Synthesis and pharmacological activity of triazolo[1,5-a]triazine derivatives inhibiting eosinophilia

In continuation of our previous work on eosinophilia inhibitors, we synthesized an additional series of inhibitors, which consisted of 5-amino-1-[(methylamino)thiocarbonyl]-1H-1,2,4-triazole derivatives and a newly developed series of 1,2,4-triazolo[1,5-a]-1,3,5-triazine derivatives. We evaluated their inhibitory activity on the airway eosinophilia model, which was induced by the intravenous (iv) injection of Sephadex particles. In the 1,2,4-triazole series with various substituents at the 3 position of the triazole ring such as 2-furyl, pyridyl, and phenoxy, none of derivatives had comparable activity to the previously reported compound GCC-AP0341, 5-amino-3-(4-chlorophenyl)-1-[(methylamino)thiocarbonyl]-1H-1,2, 4-triazole. In the triazolo[1,5-a]triazine series, 2-(4-chlorophenyl)-6-methyl-1,2,4-triazolo[1,5-a]-1,3, 5-triazine-7(6H)-thione (3h) was highly potent, and when given orally it had an ID50 value of 0.3 mg/kg, which is comparable to that of GCC-AP0341. The fact that the structure-activity relationship of these two series was quite similar suggests that a common substructure, such as the 1,2,4-triazole ring with a substituted phenyl ring at the 3 position and a thiocarbonyl moiety at the 1 position, could contribute to the activity. Our selected compound 3h was less active than GCC-AP0341 in the antigen-induced hyper-responsiveness model in guinea pigs; however, we plan to carry out further studies on eosinophil functions, especially on their activation, using our two compounds, 3h and GCC-AP0341.     

Synthesis of 6-aziridinylbenzimidazole derivatives and their in vitro antitumor activities

In search for new antitumor agents, twelve 6-aziridinylbenzimidazole derivatives were synthesized and their cytotoxicities were tested against three cancer cell lines (mouse lymphocytic leukemia P388 and B16, and human gastric carcinoma SNU-16). From 4-amino-3-nitrotoluene as the starting material, 2-(acetoxymethyl)benzimidazoles (5a-d) were obtained by Phillips reaction. These benzimidazoles were then reacted with Fremy's salt to give a mixture of three 2-(acetoxymethyl) (8a-c) and four 2-(hydroxymethyl)benzimidazole-4,7-diones (9a-d). Addition of these quinones with aziridine afforded 6-aziridinyl-2-(acetoxymethyl) (10a-c) and 6-aziridinyl-2-(hydroxymethyl)benzimidazole-4,7-diones (11a-d). Utilizing 2-(hydroxymethyl)benzimidazole-4,7-diones (9b,d), esters 10d and 13e-h were prepared by the sequential reactions of esterification and addition. The synthesized compounds show potent cytotoxicity against all of three cell lines tested. The cytotoxicities of 10a-d or 11a-d against SNU-16 were superior to those of 13e-h, and were equal to or slightly higher than that of mitomycin C. Compounds 11a-d were slightly more cytotoxic than 10a-d in all cell lines tested.     

Synthesis of some chroman derivatives and preliminary investigation on their vasodilatory activity

In this study, some N'-(chroman-4-yliden)-4-aryl-2-thiazolylhidrazide derivatives were synthesized. Their structures were elucidated by IR, NMR and microanalyses. The vasodilatory activities of the compounds obtained were examined in vitro.     

Synthesis of 5-substituted quinazolinone derivatives and their inhibitory activity in vitro

Quinazolinone derivatives I and their methyl esters were synthesized and evaluated as nonclassical lipophilic inhibitors of thymidylate synthase. Compounds Ib and Ic containing OH and CO2H as R substituents, respectively, were most effective, indicating that hydrogen bonding may contribute to the increased inhibitory activity. These compounds further showed high cytotoxic activity against tumor cells in culture.     

Synthesis of N-aryl-N'-heteroaryl-substituted urea and thiourea derivatives and evaluation of their anticonvulsant activity

Starting from amino(di)azines and 2-chloro-6-methyliso(thio)cyanate a series of aryl-substituted urea and thiourea derivatives was prepared and screened as potential antiepileptics. Among the new derivatives tested, only 2b and 3c exhibited adequate anticonvulsant effects, whereas 3d and 4d were found to be convulsants per se.     

Synthesis of adenine derivatives and their activities against herpes virus in vitro

A series of 9-(N4-substituted acetaldehyde thiosemicarbazone) adenines were synthesized and evaluated for antiherpes virus activity. Compounds 4a-l were prepared by condensation of 9-(acetaldehyde) adenine(6) and the corresponding N4-substituted thiosemicarbazides (10). The antiviral effects of all compounds 4a-l were tested in vitro in primary rabbit kidney cell cultures infected with herpes simplex virus type 1 (HSV-1) and varicella-herpes zoster virus (VZV), and in primary human embryo cell cultures infected with herpes simplex virus type 2 (HSV-2). The results showed that the minimum inhibitory concentrations (MIC) of 4e and 4f for HSV-1 and VZV were 20, 40, 20 and 20 micrograms.ml-1, respectively, and other compounds were 200 micrograms.ml-1. For HSV-2, the MIC of all tested compounds were 300 micrograms.ml-1. We also evaluated the antiherpetic effect of 4e (and 4f) by combination with acyclovir (ACV) in the ratio of 1:1 in vitro. The MIC of the combined compounds were 2 micrograms.ml-1 for 4e and 6 micrograms.ml-1 for 4f, while their minimum cytotoxicities (MCC) in the cell were markedly reduced compared with the individual compounds.     

Teratogenic and embryotoxic activity of several 2,4-diaminopyrimidine derivatives

The degree of teratogenic and embryotoxic effects is dependent not only on the period of gestation and the agent dosage but also on the chemical structure of its molecule. In the series of derivatives of 2,4-diamino-5-phenylpyrimidine with different length of the alkul radical in the 6 position the preparation with ethyl group has the greatest injuring effect. Thus, the structural distinctions in the molecules of pharmacological agents are responsible for the selective toxicity of drugs in relation to mammalian embryos.     

Synthesis and applications of phosphonoacetic derivatives

In this paper, the synthesis of new phosphonoacetic acid derivatives and their applications in fields of biotechnological interest are discussed. Phosphonoacetic acids are competitive inhibitors of alkaline phosphatase, an enzyme widely used in diagnostics, as colorimetric detection tool. The phosphonoacetic acid's inhibition activity has been exploited by us for the obtainment of an innovative technique for non-radioactive DNA probes detection, the last being based on DNA labeling with the enzyme inhibitor, followed by detection by means of the chromogenic enzyme and substrate. Moreover, we have found a further application of phosphonoacetic acids, by the preparation of an affinity chromatography support that has been revealed to be very effective in the purification of alkaline phosphatase. Finally, phosphonoacetic acid derivatives have been tested also for their antiviral activity. Some of them, examined in preliminary in vitro experiments, have been found very active against Herpes simplex virus.     

Abnormal behavior and adaptation problems in dogs and cats and their pharmacologic control

Botanicals have been used traditionally by herbalists and indigenous healers worldwide for the prevention and treatment of liver disease. Clinical research in this century has confirmed the efficacy of several plants in the treatment of liver disease. Basic scientific research has uncovered the mechanisms by which some plants afford their therapeutic effects. Silybum marianum (milk thistle) has been shown to have clinical applications in the treatment of toxic hepatitis, fatty liver, cirrhosis, ischemic injury, radiation toxicity, and viral hepatitis via its antioxidative, anti-lipid peroxidative, antifibrotic, anti-inflammatory, immunomodulating, and liver regenerating effects. Picrorhiza kurroa, though less well researched than Silybum, appears to have similar applications and mechanisms of action. When compared with Silybum, the hepatoprotective effect of Picrorhiza was found to be similar, or in many cases, superior to the effect of Silybum.     

Synthesis of 4-cyanophenyl 1,5-dithio-beta-D-glucopyranoside and its 6-deoxy, as well as 6-deoxy-5-ene derivatives as oral antithrombotic agents

Condensation of 5-thio-D-glucopyranose pentaacetate with 4-cyanobenzenethiol, in the presence of trimethylsilyl triflate, gave 4-cyanophenyl 2,3,4,6-tetra-O-acetyl-1,5-dithio-alpha-D-glucopyranoside 7 and 3,4,6-tri-O-acetyl-2,5-anhydro-5-thio-D-mannose bis(4-cyanophenyl) dithioacetal 9 in a 2:3 ratio. The latter is probably formed from the 4-cyanophenyl 2,3,4,6-tetra-O-acetyl-1,5-dithio-beta-D-glucopyranoside 6 via a transannular participation of the ring sulfur atom. When 2,3,4,6-tetra-O-acetyl-5-thio-alpha-D-glucopyranosyl bromide was used as donor and the reaction was carried out in the presence of potassium carbonate, 6, 7, 4-cyano-2-(2,3,4,6-tetra-O-acetyl-5-thio-alpha-D-glucopyranosyl)phenyl and 4-cyano-2-(2,3,4,6-tetra-O-acetyl-5-thio-beta-D-glucopyranosyl)phenyl 1,5-dithio-beta-D-glucopyranoside (14 and 16) were formed in a 23:4:2:1 ratio. The mechanism of formation of 14 and 16 is discussed. Condensation of 2,3,4,-tri-O-acetyl-6-deoxy-5-thio-alpha-D-glucopyranosyl bromide with 4-cyanobenzenethiol in the presence of potassium carbonate gave 4-cyanophenyl 2,3,4-tri-acetyl-6-deoxy-1,5-dithio-alpha- and beta-D-glucopyranoside (29 and 30) as well as 4-cyano-2-(2,3,4-tri-O-acetyl-6-deoxy-5-thio-alpha-D-glucopyranosyl)phen yl 2,3,4-tri-O-acetyl-6-deoxy-1,5-dithio-beta-D-glucopyranoside in a ratio of approximately 1:8:1. Compound 30 could be obtained in a higher overall yield using 2 as starting material and converting it via its 4-cyanophenyl 2,3,4-tri-O-acetyl-6-O-methanesulfonyl-1,5-dithio-beta-D-glucopyranoside derivative into the 4-cyanophenyl 2,3,4-tri-O-acetyl-6-deoxy-6-iodo-1,5-dithio-beta-D-glucopyranoside 33 which gave 30 on reduction with sodium borohydride-nickel(II) chloride. Treatment of 33 with silver acetate gave 4-cyanophenyl 2,3,4-tri-O-acetyl-6-deoxy-1,5-dithio-beta-D-xylo-hex-5-enopyranoside 35. The compounds obtained on deacetylation of 6, 9, 14, 30 and 35 showed a stronger oral antithrombotic effect in rats as compared to beciparcil, used as reference.     

Synthesis and antimicrobial evaluation of indole containing derivatives of 1,3,4-thiadiazole, 1,2,4-triazole and their open-chain counterparts

1. We have studied L-valine transport by the caecal segments of 6- to 8-week-old chickens. Isolated enterocytes from the proximal caecum incubated with 0.1 mM L-valine can accumulate the substrate against a concentration gradient. After 50 min incubation, the intracellular L-valine concentration reached 0.53 mM, a value higher than that observed in enterocytes from the jejunum (0.34 mM; P< 0.01). 2. Enterocytes from the medial and distal caccal regions are unable to transport L-valine uphill (cell concentration: 0.1 mM). 3. Amino acid accumulation by proximal caecal cells was Na+ -dependent and was inhibited by ouabain and 2,4-dinitrophenol. L-methionine inhibits L-valine uptake and a 2.5 mM concentration abolishes the capacity of enterocytes to accumulate the substrate. 4. The high accumulation ratios shown by the proximal caecum for L-valine suggest a role for this intestinal segment in the absorption of neutral amino acids present in the caecal chamber.     

Comparative study of the pharmacodynamic and pharmacologic effects of Betaseron and AVONEX

The aim of this 1 week study was to compare the biologic effects induced by Betaseron and AVONEX using their approved dose, route, and schedule. Sixteen healthy volunteers were randomly assigned to receive either a single i.m. dose of AVONEX (6 million International Units [MIU]) or, every other day s.c. doses of Betaseron (8 MIU). Common side effects associated with interferon-beta (IFN-beta) treatment and biologic response parameters (neopterin, beta2-microglobulin, interleukin-10 [IL-10], and MxA protein levels in blood) were measured. Ibuprofen was administered to all subjects throughout the study. Fever, chills, and myalgia occurred most frequently and with the greatest severity between 6 and 12 h after the first dose of either IFN-beta. Despite the additional dosing of subjects in the Betaseron group, the incidence, duration, and severity of the side effects were not significantly different from those in the AVONEX group. Biologic response parameters reached similar maximum concentrations in both treatment groups. In the Betaseron group, neopterin and beta2-microglobulin levels remained significantly greater than baseline throughout the 7 day study, whereas those in the AVONEX group were elevated only through day 5. Betaseron treatment significantly increased IL-10 levels above baseline, but AVONEX treatment did not. The overall induction of neopterin, beta2-microglobulin, and IL-10 (as measured by area under the concentration-time curve) was significantly greater in the Betaseron group than the AVONEX group (p = 0.031). The results of this study demonstrate that the approved Betaseron dosing regimen, in combination with ibuprofen use, provided a significantly greater and more consistently elevated biologic response compared with that of AVONEX and did so with a side effects profile comparable to that of once a week AVONEX dosing.     

Synthesis and anti-inflammatory activity of chalcone derivatives

This is a report on the surgical intervention in 79 patients with acute pancreatitis, who were operated in the Department of Surgery of the University Clinic RWTH Aachen in the period from 1986 to 1993. The main objective was the stratification of pancreatitis according to the Ranson-Score, the analysis of the surgical treatment and the timing of operation depending on the clinical condition. The average Ranson-score was 3.3 (median 3). 56 patients had necroses, which were removed because of the deteriorating clinical condition. In these cases the average Ranson-score was 4.2 (median 4). Seven patients (8.9% of the total number and 12.5% of the patients with necroses of the pancreas) died. This small number is the result of a severity-adapted management in a modern intensive care-unit and the good cooperation with the Department of Internal Medicine.     

Synthesis of new alpha-hydrazinoarylacetic acids and derivatives

The synthesis of some alpha-hydrazinoarylacetic acids (I) by reaction of alpha-bromoarylacetic acids with hydrazine, alkylhydrazines and carbobenzyloxyhydrazines is described. Reduction of the hydrazones of 2- and 3-thienylglyoxylic acids provided a general and effective route to the thienylic series. In view of the use of compounds (I) for the preparation of new penicillins, the experimental conditions for their conversion into cyclohexylamides (XI) via the corresponding carbobenzyloxyderivatives (III) were also investigated.     

Synthesis and antihypertensive activity of 4-(diazabicyclo[4.1.0]-heptenyloxy)benzopyran derivatives and their analogues

A series of 3,4-dihydro-3-hydroxy-4-[(5-oxo-3,4-diazabicyclo[4.1.0]hept- 2-en-2-yl)oxy]-2H-1-benzopyrans and their analogues were synthesized and evaluated on potassium channel opening and hypotensive activities. Compound (-)-13B with a (4-methyl-5-oxo-3,4-diazabicyclo[4.1.0]hept-2-en-2-yl)oxy group for the 4-position of the benzopyran ring was 3 times as potent as EMD 57283 (II), the lead compound, in hypotensive activity. The results would demonstrate that 5-oxo-3,4-diazabicyclo[4.1.0]hept-2-en-2-yloxy moieties are effective as the substituents at the 4-position of benzopyran-type potassium channel openers.