Although acetylenic acids are not normally found in mammalian tissues, octadecynoyl-CoA esters can serve as substrates for rat liver microsomal acyl-CoA: phospholipid acyltransferases. The relatively high rate of transfer to the 2-hydroxyl of I-acylglycerol-3-phosphorylcholine by the 5-, 9-, and I2-positional cis, tram and yne isomers of acids supports the concept that n-bonds at these position...

The human, leukemic cell line, HL-60, undergoes differentiation in response to tumor-promoting phorbol esters. Recent studies have implicated stimulation of a Na+/H+ antiporter as an initial event in cellular differentiation and/or proliferation. The effects of phorbol esters on Na+-dependent H+ efflux from HL-60 cells were studied by pH-stat titration. Tumor-promoting phorbol diesters, but not...

Novel aryl substituted pyrazaboles 2-9 with direct and acetylenic linkages were synthesized by Pd-catalyzed Suzuki or Sonogashira cross-coupling reactions. Their structural, thermal, and photonic properties were investigated. The results show that the aryl pyrazaboles 2-9 exhibit good thermal stability, high fluorescence quantum yield, and tunable photophysical properties. The aryl substituted ...

A series of benzyl propargyl ethers were synthesized and tested as inhibitors of 5-lipoxygenase, the key enzyme involved in leukotriene biosynthesis. Among these, optimum activity was displayed by 1-(2-heptynyloxymethyl) benzene 12 (IC50 1.2 microM). Addition of carboxyl group at the end of the alkyl side chain attached to the acetylenic group abolished the inhibition. Selective reduction of th...

Graphyne, a novel carbon allotrope, is a two-dimensional lattice of sp2+sp1 hybridization-type carbon atoms, similar to graphene. The initiation and development of wrinkles in single-layer graphynes (α-, β-, γ-, and 6, 6, 12-graphyne) subjected to in-plane circular shearing are investigated. In comparison with graphene, wrinkle pattern and profile characterization in relation to wave number, wa...

Recently, a shift in preen wax composition, from lower molecular weight monoesters to higher molecular weight diesters, was described for individuals of a sandpiper species (red knot, Calidris canutus) that were about to leave for the tundra breeding grounds. The timing of the shift indicated that diester waxes served as a quality signal during mate choice. Here, this hypothesis is evaluated on...

Phenylacetylene and biphenylacetylene are oxidized by cytochrome P-450 to the corresponding arylacetic acids. The acetylenic hydrogen shifts to the adjacent carbon and one atom of molecular oxygen is incorporated into the carboxylic acid group in these transformations, which are subject to a large kinetic isotope effect when the acetylenic hydrogen is replaced by deuterium. The same products an...

The use of acetylenic acid analogs differing in chain length or position of the triple bonds permitted the systemic study of structure activity relationships for the arachidonate metabolizing enzymes (i.e, cyclo-oxygenase and lipoxygenase) in platelets and the relationship of these enzymes to aggregation. We were able to demonstrate analogs that were differentially selective in altering platele...