Effects of dehydroepiandrosterone (DHEA) supplementation on cortisol, leptin, adiponectin, and liver enzyme levels: A systematic review and meta-analysis of randomised clinical trials.

BACKGROUND AND AIMS: Dehydroepiandrosterone (DHEA) supplementation has been investigated in patients with altered cortisol levels and is proposed to ameliorate the metabolic profile related to adipose tissue. However, further research is warranted and evidence is no compelling for liver safety. Hence, we aimed to meta-analyse the effects of DHEA supplementation on circulating levels of cortisol, liver enzymes, and adipokines. METHODS: We searched literature published in PubMed, Web of Science, Embase and Scopus, until December 2020. We obtained overall results using the generic inverse of variance method with a random-effects model. RESULTS: Through 10 arms, serum cortisol levels decreased significantly after DHEA supplementation [weighted mean difference (WMD): -53.581 nmol/L, 95% confidence interval (CI): -88.2, -18.9, P = .002], without significant heterogeneity (I2  = 36%, P = .117). In contrast, any significance was noted for adiponectin (WMD: -0.045 µg/mL, 95% CI: -0.56, 0.47; P = .865), leptin (WMD: -2.55 µg/mL, 95% CI: -6.2, 1.06; P = .166), aspartate transaminase (AST) (WMD: -3.7 U/L, 95% CI: -10.35, 2.95; P = .276), and alanine aminotransferase (ALT) (WMD: -1.7 U/L, 95% CI: -3.45, 0.06; P = .058). CONCLUSION: DHEA supplementation decreased circulating cortisol but did not alter adiponectin, leptin, AST, and ALT levels. Hence, DHEA supplementation could be considered as an adjunct in the management of hypercortisolaemia and is safe for the liver.

Synthesis of CBD and Its Derivatives Bearing Various C4'-Side Chains with a Late-Stage Diversification Method.

A novel synthetic route for making (-)-CBD and its derivatives bearing various C4'-side chains is developed by a late-stage diversification method. Starting from commercially available phloroglucinol, the key intermediate (-)-CBD-2OPiv-OTf is efficiently and regioselectively prepared and further undergoes Negishi cross-coupling to furnish (-)-CBD. This approach allowed an efficient synthesis of (-)-CBD in a five-step total 52% yield on a 10 g scale. Furthermore, diversification on the C4'-side chain with this method can be realized in a wide range.

Oxidative Aromatization of 3,4-Dihydroquinolin-2(1 H)-ones to Quinolin-2(1 H)-ones Using Transition-Metal-Activated Persulfate Salts.

Inorganic persulfate salts were identified as efficient reagents for the oxidative aromatization of 3,4-dihydroquinolin-2(1 H)-ones through the activation of readily available transition metals, such as iron and copper. The feasible protocol conforming to the requirement of green chemistry was utilized in the preparation of the key intermediate (7-(4-chlorobutoxy)quinolin-2(1 H)-one 2) of brexpiprazole in 80% isolated yield on a 100 g scale, and different quinolin-2(1 H)-one derivatives with various functional groups were demonstrated in 52-89% yields.

Synthesis and Properties of a Bay-Annulated-Indigo Tetramer Based on Low-Cost Spiro[Fluorene-9,9'-Xanthene] Core.

A three-dimensional bay-annulated-indigo (BAI) tetramer has been prepared by appending BAI units onto a low-cost spiro[fluorene-9,9'-xanthene] (SFX) core. The target compound 4BAI-SFX exhibits strong and broad absorption in the visible region covering the range of 450~700 nm. The electrochemical measurement illuminates the characteristics of a deep lowest unoccupied molecular orbital (LUMO) level and multiple redox states of 4BAI-SFX. These results suggest that 4BAI-SFX should be a selectable electron-transporting material for eco-friendly organic semiconductors.

Charge-patching method for the calculation of electronic structure of polypeptides.

Theoretical study of the electronic structures of protein is a fundamental challenge in computational biochemistry due to the large size of the systems. The electronic structure of a protein is important for some of the important protein functionalities, such as photosynthesis. In this study, we explored the charge-patching method to calculate the electronic structure of polypeptides. This method generates the charge densities of the systems by patching the charge motifs calculated from small prototype systems. The method was tested on a range of polypeptides, including the glycine polypeptide in 27-ribbon, α-helix, 310-helix, and ß-strand structures. After the charge density profiles of these systems were obtained, the electronic structures of these glycine polypeptides were further calculated based on density functional theory (DFT) using a folded-spectrum method. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) were analyzed and compared with conventional direct DFT calculations. The charge-patching method results were found to be in good agreement with the directed DFT results.

A new water-soluble phosphorus-dipyrromethene and phosphorus-azadipyrromethene dye: PODIPY/aza-PODIPY.

PODIPY and aza-PODIPY have been successfully prepared by the treatment of dipyrromethene and azadipyrromethene with POCl3 in the presence of Et3 N. The new PODIPY and aza-PODIPY dyes are found to have photophysical properties. PODIPY and aza-PODIPY are water-soluble, and aza-PODIPY is suited for labeling living Hep-2 cells for imaging assays in the near-infrared region. Molecular orbital calculations show that the increase in the HOMO-LUMO band gap for the lowest energy absorption bands is observed in the new phosphorus-containing aza-PODIPY, and the HOMO and LUMO energies of aza-PODIPY are found to be higher than those of aza-BODIPY.

Formal ring-opening/cross-coupling reactions of 2-pyrones: iron-catalyzed entry into stereodefined dienyl carboxylates.

Open access: Despite the exceptional level of sophistication in cross-coupling chemistry, reactions of substrates that incorporate the leaving group as an integral part into a heterocyclic scaffold are scarce. The title reaction outlines the utility of this reaction format (see scheme; acac=acetylacetonate), provides a convenient entry into stereodefined diene carboxylates, and adds a new chapter to the field of iron catalysis.

Transition-metal-catalyzed C-C bond formation through the fixation of carbon dioxide.

Carbon dioxide is an important carbon source in the atmosphere and is "problematic" toward the activities of human beings. Although carbon dioxide is a cheap, abundant and relatively nontoxic C1 source, its chemical transformations have not been widely developed so far and are still far from synthetic applications, especially in the construction of the C-C bond. This critical review summarizes the recent advances on transition-metal-catalyzed C-C bond formation through the fixation of carbon dioxide and their synthetic applications (124 references).

Near-infrared upper phenyl-fused BODIPY as a photosensitizer for photothermal-photodynamic therapy.

The introduction of a ring-fused segment into a BODIPY scaffold promoted a spectral bathochromic-shift and enhanced the intersystem crossing capability by a twisted structure. In this work, we designed and synthesized an upper ring-fused BODIPY with 4-dimethylaminostyryl groups (BBDP), which had excellent optical performance for photothermal-photodynamic therapy.

Activation of "inert" alkenyl/aryl C-O bond and its application in cross-coupling reactions.

Enol and phenol functionalities are very common in organic molecules. Utilization of these materials is very appealing in organic synthesis because they are important alternatives to organohalides in cross-coupling reactions. In this review, we summarize the transition-metal-catalyzed cross-coupling of enol- and phenol-based electrophiles, including phosphates, sulfonates, ethers, carboxylates, and phenolates.

New strategy to construct fused/bridged/spiro carbocyclic scaffolds based on the design of novel 6-C synthon precursor.

In this article we report a new strategy to build fused/spiro/bridged carbocyclic systems with a novel 6-C synthon from readily available diallyl diacetates through the sequential Pd-catalyzed double allyl alkylation and Diels-Alder annulation. Further exploration on the application of this strategy can construct useful complex scaffolds.

Investigation on the individual contributions of N-H...O=C and C-H...O=C interactions to the binding energies of beta-sheet models.

In this article, the binding energies of 16 antiparallel and parallel beta-sheet models are estimated using the analytic potential energy function we proposed recently and the results are compared with those obtained from MP2, AMBER99, OPLSAA/L, and CHARMM27 calculations. The comparisons indicate that the analytic potential energy function can produce reasonable binding energies for beta-sheet models. Further comparisons suggest that the binding energy of the beta-sheet models might come mainly from dipole-dipole attractive and repulsive interactions and VDW interactions between the two strands. The dipole-dipole attractive and repulsive interactions are further obtained in this article. The total of N-H...H-N and C=O...O=C dipole-dipole repulsive interaction (the secondary electrostatic repulsive interaction) in the small ring of the antiparallel beta-sheet models is estimated to be about 6.0 kcal/mol. The individual N-H...O=C dipole-dipole attractive interaction is predicted to be -6.2 +/- 0.2 kcal/mol in the antiparallel beta-sheet models and -5.2 +/- 0.6 kcal/mol in the parallel beta-sheet models. The individual C(alpha)-H...O=C attractive interaction is -1.2 +/- 0.2 kcal/mol in the antiparallel beta-sheet models and -1.5 +/- 0.2 kcal/mol in the parallel beta-sheet models. These values are important in understanding the interactions at protein-protein interfaces and developing a more accurate force field for peptides and proteins.

A scheme for rapid prediction of cooperativity in hydrogen bond chains of formamides, acetamides, and N-methylformamides.

A scheme is proposed in this article to predict the cooperativity in hydrogen bond chains of formamides, acetamides, and N-methylformamides. The parameters needed in the scheme are derived from fitting to the hydrogen bonding energies of MP2/6-31+G** with basis set superposition error (BSSE) correction of the hydrogen bond chains of formamides containing from two to eight monomeric units. The scheme is then used to calculate the individual hydrogen bonding energies in the chains of formamides containing 9 and 12 monomeric units, in the chains of acetamides containing from two to seven monomeric units, in the chains of N-methylformamides containing from two to seven monomeric units. The calculation results show that the cooperativity predicted by the scheme proposed in this paper is in good agreement with those obtained from MP2/6-31+G** calculations by including the BSSE correction, demonstrating that the scheme proposed in this article is reasonable. Based on our scheme, a cooperativity effect of almost 240% of the dimer hydrogen bonding energy in long hydrogen bond formamide chains, a cooperativity effect of almost 190% of the dimer hydrogen bonding energy in long hydrogen bond acetamide chains, and a cooperativity effect of almost 210% of the dimer hydrogen bonding energy in long hydrogen bond N-methylformamide chains are predicted. The scheme is further applied to some heterogeneous chains containing formamide, acetamide, and N-methylformamide. The individual hydrogen bonding energies in these heterogeneous chains predicted by our scheme are also in good agreement with those obtained from Møller-Plesset calculations including BSSE correction.

An improved synthesis of telmisartan via the copper-catalyzed cyclization of o-haloarylamidines.

A concise synthetic route was designed for making telmisartan. The key bis-benzimidazole structure was constructed via the copper-catalyzed cyclization of o-haloarylamidines. By adopting this approach, telmisartan was obtained in a 7-step overall yield of 54% starting from commercially available 3-methyl-4-nitrobenzoic acid, and the use of HNO3/H2SO4 for nitration and polyphosphoric acid (PPA) for cyclization in the reported literatures were avoided.

Cross-coupling of alkenyl/aryl carboxylates with Grignard reagent via Fe-catalyzed C-O bond activation.

Iron-catalyzed cross-coupling of alkenyl/aryl carboxylates with primary alkyl Grignard reagent was described. This reaction brought a new family of electrophiles to iron catalysis. The combination of an inexpensive carboxylate electrophile and an iron catalyst would generate ample advantages.

An analytic potential energy function for the amide-amide and amide-water intermolecular hydrogen bonds in peptides.

An analytic potential energy function is proposed and applied to evaluate the amide-amide and amide-water hydrogen-bonding interaction energies in peptides. The parameters in the analytic function are derived from fitting to the potential energy curves of 10 hydrogen-bonded training dimers. The analytic potential energy function is then employed to calculate the N-H...O=C, C-H...O=C, N-H...OH2, and C=O...HOH hydrogen-bonding interaction energies in amide-amide and amide-water dimers containing N-methylacetamide, acetamide, glycine dipeptide, alanine dipeptide, N-methylformamide, N-methylpropanamide, N-ethylacetamide and/or water molecules. The potential energy curves of these systems are therefore obtained, including the equilibrium hydrogen bond distances R(O...H) and the hydrogen-bonding energies. The function is also applied to calculate the binding energies in models of beta-sheets. The calculation results show that the potential energy curves obtained from the analytic function are in good agreement with those obtained from MP2/6-31+G** calculations by including the BSSE correction, which demonstrate that the analytic function proposed in this work can be used to predict the hydrogen-bonding interaction energies in peptides quickly and accurately.