Photokinetic experiments show that a series of chlorinated octahydro-1,4-endo, endo-5,8-dimethanonaphthaline (1-4) react intramolecular and via tripletstate to their photoisomers (1 a-4a). The formation of the compounds 1 a-4a is dependent on oxygen and nature of sensitizers.
Since serum and plasma D-dimer concentrations correlate very well, we evaluated the comparability of other haemostasis activation markers in plasma and serum. Prothrombin fragment F1+2, fibrin monomer and D-dimer concentrations were measured with commercially available immunoassays in serum and plasma. Serum to plasma ratios were evaluated to determine the direct (prothrombin fragment F1+2) and indirect (fibrin monomer, D-dimer) downstream influence of prothrombinase on the serum to plasma comparability. Prothrombin fragment F1+2 serum and plasma concentrations did not correlate (R2 = 0.09, ns), while an unexpected high degree of correlation was found for fibrin monomer (R2 = 0.66, p < 0.001), and, as expected, a very good correlation was found for D-dimer (R2 = 0.94, p < 0.001). Median serum to plasma ratios decreased from prothrombin fragment F1+2 (16.26) to fibrin monomer (2.24, p < 0.001) and D-dimer (1.00, p < 0.001), following a highly linear relationship (R2 = 0.93). Plasma and serum concentrations of the evaluated markers correlate the better the farther from prothrombinase activity the respective marker is generated. Serum is not suitable for prothrombin fragment F1+2 measurements, whereas fibrin monomer serum concentrations seem of value for research applications. With the used assay, serum seems an appropriate matrix for clinical D-dimer measurements. This would considerably simplify testing strategies. Validation in further clinical trials is needed.
Solution-phase photoreactions of 4-amino-substituted 1,2,4-triazin-5(4H)-ones (1a-j) in different solvents using UV light with wavelengths greater than 290 nm have been investigated. The results show, that the desamination reaction is influenced by both oxygen and water. The photoexperiments showed clearly that OOH-radicals take part in the first step of reaction.
Diels-Alder reactions between cyclopenta-diene and cis-crotonic acid derivatives were examined in the absorbed phase on various surfaces. The results indicate considerable differences under these conditions in the relative yields of exo and endo isomers. On silica gel, montigel, and aluminium oxide the reactions give mainly endo isomers.
Photokinetic experiments show that the deamination reaction of a series of 4-Amino-3-methylthio-1.2.4-triazin-5(4 H)-ons (1 a—e) is dependent on oxygen and nature of solvent. Experiments with a series of 6-tert-Butyl-3-methylthio-1.2.4-triazin-5(4 H)-ons (3 a—e) indicate that the formation of 6-tert-Butyl-3-methylthio-1.2.4-triazin-5-ons (2 d) occurs only in the case of an N—N-bond, but is, however, completely independent of the substituent on the nitrogen atom which is split off.
Cyclooctatetraene dimerises at high pressure (12 Kbar, 20°C) to the isomers 2 and 3. At 120°C compound 2 isomerises quantitatively to compound 3. The conversion rate of Hexamethyldewarbenzene to Hexamethylbenzene at high pressures depends on kind of solvent, whereas the influence of temperature is small in the range between 20° and 80°C.
γ-Thiovalerolactone (1), under high pressure (15 kbar, 170°C), forms the compounds 2 and 3. Under similar conditions, δ-thiovalerolactone polymerizes nearly quantitatively; at 11 kbar and 170°C, 5 is formed in 2% yield. Thiooxindole 7 reacts to yield 8 and the thermically very stable trimer 9.