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—l-Glutamate decarboxylase purified from mouse brain was found to be highly sensitive to the sulfhydryl reagents, 5,5-dithiobis (2-nitrobenzoic acid) (DTNB) and p-chloromerburibenzoate (PCMB), which were competitive inhibitors (Ki for DTNB is 1·1 · 10−8m). Iodoacetamide and iodoacetic acid were less effective inhibitors than DTNB and PCMB. The mercapto acids, 3-mercaptopropionic, 2-mercaptopropionic, and 2-mercaptoacetic acids were potent competitive inhibitors with Ki values of 1·8, 53 and 300 μm, respectively. 2-Mercaptoethanol was less effective. Aminooxyacetic acid was the most potent carbonyl-trapping reagent tested inhibiting the enzyme activity completely at 1·6 μm, followed by hydroxylamine, hydrazine, semicarbazide, and d-penicillamine. Carboxylic acids with a net negative charge were strong competitive inhibitors e.g. d-glutamate (Ki 0·9 mm), α-ketoglutarate (Ki, l·2mm), fumarate (Ki,1·8 mm), dl-β-hydroxyglutamate (Ki, 2·8 mm), l-aspartate (ki, 3·1 mm) and glutarate (Ki, 3·5 mm). 2-Aminophosphonobutyric and 2-aminophosphonopropionic acids, phosphonic analogs of glutamate and aspartate, respectively, had no effect at l0mm. γ-Aminobutyric acid, l-glutamine, l-γ-methylene-glutamine, and α,γ-diaminoglutaric acid, amino acids with no net negative charge at neutral pH, had no effect at 5 mm. Glutaric and α-ketoglutaric acids were the most potent inhibitors among the various dicarboxylic and α-keto-dicarboxylic acids tested (Ki, 3·5 and 1·2 mm, respectively). Compounds with one carbon less, succinic and oxalacetic acids, or with one carbon more, adipic and α-ketoadipic acids, were less inhibitory. The monovalent cations, Li+, Na+, NH4+, and Cs+ had no effect on l-glutamate decarboxylase activity in concentrations up to 10mm. Divalent cations, on the other hand, were very potent inhibitors. Among eleven divalent cations tested, Zn2+ was the most potent inhibitor, inhibiting to the extent of 50 per cent at 10μm. The decreasing order of inhibitory potency was: Zn2+ > Cd2+, Hg2+, Cu2+ > Ni2+ > Mn2+ Co2+ > Ba2+ > Ca2+ > Mg2+ > Sr+2, The anions, I−, Br−, Cl− and F− were only weak inhibitors. The Ki value for Cl− was 17mm. The above findings suggest minimally the presence of aldehyde, sulfhydryl and positively charged groups at or near the active site of the holoenzyme. Intermediates of glycolysis had little effect on l-glutamate decarboxylase activity, but intermediates of the tricarboxylic acid cycle, e.g. α-ketoglutarate (Ki= 1·2 mm) and fumarate (Ki= 1·8 mm) were relatively potent inhibitors. The nucleotides, ATP, ADP, AMP, cyclic AMP, GTP, GDP, GMP, and cyclic GMP were weak inhibitors. l-Norepinephrine (Ki= 1·3 mm) and serotonin were potent inhibitors, while acetylcholine, dopamine and histamine were less effective. Ethanol and dioxane inhibited the enzyme activity to the extent of 20-50 per cent at 10 per cent (v/v), while slight activation was observed at low concentrations (0·1-1 per cent) of both solvents. The possible role of Zn2+ and some metabolites in the regulation of steady-state levels of γ-aminobutyric acid also was discussed.

Die stereoisomeren Aldehyde 1a und b, dargestellt aus den Saurechloriden 5a bzw. 6a, geben verschiedene Derivate mit 2,4-Dinitrophenylhydrazin und Semicarbazid, aber die gleichen Pyridone 7a, b und das gleiche Pyridin-N-oxid 12. 12 wird in das N-Hydroxypyridon 11 und in die Pyridinderivate 13c und d ubergefuhrt. — In siedendem Tetrachlorkohlenstoff erfahren die Aldehyde 1a und b eine quantitative Valenzisomerisierung zum Pyran 2, das sich unter 1,5-Chlorverschiebung rasch in das stabile Pyran 3 umlagert. Der Reaktions-mechanismus wird durch spektroskopische und kinetische Untersuchungen belegt. 3 setzt sich mit Lewis-Sauren, Tritylperchlorat und Triathyloxonium-tetrafluoroborat bereits bei Raumtemperatur zu den Pyryliumsalzen 15 um. Die Hydrolyse von 1, 3 und 15 fuhrt zu dem Pyron 9. Rearrangements of Vinylogous Acyl Chlorides, XIII. cis-Pentadienone-2-H-Pyran Valence Isomerization and [1,5]-sigmatropic Rearrangement. Stereoisomeric 2,3,4,5-Tetrachloro-5-phenyl-2,4-pentadienals The stereoisomeric aldehydes 1a and b, prepared from the acyl chlorides 5a or 6a, yield different derivatives with 2,4-dinitrophenylhydrazine and semicarbazide but the same pyridones 7a, b and the same pyridine N-oxide 12. 12 is converted into the N-hydroxypyridone 11 and the pyridine derivatives 13c and d. — On heating 1a or b in boiling carbon tetrachloride a quantitative valence isomerization to the pyran 2 occurs. 2 rearranges rapidly by 1,5-chlorine shift into the stable pyran 3. The reaction mechanism is confirmed by spectroscopic and kinetic measurements. According to the assigned structure 3 reacts at room temperature with Lewis acids, trityl perchlorate, and triethyloxonium tetrafluoroborate to form the pyrylium salts 15. Hydrolysis of 1, 3, and 15 leads to the γ-pyrone 9.

The simultaneous addition of phenylhydrazine and p-cresol to grape catechol oxidase resulted in enhanced oxidation of p-cresol. Carbonyl reagents such as hydrazine, borohydride and semicarbazide also enhanced cresolase activity but had no effect on catecholase activity. Pretreatment of the enzyme with periodate abolished cresolase activity. The effects of periodate and ascorbate or semicarbazide on cresolase activity were mutually reversible. The simultaneous addition of phenylhydrazine and 4-methylcatechol to the enzyme did not result in inhibition of the initial rate of oxidation of the phenolic substrate. It is concluded that phenylhydrazine does not react with a carbonyl group on the enzyme. The possible involvement of conformational changes in the enzyme, determining phenylhydrazine inhibition is discussed.

Electronic and far-i.r. spectra show that the complexes of type Ni L 2 X 2 where L is semicarbazide, NH 2 NHCONH 2 , or semicarbazones, NH 2 CONHN : C R 1 R 2 ( R 1 = CH 3 , R 2 = CH 3 or CH 2 CH(CH 3 ) 2 ; C R 1 R 2 = cycloheptane and X = Cl, or Br, have tetragonal 6-co-ordinate structures. The complexes Ni L 2 X 2 . 2H 2 O contain the cation [Ni L 2 (H 2 O) 2 ] 2+ . However the complexes Ni L 2 X 2 where where L is thiosemicarbazide, NH 2 CSNHNH 2 , and X = Cl, or Br, are square planar and the corresponding thiosemicarbazones where L = NH 2 CSNHN : CR 1 R 2 have trigonal bipyramidal5-co-ordinate cations [Ni 2 X ] + in the solid state.

The effects of various substances on the viability of freeze-dried cells of Pseudomonas fluorescens and Salmonella newport were studied during storage in vacuo for 5 years. Mixtures of two organisms were dried together and studied in two factorial experiments. The first was a complete factorial using six factors and two levels; the second was a fractional replicate with four factors at two levels and three others at four concentrations. A study of ribose binding by cells of S. newport was made by using [U- 14 C]ribose. Substantial improvements in viability were obtained by drying in the presence of sucrose, glutamate, and semicarbazide. Low concentrations of ribose increased the death rate during drying, but these adverse effects were prevented by equimolar amounts of semicarbazide. Ribose binding increased with storage time and, although its incorporation changed, most of the increase in total ribose occurred after the main decrease in viability. Storage temperature caused larger changes in viability than did level changes of residual water in the cells. Although the results are complicated by a large number of interactions, they confirm and extend the hypothesis that reactions between carbonyl compounds and cellular components are a major cause of the mortality occurring during storage of dried microorganisms. A particular mixture of sucrose, glutamate, and semicarbazide is proposed as a means of reducing death when prolonged storage in the dry state is desired.

1. 1. β-Aminopropiononitrile fumarate (BAPN) and semicarbazide hydrochloride (SCH) were included, respectively, either in normal or lowcalcium diets. The diets were fed for 9 days to 3-week-old chicks. 2. 2. Percentage bone ash was depressed by the low-calcium diet and BAPN but not by SCH. 3. 3. Calcium-binding protein increased by the low-calcium diet, was not altered by BAPN and remarkably reduced by SCH. 4. 4. 45Ca transfer from ligated duodenal loops in situ was stimulated by a low mineral diet, slightly reduced by BAPN and remarkably reduced by SCH. 5. 5. Duodenal 32P absorption was unaffected significantly by any of the dietary treatments.

1-Bromisochroman (1a) oder 1-Chlorisothiochroman (1c) reagieren mit Ammoniak oder Methylamin unter Bildung von 1-Amino- bzw. 1-(Methylamino)isochroman (2a, 2b) oder -isothiochroman (2c, 2d), die unterschiedliche Stabilitat zeigen und zu den sekundaren bzw. tertiaren Aminen 3a, 3c bzw. 3b kondensieren. Carbonsaureamide wie Acetamid, Formamid, Methylformamid sowie Succinimid, Urethan oder Harnstoff bilden mit 1a und 1c die 1-Amidoisochromane 5a, 7a, 8a, 9b, 10a und 11a bzw. die 1-Amidoisothiochromane 5c, 7c, 8c, 9d, 10c und 11c. – (Isochroman-1-yl)isocyanat (13a) und (Isothiochroman-1-yl)isocyanat (13e) werden aus 1a bzw. 1c mit Silbercyanat gewonnen. Mit Ammoniak, primaren oder sekundaren Aminen liefern sie die Harnstoffe 11 und 14, mit Alkoholen die Urethane 9a–9c. Bei der Hydrolyse von 13a und 13e entstehen die symmetrischen Harnstoffe 12, bei der Reaktion mit Hydrazin die Semicarbazide 15 und bei der Reaktion mit Hydroxylamin die N-Hydroxyharnstoffe 16, wobei 16a zu dem N-Hydroxybiuret 17 weiterreagiert. Analog bilden 1a und 1c mit Silberrhodanid die Senfole 18. Uberraschenderweise reagiert 18a sowohl bei der Hydrolyse als auch bei der Umsetzung mit Ammoniak unter Abspaltung von Rhodanidionen zu Di(isochroman-1-yl)ather (19a) bzw. zu Di(isochroman-1-yl)amin (3a). Investigations in the Isochroman and Isothiochroman Series, XVII1). – Preparation, Reactions and Derivatives of 1-Aminoisochroman and 1-Aminoisothiochroman**) 1-Bromoisochroman (1a) and 1-chloroisothiochroman (1c) react with ammonia to give 1-aminoisochroman (2a) and 1-aminoisothiochroman (2c), respectively and with methylamine to give 1-(methylamino)isochroman (2b) and 1-(methylamino)isothiochroman (2d), respectively. Compounds 2a, 2b, 2c, and 2d differ in stability and can be converted into the secondary amines 3a and 3c and tertiary amine 3b. Carboxylic amides (e. g. acetamide, formamide, methylformamide, succinimide, urethane or urea) react with 1a and 1c to give the 1-amidoisochromans 5a, 7a, 8a, 9b, 10a, and 11a or the 1-amidoisothiochromans 5c, 7c, 8c, 9d, 10c, and 11c, respectively. – (Isochroman-1-yl)isocyanate (13a) and (isothiochroman-1-yl)isocyanate (13e) are obtained on reaction of 1a and 1c, respectively with silver cyanate; treatment of 13a and 13e with ammonia, or primary or secondary amines, affords the ureas 11 and 14, whereas treatment with alcohols leads to the urethans 9a–9c. Hydrolysis of 13a and 13e leads to formation of the symmetrical ureas 12; reaction with hydrazine affords the semicarbazides 15 and reaction with hydroxylamine the N-hydroxyureas 16, of which 16a undergoes further reaction to give the N-hydroxybiuret 17. The analogous reactions of 1a and 1c with silver thiocyanate yield the mustard oils 18. Surprisingly, in the case of 18a both the hydrolysis as well as the reaction with ammonia involve cleavage of thiocyanate ions – with formation of di(isochroman-1-yl) ether (19a) and di(isochroman-1-yl)amine (3a), respectively.

According to Raper's hypothesis, the quinone of 5:6-dihydroxy-2:3-dihydroindole-2-carboxylic acid is the red coloured precursor of melanin, obtained by the oxidation of tyrosine with tyrosinase. This paper deals with some derivatives of this “red substance”, the structure of which is still unknown, with phenylhydrazine and substituted phenylhydrazines. No reaction products could be isolated, however, with hydroxylamine, or with semicarbazide. In connection with observations of Jacobs and of Breijer attention is drawn to the fact, that the “red substance” may be of importance as an anti-pernicious principle and that premelanin of the skin-epidermis possibly plays a role in blood formation.

The crystal structures of two isomeric complex compounds of formula [Cu(Cl)2(NH2NHCONH2)] have been determined by X-ray diffraction methods. The orthorhombic isomer has space groupPna21 and unit cell constants:a = 6·91(1),b = 8·30(1),c = 10·24(1) A;Z = 4. The monoclinic isomer has space groupP21/c and unit cell constants:a = 6·91(1),b = 8·30(1),c = 11·32(1) A, β = 117·1(2)°;Z = 4. In both complexes coordination around copper is octahedral, with chains of coordination polyhedra along [100]. In the monoclinic compound, the two semicarbazide molecules, which are present in two adjacent octahedra along the chain, have the oxygen and nitrogen atoms in thetrans configuration, one with respect to the other, and are correlated by a centre of symmetry. In the orthorhombic compound, the two semicarbazide molecules are in thecis configuration and there is no centre of symmetry. In both compounds packing is determined by the NH···Cl and NH···O hydrogen bonds which join the chains together.

Bovine heart valves of different ages were incubated with l -proline-3H for the study of collagen biosynthesis. The synthesis of collagen in the heart valves, especially in the young, is quite active. The specific activity of hydroxyproline in collagen in all heart valves decreased with increasing age. The biosynthetic activity in the mitral valve was higher than in that of the other cardiac valves. The specific activity of hydroxyproline in the fibroblast-rich portion of the old bovine heart valve was comparatively higher than in the chondroblast-rich portion. With the in vitro system, radioactivity was detected in insoluble fibrous collagen in the heart valve. The effect of several chelating agents on collagen biosynthesis was studied. BAL, neocuproine, and a,a′-dipyridyl inhibited collagen biosynthesis completely at high concentrations (10−3, m ). On the other hand, EDTA and semicarbazide had very little effect.

The cell-free extracts of coli-aerogenes produced glyoxylate and succinate in addition to pyruvate and α-ketoglutarate when incubation was carried out with a citrate-medium. The fresh cell-extracts possessed a very poor ability to produce α-ketoglutarate from citrate, but the addition of coenzyme II (TPN) to the reaction mixtures brought about an increase in the yield of α-ketoglutarate. The degradation of citrate by the intact (washed), dried and ground cells of the bacteria also resulted in an accumulation of glyoxylate in the external medium in which semicarbazide was present. It was suggested that the concentration of coenzyme II within the bacterial cells was relatively low, so that coenzyme II-dependent isocitric dehydrogenase was not operative at such a high rate enough to effect the complete removal of citrate. The bacterial cells revealed a high potency of producing α-ketoglutarate from pyruvate or succinate under aerobic conditions. It was indicated that the major breakdown of citrate by the cel...

The far-infrared spectra (450-80 cm−1) of a number of complexes of the type CuL2X2 and CuLX2 [L = semicarbazide (sc), thiosemicarbazide (tsc), acetone semicarbazone (scac), or 1,2,4-triazole (trz); X  Cl, Br, NO3, ClO4, or 12SO4] have been studied in the solid state. The absence of copper—halogen bond stretching absorptions in the spectra of CuL2Cl2 and CuL2Br2 (L = sc, tsc, scac) is readily interpreted in terms of a high degree of tetragonal distortion along the halogen—copper—halogen axes. However, in the compounds CuLCl2 and CuLBr2 (L = sc, tsc, trz) studied, copper—halogen stretching vibrations have been identified; structures are suggested from consideration of the observed ν(CuX) and ν(CuL) modes. The compounds Cusc2(NO3)2, Cusc2(ClO4)2, and Cutsc2(SO4) appear to contain coordinated or “semi-co-ordinated” oxyanions, but Cuscac2(NO3)2 does not; with Cutsc2(NO3)2 and Cutsc2(ClO4)2 the situation is less certain. Assignments of gn(CuL), ν(Cu-halogen), and ν(Cu-oxyanion) modes are tabulated and discussed in terms of co-ordination number, geometry and bonding. Comparisons with results of mid-infrared and electronic spectral data are made.

1. Results of tests with 39 hydrazine derivatives, 30 compounds with an unsaturated aliphatic moiety, and 117 miscellaneous compounds for induction or inhibition of flowering and toxicity to the pineapple plant are given. In addition, the split pea-stem curvature test results are listed for many of the materials. 2. Ethylhydrazine, sym-diethylhydrazine, β-hydroxyethylhydrazine, unsym-bis-(β-hydroxyethyl)hydrazine, 2-hydroxyethyl N-(2-hydroxyethyl)carbazinate, and 2-(2-hydroxyethyl)semicarbazide were the only hydrazine derivatives which forced pineapple plants to flower. The latter two compounds were not active in all tests. 3. Acetylene, ethylene, and propylene were the only unsaturated aliphatic compounds which forced. Several fairly simple modifications of these compounds eliminated their forcing property. 4. A number of compounds with the functional groups named, and several of the miscellaneous compounds, were in some measure inhibitory to flowering or toxic to the pineapple plant, but it is pointed o...

1. Acrolein was detected in rat liver suspensions incubated in the presence of allyl alcohol and allyl formate. Acrolein was determined by condensation of the distilled aldehyde with semicarbazide, followed by spectrophotometric measurement of the semicarbazone at 257nm and identification by paper chromatography. 2. The transformation of allyl alcohol into acrolein occurred in the presence of NAD+. Inhibitors of rat liver alcohol dehydrogenase inhibited the reaction. 3. It is suggested that the hepatotoxic actions of allyl alcohol and of allyl formate on rat liver are related to their conversion into acrolein.

Improved conditions were described to increase the yield of 3-ketoglycosides, which are formed during the oxidation of several disaccharides and bionates by a strain of aerobic bacteria. These end-products were formed fastest when a heavy inoculum (1014–1015 cells/ml) of non-adapted organisms was used. The aeration rate was found to be very important. An oxygen absorption rate (O.A.R.) of 6 was currently used. In these conditions a 4% solution of lactose, lacto- and maltobionate was nearly quantitatively converted into the corresponding 3-keto-compounds. Maltose and saccharose gave a yield of 12 and 20% respectively. An analytical method to determine 3-ketoglycosides with semicarbazide was described. 3-Ketolactose has been obtained in the crystalline state.

Both 4.6-dimethoxy-(1c) and 4.6.7-trimethoxy-5-acetoacetylbenzofuran 1d are obtained from visnaginone (1a) and khellinone methyl ethers 1b, respectively, by a CLAISEN condensation. The β-diketones 1c and 1d couple with aromatic diazonium compounds to form the hydrazones 2a – i. 1-(4.6-Dimethoxybenzofuranyl)- and 1-(4.6.7-trimethoxybenzofuranyl)butane-1.2.3-trione-2-arylhydrazones 2 a–i react with hydrazine hydrate in acetic acid to yield the corresponding pyrazole derivatives 3a–i or 4a–i. The monohydrazones 5a–b are isolated when 2e or 2i are treated with hydrazine hydrate in ethanol. The hydrazones are converted to the respective pyrazoles by the action of glacial acetic acid. Hydroxylamine hydrochloride reacts with 1.2.3-trione-2-arylhydrazones 2a, c, e, f and i to yield the corresponding isoxazole derivatives 6a–e or 7a–e. The 2-arylhydrazones 2a, c, d, e, h and i form the corresponding pyrazole derivatives 8a–f when treated with semicarbazide hydrochloride.

1. 1. The amine oxidases of Malpighian tubules of Periplaneta americana L. and Blaberus discoidalis Serville accepted agmatine and short-chain aliphatic diamines as substrates; heptamethylene diamine was the subtrate most rapidly oxidized. 2. 2. The Blaberus enzyme did not act upon any monoamine tested. New substrates of the Periplaneta oxidase included the straight-chain aliphatic monoamines. 3. 3. These reactions were not inhibited by semicarbazide.

Mechanism of the Baudisch reaction was investigated using semicarbazide hydrochloride in lieu of hydroxylamine hydrochloride which is one of the reacting components. It was suggested that pyrocatechol-copper-hydroxylamine complex formed as a reaction intermediate is oxidized to o-benzoquinone-copper complex by hydrogen peroxide and one of the carbonyl groups of o-benzoquinone reacts with hydroxylamine hydrochloride to give o-benzoquinone monooxime, i.e. 2-nitrosophenol.

Durch Kondensation des Hydrazin-N.N′-bis-thiocarbonsaureamid-S-monomethylathers mit α-halogenierten Aldehyden, Ketonen, Ketosaureestern usw. erhalt man das S-Methyl-β-[thiazolyl-(2)]-isothiosemicarbazide bsw. seine am Thiazolkern substituierten Abkommlinge. Mit Essigsareanhydrid erfolgt unter Wasserabspaltung Ringschlus zum 1-[Thiazolyl-(2)]-3-methylmercapto-5-methyl-1.2.4-triazol bzw. zu den entsprechenden Derivaten dieser Grundverbindung. Die Prufung einzelner Derivate von beiden Stoffklassen auf ihre tuberkulostatische Wirksamkeit ergab bisher eine geringere Hemmwirkung als Tb I/698.

In phosphorylating mitochondria, isolated in 0.25 M sucrose and suspended in a glycylglycine-KC1 medium at pH 7.4, the N-methyl group of sarcosine is oxidized to formaldehyde, formate, and CO2. The initial rate of O2 uptake in this system is only about half as great as with phosphate-washed mitochondria, in which the N-methyl carbon is oxidized only to the level of “active formaldehyde” and can be recovered as serine-β-carbon and/or formaldehyde. In the glycylglycine-KC1 medium, the O2 uptake with sarcosine occurs in a biphasic manner and the initial slower rate can be extended by the addition of Mg2+, and ADP, AMP, or ATP. O2 uptake is similarly restrained by ADP in mitochondria buffered with imidazole or pyrophosphate. The ADP effect is not observed in the presence of dinitrophenol. The patterns of O2 uptake obtained with ADP in these various media are not altered when the oxidation of the formaldehyde, derived from the N-methyl group, is suppressed by the addition of either semicarbazide or rotenone. With dimethylglycine, another component of the “1-C cycle”, the initial rate of oxidation in glycylglycine or imidazole is enhanced by ADP rather than being decreased. These results together with appropriate coenzyme analyses suggest that reactions of “one carbon compounds” can provide sensitive markers for assessing compartition of cofactors such as the pyridine nucleotides, flavins, and folates in the mitochondrial matrix.

The naturally occurringcis-petroselinic acid gave the lower melting dihydroxy acid, while thetrans-isomer gave the higher melting dihydroxy acid on per-acid oxidation.

According to Zeller-P, the oxidative deamination of amines consists in the substitution of carbonyl groups for aliphatic amino groups. The enzymes which catalyse this oxidative deamination are usually called amine oxidases or dehydrogenases. The amine oxidases are divided in two main groups: the first group consisting of those which attack a-methylamines (e.g. amphetamine), and the second group of those which do not do so. Two categories are distinguishable in the second group: those enzymes which are inhibited in the presence of 10-3 M semicarbazide, and those which are not. The monoamine oxidases belong to this last group of " 10-3 M semicarbazide resistant oxidases". The different groups of amine oxidases are listed in Table 1.

A method was evolved for the determination of hydrazine and hydrazine derivatives (such as phenylhydrazine, semicarbazide, iso -nicotinic hydrazide) with the use of standard bromine monochloride solution. The titration values are not affected by the degree of acidification or by the nature of the acid used. On the basis of the experimental results the principle of the Kurtenacker method of hydrazine determination is interpreted.

A new fluorometric method using semicarbazide for the determination of pyridoxal and pyridoxal 5′-phosphate (PLP) in whole blood, red cells and plasma has been developed. Semicarbazide breaks the Schiff base of PLP and proteins by “trans-Schiffization” reaction and forms semicarbazone of PLP. The semicarbazone of PLP emits strongly at 460 nm when excited at 380 nm. Several metabolic intermediates were tested for the possible interference. Only pyridoxal was found to interfere. The interference can be corrected since pyridoxal emits at 380 nm when excited at 320 nm. Using this method we found that rabbit red cells in vivo are freely permeable to PLP.

The reaction of thiobenzoyl isocyanate with hydrazines is reported. With hydrazine hydrate, 4 H -5-phenyl-1,2,4-triazole-3(2 H )-one was obtained in a good yield. In the reaction with mono-substituted phenylhydrazines, 2,3-dihydro-2-aryl-5-phenyl-1,2,4-triazole-3(1 H )-one or 3-hydroxy-1-aryl-5-phenyl-1,2,4-triazole, or both were formed: the relative amount of the triazoles depended on the nature of the substituents. The reaction with 2,4-dinitrophenylhydrazine, however, gave the semicarbazide which, when treated with aqueous sodium hydroxide or polysphosphoric acid, suffered no ring closure to the triazole. Benzoyl isocyanate reacted with benzylhydrazine, yielding the same triazolone as that obtained from the reaction of thiobenzoyl isocyanate with the hydrazine. The products from these reactions have been identified by independent synthesis as well as IR and UV spectra.

The possible application of benzoylhydrazine, phenylhydrazine, p -nitrophenylhydrazine, 2,4-dinitrophenylhydrazine, isonicotinic acid hydrazide and semicarbazide as reductimetric titrants has been studied. The stability of these substances in various media has been determined and causes of the stability and changes of titre of the solutions are discussed. Among the compounds investigated, isonicotinic acid hydrazide has been found to be the most suitable titrant, its solutions being stable and permitting the rapid and quantitative reduction of a number of inorganic systems.

1. A difference in conformation was found between the collagen in solutions treated with semicarbazide hydrochloride and those treated with sodium chloride. This difference could be correlated with the difference in extent of aggregation between the fibrils precipitated from these solutions. 2. The action of semicarbazide hydrochloride depended on the pH and temperature of treatment in a complex manner. At constant temperature semicarbazide enhanced aggregation at pH values less than 4.3, but decreased aggregation was observed at pH values greater than 5.0. At pH 4.3 the effect of semicarbazide on aggregation varied with temperature, the tendency to increased aggregation being more pronounced at 34 degrees and 36-37 degrees . Similar increased aggregation tendencies superimposed on an overall decreased aggregation were observed at these temperatures at pH8.9. 3. A specific binding of semicarbazide to the collagen molecule was indicated.

Subsitutierte Semicarbazide reagierten in der Schmelze mit Cyanessigsaureestern zu substituierten Aminobarbitursauren; die Struktur der Verbindungen wurde mit Hilfe der Massenspektroskopie geklart. Amidine konnten hingegen mit arylsubstituierten Cyanessigsaureestern in Pyrimidinderivate uberfuhrt werden. Reactions between Substituted Ethyl Cyanoethanoates and 1.1-Disubstituted Semicarbazides Substituted semicarbazides reacted with ethyl cyanoethanoates in the melt to substituted aminobarbituric acids; the structures of these substances were elucidated by mass spectroscopy. Amidines reacted with substituted ethyl cyanoethanoates to pyrimidine derivatives.

1-Aryl-semicarbazide, die durch starke Elektronendonatoren in o- und p-Stellung des Arylrestes substituiert sind, werden durch Sauren zu Chinoniminen und Harnstoffen disproportioniert. In Abhangigkeit von ihrer Substitution werden die Chinonimine entweder hydrolysiert oder sie oxydieren ein zweites Molekul Arylsemicarbazid. Die Reaktion ist spezifisch saurekatalysiert und folgt in allen Fallen einem Gesetz 1. Ordnung bezuglich H⊕-Ionen und Substrat. — Analogien zur Disproportionierung von Hydrazobenzolen und zur Osazon-Reaktion werden aufgezeigt. The Disproportionation of Arylsemicarbazides 1-Arylsemicarbazides, when activated with strong electron donating substituents in o- or p-position, are disproportionated by acids to form quinone imines and ureas. Dependent on their substitution the quinone imines are either hydrolized or they oxidize a second molecule of semicarbazide. This reaction shows specific acid catalysis and is of first order in H⊕ ions and semicarbazide. — Similarities to the disproportionation of hydrazobenzenes and to the osazone reaction are discussed.

Methods are described for measuring the velocity of the reaction CH 2 (OH) 2 → CH 2 O+H 2 O in aqueous solution by making use of the rapid reaction of unhydrated formaldehyde with the scavenging reagents semicarbazide, hydroxylamine, phenylhydrazine, hydrazine and sulphite. The reaction exhibits general acid-base catalysis, and catalytic constants are given for 14 acids and 30 bases. Relations between acid-base strength and catalytic power extend over an unusually wide range of velocities and types of catalyst, and this behaviour is discussed in terms of reaction mechanisms. The catalytic behaviour observed shows unexpected contrasts with that reported for the hydration of carbon dioxide. It is shown that, contrary to previous reports, the rate of removal of formaldehyde from aqueous solution by a gas stream is not appreciably affected by the rate of dehydration of methylene glycol. A few experiments are reported on the application of the chemical scavenger method to measure the rate of the reaction CH 3 CH(OH) 2 → CH 3 CHO+H 2 O, and the results compared with those obtained by other methods.

SummaryXanthine dehydrogenase (XD) activity of rat serum was shown to be inhibited in vitro and in vivo by semicarbazide. The inhibition in vivo occurs during the latent period that precedes the seizures produced by the drug. It seems that the convulsant activity of SC is not related to the XD inhibition. XD activity approaches control values either by addition of NaBr (which increases the latent period) or by administration of compounds containing free carbonyl groups, such as acetone, without increasing the latent period. Sulfite oxidation by the serum enzyme is also inhibited in vitro both aerobically and anaerobically.

Sulfhydryloxidase could be concentrated with Sephadex G 2000 after centrifugation at 0° C. The inactivation-constant was 2.5–3.1 X 10a at temperatures between 65 and 69° C; the Arrhenius-energy was 6723 cal mol−1. The enzyme could be seperated incompetetively with KCN respectively with ascorbic acid and competetively with semicarbazide and guanin. Activation of sulfhydryloxidase by FAD was possible up to a maximum, which was not inereased even by further addition of FAD.

Inhibition of histamine synthesis in vivo was examined in terms of effects on the kinetics of decline of exogenous 3 H-histamine in various tissues of the female rat. Inhibition of tissue histidine decarboxylase activity by dietary pyridoxine deficiency coupled with semicarbazide administration greatly reduced rates of decline in vivo of labeled amine. On the assumption that exogenous 3 H-histamine equilibrates with endogenous amine in nonmast-cell pools, estimated rates of turnover of loosely bound histamine were reduced 30–75 per cent. The histidine decarboxylase inhibitor, NSD-1055 (4-bromo-3-hydroxybenzyloxyamine) was ineffective in reducing endogenous histamine levels and did not affect the kinetics of decline of 3 H-histamine. It is suggested that the kinetics of 3 H-histamine in vivo decline and the tissue histidine decarboxylase activity in vitro may reflect the same biochemical phenomenon—presumably the synthesis and catabolism of loosely bound nonmast-cell histamine in dynamic endogenous pools.

1. Cytidine residues of yeast RNA have been specifically converted into semicarbazide derivatives without altering any other bases. In this reaction the C-4 amino groups of cytidine residues were converted into a semicarbazido group. 2. tRNA modified with semicarbazide was completely hydrolysed to nucleoside 5′-phosphate with snake venom phosphodiesterase (orthophosphoric diester phosphohydrolase, EC 3.1.4.1). The base composition of the tRNA was estimated after separation of the nucleotides by ion-exchange column chromatography. A quantitative estimation of the modified cytidine residues in the tRNA was achieved by this method. 3. The results of sedimentation analysis and gel filtration of the tRNA modified with semicarbazide indicated that no splitting of the internucleotide bonds of the RNA occurred during the reaction. 4. The temperature-absorbance relationship plotted for the modified tRNA indicated that the secondary structure in the tRNA decreased with increasing extent of modification. 5. The rate of this modification reaction is low when cytosine groups are highly hydrogen bonded (double-stranded DNA). 6. A simple method for estimating the extent and rate of the modification reaction of cytidine residues in nucleic acids is proposed. In this procedure the specific light absorption of the 4-deamino-4-semicarbazidocytidine residue in the range 300–340 mμ at pH 13 is followed.

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Some properties of insoluble corneal collagen were studied using the specific depolymerization action of pronase, pepsin, bacterial α-amylase, 6 M urea, 2% semicarbazide, 2% semicarbazide in combination with 0,5 M Na2CO3, and 0,5 M Na2CO3 alone. Pronase and pepsin released 1.9 % and 1.2 % of the telopeptides in bovine corneal collagen similar to the amount released from other connective tissues (skin 2.6% and 1.9%). Pronase, pepsin and α-amylase solubilized 8.8 %, 2.1%, 24.7 % of insoluble bovine corneal collagen, respectively. It can be concluded that cross-links in corneal collagen are located in the body of the collagen molecule and not in the telopeptide region. The results of the polyacrylamide gel electrophoresis indicate that the α2 chain is presumably much more involved in the cross-linking interactions than α1 The only way to solubilize bovine corneal collagen is the simultaneous treatment of the collagen with semicarbazide and Na2CO3, at pH 10, which seems to be a useful tool for further structu...

Semicarbazid, H2N-CONHNH2, setzt sich mit uberschussigem PCl5 in OPCl3 so um, das die Hydrazinfunktion die Gruppierung NNPCl3 bildet. Die Amidfunktion liefert das viergliedrige System und die Carbonylfunktion setzt sich mit PCl5 und OPCl3 um, wie das von organischen Sareamiden her bekannt ist. Es entstehen Verbindungen: mit R = Cl oder OP(O)Cl2. Mit weniger PCl5 entstehen Polymere, in denen auch Hydrazinfunktionen uber PCl3 intermolekular verknupft sind. Semicarbazide, H2N=;CONHNH2, reacts with an excess of PCl5 in POCl3 yielding, from the hydrazide groups, the NNPCl3 grouping; from the amide group, the fourmembered cyclic system I (see above) is formed. Thus, compounds of the type II with RCl; OP(O)Cl2 result, whereas from semicarbazide and PCl5 in the mole ratio 1:2 polymeric compounds are formed in which hydrazine groups are interconnected by PCl3 groups.

1 . Young Wistar rats fed on a diet containing 0·3 per cent semicarbazide hydrochloride developed the characteristic lesions of osteolathyrism. This consisted of kyphoscoliosis, displacement of epiphyses and dislocations of joints. A pathological study of the skeletal lesions showed widening, disorganisation and tears of the epiphysial plate with the zone of maturing cartilage showing the greatest increase in width. The severe kyphoscoliosis was due to a derangement and displacement at and through the epiphysial plates of the twelfth thoracic or first lumbar vertebra. 2. Some of the compounds that are known to produce osteolathyrism in laboratory animals are beta aminopropionitrile, amino acetonitrile, mercaptoethylamine and semicarbazide. The mode of action of the lathyrogenic compounds was analysed in the light of a number of experiments done in this laboratory. 3. lt is possible that they interfere with the metabolism of the epiphysial plate. There appears to be a decreased polymerisation of the ground substance of the epiphysial cartilage, but the exact metabolic reaction involved is not known. Other chemicals of similar structure, with the same reactive groups, did not show lathyrogenic properties. It is concluded that it is not a particular chemical structure, configuration or specific reactive group that is responsible for the production of osteolathyrism. The chemistry of the lesions still remains to be solved.

The effect of semicarbazide on the oxidation of choline by rat liver mitochondria was studied. Semicarbazide was used to prevent both further oxidation of betainealdehyde and product inhibition of choline dehydrogenase by the aldehyde. NAD did not stimulate choline-based respiration when semicarbazide was present to prevent the oxidation of enzymatically formed betainealdehyde. In contrast, NAD did stimulate respiration when the semicarbazide was omitted. NAD stimulation of choline-supported respiration appears to be entirely due to its effect on the oxidation of betainealdehyde. In both the presence and the absence of semicarbazide, rotenone inhibited the oxidation of choline. It was concluded that the rate of choline oxidation to betainealdehyde is decreased by rotenone and that this inhibition is not due to product inhibition by betainealdehyde. Choline oxidation by submitochondrial particles was insensitive to rotenone. Inhibition of respiration by rotenone was found to be competitive with respect to choline. Acetate ion eliminated the rotenone sensitivity of choline oxidation. These results suggest that rotenone may inhibit choline oxidation by reducing the rate of entry of choline into intact mitochondria.

Summary Histaminase or diamine: oxygen oxydoreductase (E.C.1.4.3.6.) has been purified 9,600 times from human placenta. The major difficulty was to eliminate hemoglobin from the extracts. In addition, the enzyme has to be stabilized by sucrose during the last steps. As fractionation progresses, a latency time up to 3 h 30 mn modifies the enzymatic kinetic. This latency time is annihilated by preincubation without histamine at 37°C. The enzyme requires Mn++ ions and hemoglobin; there is a potentiating effect for these activators. The isoelectric point is near 6.0 and histaminase is unstable at this pH. The optimum pH is 7.4. The optimum temperature is superior to 45°C. Filtration on Biogel reveals 4 active forms whose molecular masses are multiples from 1 to 4 of 125,000 ± 5,000. Apparent Michaelis constants determined for histamine, putrescine and cadaverine are respectively 0.6 × 10−5 M, 3.3 × 10−6 M and 3.3 × 10−6 M. Histaminase is inhibited by excess histamine but other diamines do not entail this result. Monoamines are not altered by the enzyme. Aminoguanidine is the best inhibitor; semicarbazide is much less active. According to several of its physico-chemical characteristics, diamine: oxygen oxydoreductase from human placenta is different from similar enzymes already described.

1. 1. Bovine plasma and aorta amine oxidase (amine: O 2 oxidoreductase (deaminating), EC 1.4.3.4) were purified approx. 60- and 170-fold, respectively. The aorta enzyme appeared to be non-mitochondrial, did not catalyze the oxidation of common short chain diamines and, in general, possessed properties previously described for plasma amine oxidase. 2. 2. In the n -alkylamine series, CH 3 (CH 2 ) n CH 2 NH 2 , the longer chain homologues were bound more tenaciously by both enzymes than the short chain homologues. 3. 3. The aorta enzyme was inhibited by chelating agents and activity could be partially restored by addition of Cu 2+ . Activity was lost when the aorta enzyme was incubated in the presence of cyanide, hydroxylamine, semicarbazide, isoniazid and iproniazid. 4. 4. Preparations of amine oxidase from aorta catalyzed the oxidation of peptidyl lysine when lysine-vasopressin was used as substrate, but the plasma enzyme was inactive. The polyamines, spermine and spermidine, also served as substrates for the aorta enzyme and, relative to benzylamine, they were oxidized at the same rates as when the oxidation was catalyzed by the plasma amine oxidase.

All of Kern's (1966) claims concerning the mechanism and the conditions of the 3-ketolactose test for the specific detection of Agrobacterium tumefaciens and A. radiobacter, were experimentally refuted. Kern's unknown compound, which he holds to be responsible for the test, was identified by us as lactulose, an impurity arising from lactose by heatsterilization; it is not responsible for a positive test. It remains firm facts that 3-ketolactose is the only reducing end-product responsible for the test, that A. rhizogenes is 3-ketolactose negative, that buffering the test medium does not improve it and that semicarbazide can be used for the quantitative determination of 3-ketolactose.

1. The carbonyl reagents, i.e., hydroxylamine, semicarbazide and thiosemicarbazide, incite in mice the running fit which can be prevented by pyridoxine.2. Carbonyl reagents containing a quaternary amine, i.e., Girard T and Girard P reagents, however, do not incite the running fit.3. INAH and BAH, compounds analogous in structure to carbonyl reagents, incite the running or jumping fit. The seizure incited by these two compounds, however, can not be prevented by pyridoxine. Pyridoxine has, on the contrary, an intensifying effect.

Paper electrophoresis in semicarbazide hydrochloride solution has shown that uranyl ion forms unit positively charged complex at pH 2.25. In 0.4 M hydrochloric acid, no detectable uranyl-chloro complexes were formed. Electroosmotic flow created a water film extending from the cathode to the anode, and rendered the transference number of uranyl ion to zero at the margin of the water film. An improved method of paper chromatography was presented.