Isolation and identification of the cis-abienol degrading strain Klebsiella oxytoca T2L and its aroma products.

Cis-abienol, a naturally occurring labdanum diterpenoid, is believed to be an essential precursor of ambergris substances and is found on the surface of many plants. In this study, the strain Klebsiella oxytoca T2L was isolated from the soil of oriental tobacco and demonstrated effective degradation of cis-abienol. The strain was identified through morphological characteristics and 16 S rDNA sequence analysis.

Biotransformation of tobacco-derived Z-abienol into precursors of ambrox by newly identified LSC-2.

Z-abienol is a labdane diterpene present in tobacco leaves and is a key precursor for producing valuable aroma compounds such as ambrox. This study aimed to identify and characterize a bacterial strain that can efficiently degrade Z-abienol through microbial fermentation. The strain LSC-2 isolated from fresh tobacco leaves was identified as based on its morphological features and 16S rDNA phylogenetic analysis.

Glucose Oxidase Promoting Cellulase-Assisted Hydrodistillation for the Extraction of Essential Oil From Eleutherococcus Senticosus.

Eleutherococcus senticosus essential oil (ESEO) has the function of clearing heat and detoxifying, delaying aging. The ESEO yield obtained by traditional extraction methods is low because essential oils are encased in plant cell structures and are difficult to extract. In this work, we adopted the method of glucose oxidase promoting cellulase-assisted hydrodistillation, and utilized the interaction of glucose oxidase and cellulase to promote the full destruction of cellulose in plant cells, resulting in a large amount of internal essential oil flowing out and improving the yield of ESEO.

Production of 1,4:3,6-dianhydro-α-d-glucopyranose from methyl 3,6-anhydro-α-d-glucopyranoside and its taste identification.

1,4:3,6-Dianhydro-α-d-glucopyranose (DGP) is one of important biomass pyrolysis anhydro sugar products that derive from the cellulose and hemicellulose components. There is no reliable method for the preparation of DGP at present, which contributed to its high cost with limited market supply and restricted applied research. In this study, we provided a novel method for the synthesis of DGP from methyl 3,6-anhydro-α-d-glucopyranoside for the first time.

Highly efficient multigram synthesis of 1,4:3,6-Dianhydro-α-D-glucopyranose by chemical synthesis methods: Development and scale-up study of synthetic routes.

A reliable chemical synthesis method for the preparation of 1,4:3,6-dianhydro-α-D-glucopyranose (DGP) has been developed on the first time, with an overall four-step yield of 20 % on a 200g scale. The method for 2-OH regioselective benzylation protection of Methyl α-d-glucopyranoside was systematically optimized, providing a more scalable and cost-effective approach. The 3,6-anhydro pyranose intermediate was obtained through a two-step one-pot process.

Pine Needle of Pinus koraiensis (Siebold & Zucc) Essential Oil Through Liquid Nitrogen Quick-Freezing Assisted Solvent-Free Microwave Extraction Process for Antibacterial Application.

Introduction: This study investigates the composition and antibacterial properties of essential oil extracted from Pinus koraiensis (Siebold & Zucc) pine needles using a liquid nitrogen freezing treatment combined with solvent-free microwave extraction (LNSFM).

Objective: The aim is to develop a low-energy, high-efficiency extraction method for conifer essential oils, analyze their chemical composition, and evaluate their antibacterial efficacy.

Methodology: Pine needle samples were frozen with liquid nitrogen and subsequently crushed.

Quality characterization of tobacco flavor and tobacco leaf position identification based on homemade electronic nose.

A set of nine unique tobacco extract samples was analyzed using a self-developed electronic nose (E-nose) system, a commercial E-nose, and gas chromatography-mass spectrometry (GC-MS). The evaluation employed principal component analysis, statistical quality control, and soft independent modeling of class analogies (SIMCA). These multifaceted statistical methods scrutinized the collected data.

Effect of Different Carbon Sources on Antioxidant Properties of Exopolysaccharides Produced by Scleroderma areolatum (Agaricomycetes).

Five kinds of exopolysaccharides (EPS) were obtained by fermentation of Scleroderma areolatum Ehrenb. with sucrose, glucose, maltose, lactose, and fructose as carbon sources. Antioxidant abilities of the obtained EPSs were evaluated by inhibiting AAPH, HO·, and glutathione (GS·) induced oxidation of DNA and quenching 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS· and galvinoxyl radicals.

Incorporating edible oil during cooking tailors the microstructure and quality features of brown rice following heat moisture treatment.

While brown rice (BR) has numerous nutritional properties, the consumption potential of which is seriously restricted since the poor cooking quality and undesirable flavor. Here, edible oils (pork lard and corn oil, 1-5 wt%) were incorporated during the cooking of BR following heat moisture treatment. Incorporating corn oil rather than lard significantly ameliorated the texture properties (e.

Including protein hydrolysates during thermal processing mitigates the starch digestion of resulted starch-based binary matrix.

Staple foods with starch and protein components are usually consumed after thermal processing. To date, how including protein hydrolysates (with varied hydrolysis degrees) tailors the structure and digestion features of starch-based matrix with thermal processing has not yet been sufficiently understood. Here, corn starch (CS), soy protein isolate (SPI), and soy protein isolate hydrolysates (SPIH) with different hydrolysis time (5-60 min) were used to prepare starch-based binary matrices.

Enrichment of resistant starch in starch-protein hydrolysate binary matrix by modulating pH during thermal processing.

Controlling the digestion features of starch-based food matrices following thermal processing plays vital roles in reducing risks of metabolic diseases such as obesity and type II diabetes. To date, it remains largely unclear how regulating the pH during thermal processing alters the microstructure and digestion features of starch-based matrix including protein hydrolysates. Considering this, corn starch (CS) and soybean protein isolate (SPI) (or its hydrolysates (SPIH)) were used to prepare thermally-processed CS-SPI and CS-SPIH binary matrices under different pH values (3 to 9), followed by inspection of changes in the structures and digestibility using combined methods.

Synthesis and Antioxidant Properties of Psoralen Derivatives.

Five psoralen derivatives were synthesized and the structures of them were characterized by H-NMR, C-NMR, and IR. The antioxidant properties of the compounds were tested by inhibiting the free radical-initiated DNA oxidation and scavenging the radical reaction. The results showed that the effective stoichiometric factors (n) of the compounds V and IV could reach 2.

Design, synthesis, and biological evaluation of pleuromutilin derivatives containing 1,2,4-triazole linker.

A series of thioether pleuromutilin derivatives containing 1,2,4-triazole on the side chain of C14 were designed and synthesized. The in vitro antibacterial activities experiments of the synthesized derivatives showed that compounds 72 and 73 displayed superior in vitro antibacterial effect against MRSA minimal inhibitory concentration (MIC = 0.0625 μg/mL) than tiamulin (MIC = 0.

Effects of Bacillus subtilis subsp. on the microbial community and aroma components of flue-cured tobacco leaves based on metagenome analysis.

To improve the sensory quality of aged flue-cured tobacco (FCT), Bacillus subtilis subsp, H11 was inoculated on aged FCT leaves named Pingdingshan DCFB. The metagenome and thecharacteristic aroma substances of aged FCT with different fermentation times (0 h, 12 h, 24 h, and 36 h) were systematically analyzed. The results showed that the content of aroma components and sensory quality of aged FCT were significantly improved when the strain was treated at 35 °C with 25% moisture for 24 h.

An efficient turn-on fluorescence chemosensor system for Zn(II) ions detection and imaging in mitochondria.

Mitochondria-targetable fluorescent chemosensors, Rhodamine-B and rhodamine 6G bearing syringaldehyde based receptors were designed and synthesized for efficient chemosensing of Zinc(II) ions. The probes showed the very selective naked eye color change to pink from colorless upon addition of Zinc(II) ions, further these probes showing turn-on fluorescence enhancement with Zn(II) ions by opening of rhodamine spirolactam. The probes are very sensitive towards Zn(II) ions among other ions.

Study on the Effect of Salt Solution on Durability of Basalt-Fiber-Reinforced Polymer Joints in High-Temperature Environment.

Due to the low price and good comprehensive properties, FRP composite material has become a new type of civil application material in recent years. In this paper, Araldite 2012 adhesive was used to bond basalt-fiber-reinforced polymer (BFRP), and the durability of its bonded joints was investigated. Experiments were carried out at 80 °C/DI water (deionized water), 80 °C/3.

Effect of hydroxyl on antioxidant properties of 2,3-dihydro-3,5-dihydroxy-6-methyl-4-pyran-4-one to scavenge free radicals.

It is well known that 2,3-dihydro-3,5-dihydroxy-6-methyl-4-pyran-4-one (DDMP) is usually formed in the Maillard reaction and it contributes to the antioxidant properties of Maillard reaction intermediates. A series of hydroxyl group protected DDMP derivatives were synthesized to further understand the source of antioxidant activity. Antioxidant abilities of the DDMP derivatives were evaluated by scavenging the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS˙), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively.

A click chemistry approach to pleuromutilin derivatives, evaluation of anti-MRSA activity and elucidation of binding mode by surface plasmon resonance and molecular docking.

Novel series of pleuromutilin analogs containing substituted 1,2,3-triazole moieties were designed, synthesised and assessed for their antibacterial activity against Methicillin-resistant (MRSA). Initially, the antibacterial activities of these derivatives against 4 strains of (MRSA ATCC 43300, ATCC 29213, AD3, and 144) were tested by the broth dilution method. Most of the synthesised pleuromutilin analogs displayed potent activities.

Novel isoindigo compound with aggregation-induced emission: Br-Br bonding joint restriction of intramolecular motion and cell imaging properties.

6,6'-Dibromided -butyloxycarbonyl isoindigo (Br-TBOCII) has intense fluorescence in the solid state excitation with aggregation-induced emission (AIE), contrary to the classic heavy-atom effect. The unique AIE mechanism is attributed to the Br-Br bonding joint restricting intramolecular motion. Furthermore, the water-soluble nanoparticles Br-TBOCII/Pluronic® 127, possess robust photostability, low toxicity and good cell imaging performance.

Adenosine triphosphate (ATP) and zinc(II) ions responsive pyrene based turn-on fluorescent probe and its application in live cell imaging.

A novel highly selective and sensitive turn-on fluorescent chemosensor PCE to recognize Zn has been developed. The sensor PCE displays a remarkable fluorescent enhancement at 456 nm (λ = 340 nm) with Zn without the interference of other biologically important relevant metal ions in aqueous acetonitrile solution. Job's plot and mass spectral studies divulge such the interaction of PCE by Zn was 1:1 binding stoichiometry.

Synthesis of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one from maltol and its taste identification.

2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) exists in many foods, and its effect on taste is controversial. The aim of this study was to clarify whether DDMP has bitter taste or not. For this purpose, DDMP was synthesized from maltol instead of from glucose for the first time.

Microbial community and metabolic function analysis of cigar tobacco leaves during fermentation.

Cigar tobacco leaves (CTLs) contain abundant bacteria and fungi that are vital to leaf quality during fermentation. In this study, artificial fermentation was used for the fermentation of CTLs since it was more controllable and efficient than natural aging. The bacterial and fungal community structure and composition in unfermented and fermented CTLs were determined to understand the effects of microbes on the characteristics of CTLs during artificial fermentation.

Regioselective C-H sulfenylation of -sulfonyl protected 7-azaindoles promoted by TBAI: a rapid synthesis of 3-thio-7-azaindoles.

This paper describes the regioselective C-3 sulfenylation of -sulfonyl protected 7-azaindoles with sulfonyl chlorides. In this transformation, dual roles of TBAI serving as both promoter and desulfonylation reagent have been demonstrated. The reaction proceeded smoothly under simple conditions to afford 3-thio-7-azaindoles in moderate to good yields with broad substrate scopes.