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Photopharmacology relies on ligands that change their pharmacodynamics upon photoisomerization. Many of these ligands are azobenzenes that are thermodynamically more stable in their elongated trans‐configuration. Often, they are biologically active in this form and lose activity upon irradiation and photoisomerization to their cis‐isomer. Recently, cyclic azobenzenes, so‐called diazocines, have emerged, which are thermodynamically more stable in their bent cis‐form. Incorporation of these switches into a variety of photopharmaceuticals could convert dark‐active ligands into dark‐inactive ligands, which is preferred in most biological applications. This "pharmacological sign‐inversion" is demonstrated for a photochromic blocker of voltage‐gated potassium channels, termed CAL, and a photochromic opener of G protein‐coupled inwardly rectifying potassium (GIRK) channels, termed CLOGO. [ABSTRACT FROM AUTHOR]

The selective modification of α-amino acids and peptides constitutes a pivotal arena for accessing new peptide-based materials and therapeutics. In recent years, visible light photoredox catalysis has appeared as a powerful platform for the activation of small molecules via single-electron transfer events, allowing previously inaccessible reaction pathways to be explored. This review outlines the recent advances, mechanistic underpinnings, and opportunities of applying photoredox catalysis to the expansion of the synthetic repertoire for the modification of specific amino acid residues. 1 Introduction 2 Visible-Light-Mediated Functionalization of α-Amino Acids 2.1 Decarboxylative Functionalization Involving Redox-Active Esters 2.2 Direct Decarboxylative Coupling Strategies 2.3 Hypervalent Iodine Reagents 2.4 Dual Photoredox and Transition-Metal Catalysis 2.5 Amination and Deamination Strategies 3 Photoinduced Peptide Diversification 3.1 Gese-Type Bioconjugation Methods 3.2 Peptide Macrocyclization through Photoredox Catalysis 3.3 Biomolecule Conjugation through Arylation 3.4 C–H Functionalization Manifolds 4 Conclusions and Outlook [ABSTRACT FROM AUTHOR]

The article offers information on the discovery of resveratrol in wine and the correlation between coronary heart disease and cholesterol consumption. It discusses the cardioprotective ability of resveratrol, its oligomers, and other pytochemicals in wine which seemed to resolve the French Paradox. It explores the numerous biological activities of resveratrol, which include antidiabetic, anticancer and antioxidant.

An efficient synthetic route to the resveratrol oligomers quadrangularin A and pallidol is reported. It features a scalable biomimetic oxidative dimerization that proceeds in excellent yield and with complete regioselectivity. A systematic evaluation of the natural products and their synthetic precursors as radical-trapping antioxidants has revealed that, contrary to popular belief, this mode of action is unlikely to account for their observed biological activity. [ABSTRACT FROM AUTHOR]

The development of a room-temperature lignin degradation strategy consisting of a chemoselective benzylic oxidation with a recyclable oxidant ([4-AcNH-TEMPO]BF4) and a catalytic reductive C-O bond cleavage utilizing the photocatalyst [Ir(ppy)2(dtbbpy)]PF6 is described. This system was tested on relevant lignin model substrates containing β-O-4 linkages to generate fragmentation products in good to excellent yields. [ABSTRACT FROM AUTHOR]

The photoredox-mediated direct intermolecular C−H functionalization of substituted indoles, pyrroles, and furans with diethyl bromomalonate is described, utilizing the visible light-induced reductive quenching pathway of Ru(bpy)3Cl2. An analysis of reductive quenchers and mechanistic considerations has led to an optimized protocol for the heteroaromatic alkylations, providing products in good yields and regioselectivities, as well as successfully eliminating previously observed competitive side reactions. This methodology is highlighted by its neutral conditions, activity at ambient temperatures, low catalyst loading, functional group tolerance, and chemoselectivity. [ABSTRACT FROM AUTHOR]

A graphical abstract of the article "Formation and Trapping of Azafulvene Intermediates Derived from Manganese-Mediated Oxidative Malonate Coupling" is presented.

Review: 219 refs. [ABSTRACT FROM AUTHOR]

A proof-of-principle approach to address the lignin degradation is presented. [ABSTRACT FROM AUTHOR]

High density lipoproteins (HDL) are major plasma carriers of sphingosine 1-phosphate (S1P). Here we show that HDL increases endothelial barrier integrity as measured by electric cell substrate impedance sensing. S1P was implicated as the mediator in this process through findings showing that pertussis toxin, an inhibitor of Gi-coupled S1P receptors, as well as antagonists of the S1P receptor, S1P1, inhibited barrier enhancement by HDL. Additional findings show that HDL stimulates endothelial cell activation of Erk1/2 and Akt, signaling pathway intermediates that have been implicated in S1P-dependent endothelial barrier activity. HDL was also found to promote endothelial cell motility, a process that may also relate to endothelial barrier function in the context of a vascular injury response. The effects of HDL on endothelial cell Erk1/2 and Akt activation and motility were suppressed by pertussis toxin and S1P1 antagonists. However, both HDL-induced barrier enhancement and HDL-induced motility showed a greater dependence on Akt activation as compared with Erk1/2 activation. Together, the findings indicate that HDL has endothelial barrier promoting activities, which are attributable to its S1P component and signaling through the S1P1/Akt pathway. [ABSTRACT FROM AUTHOR]

The molecular structure of nanothreads produced by the slow compression of 13 C 4 -furan was studied by advanced solid-state NMR. Spectral editing showed that >95% of carbon atoms were bonded to one hydrogen (C-H) and that there were 2-4% CH 2 , 0.6% C═O, and <0.3% CH 3 groups. Alkenes accounted for 18% of the CH moieties, while trapped, unreacted furan made up 7%. Two-dimensional (2D) 13 C- 13 C and 1 H- 13 C NMR identified 12% of all carbon in asymmetric O-CH═CH-CH-CH- and 24% in symmetric O-CH-CH═CH-CH- rings. While the former represented defects or chain ends, some of the latter appeared to form repeating thread segments. Around 10% of carbon atoms were found in highly ordered, fully saturated nanothread segments. Unusually slow 13 C spin-exchange with sites outside the perfect thread segments documented a length of at least 14 bonds; the small width of the perfect-thread signals also implied a fairly long, regular structure. Carbons in the perfect threads underwent relatively slow spin-lattice relaxation, indicating slow spin exchange with other threads and smaller amplitude motions. Through partial inversion recovery, the signals of the perfect threads were observed and analyzed selectively. Previously considered syn -threads with four different C-H bond orientations were ruled out by centerband-only detection of exchange NMR, which was, on the contrary, consistent with anti -threads. The observed 13 C chemical shifts were matched well by quantum-chemical calculations for anti -threads but not for more complex structures like syn / anti -threads. These observations represent the first direct determination of the atomic-level structure of fully saturated nanothreads.