9-Benzyl-6-(dimethylamino)-9H-purines with antirhinovirus activity

A series of 9-benzyl-6-(dimethylamino)-9H-purines and 9-benzyl-2-chloro-6-(dimethylamino)-9H-purines were synthesized and tested in cell culture for activity against rhinovirus type 1B. The 9-benzylpurines that were unsubstituted in the 2-position had weak activity. However, introduction of a 2-chloro substituent resulted in a substantial increase in antiviral activity. One of the most active compounds, 2-chloro-6-(dimethylamino)-9-(4-methylbenzyl)-9H-purine (29), had an IC50 value of 0.08 microM against serotype 1B. Four compounds were tested against 18 other rhinovirus serotypes, but the majority tested were less sensitive than type 1B. The range of serotype sensitivity for 29 varied from 0.08 to 14 microM. These 9-benzyl-2-chloro-9H-purines represent a new class of antiviral agents with in vitro activity against rhinoviruses.     

Synthesis and antirhinovirus activity of 8-substituted analogues of 6-(dimethylamino)-9-(4-methylbenzyl)-2-(trifluoromethyl)-9H-purine.

Several 8-substituted analogues of 6-(dimethylamino) -9-(4-methylbenzyl)-2-(trifluoromethyl)-9H-purine (1) were synthesized and tested for activity against rhinovirus type 1B. Among 16 8-substituted analogues, the 8-amino (3) and 8-bromo (2) analogues were most active with IC50s of 0.36 and 1.4 microM, respectively, under conditions where 1 had an IC50 of 0.03 microM.     

Synthesis and structure-activity relationships of 2-substituted-6-(dimethylamino)-9-(4-methylbenzyl)-9H-purines with antirhinovirus activity

A series of 2-substituted-6-(dimethylamino)-9-(4-methylbenzyl)-9H-purines where the 2-substituent was H, F, Cl, CF3, CH3, CH2CH3, NH2, NHCH3, N(CH3)2, SCH3, or SO2CH3 was synthesized and tested for antirhinovirus activity to evaluate the effect of 2-substituents on antiviral activity. Intuitive and quantitative structure-activity relationship (QSAR) analysis showed that optimum antirhinovirus serotype 1B activity was associated with 9-benzylpurines that contained a C-2 lipophilic, electron-withdrawing substituent. The most active compound, 6-(dimethylamino)-9-(4-methylbenzyl)-2-(trifluoromethyl)-9H-purine (14), had an IC50 = 0.03 microM against serotype 1B, but its activity against 18 other serotypes was not uniform; the IC50s ranged over 260-fold.     

6-(Alkylamino)-9-benzyl-9H-purines. A new class of anticonvulsant agents

Several 9-alkyl-6-substituted-purines were synthesized and tested for anticonvulsant activity against maximal electroshock-induced seizures (MES) in rats. Most compounds were prepared in three steps from 5-amino-4,6-dichloropyrimidine or in two steps via alkylation of 6-chloropurine. Potent anticonvulsant activity against MES resided in compounds that contain a benzyl substituent at the 9-position of 6-(methylamino)- or 6-(dimethyl-amino)purine. Among commonly used agents for control of seizures, this type of structure represents a new class of potent anticonvulsant agents.     

Benzodiazepine receptor binding activity of 8-substituted-9-(3-substituted-benzyl)-6-(dimethylamino)-9H-purines

A series of 8-substituted analogues of 9-(3-aminobenzyl)-6-(dimethylamino)-9H-purine (8) were synthesized and tested for their ability to bind to the benzodiazepine receptor (BZR) in rat brain tissue. The most active compound was the 8-bromo-9-(3-formamidobenzyl) analogue 16 (IC50 = 0.011 microM), which was 1000-fold more active than the parent 9-benzyl-6-(dimethylamino)-9H-purine (1) and nearly as active as diazepam. Although substitution of a m-formamido group and an 8-bromo substituent on 1 imparted potent BZR binding activity, neither 16 nor 11 analogues exhibited significant anxiolytic activity on a modified Geller-Seifter conflict schedule.     

Benzodiazepine receptor binding activity of 9-(1-phenylethyl)purines

Several alpha-methyl analogues of the 9-benzylpurines that bind to the benzodiazepine receptor (BZR) were synthesized and tested for BZR-binding activity. Although introduction of a m-amino group and an 8-bromo substituent gave an additive increase in BZR affinity with 9-(3-aminobenzyl)-8-bromo-6-(dimethylamino)-9H-purine (4), addition of an alpha-methyl group to 4 resulted in a loss in BZR affinity. This loss in affinity is apparently due to repulsive, steric interactions between the 8-bromo and 9-(1-phenylethyl) substituents, which results in a conformation that is not optimal for interaction with the BZR. Several compounds were tested on a modified Geller-Seifter conflict schedule, but none exhibited significant anxiolytic activity.     

4-substituted 5-[m-(trifluoromethyl)phenoxy]primaquine analogues as potential antimalarial agents

Five 4-substituted 5-[m-(trifluoromethyl)phenoxy]primaquine analogues were synthesized and tested for radical curative activity against Plasmodium cynomolgi in Rhesus monkeys and for blood schizonticidal antimalarial activity against Plasmodium berghei in mice. In addition, they were evaluated for causal prophylactic antimalarial activity against Plasmodium berghei yoelii in mice. One compound, 4-ethyl-5-[m-(trifluoromethyl)phenoxy]primaquine (2b), showed radical curative activity equivalent to 4-methyl-5-[m-(trifluoromethyl)phenoxy]primaquine (2a). A second compound showed radical curative activity slightly less than 2a and 2b; the remaining three compounds were not active against P. cynomolgi. All five compounds showed much higher blood schizonticidal activity and less toxicity than primaquine; however, none of the compounds were as active as 2a. Three of four compounds tested showed high activity against P. berghei yoelii.     

1-(1 H-1, 2, 4-三唑-1-基)-2-(2, 4-二氟苯基)-3-[N-异丙基-N-(4-取代苄基)]-2-丙醇的合成及抗真菌活性

目的研究具有异丙基结构的氮唑类化合物的抗真菌活性。方法引入4位羧酸酯取代的苄基侧链结构,合成一系列目标化合物,所有化合物结构均经MS、1H-NMR等谱确证;选择8种真菌为实验菌株,测定其体外抗真菌活性。结果合成了14个未见文献报道的目标化合物;所有化合物对所选真菌均表现出了一定的抑菌活性,其中化合物(1)和(2)对除薰烟曲霉菌外的7种菌都表现出了较好的抑菌活性。结论 4位羧酸酯取代的苄基侧链结构的引入对目标化合物的抗菌活性有一定的影响,侧链越短,抑菌活性越好。     

9-(2-Fluorobenzyl)-6-(alkylamino)-9H-purines. A new class of anticonvulsant agents

Several substituted aryl and 6-alkylamino analogues of the anticonvulsant purine 9-(2-fluorobenzyl)-6-(methyl-amino)-9H-purine (1) were synthesized and tested for anticonvulsant activity against maximal electroshock-induced seizures (MES) in rats. Derivatives with a second fluoro substituent in the 5- or 6-position of the aryl moiety were very active with ip ED50's that ranged from 2 to 4 mg/kg. Congeners in which the purine 6-substituent was varied among a number of alkylamino groups possessed potent activity against MES that was comparable to or several times better than phenytoin.     

1-(1H-1,2,4-三唑-1-基)-(2,4-二氟苯基)-3-[N-环丙基-N-(4-取代苄基)]-2-丙醇的合成及抗真菌活性

目的：以氟康唑为先导化合物,设计合成新的三唑醇类化合物,并研究其抗真菌活性。方法：引入4位羧酸酯取代的苄基侧链结构,合成一系列目标化合物,所有化合物结构均经MS、^1H-NMR等谱确证;选择8种真菌为实验菌株,测定其体外抗真菌活性。结果：合成了15个未见文献报道的目标化合物;所有化合物对所选真菌均表现出了一定的抑菌活性,其中化合物（1）,（2）和（3）对除薰烟曲霉菌外的7种菌都表现出了较好的抑菌活性。结论：4位羧酸酯取代的苄基侧链结构的引入对目标化合物的抗菌活性有一定的影响,侧链越短．抑菌活性越好.     

Synthesis and antiviral evaluation of 6-(trifluoromethylbenzyl) and 6-(fluorobenzyl) analogues of HIV drugs emivirine and GCA-186

The present study describes the synthesis and antiviral evaluation of a series of novel 6-(3-trifluoromethylbenzyl) and 6-(fluorobenzyl) analogues of the HIV drugs emivirine and GCA-186. The objective was to investigate whether the fluoro or trifluoromethyl substituents could lead to an improved antiviral activity against HIV-1 wild type and mutants resistant to non-nucleoside RT inhibitors. The biological test results showed that the most of theses compounds showed good activity against wild type HIV-1. Among them, compound 1-(ethoxymethyl)-6-(3-fluorobenzyl)-5-isopropyluracil (9i) showed the largest inhibitory potency (EC(50) = 0.02 microM), resulting equally potent than emivirine against wild type HIV-1. Furthermore, compound 9i showed marginal better activity against resistant mutants than emivirine. The key steps in the synthesis of the target compounds were either reaction of an appropriate beta-keto ester with thiourea or a cross-coupling reaction of 6-chloro-2,4-dimethoxypyrimidines with benzylic Grignard reagents.     

Synthesis and characterization of (Z)-N-(1-[2-{3-[(dimethylamino)methyl)]-2-methoxyphenyl}-5-(pyridin-4-yl)-1,3,4-oxadiazol-3(2H)-yl]ethylidene) benzenamine derivatives as potent antifungal agents

In the present study, a series of (Z)-N-(1-[2-{3-[(dimethylamino)methyl)]-2-methoxyphenyl}-5-(pyridin-4-yl)-1,3,4-oxadiazol-3(2H)-yl]ethylidene)benzenamine derivatives have been synthesized and characterized by IR, 1H NMR and 13C NMR spectra. All the synthesized compounds were evaluated for their antifungal activity and were compared with the standard drug, clotrimazole. The compounds demonstrated excellent to weak antifungal activity. Among the synthesized derivatives, 4f and 4h showed significant activity and 4c exhibited moderate activity against Candida albicans, Candida tropicalis and Aspergillus niger as compared with the standard antifungal agent - clotrimazole. The minimum inhibitory concentration of the compounds was in the range of 1.62-25 microg/mL against fungi. Furthermore, the substitution of chloro, nitro and methoxy groups at para position of benzene moiety play an important role in enhancing the antifungal activity of this class of compounds.     

Synthesis of Novel Uracil Non-Nucleoside Derivatives as Potential Reverse Transcriptase Inhibitors of HIV-1

Novel emivirine and TNK-651 analogues 5a – d were synthesized by reaction of chloromethyl ethyl ether and / or benzyl chloromethyl ether, respectively, with uracils having 5-ethyl and 6-(4-methylbenzyl) or 6-(3,4-dimethoxybenzyl) substituents. A series of new uracil non-nucleosides substituted at N-1 with cyclopropylmethyloxymethyl 9a – d , 2-phenylethyloxymethyl 9e – h , and 3-phenylprop-1-yloxymethyl 9i – l were prepared on treatment of the corresponding uracils with the appropriate acetals 8a – c . Some of the tested compounds showed good activity against HIV-1 wild type. Among them, 1-cyclopropylmethyloxymethyl-5-ethyl-6-(3,5-dimethylbenzyl)uracil 9c and 5-ethyl-6-(3,5-dimethylbenzyl)-1-(2-phenylethyloxymethyl)uracil 9g showed inhibitory potency equally to emivirine against HIV-1 wild type. Furthermore, compounds 9c and 9g showed marginal better activity against NNRTI resistant mutants than emivirine.     

Synthesis, biological activity, and SAR of antimycobacterial 9-aryl-, 9-arylsulfonyl-, and 9-benzyl-6-(2-furyl)purines

9-Aryl-, 9-arylsulfonyl- and 9-benzyl-6-(2-furyl)purines were synthesized by N-alkylation or N-arylation of the purine followed by Stille coupling to introduce the furyl substituent in the 6-position and the compounds screened for activity against Mycobacterium tuberculosis. The 9-aryl- and 9-sulfonylarylpurines exhibited weak activity toward the bacteria, but 9-benzylpurines were good inhibitors especially those carrying electron-donating substituents on the phenyl ring. A chlorine atom in the purine 2-position further enhanced activity. The high antimycobacterial activity (MIC 0.39 microg/mL against M. tuberculosis), low toxicity against mammalian cells and activity inside macrophages found for 2-chloro-6-(2-furyl)-9-(4-methoxyphenylmethyl)-9H-purine makes this compound a highly interesting potential antituberculosis drug.     

1-(1H-1,2,4-三唑-1-基)-(2,4-二氟苯基)-3-(N-异丙基-N-取代氨基)-2-丙醇的合成及抗真菌活性

目的：以氟康唑为先导化合物,设计合成新的三唑醇类化合物,并研究其抗真菌活性。方法：引入异丙基及取代氨基侧链结构,合成一系列目标化合物,所有化合物结构均经MS、^1H—NMR等谱确证;选择8种真菌为实验菌株,测定其体外抗真菌活性。结果：合成了15个目标化合物;所有化合物对所选真菌均表现出了一定的抑菌活性,其中化合物（6c）,（6d）,（6e）,（6f）和（6g）对除薰烟曲霉菌外的7种菌株都表现出了较好的抑菌活性。结论：取代氨基侧链结构的引入对目标化合物的抗菌活性有一定的影响,侧链为取代苄基活性较好,且取代苄基侧链越短,抑菌活性越好。     

Antirhinovirus activity of 6-anilino-9-benzyl-2-chloro-9H-purines

A series of 6-anilino-9-benzyl-2-chloropurines was synthesized and tested for antirhinovirus activity. Most of the compounds were prepared by reaction of the appropriate aniline with 9-benzyl-2,6-dichloro-9H-purine. Structure-activity relationship studies revealed that compounds with small, lipophilic para substituents were good inhibitors of serotype 1B. Several compounds had good activity against four representative serotypes.     

Synthesis and antileukemic activity of novel 2-(4-(2,4-dimethoxybenzoyl)phenoxy)-1-(4-(3-(piperidin-4-yl)propyl)piperidin-1-yl)ethanone derivatives

A series of novel 2-(4-(2,4-dimethoxybenzoyl)phenoxy)-1-(4-(3-(piperidin-4-yl)propyl) piperidin-1-yl)ethanone derivatives 9(a-e) and 10(a-g) were synthesized and characterized by (1) H NMR, IR, mass spectral, and elemental analysis. These novel compounds were evaluated for their antileukemic activity against two human leukemic cell lines (K562 and CEM) by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay. Some of the tested compounds showed good antiproliferative activity with IC(50) values ranging from 1.6 to 8.0 μm. Compound 9c, 9e, and 10f with an electron-withdrawing halogen substituent at the para position on the phenyl ring showed excellent in vitro potency against tested human leukemia cells (K562 and CEM).     

(9S)-9-羟基-12-亚甲基红霉素A衍生物的合成

为了合成具有抗菌活性的红霉素衍生物,本文以红霉素A为原料,合成了6-位烯丙基取代中间体12,21-双键-2′-O,4″-O-二苯甲酰基-(9S)-9-O,11-O-异丙基-6-O-烯丙基红霉素A 12,得到(9S)-9-羟基-12-亚甲基衍生物6和6,7-去氢-(9S)-9-羟基-12-亚甲基衍生物11。经¹³C NMR,FAB-MS确证产物结构。所得化合物进行了体外抗菌活性测定。6和11均显示出较弱的抑菌活性。     

1-(1-取代苯基)-2-(1H-1,2,4-三唑或苯并三唑基)-O-(取代苄基)乙酮肟醚类化合物的合成及抗真菌活性

报道了29个新的1-(1-取代苯基)-2-(1H-1,2,4-三唑或苯并三唑基)-O-(取代苄基)乙酮肟醚类化合物的合成与体外抗菌试验。结果表明,大多数化合物对大部分真菌有抑菌活性,化合物T₁,T₄,T₆,T₁₁,T₁₂,B₁,B₃,B₄和B₆对部分真菌抑菌活性优于或相当于奥昔康唑。     

Synthesis and biological evaluation of iodinated and fluorinated 9-(2-hydroxypropyl) and 9-(2-hydroxyethoxy)methyl purine nucleoside analogues

The novel fluorinated and iodinated purine derivatives containing 9-(2-hydroxypropyl) (1a-7a and 9a-13a) and 9-(2-hydroxyethoxymethyl) (1b-3b, 5b, and 7b-12c) side chains were synthesized by a multistep synthetic route involving Baltz-Schiemann's fluorination and diazotation/iodination as key reactions. An unequivocal proof for the stereostructure of 5b was obtained by X-ray structure analysis. New compounds were evaluated for their cytostatic activity against murine leukemia (L1210); mammary carcinoma (FM3A); and human T-lymphocytes (Molt4/C8 and CEM), melanoma (HBL), cervical carcinoma (HeLa), colon carcinoma (HT29 and SW620), laryngeal carcinoma (Hep2), and pancreatic carcinoma (MiaPaCa2) as well as diploid fibroblasts (WI38). Of all the compounds, the 2-aminopurin-6-thione derivative 9a showed the most pronounced inhibitory activity against human SW620 cells. The 2-aminopurin-6-thione derivative 9b exhibited the most selective inhibitory activity against human HeLa, Hep2, SW620, and murine L1210 cell proliferation as compared to normal fibroblast (WI38) cell proliferation. None of the compounds showed inhibitory activities against HIV-1, HIV-2, HSV-1, and HSV-2, vaccinia, vesicular stomatitis, parainfluenza-3, reovirus-1, Sindbis, Coxsackie B4, or respiratory syncytial virus. The new purine derivatives, and particularly 9a and 9b, appear to demonstrate sufficient cytostatic potency and selectivity to justify further evaluation of their potential.