in English:The following page (106) from the inaugural dissertation with the subject

INVESTIGATIONS TO[0] 

REACTIONS FROM DEHYDROASCORBIC AND DIKETOGULONIC ACID

WITH THE HELP OF CALCULATOR-SUPPORTED INFRARED SPECTROSCOPY (German)

presented[32]  by Detlef Pagel from Hermannstein / Kreis Wetzlar, Germany

Giessen 1992

was typed and translated by and put into the world wide web with kind permission of the author ©2016.

106

5 Summary

In this dissertation, the oxidation[24]  and reduction of the ascorbic acid / dehydroascorbic acid redox system as well as the alkaline hydrolysis from dehydroascorbic (DHA) to diketogulonic acid (DKG) were analyzed[2] . With the help of the ascertained[18]  band parameters, standard and calibration spectra from the infrared measurements in substances[27], which contain H–O - and C=O - bond groups[26], as well the methodology for observing the reactions with infrared[4]  spectroscopy as the interpretation experienced an essential support.

In this context, the problems of the keto-enol tautomerism were studied in acetylacetone and (iso-)ascorbic acids. Furthermore it turned out[28], that the square root values of the integral extinction coefficient of the O=C-stretching vibration modes, which are proportional to the dipole moment changes, varied themselves comparably through the substitution[5]  of neighboring bond groups[14]. The phenomenon of the hydration of keto groups was able to be pursued infrared spectroscopically[33] in a simple molecule (butanal[15]). With the dehydroascorbic acids in solution, the interpretation is still ambiguous[22]  because of several[7]  effects of mutual influence[8] . However between crystalline bis-DHA and the hydrated DHA form, clear differences appeared[12]  in the H–O- and O=C-stretching vibration area. Unambiguously[23], the deuteration[6]  of the HO groups was successfully for bis-DHA. For the process of saponification of the DHA, functional relationships[29] of temperature and pH with an activation energy of 79.3 kJ/mol were determined. With the help of the electronic data processing (EDP), up to three infrared standard spectra, namely of DHA, DKG, and another one reductone-like substance, were able to be separated from D2O solutions. The pKa value of the soap making product (DKG), investigated by pH-titration and by infrared spectroscopy, corresponds to known pKa values of oxocarboxylic acids (oxocarbonic acids). The evolution[9]  of CO2 in spectra of pellets can be backtraced[21]  to the decarboxylating[3]  DKG. However, DKG is still quite stable in high concentrations in solution at 37°C. The DKG decomposition reactions were examined qualitatively, starting[19]  from DKG-stock solutions also in the neutral and alkaline pH range, except with the infrared spectroscopy, still with the spectrophotometry, the fluorescence and also the electron paramagnetic resonance (EPR) spectroscopy. The ruby-red substance, evolved[16]  at high pH value from both[17]  DHA and DKG, unstable opposite[25]  to aerial influences, can be associated[20]  with free radicalic processes. It was found one EPR signal, indicating R–O ● radicals.

It is problematic that reduction and oxidation[24]  are influenced[34] by instabilities[10]  of DHA and DKG. Thus[35], equimolar NADH concentrations reduce the DHA only incompletely[30] in the physiological pH range because of the additional DHA saponification. The same is valid[13]  with reductions by H–S-group containing substances for which[31]  an apparent reaction order similar to the DHA saponification was found. However, one intermediate state to which[36] the real reduction reaction of DHA follows is proven[1]  infrared spectroscopically[33] during reactions by H–S groups. Clear infrared spectroscopic differences were found at oxidation[24]  reactions between derivatives, which are incapable or capable of C(6)–O–C(3) - cyclization[11].
Nota: English synonyms:
Words of the same sense (words of common sense):
Words of similar meaning:
Englische Synonyme:
 0)  on
to
 1)  proven [Partizip Perfekt]
proved [Partizip Perfekt; Imperfekt]
controlled
checked
tested
 2)  analyzed
analysed
 3)  decarboxylating [often]
decarboxylizing [rare]
decarboxylising [very rare]
decarboxylation doing [extremely rare]
 4)  infrared
ultrared
ultra red
 5)  substitution
replacement
application
 6)  deuteration
deuteriation
 7)  several
a number of
 8)  effects of mutual influence
cross-influence effects
effects of interaction
 9)  development
evolution
 10)  instabilities
unstablenesses
 11)  cyclization
cyclisation
ring forming
 12)  appeared
resulted
arose
 13)  is valid with
applies to
does apply to
goes for
 14)  neighboring bond groups[26]
neighbouring bond groups[26]
adjacent bond groups[26]
 15)  butanal
butyraldehyde
 16)  evolved
developed itself
 17)  from both ... and ...
from ... as well as ...
 18)  ascertained
determined
found-out
identified
 19)  starting from
beginning with
 20)  associated with
related to
 21)  backtraced
traced back
retraced
referred
followed back
 22)  ambiguous
equivocal
 23)  unambiguously
unequivocally
clearly
 24)  oxidation
oxydation
oxidisation
oxidization
 25)  opposite to
against
 26)  functional groups
bond groups
 27)  in substances, which contain H–O - and C=O - bond groups[26]
in substances containing H–O - and C=O - bond groups[26]
in H–O - and C=O - bond groups[26]-containing substances
 28)  it turned out
it became apparent
 29)  functional relationships [Pl.]
functional coherencies
 30)  reduce ... only incompletely
makes reduction ... only incompletely
does not reduce ... completely
does not make reduction ... completely
 31)  for which
for what
wherefore
 32)  presented
submitted
 33)  with infrared spectroscopy
infrared spectroscopically
 34)  are influenced by
are affected by
 35)  thus
so
therefore
consequently
 36)  state to which the real reduction reaction of DHA follows
state which the real reduction reaction of DHA follows to
state that the real reduction reaction of DHA follows to
state the real reduction reaction of DHA follows to

Keywords (/index term): Detlef, Pagel, Giessen, 1992,
DHA, DKG, EPR, NADH, pH, pKa,
acetyl, acetone, acid, activation, alkaline, ascorbic, bis, bond, butanal, calibration, carbonic, carboxylic, coefficient, concentration, crystallin, cyclization, decomposition, dehydro, deuteration, diketo, dipole, dissertation, electron, energy, enol, fluorescence, group, gulonic, hydration, hydrolysis, inaugural, infrared, instabilities, integral, intermediate, interpretation, iso, keto, making, measurement, moment, neutral, order, oxidation, oxo, paramagnetic, parameter, pellet, photometry, physiological, radicalic, range, reactions, redox, reduction, reductone, relationship, resonance, saponification, solution, soap, spectro, spectroscopic, spectroscopy, state, stock, stretching, subject, substitution, summary, tautomerism, temperature, titration, ultrared, value, vibration
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