Some Doping Agents, Relations of Gas Phase Energetics, Thermal Properties and Biosynthesis

Öz

The most important characteristics of steroid hormones unlikc other hormones are that they are not storcd for subsequent secretion, but when required the steroid levels are controlled by the rate of biosynthesis. The second important characteristics are related to the enzymes of the pathway, e.g. Il-HSD acts as hydrogenase or dehydrogenase depending on the organ which the enzyme works in it. This study has been carried out to find the relationships between multistep fast biosynthesis and energetics of steroid molecules. Ionisation (1), Appearence potentials (A) and Activation energies (Ea) by using gas phase low energy electron impact ion source of VARIAN -MA 1'-112 Mass spectrometer to obtain I and A, and Shimadzu-DT-30 Thennal analyser to obtain thermal data. Results of energetics has shown that the intermediates of biosynthesis are available for fast chain reactions. Furthennore some of the appearance potentials of the residues which were obtained by loosing the well known biologically activc sites C-3 (-OH), C-3 (=0), C-IO (-CHJ), C-ll (-OIl), C-13 (-CH»), C-17 (-OIl), C-17 (=0) and C-21 (-CIl 20H) were found to be lower than ionisation potentials of the related whole molecules. These findings also confinn that steroids are unstable in the gas phase and but active under biological conditions.

Anahtar Kelimeler

• Steroids
• Gas phase energetics
• Mass spectrometry

Kaynakça

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