NH-type of chiral Ni(II) complexes of glycine Schiff base: design, structural evaluation, reactivity and synthetic applications.

The work being reported here deals with the design of a new type of "N-H" Ni(II) complexes of glycine Schiff bases and study general aspects of their reactivity. It was confirmed that the presence of NH function in these Ni(II) complexes does not interfere with the homologation of the glycine residue, rendering these derivatives of high synthetic value for the general synthesis of α-amino acids. In particular, the practical application of these NH-type complexes was demonstrated by asymmetric synthesis of various β-substituted pyroglutamic acids via Michael addition reactions with chiral Michael acceptors.

trans-(-)-ε-Viniferin increases mitochondrial sirtuin 3 (SIRT3), activates AMP-activated protein kinase (AMPK), and protects cells in models of Huntington Disease.

Huntington disease (HD) is an inherited neurodegenerative disorder caused by an abnormal polyglutamine expansion in the protein Huntingtin (Htt). Currently, no cure is available for HD. The mechanisms by which mutant Htt causes neuronal dysfunction and degeneration remain to be fully elucidated.

Reappraising the structures and distribution of metabolites from black aspergilli containing uncommon 2-benzyl-4H-pyran-4-one and 2-benzylpyridin-4(1H)-one systems.

To date, natural products containing 2-benzyl-4H-pyran-4-one and 2-benzylpyridin-4(1H)-one substructures have been encountered in relatively few fungi outside of the black aspergilli clade. While exploring the occurrence of these compounds among Aspergillus spp., it was determined that the structures of the unusual furopyrrols tensidols A and B (5 and 6) and JBIR-86 and JBIR-87 (9 and 10) were incorrect and should be reassigned as 2-benzyl-4H-pyran-4-ones (7, 8, 11e, and 12, respectively).

21-(4-Methyl-phenyl-sulfon-yl)-4,7,13,16-tetra-oxa-1,10,21-triaza-bicyclo-[8.8.5]tricosane-19,23-dione: an N-tosyl-ated macrobicyclic dilactam.

The macrobicyclic title compound, C(23)H(35)N(3)O(8)S, contains two tertiary amide bridgehead N atoms and a toluene-sulfonamide N atom in the center of the five-atom bridging strand. The mol-ecule has a central cavity that is defined by the 18-membered ring identified by the N(2)O(4) donor atom set and two 15-membered rings with N(3)O(2) donor atom sets. The toluene-sulfonamide N atom adopts an exo orientation with respect to the central cavity, and the tosyl group is oriented on one side of the aza-bridging strand that connects the bridgehead N atoms.

Chemical epigenetics alters the secondary metabolite composition of guttate excreted by an atlantic-forest-soil-derived Penicillium citreonigrum.

Chemical epigenetic manipulation of Penicillium citreonigrum led to profound changes in the secondary metabolite profile of its guttate. While guttate from control cultures exhibited a relatively simple assemblage of secondary metabolites, the guttate collected from cultures treated with 50 muM 5-azacytidine (a DNA methyltransferase inhibitor) was highly enriched in compounds representing at least three distinct biosynthetic families. The metabolites obtained from the fungus included six azaphilones (sclerotiorin (1), sclerotioramine (6), ochrephilone (2), dechloroisochromophilone III (3), dechloroisochromophilone IV (4), and 6-((3E,5E)-5,7-dimethyl-2-methylenenona-3,5-dienyl)-2,4-dihydroxy-3-methylbenzaldehyde (5)), pencolide (7), and two new meroterpenes (atlantinones A and B (9 and 10, respectively)).

Efficient synthesis of 2-aminoindane-2-carboxylic acid via dialkylation of nucleophilic glycine equivalent.

An efficient, easy to scale-up method for preparing 2-aminoindane-2-carboxylic acid via two-step alkylation of a Ni(II)-complex of glycine Schiff base with 2-[N-(alpha-picolyl)amino]benzophenone (PAAP) (2b) with o-dibromoxylylene (3) is reported. The first step, monoalkylation of 2b with 3, conducted under phase-transfer conditions, gave the corresponding complex 6 in excellent chemical yield (97.2%).