Synthesis and antiinflammatory activity of coumarin derivatives

The synthesis of several coumarin Mannich bases is described. The structures of the synthesized compounds were confirmed by spectral and elemental analysis. Their lipophilicity was determined experimentally by RPTLC method. All compounds were evaluated for their antiinflammatory and antioxidant activity and for their ability to inhibit in vitro lipoxygenase. The derivatives were found to present antioxidant and antiinflammatory activities. The tested derivatives inhibited carraggeenin-induced hind paw edema. They also significantly suppressed the arthritis induced by Freund's adjuvant. Compound 10, the most active in vivo, was found to possess protective properties against adjuvant-induced arthritis in rats. The biological in vitro activities were concentration dependent. Hydrophilicity, the presence of a free 7-OH, and steric requirements for the substituent at position 8 are the most important factors in terms of SAR. An attempt was made to correlate several physicochemical properties of the molecules with their in vivo/in vitro activity.     

Synthesis and antimalarial activity of sulfonamide chalcone derivatives

A series of sulfonamide chalcone derivatives were synthesized and investigated for their abilities to inhibit beta-hematin formation in vitro and their activity against cultured Plasmodium falciparum parasites. Inhibition of beta-hematin formation was minimal in the aromatic ring of the chalcone moiety as it appeared for compounds 4b, 4d-f, and greatest with compounds 4g (IC50 0.48 microM) and 4k (IC50 0.50 microM) with a substitution of 3,4,5-trimethoxyl and 3-pyridinyl, respectively. In this study, the most active compound resulted 1[4'-N(2',5'-dichlorophenyl) sulfonyl-amidephenyl]-3-(4-methylphenyl)-2-propen-1-one 4i, effective as antimalarial by the inhibition of cultured P. falciparum parasites (1 microM). These studies open up the novel possibility of development of sulfonamide derivatives as antimalarials that target beta-hematin formation and the inhibition of the development of cultured P. falciparum parasites, which should help delay the rapid onset of resistance to drugs acting at only a single site. Results with these assays suggest that chalcones exert their antimalarial activity via multiple mechanisms.     

Synthesis and evaluation of new antimalarial phenylurenyl chalcone derivatives

Phenylurenyl chalcone derivatives have been synthesized and tested as inhibitors of in vitro development of a chloroquine-resistant strain of Plasmodium falciparum, activity of the cysteine protease falcipain-2, in vitro globin hydrolysis, beta-hematin formation, and murine Plasmodium berghei malaria. The most active antimalarial compound was 1-[3'-N-(N'-phenylurenyl)phenyl]-3(3,4,5-trimethoxyphenyl)-2-propen-1-one 49, with an IC(50) of 1.76 microM for inhibition of P. falciparum development. Results suggest that chalcones exert their antimalarial activity via multiple mechanisms.     

Synthesis and antimicrobial evaluation of 1,3,4-oxadiazole-based chalcone derivatives

A series of chalcones-bearing 1,3,4-oxadiazole derivatives was synthesized as novel bio-active antimicrobial agents against multidrug-resistant bacteria and fungi. The lead compounds (Z)-2-(5-(3-nitrophenyl)-1,3,4-oxadiazol-2-ylthio)-N-(4-(3-(aryl)acryloyl)phenyl)acetamides 5a–n were synthesized via acid-catalyzed aldol condensation (SOCl₂) by reacting N-(4-acetylphenyl)-2-(5-(3-nitrophenyl)-1,3,4-oxadiazol-2-ylthio)acetamide (4) with differently substituted aldehydes. Compound (4) was obtained by reacting 5-(3-nitrophenyl)-1,3,4-oxadiazole-2-thiol (2) with N-(4-acetylphenyl)-2-chloroacetamide (3) in the presence of K₂CO₃. The intermediates (2) and (3) were synthesized simultaneously from 3-nitrobenzohydrazide (1) and 4-aminoacetophenone, respectively. The formation of intermediates and targeted compounds were confirmed for their structure by means of various spectral–analytical techniques like IR, ¹H NMR, ¹³C NMR, elemental analysis, and mass spectra. Antimicrobial properties of all the synthesized compounds have been evaluated against broad panel of bacteria and fungi.     

Synthesis and antiinflammatory activity of various 1,4-benzothiazine derivatives

A new series of dihydro-4H-1,4-benzothiazine derivatives was prepared. These compounds were obtained by reductive N-alkylation reaction with sodium borohydride in acetic acid of the corresponding 4H-1,4-benzothiazine. Some of the latter compounds were synthesized by a new synthetic method employing 2-aminobenzenethiol and alkynes as starting material. Preliminary pharmacological data on the antiinflammatory activity of these compounds by using carrageenin paw edema assay are reported.     

Synthesis and antimicrobial activity of chalcone derivatives of indole nucleus

A series of previously unreported (2Z)-2-(1H-indol-1-yl)-3-(4-substituted phenyl)-1-phenylprop-2-en-1-one (5a–d) have been synthesized from easily accessible 2-(1H-indol-1-yl)-1-phenylethanone (3), which was obtained via a reaction of indole (1) with chloromethylphenyl ketone (2). The structures of the synthesized products have been elucidated using IR, ¹H NMR, and mass-spectroscopic data and elemental analyses. The final products were screened for their antimicrobial activity. Excellent results were obtained against both bacteria and fungi. In conclusion, we have developed a novel, convenient and simple method for the preparation of indole – chalcone hybrid compounds via the reaction of indole derivative with carbonyl compounds in the presence of a strong base. The rapid conversion, excellent yield, utilization of a base, and operational simplicity are great advantages of the proposed method.     

Synthesis and antiinflammatory activity of acyl substituted benzodioxa heterocycles and o-dialkoxybenzenes

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 23, No. 4, pp. 435–437, April, 1989.     

Synthesis,anti-inflammatory and antioxidant activity of ring-A-monosubstituted chalcone derivatives

A library of ring-A-monosubstituted chalcone derivatives (4a–4i, 5a and 5b) was designed and synthesised. The structures as well as the identities of these compounds were established on the basis of spectral (¹H NMR, ¹³C NMR, FT-IR and Mass) and elemental (C, H, N) analyses. All the derivatives were evaluated for their anti-inflammatory and antioxidant activities in vitro using the inhibition of protein denaturation and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays, respectively. The results indicated a promising anti-inflammatory activity for most of the synthesised compounds with many derivatives showing activities similar to or greater than that of the standard. The sulphonamide-substituted chalcones 4h, 4i, 5a and 5b were found to be the most active derivatives across the concentration range tested. However, all the derivatives exhibited rather mild antioxidant activity compared to the ascorbic acid standard. Interestingly, it was observed that the unsubstituted parent chalcone was one of the optimal compounds with only the trifluoromethyl analogue 4a showing better activity as an antioxidant. The two regioisomeric aminochalcones and 4′-cyanochalcone 4b also seemed to possess decent antioxidant potential.     

Synthesis of variously substituted 1,8-naphthyridine derivatives and evaluation of their antimycobacterial activity

A series of 1,8-naphthyridine derivatives variously substituted in the 2, 3, 4 and 7 positions were synthesized for in vitro evaluation of antimycobacterial activity in accordance with an international program with the tuberculosis antimicrobial acquisition and coordinating facility (TAACF). Several compounds 4, 8, 12, 14, 19, 29 and 30, when tested at a concentration of 6.25 microg/ml against Mycobacterium tuberculosis H37Rv, showed an interesting activity with % inhibition in the range 38-96%. The most effective substituent in position 2, 4 or 7 of the 1,8-naphthyridine nucleus seem to be the piperidinyl group.     

Synthesis,antiinflammatory and analgesic activity of new hexahydropyrimidine derivatives

A number of potentially active hexahydropyrimidine derivatives of pharmaceutical interest have been synthesized. Various diSchiff's bases prepared by reacting different aromatic aldehydes with 1,3-diaminopropane were suitably reduced to give their tetrahydro derivatives which were then condensed with appropriate aldehydes to give a series of hitherto unreported hexahydropyrimidines. The resulting products were evaluated by oral route for their antiinflammatory activity. The activity of compounds 11, 23 and 4 was excellent and comparable to indomethacin. In addition to oral route of administration, the antiinflammatory activity of hexahydropyrimidine derivatives was also studied topically through transdermal gels. Compounds 11, 23, 4 and 22 produced significant inhibition in edema and showed good antiinflammatory activity comparable to diclofenac sodium gel (Relaxyl gel). All these compounds were also tested for their analgesic activity and their LD50 determined. Compounds 11, 20 and 23 showed a comparable activity with aspirin. The MTD for all the compounds was found to be > 1800 mg/kg.     

Synthesis of some indole derivatives with potential antiinflammatory activity

2-Methylindole-3-acethydrazide (1) was reacted with arylisothiocyanate to give the corresponding 4-arylthiosemicarbazides 2a-d. Cyclization of the latter gave the corresponding 3-mercapto-5-[3-(2-methylindolyl)methyl]-1,2,4-triazoles 3a-d. Compounds 3a-c reacted with chloroacetic acid to give the corresponding indolyl-1,2,4-triazolythioglycolic acids 4a-c. The methylmercapto derivative 5 was also obtained from 3a and methyliodide. The hydrazide 1 was also reacted with carbon disulfide to give the corresponding indolymethyl-1,3,4-oxadiazole-2-thione (6) which was condensed with piperidine and formaldehyde to give the corresponding Mannich base 7. Condensation of 1 with aromatic aldehydes gave the corresponding hydrazones 8a-c which were converted into the corresponding oxadiazolines 9a-c.     

Synthesis and antimalarial activity of substituted pyrazole derivatives

The development of new antimalarial drugs is an urgent priority considering the increasing prevalence of drug-resistant Plasmodium falciparum parasites. A series of pyrazoles are described as part of efforts directed toward the synthesis of some potent antimalarial agents. The replacement of the ester group as a substituent in the pyrazole ring by nitrile group caused a precipitous loss of activity as antimalarial due to the lack of hydrogen-bond formation. Further modification of the heterocyclic ring to give substituted aryl derivatives afforded potent antimalarial derivatives: methyl 5-amino-3-anisidinepyrazole-4-carboxylic acid 3a (IC50: 0.149 mumol/l) and methyl 5-amino-3-(m anisidin)pyrazole-4-carboxylic acid 3c (IC50: 0.15 mumol/l). The synthesis, structure-activity relationships (SAR), X-ray crystallography and pharmacological activity associated with these series of compounds are discussed.     

取代环戊酮曼尼希碱的合成及其抗炎活性

目的 对环戊酮曼尼希碱类化合物JC9118进行结构改造，设计合成其类似物并初步评价抗炎活性。方法 以N－环戊烯基吗啉，对异丁基苯甲醛，对异丁基苯乙酮及多种胺类为原料经Stork反应，Mannich反应和胺交换反应合成目标化合物，并以二甲苯致小鼠耳肿胀模型测试目标化合物的抗炎活性。结果 合成9个新化合物，经IR，^1H-NMR和MS确证其结构；其中5个化合物具有显著的抗炎活性。结论 JC9118的芳胺曼尼希碱类似物无抗炎活性；羰基α位的取代亚苄基对保持化合物的抗炎活性起重要作用。     

Synthesis and antiinflammatory evaluation of 9-anilinoacridine and 9-phenoxyacridine derivatives

Mast cells, neutrophils, and macrophages are important inflammatory cells that have been implicated in the pathogenesis of acute and chronic inflammatory diseases. To explore a novel antiinflammatory agent, we have synthesized two types of acridines, 9-anilinoacridine and 9-phenoxyacridine derivatives, for evaluation on the grounds that acridine is a versatile heterocycle possessing a wide variety of biological properties. The title compounds were synthesized by reaction of 9-chloroacridine with appropriate Ar-NH(2) and Ar-OH, and their antiinflammatory activities on inhibitory effects on the activation of mast cells, neutrophils, and macrophages were studied. Three acridine derivatives 4, 10, and 11 were proved to be more potent than the reference inhibitor mepacrine for the inhibition of rat peritoneal mast cell degranulation with similar IC(50) values (16-21 microM). Compound 3 also showed potent inhibitory activity (IC(50) = 8.2 and 4.4 microM, respectively) for the secretion of lysosomal enzyme and beta-glucuronidase from neutrophils. Moreover, compounds 5 and 9 were shown to be efficacious inhibitors of TNF-alpha production in macrophage-like cell lines RAW 264.7. Compounds 2 and 12 were the potent inhibitors of TNF-alpha production in murine microglial cell lines N9. To further explore the cytotoxic properties of these acridine derivatives, (E)-12 was selected for NCI's in vitro disease-oriented tumor cells screen. The results indicated that this compound had no significant cytotoxicity with a mean GI(50) of 58.0 microM. These results indicated that the antiinflammatory effects of acridine derivatives were mediated, at least in part, through the suppression of chemical mediators released from mast cells, neutrophils, and macrophages and that these compounds have the potential to be novel antiinflammatory agents with no significant cytotoxicity.     

氨甲酰取代的苯氧烷胺衍生物的合成及其活性测试

目的 设计合成氨甲酰取代的苯氧烷胺类α1-肾上腺素受体 (α₁-AR) 拮抗剂,并研究其对大鼠肛尾肌收缩功能的影响。方法 以2,4-二羟基苯甲酸甲酯或2,5-二羟基苯甲酸甲酯为原料,经多步反应合成关键中间体4a、4b,该中间体再与取代苯乙胺经还原胺化反应制得目标化合物,并测试它们对α₁-AR的拮抗活性。结果 共合成了12个新的氨甲酰取代的苯氧烷胺类化合物,其结构经IR、MS、¹H-NMR谱确证。结论 生物活性测试显示目标化合物均具有一定的α1-AR拮抗作用。     

Synthesis and antibacterial activity of various substituted oxadiazole derivatives

Some new 2-(2-(4(4-substitutedbenzoyl-2-methylphenoxy)acetyl)-N-(2-substitutedphenyl) hydrazinecarbothioamides (4a-4j) and (4-((5-(2-substitutedphenylamino)-1,3,4-oxadiazol-2-yl)methoxy)-3-substitutedphenyl)(phenyl)methanones (5a-5j) have been synthesized from 2-(4-(3-substitutedbenzoyl)-2-methylphenoxy)acetohydrazides (3a, 3b). These newly synthesized compounds (4a-4j and 5a-5j) were characterized by elemental and spectral (IR, (1)H-NMR and MS) analysis. All the synthesized compounds have been screened for their antibacterial activity against both types of Gram negative and Gram positive bacteria. The most potent antibacterial compound of this series was compound 5i which has the low MIC 3.75-0.9375 μg/mL value. Both minimal inhibitory concentration (MIC) and inhibition zones were determined in order to monitor the efficacy of the synthesized compounds. Certain compounds inhibit bacterial growth with low MIC (μg/mL) value.