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11.
Katharina Schiedt Max Vecchi Ernst Glinz Trond Storebakken 《Helvetica chimica acta》1988,71(4):887-896
Diets supplemented with astaxanthin and canthaxanthin, respectively, and a control diet without carotenoid additions, were fed to 1½-year-old Atlantic salmon (Salmo salar, L.) for one year. The integuments were investigated as to their quantitative and qualitative carotenoid composition. Astaxanthin and canthaxanthin deposited in the skin amounted to 20 and 14% of the total carotenoids only. Seventy % must be considered as metabolites of astaxanthin and canthaxanthin and 10% as basic xanthophylls also present in the control groups. Astaxanthin apparently underwent the following metabolic pathway: astaxanthin→idoxanthin→adonixanthin→zeaxanthin→zeaxanthin 5,6-epoxides. Reduction of the 4′-carbonyl group was stereospecific leading to the (4′R)-idoxanthin. Canthaxanthin was obviously converted to β,β-carotene via 4′-hydroxyechinenone, echinenone, and 4-hydroxy-β,β-carotene. 相似文献
12.
Experimental Investigations of Ionisation and Charge-transfer of Alcohols by 6-25 keV Hydrogen Ions Ionisation and charge-transfer cross sections were measured for the interaction of H+, H and H ions (in the energy range 6-25 keV) with alcohols (methanol-octanol). The cross sections depend significantly on the target molecular structure like molecular length, ionisation potential, polarizability and atomic bonds in the target molecule. 相似文献
13.
An Application of GRYZINSKY -theory to Calculations of Ionisation and Charge-transfer Cross Sections for the Interaction of Hydrogen Ions with Alcohol Molecules Ionisation and charge-transfer cross sections were calculated for the interaction of H+, H and H ions (energy range 5-25 keV) with alcohols (methanol-butanol). A modified GRYZINSKY approximation is used for the calculation of the cross sections. The calculated values have been compared with experimental determined cross sections. The agreement between experimental results and theoretical results is satisfactory. 相似文献
14.
Hans‐Dietrich Stachel Barbara Zimmer Eduard Eckl Katharina Semmlinger Wolfgang Weigand Ralf Wünsch Peter Mayer 《Helvetica chimica acta》2005,88(6):1208-1220
The 1,2‐dithiolosultam derivative 14 was obtained from the (α‐bromoalkylidene)propenesultam derivative 9 (Scheme 1). Regioselective cleavage of the two ester groups (→ 1b or 2b ) allowed the preparation of derivatives with different substituents at C(3) in the dithiole ring (see 27 and 28 ) as well as at C(6) in the isothiazole ring (see 17 – 21 ; Scheme 2). Curtius rearrangement of the 6‐carbonyl azide 21 in Ac2O afforded the 6‐acetamide 22 , and saponification and decarboxylation of the latter yielded ‘sulfothiolutin’ ( 30 ). Hydride reductions of two of the bicyclic sultams resulted in ring opening of the sultam ring and loss of the sulfonyl group. Thus the reduction of the dithiolosultam derivative 14 yielded the alkylidenethiotetronic acid derivative 33 (tetronic acid=furan‐2,4(3H,4H)‐dione), and the lactam‐sultam derivative 10 gave the alkylidenetetramic acid derivative 35 (tetramic acid=1,5‐dihydro‐4‐hydroxy‐2H‐pyrrol‐2‐one) (Scheme 3). Some of the new compounds ( 14, 22, 26 , and 30 ) exhibited antimycobacterial activity. The oxidative addition of 1 equiv. of [Pt(η2‐C2H4)L2] ( 36a , L=PPh3; 36b , L=1/2 dppf; 36c , L=1/2 (R,R)‐diop) into the S? S bond of 14 led to the cis‐(dithiolato)platinum(II) complexes 37a – c . (dppf=1,1′‐bis(diphenylphosphino)ferrocene; (R,R)‐diop={[(4R,5R)‐2,2‐demithyl‐1,3‐dioxolane‐4,5‐diyl]bis(methylene)}bis[diphenylphosphine]). 相似文献
15.
John D. Mertens Katharina Kohse-Hinghaus Ronald K. Hanson Craig T. Bowman 《国际化学动力学杂志》1991,23(8):655-668
The reaction of atomic hydrogen with isocyanic acid (HNCO) to produce the amidogen radical (NH2) and carbon monoxide, has been studied in shock-heated mixtures of HNCO dilute in argon. Time-histories of the ground-state NH2 radical were measured behind reflected shock waves using cw, narrowlinewidth laser absorption at 597 nm, and HNCO time-histories were measured using infrared emission from the fundamental v2-band of HNCO near 5 μm. The second-order rate coefficient of reaction (2(a)) was determined to be: cm3 mol?1 s?1, where f and F define the lower and upper uncertainty limits, respectively. An upper limit on the rate coefficient of was determined to be: 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
20.
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献