, which reveals the presence of not only C(δ+)-H···O(δ-) bonds between the host framework and CO2 but also quadrupole-quadrupole (CO2(δ-)···(δ+)CO2) interactions between the CO2 molecules. Furthermore, [Cu(tba)2]n will suffer divergent kinetic and thermodynamic hydration processes to form its isostructural hydrate {[Cu(tba)2](H2O)}n and a mononuclear complex [Cu(tba)2(H2O)4] via single-crystal to single-crystal transformations.

[Study on rapid screening and identifying hepatotoxic compounds in toosendan fructus].

Fluorescein diacetate-labeled HepG2 cells model and flouresence automatic microscopy screening assay were used for fast screening 23 components from Toosendan Fructus, in which 5 components showed significant toxicity on HepG2 cells. The 10 compounds in the 2 components were tentatively identified with LC-MS(n), and 3 of them (meliasenin B, trichilinin D and 1-O-tigloy-1-O-debenzoylohchinal) were prepared and identified. Further experiments showed that the 3 compounds displayed dose-dependent toxicity on HepG2 cells, suggesting that these compounds in Toosendan Fructus may cause hepatotoxicity.

[Determination of salvianolic acid B and paeoniflorin in Shuangdan granules by HPLC].

OBJECTIVE: To develop a method for the determination of salvianolic acid B and paeoniflorin in Shuangdan granules. METHOD: The chromatographic separation was performed on a Zorbax SB C18 column with a linear gradient elution of phosphoric acid-water (0.05:100) and phosphoric acid-acetonitrile-methanol (0.05:4:96) was used. The flow rate was 1 mL x min(-1) and column temperature was set at 25 degrees C. The UV detection wavelength was set at 230 nm. RESULT: The linear ranger was of 0.710-22.7 microg for salvianolic acid B and 0.103-3.30 microg for paeoniflorin. Three batches of Shuangdan granules were analyzed, and the content of salvianolic acid B ranged from 6.46-11.6 mg x g(-1) and paeoniflorin ranged from 1.44-1.78 mg x g(-1). CONCLUSION: The method was accurate, reproducible, reliable, and could be used for quantitative control of Shuangdan granules.

Quality evaluation of cortex moutan by high performance liquid chromatography coupled with diode array detector and electrospary ionization tandem mass spectrometry.

An high performance liquid chromatography (HPLC) coupled with diode array detector (DAD) and electrospray ionization tandem mass spectrometry (ESI/MS(n)) method was developed for quality evaluation of Cortex Moutan through identification of common constituents based on chromatographic fingerprints and determination of key pharmacological compounds. The representative chromatographic fingerprints of Cortex Moutan were obtained by analyzing 10 batches of samples under the optimized HPLC conditions and the results showed that the chromatographic profiles of the analyzed samples were very similar. Total of nineteen common peaks were detected and seventeen of them were identified rapidly by their characteristic UV profile and the information of molecular structure provided by ESI/MS(n) experiments. Simultaneously, five key pharmacological compounds, namely gallic acid, oxypaeoniflorin, paeoniflorin, benzoylpaeoniflorin and paeonol, were determined by the validated HPLC-DAD method. The linear calibration curves were acquired with correlation coefficients higher than 0.999. The precisions of intra-day and inter-day were not exceeding 3.1%, and the recoveries of five analytes were from 92.86 to 99.35%. This developed method that combined the chromatographic fingerprints and quantification assay ensured the phytoequivalence and pharmacological effects of Cortex Moutan and was successfully applied to the quality control of Cortex Moutan.