The Expression Profile of Genes Related to Carotenoid Biosynthesis in Pepper Under Abiotic Stress Reveals a Positive Correlation with Plant Tolerance.

In light of the increasingly adverse environmental conditions and the concomitant challenges to the survival of important crops, there is a pressing need to enhance the resilience of pepper seedlings to extreme weather. Carotenoid plays an important role in plants' resistance to abiotic stress. Nevertheless, the relationship between carotenoid biosynthesis and sweet pepper seedlings' resistance to different abiotic stresses remains uncertain.

Asymmetric Construction of Chiral 2-Azetines and Axially Chiral Tetrasubstituted Allenes Via Phosphine Catalysis.

Chiral 2-azetines and allenes are highly valuable structural units in natural products and useful chemicals. However, enantioselective synthesis of both 2-azetines and allenes has been extremely challenging. Herein, we present asymmetric construction of chiral 2-azetines (70-98 % yields and up to 96 % ee) through chiral phosphine-catalyzed [2+2] annulation of yne-enones with sulfamate-derived cyclic imines.

Catalyst-Free α--Selective Hydroboration and ()-Selective Deuterated Semihydrogenation of Alkynyl Sulfones.

Here, we present a straightforward α--selective hydroboration of alkynyl sulfones with NHC-boranes without the need for a catalyst. This reaction is compatible with a wide range of substrates for efficiently producing structurally diverse α-borylated vinyl sulfones in satisfactory yields. The hydride transfer from NHC-borane to alkynyl triflone is studied by density functional theory (DFT) calculations for -hydroboration.

A chromosome-scale genome provides new insights into the typical carotenoid biosynthesis in the important red yeast Rhodotorula glutinis QYH-2023 with anti-inflammatory effects.

Rhodotorula spp. has been studied as one powerful source for a novel cell factory with fast growth and its high added-value biomolecules. However, its inadequate genome and genomic annotation have hindered its widespread use in cosmetics and food industries.

Syntheses of Tetracyclic Indoline Derivatives Via Gold(I)-Catalyzed Hydroamination/Cycloisomerization Cascade of 2-Ethynyltryptamides.

A gold(I)-catalyzed hydroamination/cycloisomerization cascade reaction was developed to yield indolizino[8,7-]indole and indolo[2,3-]-quinolizine derivatives from 2-ethynyltryptamides. The optimal conditions were determined by condition screening, and the functional group tolerances of these reactions were explored based on synthetic substrates. An insight into the explanation on the selectivity of the ring closure was obtained by density functional theory calculations.

Divergent Synthesis of Quinolines: Exploiting the Duality of Free Radicals.

Herein, we present a green scheme for the divergent synthesis of two polysubstituted quinolines from a singular substrate via exploiting free-radical duality. Photocatalytically generated imine radicals produce 3,4-disubstituted quinolines via a novel rearrangement in the presence of an inorganic base. Alternatively, they react in the presence of an organic base to furnish 2,3-disubstituted quinolines.

Dual roles of nanocrystalline cellulose extracted from jute ( L.) leaves in resisting antibiotics and protecting probiotics.

Antibiotics can cure diseases caused by bacterial infections, but their widespread use can have some side effects, such as probiotic reduction. There is an urgent need for such agents that can not only alleviate the damage caused by antibiotics, but also maintain the balance of the gut microbiota. In this study, we first characterized the nanocrystalline cellulose (NCC) extracted from plant jute ( L.

Numerical analysis of dispersion characteristics of underwater gas-oil two-phase leakage process.

Fatigue failure, third-party destruction and internal corrosion may easily trigger gas and oil leakage during the operation of submarine multiphase pipelines. In order to analyze the underwater gas-oil plume development and migration law, a 3D model based on coupled Eulerian-Lagrangian numerical approach is proposed. The model is validated by laboratory experiment and the dynamic dispersion process of gas-oil plume in a large scale shallow sea environmental is further explored.

Gold(I)-Catalyzed Substitution-Controlled Syntheses of Spiro[indoline-3,3-pyrrolidine] and Spiro[indoline-3,3-piperidine] Derivatives.

Spiro[indoline-3,3-pyrrolidine] and spiro[indoline-3,3-piperidine] derivatives were synthesized in a substitution-controlled manner under the catalysis of cationic gold(I) species in the presence of Hantzsch ester (HEH). The optimal reaction condition was determined by screening, and the functional group tolerances of these two pathways were examined by readily synthetic substrates. The and selectivities of these cyclizations were elucidated by density functional theory calculations, and a plausible mechanism for these transformations was proposed.

Quantum Mechanical Prediction and Experimental Verification of Au(I)-Catalyzed Substitution-Controlled Syntheses of 1-Pyrido[4,3-]indole and Spiro[indoline-3,3'-pyridine] Derivatives.

Density functional theory calculations were applied to predict the pathways of gold(I)-catalyzed cycloisomerization of the indole substrates with 1,6-enynes, which were consistent with the ensuing experimental results. The substitution-controlled synthesis led to the formation of 1-pyrido[4,3-]indole and spiro[indoline-3,3'-pyridine] derivatives in a tunable way. The reactions had good functional group tolerances, and a possible mechanism was proposed based on the computational and experimental results.

An amphiphilic macrocyclic acylhydrazone dimer: Facile synthesis and dual channel detection and removal of phthalate anion.

Despite the large number of dicarboxylates' receptors, the dual channel ones capable of recognizing and removing of phthalate anion are rare and the task remains challenging. In this paper, a facilely synthesized amphiphilic macrocyclic acylhydrazone dimer (AMAD) can not only detect phthalate anion selectively, through both color changes and turn-on fluorescence in solution as well as in solid state, but is also able to remove it from either water or organic solvents. The current study paves the way for the search of more multiple functional receptors of dicarboxylates anions.

N-Embedded Cubarene: A Quadrangular Member of the Macrocycle Family.

Despite the large number of synthetic macrocycles, the cubarenes, the quadrangular-shaped macrocyclic arenes, remain less investigated, possibly due either to synthetic challenges or to the lack of suitable building blocks. In this paper, a N-embedded cubarene () is facilely synthesized by FeCl·6HO-catalyzed cyclization in dichloromethane. The endo cavity of can bury quaternary ammonium salts in an intramolecular manner, whereas the intermolecular interaction between its exo walls with Cu generates two-dimensional supramolecular tessellation.

Visible-Light-Initiated Sequential Trifluoromethylation/Remote C(sp)-H Alkynylation of Vinyl Azides by Radical Relay.

A visible-light-initiated trifluoromethylation/remote aliphatic C-H alkynylation of α-alkyl-substituted vinyl azides using acetylenic triflones as both the trifluoromethyl and alkyne donors is described. The reaction occurred under environmentally benign and radical initiator-free reaction conditions, affording γ-alkynylated trifluoromethyl ketone derivatives with a broad scope of substituents. Mechanistic studies suggested that the reaction is initiated a triplet-triplet energy transfer between the 4CzIPN catalyst and acetylenic triflone, followed by fragmentation to generate a trifluoromethyl radical and an alkynyl radical.

Computational insight into gold(I)-catalyzed intramolecular regioselectivity of tryptamine-ynamide cycloisomerizations.

The regioselectivity for gold(I)-catalyzed intramolecular cycloisomerizations of tryptamine-ynamides has long been elusive despite various synthetic examples of similar substrates being available. Computational studies were carried out to provide insight into the mechanisms and the origin of the substrate-dependent regioselectivity of these transformations. Based on the analyses of non-covalent interactions, distortion/interaction, and energy decomposition on the interactions between the terminal substituent of alkynes and the gold(I) catalytic ligand, the electrostatic effect was determined to be the key factor for α-position selectivity while the dispersion effect was determined to be the key factor for β-position selectivity.

Development of Rofecoxib-Based Fluorophores from ACQ to AIE by Positional Regioisomerization.

The development of aggregation-induced emission luminogens (AIEgens) has attracted increasing attention due to their potential applications in various areas in recent years. In this study, a facile conversion from aggregation-caused quenching (ACQ) to aggregation-induced emission (AIE) was achieved by an efficient regioisomerization strategy based on the rofecoxib scaffold. Two compounds, named PYR2 and PYR4, were identified as regioisomers of rofecoxib derivatives to show dramatically different fluorescent properties.

Ag(I)/PPh-catalyzed diastereoselective syntheses of spiro[indole-3,4'-piperidine] derivatives cycloisomerizations of tryptamine-ynamides.

A Ag(I)/PPh-catalyzed chelation-controlled cycloisomerization of tryptamine-ynamide was developed to access the spiro[indole-3,4'-piperidine] scaffold in a racemic and diastereoselective manner. The diastereoselective products were achieved by a chiron approach. Density functional theory (DFT) calculations indicated that strong non-covalent effects between the substrate and catalyst/ligand complex stabilized the spiroindoleninium intermediate cation-π-π interactions.

Achieving Molecular Fluorescent Conversion from Aggregation-Caused Quenching to Aggregation-Induced Emission by Positional Isomerization.

In this work, we synthesized a pair of positional isomers by attaching a small electron-donating pyrrolidinyl group at ortho- and para-positions of a conjugated core. These isomers exhibited totally different fluorescent properties. PDB2 exhibited obvious aggregation-induced emission properties.

Discovery of novel ID2 antagonists from pharmacophore-based virtual screening as potential therapeutics for glioma.

Glioma, especially the most aggressive type glioblastoma multiforme, is a malignant cancer of the central nervous system with a poor prognosis. Traditional treatments are mainly surgery combined with radiotherapy and chemotherapy, which is still far from satisfactory. Therefore, it is of great clinical significance to find new therapeutic agents.

Grafting Cucumber Onto Pumpkin Induced Early Stomatal Closure by Increasing ABA Sensitivity Under Salinity Conditions.

During early periods of salt stress, reduced stomatal opening can prevent water loss and wilting. Abscisic acid (ABA) signal plays an important role in this process. Here, we show that cucumber grafted onto pumpkin exhibits rapid stomatal closure, which helps plants to adapt to osmotic stress caused by salinity.

Root respiratory burst oxidase homologue-dependent H2O2 production confers salt tolerance on a grafted cucumber by controlling Na+ exclusion and stomatal closure.

Plant salt tolerance can be improved by grafting onto salt-tolerant rootstocks. However, the underlying signaling mechanisms behind this phenomenon remain largely unknown. To address this issue, we used a range of physiological and molecular techniques to study responses of self-grafted and pumpkin-grafted cucumber plants exposed to 75 mM NaCl stress.