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By a novel addition reaction of o-aminobenzenethiol to 5-methoxycarbonylmethylidene-2-thioxo (or oxo)-4-thiazolidones (I) were obtained 5-(3-oxo-2, 3-dihydro-4H-1, 4-benzothiazin-2-yl)-2-thioxo (or oxo)-4-thiazolidones (III). I was also found to reat with thiols to afford 1 : 1 adducts (II and VI) in the presence of a catalytic amount of triethylamine. Thermal cyclization of the adducts (II) to III was observed. The adducts (VI) were proved to dissociate into I and thiols when heated above their melting points or dissolved in acetone or ethanol. Oxidation of III and VI gave the dehydro-compounds (IV and VIII), respectively.

The effect of H 77/77 on motility was investigated after s. c. injection to rats in a familiar cage. The doses 2.5 and 5 mg/kg produced hypermotility consisting of locomotion, sniffing, rearing, head twitch and various grooming movements. H 77/77 5 mg/kg was administered to rats treated s. c. with various drugs affecting brain monoamines. The H 77/77-hyperactivity was antagonized by: the tyrosine hydroxylase inhibitor H 44/68 (250 mg/kg), the dopamine-Β-hydroxylase inhibitor FLA 63 (40), the NA receptorblockers aceperone (1.1) and phenoxybenzamine (0.8), the thymoleptics imipramine (0.7), desipramine (6.3), chlorimipramine (1.5), amitriptyline (0.1), nortriptyline (1.0), protriptyline (0.7) and doxepine (0.3) as well as the neuroleptics chlorpromazine (0.015), thioridazine (0.7), perphenazine (0.008), chlorprotixene (0.03), haloperidol (0.02), spiramide (0.03), pimozide (0.04) and clozapine (0.014). The serotonin synthesis inhibitor H 69/17 (200), the Β-blocker propranolol (10) and the antiparkinsonian agent benztropine (10) showed no H 77/77 antagonism. These results indicate that release of catecholamines, especially NA, is involved in the mediation of H 77/77-induced hypermotility and that NA-membrane blocking thymoleptics inhibit uptake of H 77/77 into brain NA-neurons. Activation of both NA- and DA-receptors are necessary for the production of the H 77/77 behavioral syndrome as selective blockade of either system can prevent it.

Crystal deposits in human kidney and thyroid, identified as calcium oxalate by microincineration and Solubility tents, were used to assess the staining of oxahtes by selected methods for calcium. No method that stained the crystals was considered specific for calcium oxalate, but, after removal of possible phosphate and carbonate with 2 M acetic acid, the silver nitrate-rubeanic acid sequence was found to give the best visualisation of the crystals, and could be considered reasonably selective. Deposits in kidneys included a pronounced colloidal matrix composed chiefly of acid mucopolysaccharides. This matrix often showed a lamellar pattern and was well-demonstrated by alcian blue at pH 25 and by dialysed iron after removal of the crystals with 1 N hydrochloric acid. Such a matrix Could only be detected in trace amount in the thyroid deposits.

Rat cortex slices were incubated with 3H-dopamine (3H-DA), and the effect of desipramine (DMI) was studied on the accumulation of 3H-DA and 3H-noradrenaline (3H-NA) in the tissue and the concentrations of 3H-DA and 3H-NA in the incubation medium. This effect was compared with the effect of cocaine, reserpine and FLA 63 studied by the same technique, in order to elucidate the mechanisms of action of DMI. All the drugs induced a significant decrease of 3H-NA accumulation in the cortical tissue. The 3H-DA retention varied: cocaine and reserpine caused a significant decrease, FLA 63 a marked, significant increase, and DMI a slight, but significant increase. In the incubation medium, 3H-DA significantly increased after DMI, cocaine and reserpine, and remained unchanged after FLA 63. In all experiments 3H-NA in the medium was very low. It is suggested that DMI in cortex slices may exert a double mechanism of action on the final step in the noradrenaline biosynthesis: 1. an inhibition of the 3H-DA uptake at the level of the noradrenergic cell membrane, and 2. an inhibition of the intraneuronal transport of 3H-DA to sites where it is converted to 3H-NA, concomitant with an increased intraneuronal 3H-DA accumulation. Other possibilities are discussed.

1. The reactions of 2,2'- and 4,4'-dipyridyl disulphide (2-Py-S-S-2-Py and 4-Py-S-S-4-Py) with l-ergothioneine (2-mercapto-l-histidine betaine), 2-mercaptoimidazole, 1-methyl-2-mercaptoimidazole, thiourea, thioacetamide, 2-thiopyridone (Py-2-SH) and 4-thiopyridone (Py-4-SH) were investigated spectrophotometrically in the pH range approx. 1-9. 2. These reactions involve two sequential reversible thiol-disulphide interchanges. 3. The reaction of l-ergothioneine with 2-Py-S-S-2-Py and/or with the l-ergothioneine-Py-2-SH mixed disulphide, both of which provide Py-2-SH, is characterized by at least three reactive protonic states. This provides definitive evidence that neutral l-ergothioneine is a reactive nucleophile, particularly towards the highly electrophilic protonated disulphides. 4. A similar situation appears to obtain in the reactions of l-ergothioneine and Py-2-SH with 4-Py-S-S-4-Py and in the reactions of the other 2-mercaptoimidazoles, thiourea and Py-4-SH with 2-Py-S-S-2-Py. The nucleophilic reactivity of Py-4-SH suggests that general base catalysis provided by the disulphide in a cyclic or quasi-cyclic transition state is not necessary to generate nucleophilic reactivity in the other amino-thiones whose geometry could permit such catalysis. 5. The existence of a positive deuterium isotope effect in the l-ergothioneine-2-Py-S-S-2-Py system at pH6-7 provides no evidence for general base catalysis but is in accord with a mechanism involving specific acid catalysis and post-transition-state proton transfer. 6. The pH-dependences of the overall equilibrium positions of the various thiol-disulphide interchanges are described. 7. Reaction of thioacetamide with a stoicheiometric quantity of 2-Py-S-S-2-Py at pH1 provides 2 molecules of Py-2-SH per molecule of thioacetamide and elemental sulphur; these findings can be accounted for by thiol-disulphide interchange to provide a thioacetamide-Py-2-SH mixed disulphide followed by fragmentation to provide CH(3)CN, S and Py-2-SH. 8. Provision of high reactivity in the neutral forms of the members of this series of sulphur nucleophiles by electron donation by the amino group is compared with the well known alpha effect that provides enhanced nucleophilicity in compounds containing an electronegative atom adjacent to the nucleophilic atom. 9. The decrease in the u.v. absorption of l-ergothioneine at 257nm consequent on transformation of its aminothione moiety into an S-alkyl-2-mercaptoimidazole moiety provides a convenient method of following the alkylation of l-ergothioneine by iodoacetamide. 10. The pH dependence of the extinction coefficient of l-ergothioneine at 257nm is described by epsilon(257)={8x10(3)/(1+K(a)/[H(+)]} +6x10(3)m(-1).cm(-1) in which pK(a)=10.8. 11. In the pH range 3-11 the reaction is characterized by two reactive protonic states (X and XH). 12. The X state, reaction of the ionized 2-mercaptoimidazole moiety of the l-ergothioneine dianion with neutral iodoacetamide, is characterized by the second-order rate constant 4.0m(-1).s(-1) (25.0 degrees C, I=0.05). The XH state, characterized by the second-order rate constant 0.03m(-1).s(-1), is interpreted as reaction of the thione form of the neutral 2-mercaptoimidazole moiety of the l-ergothioneine monoanion with neutral iodoacetamide. 13. The XH state of the alkylation reaction does not exhibit a deuterium isotope effect.

Safety evaluation data have been presented for a shampoo formulation containing zinc 2-pyridinethiol 1-oxide at 2% and 10% levels. In addition toxicity studies have been carried out in dogs with a w o emulsion of ZnPT. The dog seems to be the species most susceptible to the effects of the compound itself, but it shows no effects to the shampoo formulation. The Rodentia show paralytic symptoms when the material is ingested in the diet at rather low levels for a period of several weeks. No ocular toxicity is observed in rabbits, rats, or monkeys, but it is observed in the dog. The shampoo containing ZnPT did not produce sensitization or undue irritation of the skin. In addition the effect of the shampoo vehicle on rabbit eyes was not increased by the incorporation of ZnPT. Since the shampoo formulation investigated is emetic and does not penetrate the skin, there would appear to be no hazard associated with its use.

Rapeseed meals derived from heat-treated seed samples representing a large variation in glucosinolate content, which was principally due to genetic differences, were fed to mice as the only protein source. A glucosinolate content corresponding to a level of more than 1 mg potential isothiocyanates and oxazolidinethiones per g of diet depressed the 11-day growth of mice as well as feed consumption and protein efficiency ratios.

The activity of the enzymes glutamate decarboxylase (GAD) and GABA-2-oxoglutarate transaminase (GABA-T), the endogenous GABA and glutamate levels and the half-lives ( t 1 2 values) of radioactive GABA and glutamate have been measured in the brains of untreated rats and in those injected with aminooxyacetic acid (AOAA), thiosemicarbazide (TSC) and haloperidol. The effect of the drugs in vitro on a purified preparation of glutamate dehydrogenase (GDH) was also measured. AOAA profoundly inhibited GABA-T, did not inhibit GAD and in in vitro experiments activated GDH. Brain glutamate levels were unaffected by the drug as was the half-life for glutamate. Brain GABA levels were elevated after AOAA and the rate of disappearance of radioactive GABA slowed. TSC did not significantly alter either GABA or glutamate brain levels but did significantly inhibit GAD and GDH activities. In addition, TSC had no effect on the half-life of either GABA or glutamate. Haloperidol was an effective inhibitor of GDH in vitro and reduced brain glutamate concentrations in vivo. Moreover, the rate of disappearance of radioactive GABA was increased whereas that of glutamate was decreased. The drug had no effect on GAD and GABA-T activities or on brain levels of GABA. It is suggested that the behavioural effects of haloperidol might in part be due to actions on the metabolism of GABA and glutamate. Interaction of TSC with glutamate metabolism might be a factor in seizure-provoking activity of the drug.

2,3-Dichloro-1,4-naphthoquinone is reacted with thioamides in microquantities in the presence of ammonia in an alcoholic medium to give colored products showing absorbance maxima between 530 and 540 nm. The reaction is specific for thioamides and forms the basis of its spot test. The reaction is also used for the quantitative determination of ethionamide in tablets. The results compare favorably with those obtained by the official BP method. The method is simple, accurate, and precise.

ConclusionThis work demonstrates that the inhibition of gonadotropin-induced ovulation by an extract of the bovine pineal gland is caused by the presence of a neuraminidase-type enzyme that rapidly deactivates the HCG. It is of interest to note that a gonadotropin-inhibiting substance isolated from bovine pituitary extracts, which is capable of inhibiting the ovarian weight increase caused by follicle-stimulating hormone and HCG in rats, has been found to contain a neuraminidase enzyme (9).Thus the present paper may help to elucidate the reported gonadotropin-inhibiting properties of several pineal extracts. Where previous studies (10–12) have demonstrated that the extracts suppress the stimulatory effect of HCG, human menopausal gonadotropin, or PMS on the rodent gonad or uterus (an effect not caused by melatonin (10)), the presence of this neuraminidase-type enzyme may now explain this inhibition of the action of gonadotropin.

Some 3-substituted 1,2,3,4-tetrahydroquinazoline-2-thiones were prepared by first synthesizing the N-substituted- o -nitrobenzylamines, then the corresponding N-substituted- o -aminobenzylamines. The tetrahydroquinazoline-2-thiones were then obtained by refluxing the diamine with carbon disulfide. It is suggested that antithyroidal, antitubercular, and/or antifungal properties might be present in these condensed ring thiones.

Summary. The behaviour of 70 strains of salmonellae belonging to 44 serotypes in Rappaport's broth and in Muller-Kauffmann's tetrathionate broth was examined. With an inoculum of 5–25 cells, 5 strains did not grow in Rappaport's medium, 2 multiplied slowly and 63 grew strongly in 24 h. With an inoculum of 100–500 organisms all but one strain grew readily in 24 h. In Muller–Kauffmann's tetrathionate broth inoculated with pure cultures of salmonellae, growth of many strains was markedly inhibited, in the absence of added faeces, at 37° and 43°. This inhibition was more severe with light inocula at 43°. The addition of 0.05% (w/v) of salmonella-free human faeces to Muller–Kauffmann's tetrathionate broth, did not stimulate growth of salmonellae. In contrast, the addition of 5% (w/v) of human stools to this medium resulted in a heavy growth of the added salmonellae, especially at 43°.

The sodium salt of 1-allyl-2-tetrazoline-5-thione (NaATT-5) is proposed as a new reagent for the detection of IO3−, I−, and Bi(III) ions. An aqueous solution of NaATT-5 reduces IO3− in acid medium to free iodine (formed via iodide) which is detected by reaction with starch. S2O32− is the only interfering species. I− and NO2− interfere only when both are present together. NaATT-5 also reacts with bismuth to form a canary yellow precipitate of [BiL2]+ X− (where X=a univalent anion other than I−; L=ATT-5). When the yellow precipitate is treated with iodide, X− is replaced by I− to form a complex [BiL2]+I−, which is orange in colour. This reaction provides the basis for the detection of bismuth as well as of I−. In the test for bismuth, Cu(II), Fe(III), S2O32−, IO3−, IO4−, and large quantities of NO2− interfere. The last four anions also interfere in the test for iodide. A method for the preparation of NaATT-5 is also reported.

3-Alkyl benzoate/benzhydrazide aminomethyl benzoxazole/benzthiazole-2-thiones were synthesized and evaluated for their ability to affect the respiratory activity of rat brain homogenate. All compounds were found to inhibit selectively the nicotinamide adenine dinucleotide (NAD)-dependent oxidation of DL-isocitrate, α-ketoglutarate, and pyruvate while NAD-independent oxidation of succinate remained unaltered. Inhibition of monoamine oxidase by 3-benzhydrazide aminomethyl benzoxazole/benzthiazole was greater with benzthiazoles as compared to the corresponding benzoxazoles. Anticonvulsant activity exhibited by these benzoxazole/benzthiazole derivatives against pentylenetetrazol-induced seizures was found to be unrelated to their enzyme inhibitory properties.

A colorimetric method for the determination of iota-carrageenan is described, based on the measurement of the yellow colour developed by the reaction of the 3,6-anhydro-D-galactose residue with 2-thiobarbituric acid and hydrochloric acid. The method has a sensitivity equivalent to 0·01 mg ml–1 of carrageenan and can also be used to determine carrageenan in blood and urine in concentrations of 0·02 and 0·01 mg ml–1, respectively. The method has advantages of sensitivity, relative specificity, a small sample-volume requirement and convenience over previously published methods for the determination of sulphated polysaccharides, thus providing a means of extending quantitative biological investigations of this group of substances.

Thin-layer chromotographic techniques are described for the preparation and separation of water-soluble compounds formed by the autoxidation of pure linoleic and linolenic acids. Location of 15 main fractions with Schiffs reagent on fibreglass sheets was possible. These could be eluted for biological testing and chromogenic behaviour with thiobarbituric acid reagent. At least 7 bands from autoxidized linoleic acid and 9 from autoxidized linolenic acid had peak absorbance maxima at 532 nm identical to that characteristically given by malonyldialdehyde (MDA). Possible reactions and interpretations for the MDA test are discussed.

Anaerobic reversal of catabolite repression was partially eliminated if tetrathionate was reduced to thiosulphate.

The hydrolysis of ®NH3· (CH2)5· CS · S · C2H5 [C7H7SO3⊖] ethyl 6-ammoniumdithiohexonate p-toluene sulfonate is catalyzed by trypsin, its Michaelis-Menten parameters being (pH = 6.6, 25°C, [KCl] = 0.1 M): Km= 5.1 ± 0.4 mM, kcat= 0.0275 ± 0.006 s−1. This is the first example of a trypsin-catalyzed hydrolysis of dithioamino-acid esters. The final product of the tryptic hydrolysis is the corresponding dithio acid. The ester proved to be a competitive inhibitor for the tryptic hydrolysis of the specific substrate N2-benzyl-l-lysine ethyl ester p-toluene sulfonate, the inhibition constant K1 being equal to Km. These experiments indicate that the cleavage of the dithioamino acid ester takes place in the same active area of the enzyme as that of the specific substrate. However, in the case of ethyl 6-ammoniumdithiohexanoate p-toluene sulfonate, trypsin catalyzes the S-alkyl cleavage. This appears to be the first example of a hydrolysis by a proteolytic enzyme where the intermediate formation of an acyl enzyme is excluded.

Rats were perfused with a l2% solution of polyvinyl pyrrolidone (pH 7.25). Frozen sections were prepared from spinal cord and kidney and incubated under conditions that are known to be optimal for demonstrating the p-nitrophenylphosphatase activity of (Na+-K+)-adenosine triphosphatase (ATPase). After incubation, the sections were treated sequentially with cobalt chloride and ammonium sulfide to visualize the reaction product. The reaction product was localized perferentially to the neuropil of the spinal cord and to the distal tubules of the kidney. In addition to the histologic localization, the following observations indicate that the histochemical reaction is specific for demonstrating (Na+-K+)-ATPase activity: (a) the conditions that are optimal for the p-nitrophenylphosphatase activity of purified (Na+-K+)-ATPase were also optimal for our histochemical method; (b) the histochemical reaction was inhibited by ouabain; and (c) the p-nitrophenylphosphatase reaction occurred under conditions that inhibit alkaline phosphatase activity. An additional advantage of this procedure is that it employs a perfusion solution which, although it contains no fixative, preserves the integrity of the tissue after freezing to a degree suitable for light microscopic examination.

Recovery of Salmonella from low-moisture foods was studied using selective enrichment in tetrathionate brilliant green and selenite-cystine broths at 35C and 43C. A total of 1375 samples of dried dairy, soya, and rendered animal by-products were analyzed. All samples were preenriched before selective enrichment. No significant difference in recovery was detected between tetrathionate brilliant green and selenite cystine at either temperature, which is in contrast to our earlier findings with red meats. Pairing of enrichment conditions resulted in the detection of more positive samples than the use of any single enrichment condition.