2,4-Diynoic acid

Changes in thermal stability and mass due to the formation of CdS nanoparticles in LB films were examined [180]. The LB films were formed onto gold-coated quartz oscillators from monolayers of arachidic acid or nonacosa-10,12-diynoic acid on CdCH containing subphases. The films were exposed to H2S gas until the mass change indicated complete conversion of Cd to CdS. The thermal stability of the H2S-treated films was reduced, with significant mass loss initiating at 55°C, compared to minimal mass loss in the untreated films up to at least 80°C under mild vacuum. The average CdS-particle size... 

In addition to chemotype patterning revealed by statistical analysis of the data, latitudinal relationships emerged as well. Concentrations of cichoric acid and echinacoside and one of the amides, undeca-2Z,4Z-diene-8,10-diynoic acid 2-methylbutyl amide [246], with a larger amine-bearing group increased with latitude. The inverse relationship was observed for caftaric acid and hexadeca-2 , 9Z-diene-12,14-diynoic acid isobutylamide. The latitudinal differences may be of importance in helping to identify populations for selection of seed for propagation. 

Separate studies of x-ray induced of film forming disubstituted demonstrated quantum efficiencies as In contrast to uv photons, absorbed x-ray photons provide a natural gain mechanism by creating large numbers of secondary electrons and other photons that actually cause polymerization. An example of pentacosa-11,12-diynoic acid is shown in Figure 16. 

Ray induced polymerization ofpentacosa-l0,12-diynoic acid with quantum efficiency of 10 12 (CuKa). 

Crombie, L. and J. C. Williams Lipids. Pjirt VIII. Syntheses of cis-13-and trans-Octadec-13-cne-9,ll-diynoic Acids, and Octadeca-cis-13,trans-15- and -trans-13,trans-15-diene-9,ll-diynoic Acids Their Status in Nature. J. Chem. Soc. (London) 1962, 2449. 

For example, Scott et al. derivatized pentacosa-10,12-diynoic acid by reaction of the terminal carboxylic acid with silanes and amines, and assembled these... 

Polymerized LB films prepared from nonacose-10,12-diynoic acid and LB films prepared from mixed (dihexadecylphosphate and diynoic acid dimethyl dioctadecylammonium bromide and diynoic acid) surfactants) Size-quantized CdS, CdSe < CdTe, CdS.Se ., CdS Te,and CdSe.Te, particles formed in situ between the polar headgroups of LB films... 

Dissolution in sulfuric acid is sufficient to convert 5-(4-chlorophenyl)penta-2,4-diynoic acid into the 6-aryl-4-hydroxypyran-2-one (73BSF1293) other p-substituents are compatible with the synthesis. The intermediacy of a 2,4-diketo acid is assumed. Preparation of the alkynic acids is achieved through the coupling of 2-aryl-1-bromoacetylenes with propynoic acid. 

Along a more biological approach, D. Chapman 116) has described the biosynthetic incorporation of diacetylene acids into the biomembranes of Acholeplasma laidlawii A, an unsaturated fatty acid auxotroph bacterium. As much as 90% of the membrane lipid acyl chains were found to consist of C20-diynoic acid. Upon irradiation with UV-light, the cells and isolated membranes become coloured, due to the crosslinking of lipids by photopolymerization. 

Figure 5.2. Tricosa-m, n-diynoic acid (a diacetylene fatty acid). This is a schematic diagram to illustrate the definition of m and n. n = m + 2.

Linear acetylenic compounds, such as pentadeca-6,8,10-triynoic acid, isolated from the bark of an Ecuadorian medicinal plant, Heisteria acuminata (Humb. Bonpl.) Engl. (Olacaceae), showed potent COX inhibition with IC50 around 13 pM. However, the compounds with double bond, such as cis-hexadec-1 l-en-7,9-diynoic acid, had selectivity against LOX with 45% inhibitory activity at 5 pM [125],... 

Mycomycin is a naturally occurring antibiotic produced by the fungus Nocardia acidophilus. The molecular formula of the substance is Ci3Hi0O2, and its systematic name is 3,5,7,8-tridecatetraene-10,12-diynoic acid. Draw the structure of mycomycin. 

Other workers have reported that substantial amounts (c . 10%) of double-bond isomers are formed even with the diynoic acid 210 . 

To date, only one study has evaluated the pharmacokinetics of the alkamides contained in the Echinacea products administered to humans (27). Subjects (n - 11) received a single oral 2.5-mL dose of the 60% ethanolic extract from E. angustifolia roots or placebo (60% ethanol). Six different alkamides were analyzed (1) Undeca-2D/Z-ene-8,10-diynoic acid isobutylamides (2) Dodeca-2D,4Z-diene-8,10-diynoic acidisobutylamide (3) Dodeca-2E-ene-8,10-diynoic acid isobutylamide (4) Dodeca-2E,4E,8Z,10E/ Z-tetraenoic acid isobutylamides (5) Dodeca-2E,4E,8Z-trienoic acid isobutylamide and (6) Dodeca-2E,4E-dienoic acid isobutylamide. The extract contained approx 2.5 mg of (4), and approx 0.5 mg of all other components. The Cmax and area under the curve (AUC) for (4) were approx 10-fold that achieved with each of the other components. Thus, despite a fivefold higher amount per dose, the 10-fold greater Cmax and AUC achieved with (4) suggest it exhibits a greater bioavailability than the other components. 

Dodeca-2 ,4E,8Z,10 ,-tetraenoic acid isobutylamide Undeca-2.E,4Z-diene-8,10-diynoic acid isobutylamide... 

Hexadeca-2,9-diene-12,14-diynoic acid isobutylamide Dodeca-2 , 4Z-diene-8,10-diynoic acid 2-methylbutylamide... 

Nineteen alkamides have been identified (Bauer and Remiger, 1989 Perry et al., 1997). In E. purpurea, dodec-2 , 4 , 8Z, lOZ-tetraenoic acid isobutylamide accounted for 45% and 76% of the alkamides from the roots and aerial parts, respectively. Undeca-2Z,4 -diene-8,10-diynoic acid isobutylamide and dodcca-2/(,4Z-dicnc-8,10-diynoic acid isobutylamide accounted for an additional 18% and 15%, respectively, in the root. However, neither compound was found in the aerial parts. Undeca-2 , 4Z-diene-8,10-diynoic acid isobutylamide accounted for 20% of the alkamides in the aerial parts and only 6% in the root of E. purpurea (Wills and Stuart, 1999). Perry et al. (1997) observed that dodec-2 , 4 , 8Z,10Z( )-tetraenoic acid isobutylamide accounted for 27% of the alkamides in the roots, but that 6.6% of the total amount of this compound was derived from the roots. The majority (55%) of this compound was found in the vegetative stems, and 22% was found in the rhizome. 

Diatretyne II. -Cyano-2.heptene-4,6-diynoic acid diatretyne nitrile nudic acid B. C8HjNO. mol wt... 

Tieke B, Lieser G and Weiss K 1983 Parameters influencing the polymerization and structure of long-chain diynoic acids in multilayers Thin Solid Films 99 95-102... 

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