Synthesis of Asp-based lactam cyclic peptides using an amide-bonded diaminodiacid to prevent aspartimide formation.

Asp-based lactam cyclic peptides are considered promising drug candidates. However, using Fmoc solid-phase peptide synthesis (Fmoc-SPPS) for these peptides also causes aspartimide formation, resulting in low yields or even failure to obtain the target peptides. Here, we developed a diaminodiacid containing an amide bond as a β-carboxyl-protecting group for Asp to avoid aspartimide formation.

Comparison of inhibitory effects and mechanisms of lactonic sophorolipid on different pathogenic bacteria.

Crude sophorolipids (SLs) have been proven to perform varying degrees of inhibitory effects on different pathogenic bacteria. However, systematic comparative studies of pure lactonic sophorolipid (LSL) among different types of bacteria are few. In this study, the antibacterial effects and mechanisms of LSL on pathogenic bacteria of , sp.

Chemoselective tandem S2'/S2''/inter- or intramolecular Diels-Alder reaction of γ-vinyl MBH carbonates with phenols and -hydroxychalcones.

An unprecedented consecutive S2'/S2'' addition of phenol to γ-vinyl MBH carbonate forms a reactive diene intermediate, followed by a dimerization/elimination process to give functionalized exocyclohexenes with excellent chemoselectivity. When using -hydroxychalcones as pronucleophiles, an S2'/S2''/intramolecular Diels-Alder reaction sequence occurs, selectively producing a series of pharmaceutically intriguing tricyclic chromane derivatives with good diastereoselectivity. The good nucleophilicity and fair nucleofugicity exhibited by phenoxy anion play a pivotal role in the S2'' addition step.

Degradation and Transformation of Lignin by a Fungus Strain F-1.

Background: Lignin is the largest natural aromatic polymer in nature and is also a unique aromatic-based biopolymer, accounting for nearly 30% of the earth's organic carbon. Generally, lignin is regarded as waste and is mainly used as a low- value fuel that is burned to generate heat and energy to solve the problem of biomass waste; for this obstacle of lignin, highly efficient biodegradation plays a critical role in developing an environmentally friendly technique for lignin biotransformation.

Objectives: This study intends to isolate and purify several microbial strains from nature.

The complete chloroplast genome sequence of Red Asparagus Lettuce ( var. L. ) (Asteraceae), endemic to China.

Red Asparagus Lettuce ( var. L. ) is an endemic vegetable species to China.

P(NMe) mediated cyclopropanation of α-methylene-β-lactams for rapid syntheses of spirocyclopropyl β-lactams.

An expedient cyclopropanation of α-methylene-β-lactams with α-ketoesters mediated by P(NMe2)3 has been developed. This reaction enables rapid access to a series of functionalized spirocyclopropyl β-lactams in good yields from bench-stable starting materials under mild conditions. The experimental results indicated that the C3-substituent of the α-methylene-β-lactam not only significantly impacted the reaction efficiency and stereochemistry but also played a pivotal role in determining the chemoselectivity of the reaction.

Mutant breeding of Starmerella bombicola by atmospheric and room-temperature plasma (ARTP) for improved production of specific or total sophorolipids.

To enhance specific or total sophorolipids (SLs) production by Starmerella bombicola for specific application, mutant library consisting of 106 mutants from 7 batches was constructed via atmospheric and room-temperature plasma (ARTP). When compared to the wild strain, 11, 36 and 12 mutants performed increases over 30% in lactonic, acidic or total SLs production. Genetic stability investigation showed that 8, 7, and 4 mutants could maintain the improved SLs production capacity.

Revealing differences in metabolic flux distributions between a mutant strain and its parent strain Gluconacetobacter xylinus CGMCC 2955.

A better understanding of metabolic fluxes is important for manipulating microbial metabolism toward desired end products, or away from undesirable by-products. A mutant strain, Gluconacetobacter xylinus AX2-16, was obtained by combined chemical mutation of the parent strain (G. xylinus CGMCC 2955) using DEC (diethyl sulfate) and LiCl.

One-step fermentation of pretreated rice straw producing microbial oil by a novel strain of Mortierella elongata PFY.

A fungus strain producing microbial oils utilizing pretreated rice straw was isolated from soil. This strain was identified as Mortierella elongata PFY based on the morphology and internal transcribed spacer sequence. Using pretreated rice straw as substrate, the average yield of total lipids was 7.

The co-transduction of Nurr1 and Brn4 genes induces the differentiation of neural stem cells into dopaminergic neurons.

Fetal brain tissue can be used in cell replacement therapy for PD (Parkinson's disease), but there is a poor donor supply of this tissue. NSCs (neural stem cells) may overcome this problem as they can be isolated and expanded in vitro. However, the usage of NSCs is limited because the differentiation of NSCs into specific dopaminergic neurons has proven difficult.

Structure and saccharification of rice straw pretreated with sulfur trioxide micro-thermal explosion collaborative dilutes alkali.

In this paper, a sulfur trioxide collaborative dilutes alkali method has been developed to pre-treat rice straw and it has been studied that the pre-treated rice straw structure affected the saccharification of the rice straw hydrolyzed by cellulose enzymatic hydrolysis. The results show that the reaction of the sulfur trioxide with rice straw resulted in the internal micro-thermal explosion, and the saccharification rate was 91% based on the pretreated rice straw with sulfur trioxide for 4h following 1% w/v NaOH treatment for 7h at 50°C.

Effects of Brn-4 on the neuronal differentiation of neural stem cells derived from rat midbrain.

NSCs (neural stem cells) provide a powerful research tool for the design and discovery of new approaches to cell replacement therapy during brain repair. However, the usefulness of this tool has been particularly obstructed by limited neuronal differentiation of NSCs. Brn-4, a member of the POU domain family of transcription factors, has been previously implicated in the development of neurons by expression analysis.

[Effect of blocking transforming growth factor beta signalling on culture-activated rat hepatic stellate cells].

Objective: To study the effects of blocking transforming growth factor beta (TGF-beta) signalling on culture-activated rat hepatic stellate cells (HSCs).

Methods: After cultured in plastic dish for two days, HSCs were infected with adenovirus vector AdT beta-ExR or AdLacZ (control) at 10 multiplicity of infection (MOI) and incubated for four days. The expression of type I collagen, alpha-smooth muscle actin (alpha-SMA) and the proliferation of HSCs were analyzed by ELISA, western blot, immunocytochemistry and BrdU uptake respectively.