Synthesis and pharmacological activity of 2-(substituted)-3-{2-[(4-phenyl-4-cyano)piperidino]ethyl}-1,3-thiazolidin-4-ones

Loperamide is a well-known peripherally acting opiate used for the treatment of diarrhoea. To gain more knowledge on the structure-activity relationships of antidiarrhoeal drugs and to develop new active molecules, a series of aryl-cyano-piperidinoalkyl-thiazolidinones related to Loperamide was synthesized and screened for antidiarrhoeal activity in mice by castor oil test. To characterize the potency and toxicity of the synthesized compounds ED50 and LD50 values were also determined. The thiazolidinones 2-6 displayed antidiarrhoeal activity at doses ranging between 15 and 82 mg/kg. Although the results show that the synthesized compounds are 15- to 80-fold less active respect to the reference compound, Loperamide, they are much less toxic (> or = 1000 mg/kg and 108.9 mg/kg, respectively). Besides, to evaluate the involvement of opioid receptors in antidiarrhoeal activity, Naloxone was administered prior to test the 2-phenyl-3-{2-[(4-phenyl-4-cyano)piperidino]ethyl}-1,3-thiazolidin-4-one (2), the more active compound of this series. The results obtained by this study, suggest that the antidiarrhoeal activity of this series of thiazolidinone derivatives could involve the opioid receptors.     

Synthesis and anticonvulsant properties of new N-[(4-arylpiperazin-1-yl)-methyl] derivatives of 3-aryl pyrrolidine-2,5-dione and 2-aza-spiro[4.4]nonane-1,3-dione

A series of N-[(4-arylpiperazin-1-yl)-methyl] derivatives of 3-arylpyrrolidine-2,5-dione and 2-aza-spiro[4.4]nonane-1,3-dione were synthesized and tested for anticonvulsant activity in the maximum electroshock seizure (MES) and metrazole seizure threshold (sc.MET) tests. The most potent in the series were N-[[4-(3-chlorophenyl)-piperazin-1-yl]-methyl]-3-(2-chlorophenyl)-pyrrolidine-2,5-dione (ED50=14.18 mg/kg) and N-[[4-(2-methoxyphenyl)-piperazin-1-yl]-methyl]-3-(3-bromophenyl)-pyrrolidine-2,5-dione (ED50=33.64 mg/kg). Structures of the novel compounds were confirmed by elemental and spectral analyses.     

Synthesis, antimicrobial and antioxidant activities of 2-[1-{3,5-diaryl-4,5-dihydro-1H-pyrazolenyl}]-4-(4-nitrophenyl)-[1,3]-thiazoles

In this study, various substituted chalcones, prepared by condensing substituted acetophenones with substituted aldehydes/arylfurfurals, were treated with thiosemicarbazide in basic media to produce 1-thiocarbonyl-3,5-disubstituted pyrazolines which on further reaction with substituted phenacyl bromides afforded the title compounds in good yield. Structures of the newly synthesized compounds were assigned on the basis of elemental analyses, IR, ¹H NMR, and mass spectral studies. The newly synthesized compounds were tested for their in vitro antibacterial and antifungal activities against a variety of microorganisms and antioxidant activities by diphenylpicrylhydrazyl radical scavenging assay. Among the derivatives, compounds 3b, 3e, 6a, and 6h were identified as potent antioxidants. Compounds 3d, 3e, and 6a–f have emerged as the most promising antimicrobial agents displaying the maximum activity against all the tested microorganisms.     

Synthesis and Antibacterial Assessment of N-[4-(4-substituted phenyl)-1,3-thiazol-2-yl]-1,3,5-triazin-2-amine

In a wide search program towards new and efficient antibacterial agents, we assessed the extent to which physicochemical properties can be exploited to promote antibacterial activity associated with a series of substituted s-triazine. The synthesized compounds (1a-12b) were subsequently screened for their in vitro antibacterial activity against three gram positive (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus) and three Gram-negative microorganism (Salmonella typhi, Escherichia coli, Klebsiella aerogenes) by the broth dilution technique, recommended by European Committee for antimicrobial susceptibility testing with reference to streptomycin.     

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 anti-HIV activity of 2,3-diaryl-1,3-thiazolidin-4-(thi)one derivatives

Several 2,3-diaryl-1,3-thiazolidine-4-thione derivatives and 2,3-diaryl-1,3-thiazolidin-4-ones bearing a methyl group at C-5 position have been synthesized and tested as anti-HIV agents. The results of the in vitro tests showed that some of them proved to be effective inhibitors of HIV-1 replication.     

Synthesis of Some New 2-Substituted 3-[4-(N′-Arylsulphonylbiguanido)phenyl]quinazolin-4-one Hydrochlorides as Potential Anthelminthic Agents

The title compounds 3--37 have been synthesised. Their in vivo cestodicidal activities were evaluated against Hymenolepis nana infection in rats. Compound 32 was found to be the most active of the series showing 81.0% clearance of infection at a dose of 250 mg/kg for 3 days.     

Synthesis and Antimicrobial Activity of Some New 2-(3-(4-Aryl)-1-phenyl-1H-pyrazol-4-yl) Chroman-4-ones

Seven new 2-(3-(4-aryl)-1-phenyl-1H-pyrazol-4-yl) chroman-4-ones (4a-4g) have been synthesized by cyclization of 2-hydroxychalcone analogues of pyrazole 3a-3g using conc. HCl in acetic acid. The structures of the compounds 4a-4g were established by the combined use of (1)HNMR, IR and mass spectra. All the seven compounds were tested in vitro for their antibacterial activity against two Gram positive bacteria namely Staphylococcus aureus and Bacillus subtilis and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The compounds 4b, 4c, 4e, 4f, 4g have displayed good antibacterial activity when compared with commercially available antibiotic, ciprofloxacin. These compounds also were screened for their antifungal activity against two ear pathogenic fungi, namely Aspergillus Niger and A. flavus. The compounds 4a, 4c, 4d, 4g exhibited good antifungal activity when compared with commercially available antifungal, fluconazole.     

Synthesis and antimicrobial activity of N-[4-(1,3-benzodithiol-2-yl)phenyl]-and N-[4-(4-aryl-1,3-dithiol-2-yl)phenyl]-substituted N-arylmethylamines

Methods for the synthesis of secondary aromatic amines containing 1,3-benzodithiol or 4-aryl-1,3-dithiol cycles have been developed. The antimicrobial activity of the synthesized compounds has been determined. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 10, pp. 28–29, October, 2006.     

PEG Mediated Synthesis and Biological Evaluation of Asymmetrical Pyrazole Curcumin Analogues as Potential Analgesic,Anti-Inflammatory and Antioxidant Agents

The new series of asymmetrical pyrazole curcumin analogues 4a – g were synthesized by using polyethylene glycol (PEG-400) as a green reaction medium and evaluated for their in vivo analgesic and in vitro antioxidant (H₂O₂, DPPH, Ferrous reducing power and Nitric oxide scavenging activity) and anti-inflammatory activities. All the compounds synthesized 4a – g showed the potential to demonstrate analgesic activity as compared to the standard ibuprofen. Among the tested series, compounds 4e and 4b exhibited good hydrogen peroxide scavenging activity as compared to the standard butylated hydroxy toluene (BHT). Compounds 4b , 4d , 4f , and 4g showed good DPPH free radical scavenging activity. Compounds 4b , 4c , 4d , 4e and 4g showed excellent ferrous-reducing power activity, whereas all the compounds showed better nitric oxide scavenging activity than standard ascorbic acid. Additionally, all the synthesized compounds were also screened for their in vitro anti-inflammatory activity. Compounds 4b , 4d , 4f and 4g showed good anti-inflammatory activity as compared to standard diclofenac sodium.     

Synthesis and Biological Activity of New [1,3]Thiazolo[4,5-d]pyridazin-4(5H)-ones

A series of novel 2-(N-pyrrolidino, N-piperidino or N-morpholino)-7-phenyl(α-furoyl or α-thienyl)-[1,3]thiazolo[4,5-d]pyridazinones 10a–c, 14–16a,b was synthesized in 78–87% yields via the reaction of methyl 5-benzoyl(α-furoyl or α-thienyl)-2-aminosubstituted-thiazol-4-carboxylates 9a–c, 13a–e with hydrazine. These new compounds have been tested for their in vivo analgesic and anti-inflammatory activities. All compounds have been characterized by ¹H-NMR, ¹³C-NMR spectroscopy, and liquid chromatography–mass spectrometry.     

Synthesis of N-aryl-N'-[2-phenyl-3-quinazoline(3H)-4-one] acylthiourea derivatives as anticonvulsants.

By the reaction of [2-phenyl-3-quinazolineo (3H)-4-one] acyl isothiocynates and appropriate aryl amines in acetone, 24 new compounds, having a substituted thiourea grouping at the 3-position of the quianozolone moiety, were prepared. All compounds, except two, showed different degree of protection against pentetrazol induced seizures test in albino mice. While studying the effect of structural variation no definite pattern could be observed due to variations in 1-aryl moiety, but it was noticed that generally the branching or lengthening of 3-acyl chain either diminishes or does not effect the activity.     

3-(4-氨基-5-甲基-均三唑-3-硫基)-1-苯丙-1-酮-O-(5-取代苯基-［1,3,4］噁二唑-2-甲基)肟的合成及抗菌活性

目的研究氨基杂环肟类化合物的合成方法和抗菌活性。方法用4-氨基-3-甲基-5-巯基-［1,2,4］三唑与β-氯苯丙酮缩合、肟化、醚化得3-(4-氨基-5-甲基-均三唑-3-硫基)-1-苯丙-1-酮-O-(5-取代苯基-［1,3,4］噁二唑-2-甲基)肟醚目标化合物。用二倍试管稀释方法研究了目标化合物的体外抑菌活性。结果合成了12个新化合物，其结构经MS，IR，¹H NMR和元素分析确证。10个目标化合物在体外有一定的抗菌活性。结论该类杂环化合物有待进一步的结构优化研究。     

Synthesis, physicochemical and anticonvulsant properties of new N-(pyridine-2-yl) derivatives of 2-azaspiro[4.4]nonane and [4.5]decane-1,3-dione. Part II

A series of N-(pyridine-2-yl) derivatives of 2-azaspiro[4.4]nonane- (1a-e), 2-azaspiro[4.5]decane- (2a-e) and 6-methyl-2-azaspiro[4.5]decane-1,3-dione (3a-e) were synthesized and tested for their anticonvulsant activity in the maximum electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure threshold tests. To explain the possible mechanism of action, the most active compounds N-(3-methylpyridine-2-yl)-2-azaspiro[4.4]nonane-1,3-dione (1b), N-(3-methylpyridine-2-yl)-2-azaspiro[4.5]decane-1,3-dione (2b), N-(4-methylpyridine-2-yl)-2-azaspiro[4.5]decane-1,3-dione (2c), and N-(3-methylpyridine-2-yl)-6-methyl-2-azaspiro[4.5]decane-1,3-dione (3b) were tested in vitro for their influence on voltage-sensitive calcium channel receptors, however, they revealed low affinities. For all synthesized compounds the lipophilicity was determined by use of RP-TLC method. The correlation between the lipophilicity and anticonvulsant activity was obtained--the higher the lipophilicity the stronger the anticonvulsant efficacy.     

Synthesis and evaluation of biological and nonlinear optical properties of some novel 2,4-disubstituted [1,3]-thiazoles carrying 2-(aryloxymethyl)-phenyl moiety

A series of 2,4-disubstituted-[1,3]-thiazoles (4a–p and 6a–l) was synthesized from 2-(aryloxymethyl)benzoic acids (1a–d) through a multistep reaction sequence in good yield. The structures of the new compounds were established on the basis of their elemental analyses, IR, ¹H-NMR, ¹³C-NMR and mass spectral data. All the synthesized compounds were screened for their antimicrobial and anti-inflammatory activities. Preliminary results indicated that some of them exhibit promising activities and they deserve more consideration as potential antimicrobial and anti-inflammatory agents. The nonlinear optical (NLO) property of 4a–p was also studied. The compound 4n with 2-(3-methylphenoxymethyl)phenyl and 4-nitrophenyl substituents showed very good NLO property compared to other compounds and also the reference compound, urea.     

Synthesis, physicochemical and anticonvulsant properties of new N-4-arylpiperazin-1-yl amides of (2-aza-1,3-dioxospiro[4.4]non-2-yl)- and [4.5]dec-2-yl)-propionic acid

In continuation of the search of new anticonvulsants, a series of N-4-arylpiperazin-1-yl 2-aza-1,3-dioxospiro[4.4]non-2-yl- (5-8) and [4.5]dec-2-yl- (9-15) propionamides, structurally related to the previously described N-4-arylpiperazin-1-yl amides of 2-aza-1,3-dioxospiro[4.5]dec-2-yl-acetic acid, were synthesized. The designed compounds 5-15 were prepared by condensation of the formerly obtained (2-aza-1,3-dioxospiro[4.5]dec-2-yl)- (3) and (2-aza-1,3-dioxo[4.4]non-2-yl)-(4) propionic acids with the appropriately substituted 4-arylpiperazines, in the presence of the N,N-carbonyldiimidazole (CDIM) reagent. All the compounds were tested for their anticonvulsant activity in the maximum electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure threshold tests. Several compounds 7-10, 13 and 14 revealed protection in the MES screening.     

7-[(2S)-2-羟甲基-4-氨基-1-吡咯烷基]氟喹诺酮类化合物的合成及体外抗菌活性

用反式-L-羟脯氨酸经对甲苯磺酰氯保护、甲酯化、氧化、肟化、四氢铝锂还原、叔丁氧基羰基保护后脱除对甲苯磺酰保护基,与不同的氟喹诺酮中间体缩合,最后经脱除叔丁氧基羰基等反应得到目标物,结构经1HNMR和FAB-MS确证,并进行了体外抗菌活性试验.结果表明,除化合物13对供试的大部分菌株,特别是对链球菌的体外活性相当于或优于对照药加替沙星和环丙沙星外,其余3个目标物总体活性均低于对照品.     

7β-[2-(2-取代氨基噻唑-4-基)-(Z)-2-甲氧亚氨乙酰氨基]-3-季铵基甲基头孢菌素的合成及抗菌活性

为了寻找抗菌谱更广,抗菌活性更强的新型头孢菌素类化合物,本研究以2-(2-氨基噻唑-4-基)-(Z)-2-甲氧亚氨基乙酸乙酯（1）为原料,经酰化、取代、水解、活泼酯化、缩合、成盐得到目标化合物（N₁-N₉）。所合成的9个新型第四代头孢菌素的结构经红外、核磁共振氢谱、质谱和元素分析确证。体外抗菌实验结果表明, 所合成的化合物具有不同程度的抗菌活性,它们对革兰氏阳性菌的活性总体上相当于或优于硫酸头孢匹罗,特别是对金葡菌、表皮葡球菌表现出比硫酸头孢匹罗更好的活性。