Butlerlauritzen7901
The use of low-intensity NIR light to operate molecular switches offers several potential advantages including enhanced penetration into bulk materials, in particular biological tissues, and reduced radiation damage due to the limited photon energies. The latter, however, pose a challenge for designing reasonably bistable systems. We have developed a general design strategy for direct one-photon NIR photoswitches based on negative photochromic dihydropyrenes carrying opposing strong donor-acceptor substituents either along the long axis of the molecule or across it. Thus, two series of 2,7- and 4,9-disubstituted dihydropyrenes were synthesized, and their photothermal properties investigated as a function of the type, strength, and position of the attached donor and acceptor substituents as well as the polarity of the environment. By shifting the excitation wavelength deep into the NIR, both NIR one-photon absorption cross-section and photoisomerization efficiency could be maximized while retaining a reasonable thermal stability of the metastable cyclophanediene isomer. Thus, the lowest optical transition was shifted beyond 900 nm, the NIR cross-section was enhanced by two orders of magnitude, and the thermal half-lives vary between milliseconds and hours. These unique features open up ample opportunities for noninvasive, optically addressable materials and material systems.Enterobacterial common antigen (ECA) is a surface glycolipid shared by all members of the Enterobacteriaceae family. In addition to lipopolysaccharides (LPS), ECA is an important component in the outer membrane (OM) of Gram-negative bacteria, making the OM an effective, selective barrier against the permeation of toxic molecules. Previous modeling and simulation studies represented OMs exclusively with LPS in the outer leaflet. In this work, various ECA molecules were first modeled and incorporated into symmetric bilayers with LPS in different ratios, and all-atom molecular dynamics simulations were conducted to investigate the properties of the mixed bilayers mimicking OM outer leaflets. Dynamic and flexible conformational ensembles are sampled for each ECA/LPS system. Incorporation of ECALPS (an LPS core-linked form) and ECAPG (a phosphatidylglycerol-linked form) affects lipid packing and ECA/LPS distributions on the bilayer surface. Hydrophobic thickness and chain order parameter analyses indicate that incorporation of ECAPG makes the acyl chains of LPS more flexible and disordered and thus increases the area per lipid of LPS. The calculated area per lipid of each ECA/LPS provides a good estimate for building more realistic OMs with different ratios of ECA/LPS, which will be useful in order to characterize their interactions with outer membrane proteins in more realistic OMs.The production, biochemical characterization, and carbohydrate specificity of LacA β-galactosidase (locus lp_3469) belonging to the glycoside hydrolase family 42 from the probiotic organism Lactobacillus plantarum WCFS1 are addressed. The β-d-galactosidase activity was maximal in the pH range of 4.0-7.0 and at 30-37 °C. click here High hydrolysis capacity toward the β(1 → 4) linkages between galactose and glucose (lactose) or fructose (lactulose) was found. High efficiency toward galactosyl derivative formation was observed when lactose and glycerol, xylitol, or erythritol were used. Galactosyl derivatives of xylitol were characterized for the first time as 3-O-β-d-galactopyranosyl-xylitol and 1-O-β-d-galactopyranosyl-xylitol, displaying high preference of LacA β-galactosidase for the transfer of galactosyl residues from lactose to the C1 or C3 hydroxyl group of xylitol. These results indicate the feasibility of using LacA β-galactosidase for the synthesis of different galactosyl-polyols, which could be promising candidates for beneficial and appealing functional and technological applications such as novel prebiotics or hypocaloric sweeteners.Ten of the 22 phthalate esters (PAEs) and five of the eight monoalkyl phthalates (MPEs) were detected in six types of porcine tissues of 16 pigs. The total concentrations of detected PAEs were 60.5-439.4 ng/g wet weight (ww). Dibutyl phthalate, the predominant PAE, was detected in all six types of porcine tissues (7.3-187.9 ng/g ww). The total concentrations of MPEs were 9.9-94.0 ng/g ww. Monobutyl phthalate (MBP) was the predominant MPE, with the highest concentration in porcine liver (55.1 ng/g ww). Levels of PAEs and MPEs were highest in the muscle and liver, respectively, indicating that these two classes of compounds have different distribution patterns in pigs. The concentrations of MBP and monoethyl phthalate were positively correlated with their corresponding parent compounds in the porcine liver (p less then 0.05), suggesting that the liver is the primary metabolic organ for most PAEs.Oxidative stress and neuroinflammation are considered as crucial culprits in Alzheimer's disease (AD). Torularhodin, a carotenoid pigment, possesses powerful antioxidant activity. This study aimed to elucidate the protective effects of torularhodin in the AD-like mouse model and investigated the underlying mechanisms. Behavioral and histopathological results suggested that torularhodin relieved cognitive impairments, attenuated Aβ accumulation, and inhibited glial overactivation in d-gal/AlCl3-induced ICR mice. Simultaneously, torularhodin also markedly increased antioxidant enzyme capacities, lowered the contents of RAGE, and reduced levels of inflammatory cytokines. Western blot results showed that torularhodin ameliorated neuronal oxidative damage via activation of Nrf2 translocation, upregulation of HO-1, and inactivation of NF-κB in vivo and in vitro. Thus, torularhodin effectively ameliorated cognitive impairment, oxidative stress, and neuroinflammation, possibly through the Nrf2/NF-κB signaling pathways, suggesting torularhodin might offer a promising prevention strategy for neurodegenerative diseases.The present report describes an organocatalytic cascade reaction between 2-alkylidene benzo[b]thiophenone derivatives and enones in the presence of the Cinchona alkaloid amine. Spirobenzothiophenonic cyclohexane derivatives containing three stereocenters were prepared via one-step synthesis in yields ranging from 88 to 96% and in enantioselectivities (enantiomeric excess (ee)) ranging from 85 to 97%, with diastereoselectivities of approximately 14/2/1. Therefore, this method provides an efficient route for the synthesis of a new class of optically active 2-spirobenzothiophenones.