The heterospin cobalt complexes: peculiarities of high-resolution NMR spectra.

The high-resolution 1H and 13C NMR spectra (CHCl3 solution) of sterically non-rigid heterospin complexes CoL2, CoL2-dipy, and CoL2-phen (where L is 4-(3',3',3'-trifluoro-2'-oxopropylidene)-2,2,5,5-tetramethyl-3-imidazolidine-1-oxyl) have been studied. The specific of the NMR phenomenon in paramagnetic systems is briefly analyzed. It is shown that the NMR spectra modified by hyperfine coupling can be successfully employed for investigation of the complexation processes. In accordance with the common protocols, the 1H and 13C NMR signals are assigned using the information on 13С - 1Н spin-spin coupling. In addition, the preliminarily recorded 1H and 13C NMR spectra of radical L are also used in the work. The temperature dependences of 1H and 13C paramagnetic shifts in the complexes under study have been obtained. A fundamental feature of these dependences is that they obey to the Curie law in a fairly wide temperature range (up to 100 °C). This observation can be used to control intramolecular processes of sterically nonrigid heterosystems in solutions.

Transition metal-free one-pot double C-H functionalization of quinolines with disubstituted electron-deficient acetylenes.

Transition metal-free one-pot reaction of quinolines with acylarylacetylenes and water proceeds in the presence of KOH (55-60 °C, MeCN, 48 h) to afford 2-aryl-3-acylquinolines in up to 66% yield. Here, a formal replacement of the acetylene moiety by the aryl and acyl substituents in the quinoline scaffold takes place. In fact, it has been proved experimentally that the reaction involves the ring cleavage, accompanied by the rearrangement and insertion of the electron-deficient acetylene moiety to form a dihydroquinoline intermediate with an aldehyde functional group in position 4. This intermediate gives the corresponding doubly functionalized quinolines.

2-(1-Hydroxypropyn-2-yl)-1-vinylpyrroles: the first successful Favorsky ethynylation of pyrrolecarbaldehydes.

1-Vinylpyrrole-2-carbaldehydes react with acetylene at atmospheric pressure in a NaOH/EtOH/DMSO system at 7-10 °C to afford 2-(1-hydroxypropyn-2-yl)-1-vinylpyrroles in 53-94% yield. Thus, the first base-mediated direct ethynylation of pyrrolecarbaldehydes with free acetylene under modified conditions of the Favorsky reaction has been implemented to pave an expedient route to important biomolecules containing a pyrrole ring.

Possible mechanism of microgravity impact on Carausius morosus ontogenesis.

Experiments aboard "Spacelab-D1" and "Cosmos-1887" revealed an adverse effect of space flight on Carausius morosus embryos. The main influencing factor for stick insect eggs turned out to be microgravity, while the contribution of HZE particles of cosmic radiation was relatively low. Flight experiments indicated an increased vulnerability of stick insect eggs to microgravity at intermediate stages of development, that could support the "convection" hypothesis.

Gravitational biology experiments aboard the biosatellites "COSMOS" # 1887 and # 2044.

A number of experiments have been carried out in space flight using Protozoans, cell cultures, plants, flat worms, insects and amphibians. No qualitative, strictly unfavorable effects of microgravity could be detected. Microgravity may only slightly stimulate or inhibit some biological processes.

Effects on ontogenesis of Carausius morosus hit by cosmic heavy ions.

Among the biological problems that arise in long duration spaceflights, the effects of weightlessness and ionizing radiation appear to be the two main risk factors. Eggs of the stick insect Carausius morosus were exposed to spaceflight conditions during the 12.56 day Biosatellite mission Cosmos 1887. Five different ages were used, representing different sensitivities to radiation and different capacities for regeneration. During spaceflight the eggs continued their development. Already, in the Spacelab D1 mission in 1985, it has been shown that microgravity leads to a reduced hatching rate of eggs exposed during the early steps of development. When the eggs were hit by a heavy ion, a further but not significant reduction of the hatching rate was observed. Hatching was normal for eggs which were exposed on a 1 g reference centrifuge in space. Heavy ion hits caused body anomalies. The combined action of heavy ions and microgravity resulted in an unexpectedly high rate of anomalies. In the experiment on Cosmos 1887 these results were confirmed. Studies on the embryonic development before hatching showed no major difference between flight and ground control specimen, neither in speed of development nor in morphological anomalies. Hatching therefore seems to be the critical point in insect ontogenesis.

Influence of cosmic radiation and/or microgravity on development of Carausius morosus.

Eggs of Carausius morosus were exposed to spaceflight conditions in two spaceflight missions, the German 7 day Spacelab Mission D1 and the Soviet 12.56 day Biosatellite Mission "COSMOS 1887". During spaceflight the eggs continued their development. Eggs of five different ages representing different sensitivity to radiation and different capacity to regeneration were used to investigate the influence of cosmic radiation and/or microgravity on insect development. Using the Biostack concept--eggs in monolayers sandwiched between nuclear track detectors--and the 1 g reference centrifuge of BIORACK in D1 we were able to separate effects of heavy ions of the cosmic radiation from microgravity effects and also from combined effects of these two factors in space. After retrieval, hatching rates, embryonic and larval growth kinetics and anomaly frequencies were determined. Microgravity leads to a reduced hatching rate of eggs exposed in the early stages of development. Hatching was normal in eggs which were exposed on the 1 g reference centrifuge. Hits by heavy ions caused body anomalies. The combined action of heavy ions and microgravity resulted in an unexpectedly high frequency of anomalies. These results obtained from the Spacelab Mission D1, were confirmed in an experiment onboard of COSMOS 1887. In addition to the previous analysis, embryonic development before hatching was followed which showed no major difference between flight and the ground control specimens. Since a reconfirmation of reduced hatching rates was observed in COSMOS 1887, too, the above results suggest some microgravity induced functional impairment of the hatching activity, rather than blockage in embryonic development.