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.     

哒嗪酮酸类化合物的合成及其抗惊活性的研究

以ａ－酮戊二酸与水合肼与水合肼为原始原料合成了１５个Ｎ－（３’－磷酸二乙酯丙基）－１，６－二氢－６－氧－３－哒嗪酰胺类化合物，并对它们进行了最大电休克发作（ＭＥＳ）实验，结果表明其中４个化合物表现出中等强度的抗惊活性。     

Non-genotoxic mode of action and possible threshold for hepatocarcinogenicity of Kojic acid in F344 rats

Kojic acid (KA), a naturally occurring compound, is contained in traditional Japanese fermented foods and is used as a food additive, preservative and a dermatological skin-lightening agent. In the present experiment, initiation (experiment 1) and promotion (experiment 2) effects of KA-induced hepatocarcinogenesis were studied by rat medium-term bioassay for carcinogenicity. Male F344 rats were administered a diet containing 0-2% KA. Experiment 1 demonstrated that KA had no effect on induction of liver preneoplastic lesions or glutathione S-transferase placental form (GST-P) positive foci, in either number or area. In experiment 2, 2% KA treatment significantly increased the number and area of GST-P positive foci, but concentrations less than 0.5% did not. Moreover, 2% KA treatment significantly increased 8-OHdG levels and PCNA positive hepatocytes. The results indicated that low concentrations of KA do not have initiation effects on rat hepatocarcinogenesis, while higher concentrations of KA do promote hepatocarcinogenesis in rats. Thus, the results indicate that KA is a non-genotoxic hepatocarcinogen, showing the possible existence of a perfect threshold.     

6,8-二氯硫色满酮衍生物的合成及抗真菌活性(英)

本文设计并合成了一系列6,8-二氯硫色满酮衍生物。其中12个为未见文献报道的新化合物。对所合成的化合物进行了体外抑菌活性试验,其结果表明某些化合物对6种供试真菌有较好的抑制作用。     

Synthesis and Anticonvulsant Properties of New Mannich Bases Derived from 3,3-Disubstituted Pyrrolidine-2,5-diones. Part IV

A library of 21 new N-Mannich bases of 3,3-diphenyl- (5a-g), 3-methyl-3-phenyl- (6a-g), and 3-ethyl-3-methylpyrrolidine-2,5-diones (7a-g) were synthesized and evaluated for their anticonvulsant activity in the maximum electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure tests after intraperitoneal injection into mice. The acute neurological toxicity was determined applying the rotarod screen. The results in mice showed that 13 compounds were effective in the MES or/and scPTZ screen. From these, seven molecules were tested in the MES seizures after oral administration in rats. The quantitative studies showed that N-[{4-(2-hydroxyethyl)-piperazin-1-yl}-methyl]-3-methyl-3-phenylpyrrolidine-2,5-dione (6c) and N-[(4-benzylpiperidin-1-yl)-methyl]-3-methyl-3-phenylpyrrolidine-2,5-dione (6f) revealed higher protection in the MES and scPTZ tests than valproic acid or ethosuximide which were used as reference antiepileptic drugs. Four compounds (5c, 6c, 6e, 6f) showed high effectiveness in the 6-Hz psychomotor seizure model of partial and therapy resistant epilepsy.     

6，8—二氯硫色满酮衍生物的合成及抗真菌活性

本文设计并合成了一系列6,8－二氯硫色满酮衍生物,其中12个为未见文献报道的新化合物,对所合成的化合物进行了体外抑菌活性试验,其结果表明某些化合物对6种供试真菌有较好的抑制作用。     

苯基哒嗪酮及其GABA衍生物的合成、抗惊活性及构效关系的研究

本文报道了14个6－芳基－4，5－二氢－3（2H）哒嗪酮，15个6－芳基－3（2H）哒嗪酮和17个6－芳基哒嗪的3位GABA衍生物的合成及其抗电惊活性。活性最强的是2′，4′－二氯苯基－3（2H）哒嗪酮（ED50＝10.15mg/kg）。对芳基哒嗪酮类的构效分析表明，苯环上的取代基对化合物的抗惊活性有明显影响，吸电子取代基和疏水性参数值较大的取代基有利于提高化合物的抗惊活性。     

Synthesis of Novel 2,5‐Disubstituted 1,3,4‐Thiadiazoles for Their Potential Anticonvulsant Activity: Pharmacophoric Model Studies

A series of novel N¹‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N⁴‐(4‐substituted benzaldehyde)‐semicarbazone 1 – 12 , N¹‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N⁴‐[1‐(4‐substituted phenyl)ethanone]‐semicarbazone 13 ‐ 16 , and N¹‐[5‐(4‐substituted phenyl)‐1,3,4‐thiadiazol‐2‐yl]‐N⁴‐[1‐(4‐substituted phenyl) (phenyl) methanone]‐semicarbazone 17 – 20 were synthesized for their anticonvulsant activity. The chemical structures of the compounds were proved by elemental and spectral (IR, ¹H‐NMR, ¹³C‐NMR, and MS) analysis. The anticonvulsant potential of the compounds was investigated using maximal electroshock seizure (MES) and subcutaneous pentylenetrtrazole (scPTZ) models. Compound 19 was found to possess significant anticonvulsant activity in both the models employed for anticonvulsant evaluation. Compounds 8 , 13 , 15 , and 16 also demonstrated a marked anticonvulsant property. The results of the present study validated that the pharmacophore model with four binding sites is essential for anticonvulsant activity. The efforts were also made to establish structure‐activity relationships among the synthesized compounds.     

Design and Synthesis of Some Novel 4-(4-substituted aryl) Semicarbazones as Anticonvulsant Agents

In the present study, a series of 4-(4-substituted aryl) semicarbazones were synthesized from substituted anilines and subsequently evaluated for their anticonvulsant activities. The anticonvulsant activities were established by the anticonvulsant drug development (ADD) programme NIH, USA using experimental animal, adult male FCM mice (20-25 g) and adult Sprague-Dawley rats (100-150 g) and screened against electroshock seizure, subcutaneous metrazole and minimal neurotoxicity tests in mice. Compound 7 was found equipotent to carbamazepine in both MES and ScPTZ tests. This study has highlighted the importance of distal alkyl chain which influences the anticonvulsant activity.     

Synthesis and Anticonvulsant Activity Evaluation of 5‐Phenyl‐[1,2,4]triazolo[4,3‐c]quinazolin‐3‐amines

In the present study we describe the syntheses and anticonvulsant activity evaluation of 5‐phenyl‐[1,2,4]triazolo[4,3‐c]quinazolin‐3‐amine derivatives. Their anticonvulsant activity and neurotoxicity were evaluated by the maximal electroshock seizure test (MES) and the rotarod test, respectively. The majority of the compounds prepared were effective in the MES screens at a dose level of 100 mg/kg. Of these compounds, the most promising was compound 8h , which showed an ED₅₀ value of 27.4 mg/kg and a protective index (PI) value of 5.8. These values were superior to those provided by valproate (ED₅₀ and PI values of 272 and 1.6, respectively) in the MES test in mice. As well as its anti‐MES efficacy, the potencies of compound 8h against seizures induced by pentylenetetrazole and thiosemicarbazide were also established, with the results suggesting that the GABAergic system‐mediated mechanisms might be involved in its anticonvulsant activity.     

Leishmanicidal Evaluation of Novel Synthetic Chromenes

In the present paper, twelve chromenes were synthesized by coupling of 2,2,8,8‐tetramethyl‐8H‐pyrano[2,3‐f]chroman‐4‐one 1 with various aryl and benzylmagnesium chlorides. The synthetic compounds were examined for in‐vitro activity against Leishmania major, and some of them displayed efficient anti‐leishmanial activity. Among the compounds tested, compounds 9 (4‐(2‐chloro‐benzylidene)‐2,2,8,8‐tetramethyl‐3,4‐dihydro‐2H,8H‐pyrano[2,3‐f]chromene 9a and 4‐(2‐chloro‐benzyl)‐2,2,8,8‐tetramethyl‐2H,8H‐pyrano[2,3‐f]chromene 9b ) were the most active with an inhibitory activity of 73.4%.