Showing papers in "Archiv Der Pharmazie in 2000"

Design and synthesis of some oxadiazolyl, thiadiazolyl, thiazolidinyl, and thiazolyl derivatives of 1H-pyrazole as anti-inflammatory antimicrobial agents.

Abstract: Four series of 1H-pyrazole derivatives have been synthesized. The first series was prepared by cyclization of the intermediate 3-(5-bromo-2-thienyl)-1-phenyl-1H-pyrazole-4-carbaldehyde aroyl-hydrazone 4a-c with acetic anhydride to afford the corresponding oxadiazoline derivatives 5a-c. The other series were prepared by the cyclization of the intermediate 3-(5-bromo-2-thienyl)-1-phenyl-4-substituted thiocarbamoylhydrazonomethyl-1H-pyrazole 6a-c with acetic anhydride, ethyl bromoacetate or phenacyl bromide giving rise to 3-(5-bromo-2-thienyl)-1-phenyl-4-[3-acetyl-5-(N-substituted acetamido)-2,3-dihydro-1,3,4-thiadiazol-2-yl]-1H-pyrazoles 7a-c, 3-(5-bromo-2-thienyl)-1-phenyl-4-(3-substituted- 4-oxothiazolidin-2-ylidenehydrazonomethyl)-1H-pyrazoles 8a-c, or 3-(5-bromo-2-thienyl)-1-phenyl-4-(3-substituted-4- phenyl-2,3-dihydrothiazol-2-ylidenehydrazonomethyl)-1H-pyraz oles 9a-c respectively. Some of these compounds showed anti-inflammatory, antibacterial or antifungal activities comparable to that of Proquazone, Ampicillin, or Clotrimazole respectively.

Synthesis and in vitro antifungal and cytotoxicity evaluation of thiazolo-4H-1,2,4-triazoles and 1,2,3-thiadiazolo-4H-1,2,4-triazoles.

Abstract: The increasing clinical importance of drug-resistant fungal pathogens has lent additional urgency to microbiological and antifungal research. Various thiazolo(or 1,2,3-thiadiazolo)thiosemicarbazides (2a-2e), 3-thiono-1,4-dihydrotriazolothiazoles-(or 1,2,3-thiadiazoles) (3a-3e), their related substituted thio-4H-1,2,4-triazoles (4a-4p) and sulfones (5a-5o) were synthesized. Most of the compounds tested for antifungal activity exhibited significant effects against Cryptococcus neoofrmans and Sacchromyces cerevisiae at MIC ranges of 0.53 to 12.5 micrograms/mL, whereas their activities were moderate against Candida albicans and weak against Aspergillus fumigatus. At 10 ppm concentration, all compounds showed low toxicity on brine shrimps (higher than 80% survival), except compounds 4c and 2c. At 100 ppm concentration most of the compounds showed toxicity except compounds 2b, 2e, 3c, 3d, 3e, and 4e. Compounds 4b, 4c, and 4h showed in vitro cytotoxicity against Kbalb cell lines and compounds 4c and 4g against 143B cell lines at 0.1 mM concentration.

Synthesis and anticonvulsant activity of acetylenic quinazolinone derivatives.

Abstract: Acetylenic derivatives of quinazolinones and quinazolinediones were synthesized and evaluated for their anticonvulsant activity. Most compounds displayed seizure-antagonizing activity in the maximal electroshock test (MES test) in most cases associated with little or no acute neurotoxicity determined in the rotorod test. Only three compounds exhibited significant activity in the seizure threshold test with subcutaneous pentylenetetrazole (scMet test). Based on the ED 50 in the MES test, 1,3-bis-(prop-2-ynyl)-quinazoline-2,4-( 1 H,3H)-dione (9a) was about ten-fold less active than phenytoin or carbamazepine but about as active as mesuximide.

Cytotoxic activity of cerium complexes with coumarin derivatives. Molecular modeling of the ligands.

Abstract: Cerium complexes of Umbellipherone, Mendiaxon, Warfarin, Coumachlor, and Niffcoumar have been synthesized by reaction of the ligands with cerium nitrate in a stoichiometric ratio of 1:2. The formation of the complexes has been proved on the basis of elemental analysis, conductivities, IR spectroscopy, and 1H-NMR spectroscopy. The molecules of the ligands were optimized by means of the semiempirical quantum mechanical method PM3 to the energetically most stable conformers. All the ligands were characterized by molecular and submolecular electronic indices and the putative donor centers are proposed. It is concluded that the lactone- and the keto-carbonyl groups of Warfarin, Coumachlor, and Niffcoumar are bonded to the metal ion as bidentate ligands. The other two coumarins are bonded as monodentate ligands. Conductivity measurements show the non-electrolytic nature of the complexes. Cytotoxic screening by MTT assay was carried out. The cerium complexes were found to be more active than the inorganic salts.

Synthesis, DNA-binding, and antiviral activity of certain pyrazolo[3,4-d]pyrimidine derivatives.

Abstract: Some new pyrazolo[3,4-d]pyrimidine derivatives have been prepared and tested for their antiviral and DNA-binding activities. Compounds 4, 5, and 6 showed high binding affinity to DNA at concentrations of 19, 27, and 28 μg/ml, respectively. On the other hand, compounds 6 and 10 reduced the number of viral plaques of Herpes simplex type-1 (HSV-1) by 66 and 41%, respectively. The detailed synthesis and spectroscopic and biological data are reported.

Studies on some 3(2H)-pyridazinone derivatives with antinociceptive activity.

Abstract: Nineteen new [6-(4-methoxyphenyl)-3(2H)-pyridazinone-2-yl]-acetamide (1-10) and 3-[6-(4-methoxyphenyl)-3(2H)-pyridazin-one-2-yl]propanamide (11-19) derivatives have been synthesized in this study. The structures of the compounds have been elucidated by their IR and NMR spectral data and elemental analysis. Antinociceptive activity of the compounds has been investigated by modified Koster's Test in mice, using aspirin as a reference. All the compounds (at 100 mg/kg dose) except 1 and 9 have been found more potent than aspirin. Compound 6 in the group of acetamide derivatives and compound 15 in the group of propanamides exhibited the highest antinociceptive activity. In addition, the propanamides have generally been found more potent than acetamides. In addition to these studies, the quantitative relationships between some structural parameters (such as log P, parachor, molar refractivity, and molecular connectivity indices) and antinociceptive activity of the compounds have been investigated. Statistical regression analysis has shown a close relationship to exist between the first-order molecular connectivity index (1 chi) and the antinociceptive activity.

Crosslinked polyvinylalcohol hydrogels as vehicles for hydrophilic drugs.

Abstract: Polyvinylalcohol crosslinked with succinyl, adipoyl, or sebacoyl chloride at two different degrees of crosslinking was prepared and employed as a supporting material for aqueous topical gels containing propranolol hydrochloride, which was chosen as a hydrophilic model drug suitable for transdermal delivery. We analysed the effect of the nature of the crosslinker and the degree of crosslinking on drug permeation through porcine skin by means of the permeation parameters obtained from the gels and the corresponding aqueous solution. The gels showed greater drug permeation than the liquid solution due to an increase in drug solubility in the skin. Increasing degree of crosslinking and decreasing crosslinker acyl chain length in the gel enhance the drug permeability through the skin.

New tetrahydro-2H-1,3,5-thiadiazine-2-thione derivatives as potential antimicrobial agents.

Abstract: The deacylated chloramphenicol amine D-(-)-threo-2-amino-1-(4-nitrophenyl)-1,3-diol (D-amine, 1a), and its enantiomer, the L-(+)-threo-form (L-amine, 1b), were introduced into a tetrahydro-2H-1,3,5-thiadiazine-2-thione (THTT) skeleton. They are incorporated in three ways (Chart 1, types I-III) at N3 (type I), N5 (type II) or both N3 and N5 (type III) of the THTT system. These selections were made in order to investigate the effect of combining the structural features of the THTT and the D-amine on the antimicrobial activity, if any.

Structure-activity relationships of polycyclic aromatic amines with calcium channel blocking activity.

Abstract: 8-Benzylamino-8, 11-oxapentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane (1) inhibits the calcium current in L-type calcium channels. A series of nitrobenzylamines (2, 3, 4), methoxybenzylamines (5, 6, 7), methylpyridines (8, 9, 10), and a phenylhydrazine derivative (11) of 8,11-oxapentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane was synthesized. By substituting the 8,11-oxapentacyclo-[5.4.0.0(2,6).0(3,10).0(5,9)]undecane skeleton with 3-hydroxyhexacyclo-[6.5.0.0(3,7).0(4,12).0(5,10).0(9,13)]tridec ane (12), 8,13-dioxapentacyclo[6.5.0.0(2,6).0(5,10).0(3,11)]tridecane- 9-one (13), and pentacyclo-[5.4.0.0(2,6).0(3,10).0(5,9)]undecane (14), the effect of the polycyclic skeleton could also be investigated. Increased inhibition of calcium current was observed with aromatic substitution (especially ortho and meta substitution) in the pentacycloundecane series. The calcium channel activities of the methoxy compounds were slightly higher than those of the corresponding nitro compounds while a definite decrease in activity was observed for the phenylhydrazine and aminomethylpyridine derivatives. Increased inhibition of the calcium current was also observed for structures in which the polycyclic 'cages' were enlarged. Structure-activity relationships in this series of compounds therefore appear to be dominated by geometric or steric constraints.

β‐Lactam Derivatives as Enzyme Inhibitors: 1‐Peptidyl Derivatives of 4‐Phenylazetidin‐2‐one as Inhibitors of Elastase and Papain

Abstract: N-Peptidyl substituted azetidin-2-ones were synthesized and evaluated as inhibitors of the serine protease elastase, and the cysteine protease papain. All compounds were synthesized from 4-phenylazetidin-2-one, either from the racemate or from the pure enantiomers. The (S)-enantiomer was prepared by enantioselective synthesis from (S)-beta-phenyl-beta-alanine, while the (R)-enantiomer was obtained by enzymatic resolution with alpha-chymotrypsin. N-Alkylation with bromoacetates introduced a spacer group which, after hydrolysis to the free acid, was acylated with amino acid esters or di- or tripeptide esters. The enzymatic assays proved some derivatives to be effective inhibitors of PPE and/or papain. N-BOC protected amino acid derivatives without a spacer group inhibited PPE reversibly, while derivatives with spacer group showed either weak or no inhibitory properties. On the other hand, papain was inactivated irreversibly by ethyl (RS)-2-oxo-4-phenylazetidin-1-acetate. The highest inhibitory activity against papain was found for the diastereomers of N-(2-oxo-4-phenylazetidin-1-acetyl)-L-alanyl-L-valine benzyl ester, a compound with a spacer group.

The cytotoxicity of symmetrical and unsymmetrical bis(thiosemicarbazones) and their metal complexes in murine and human tumor cells.

Abstract: A number of thiosemicarbazones have been tested previously and herein are included three bis(thiosemicarbazones) for comparison to the previous derivatives. In general the uncomplexed thiosemicarbazones were more potent in the cytotoxic screens than the bis(thiosemicarbazone) except in the murine L1210 and the human colon SW480 screens. Mode of action studies have only demonstrated slight differences in the effects of the two types of compounds on nucleic acid metabolism. The symmetrical and unsymmetrical bis(thiosemicarbazones) complexes of copper, nickel, zinc, and cadmium have been examined to compare them to the heterocyclic N(4)-substituted thiosemicarbazones metal complexes. These new derivatives demonstrated excellent activity against the growth of suspended lymphomas and leukemias although it should be pointed out that generally they were not as active as the copper complexes of N(4)-substituted thiosemicarbazones. Nevertheless, selected bis(thiosemicarbazones) complexes were active against the growth of human lung MB9812, KB nasopharynx, epidermoid A431, glioma UM-86, colon SW480, ovary 1-A9, breast MCK-7, and osteosarcoma Saos-2. In human HL-60 promyelocytic leukemia cells the complexes preferentially inhibited DNA and purine syntheses over 60 min. The regulatory enzyme of the de novo purine pathway, IMP dehydrogenase, appeared to be a major target of the complexes. However, minor inhibition of the activities of DNA polymerase alpha, PRPP-amido transferase, ribonucleotide reductase, and nucleoside kinases occurred over the same time period. No doubt these effects of the complexes on nucleic acid metabolism were additive since the d[NTP] pool levels were reduced after 60 min as was DNA synthesis. The symmetrical and unsymmetrical bis(thiosemicarbazones) and their metal complexes did not cause as severe DNA fragmentation as the heterocyclic N(4)-substituted thiosemicarbazone metal complexes; furthermore, their metabolic effects in the tumor cell were more focused on a single synthetic pathway.

A qualitative model for the histamine H3 receptor explaining agonistic and antagonistic activity simultaneously.

Abstract: A pharmacophore model for histamine H3 ligands is derived that reveals the putative interaction of both H3 agonists and antagonists with an aspartate residue of the receptor. This interaction is determined by applying the density functional theory implemented in a program package adapted for parallel computers. The model reveals a molecular determinant explaining efficacy as the conformation of the aspartic acid residue differs according to whether it is binding to agonists or antagonists. The differences in structure-activity relationships (SAR) observed for the lipophilic tails of different classes of H3 antagonists are now explained, since the model reveals two distinct lipophilic pockets available for antagonist binding.

Synthesis and antifungal activity of some new quinazoline and benzoxazinone derivatives.

Abstract: The hitherto unknown 2-isopropyl-6,8-dibromo-4H-3,1-benzoxazin-4-one (2) was subjected to condensation with either primary or secondary amines affording the benzamide derivatives (3-7), while with alcohols in presence of the base, corresponding esters were obtained (8 and 9). Acylation of the hydrazide (12) or its cyclized form (13) gave (14-17). The quinazolinone derivative (18) was obtained either when (12) was reacted with nitrous acid or via fusion of (2) with ammonium acetate. The thione (20) which was obtained via reaction of (18) with Lawesson's reagent, was subjected to either alkylation yielding (21-25) or desulphurization with primary amines affording (26 and 27). Treatment of (18) as well as (20) with a chlorinating agent provided (29, 30) and (28, 29) mixtures, respectively. Ten of our compounds were examined against Sclerotium cepivorum as well as Botrytis allii on PDA media. These compounds showed a significant reduction of mycelial growth and scleratia number of these fungi which cause the white rot and neck rot diseases of onion.

Synthesis and antinociceptive activity of (5-chloro-2-benzothiazolinon-3-yl)acetamide derivatives.

Abstract: The synthesis of (5-chloro-2-benzothiazolinon-3-yl)acetamide derivatives is reported. The structure of these compounds is supported by their IR and 1 H-NMR spectra. The compounds were tested for antinociceptive activity.

A new flavonoid from Limonium axillare.

Abstract: A new flavonol glycoside identified as myricetin 3-O-beta-D-sorboside (1) has been isolated from the leaves of L. axillare. The new compound showed a moderate inhibition of Ehrlich ascites carcinoma cells.

Effect of flavonol derivatives on the carrageenin-induced paw edema in the rat and inhibition of cyclooxygenase-1 and 5-lipoxygenase in vitro.

Abstract: Alkoxyflavonols were synthesized by the Algar-Flynn-Oyamada (AFO) cyclization of chalcones. Hydroxyflavonols were prepared by dealkylation of methoxyflavonols by refluxing in hydroiodic acid. The alkoxyflavonols 3-hydroxy-2-(2,3,4-trimethoxyphenyl)-4H-chromen-4-one (6), 2-(4-ethoxyphenyl)-3-hydroxy-4H-chromen-4-one (7), 2-(4-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (10), and 2-(3-n-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (11) as well as the trihydroxy derivative 3-hydroxy-2-(3,4,5-trihydroxyphenyl)-4H-chromen-4-one (18) displayed high anti-inflammatory activity in carrageenin-induced rat paw edema. Additionally, the inhibition of enzymes of the arachidonic acid cascade by the derivatives was investigated in vitro. In contrast to the natural compound quercetin, the compounds were more potent inhibiting cyclooxygenase-1 than 5-lipoxygenase except for 3-hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (5). No correlation between the anti-inflammatory activity in the rat paw edema test and the inhibition of 5-lipoxygenase or cyclooxygenase-1 could be observed. In conclusion, the present results suggest that other effects than inhibition of these enzymes of the arachidonic acid cascade are important for the anti-inflammatory activity of the investigated alkoxyflavonols.

Azepino- and diazepinoindoles: synthesis and dopamine receptor binding profiles.

Abstract: Starting from the readily available building blocks 7, 10, 11, and 15, the synthesis of the fused indoles 1, 2. 5, and 6, respectively, is reported. The syntheses involved Pictet-Spengler cyclizations. Michael addition reactions, lactamization, directed metallation, and reductive amination as the key reaction steps. Radioligand displacement studies comprising the dopamine receptor subtypes D 1 , D 2long D 2staat , D 3 , and D 4 were performed when the diazepinoindole 6 revealed D 4 and D 4 affinities (K i = 0.11 μM and 1.7 μM, respectively) which are comparable to the partial D 1 agonist SKF 38393 (3b). In contrast to the benzazepine 3b, the indole based test compounds turned out less selective over the D 2 and D3 receptor subtype.

Studies on Synthesis, Chromatographic Resolution, and Antiinflammatory Activities of Some 2‐Thioxo‐1,2,3,4‐tetrahydropyrimidines and Their Condensed Derivatives

Abstract: In this study, the synthesis of some new 2-thioxo-1,2,3,4-tetrahydropyrimidines and their condensed derivatives, thiazolo[3,2-a]pyrimidines, are described. The structures of the compounds were confirmed by 1R, 1H-NMR, 13C-NMR, and mass spectroscopy. The direct high-performance liquid chromatographic separation of the compounds on derivatized cellulose chiral stationary phases such as cellulose tris(3,5-dimethylphenylcarbamate) (OD), cellulose tris(4-methylphenylcarbamate) (OG), and cellulose tris(4-methylbenzoate) (OJ) was studied. All of the compounds were screened for their antiinflammatory activity and also investigated histopathologically. Compounds 3 and 1a were found to be the most promising antiinflammatory agents in this group.

Antiestrogenic activities of 3,8-dihydroxy-6,11-dihydrobenzo[a]carbazoles with sulfur-containing side chains.

Abstract: The objective of this study was to explore whether the conversion of the 2-phenylindole system into the tetracyclic benzo[a]carbazole changes the endocrine profile when the side chain structure was kept constant. Five different sulfur-containing side chains were linked to the nitrogen of the tetracycle. The biological evaluation revealed that the character of the indole derivatives remained unchanged after the conversion to the respective benzocarbzoles but the potency decreased by one order of magnitude. In vitro, all derivatives acted as pure antiestrogens without any agonist activity. They strongly inhibited the growth of estrogen-sensitive MCF-7 breast cancer cells with IC50-values in the nanomolar range. In the mouse uterine weight test, the derivatives with an aliphatic side chain were devoid of estrogenic activity and antagonized the effect of estradiol. The presence of an aromatic ring in the side chain gave rise to significant agonist activity in vivo independently of the carrier structure. All data revealed the equivalence of both carrier structures in respect to the endocrine profile but showed a decrease in potency upon the conversion of the 2-phenylindole system into the benzocarbazole structure.

Diazabicyclo[3.3.1]nonanone-type ligands for the opioid receptors.

Abstract: Previously 2,4-dipyridine substituted 3,7-diazabicyclo[3.3.1]nonanone diesters were found to have a high affinity and selectivity towards the kappa-opioid receptor. The purpose of this study was to check the influence of substituents at position N3 on the affinity to the mu-, delta-, and kappa-receptors. Whereas a phenylethyl group is able to create affinity to the mu-receptor, small substituents such as a hydrogen or a methyl group are responsible for a high affinity to the kappa-receptor. In addition, a dimeric compound was found to have affinity to the kappa-receptor. Although all compounds will bear at least one positive charge under physiological conditions they show a considerable lipophilicity, indicating the possibility of passing the blood-brain barrier.

Synthesis and cytotoxicity of 2,4-disubstituted and 2,3,4-trisubstituted brominated pyrroles in murine and human cultured tumor cells.

Abstract: The 2,4-disubstituted and 2,3,4-trisubstituted brominated pyrroles were successfully prepared and demonstrated potent cytotoxicity against the growth of suspended murine and human tumors, i.e. leukemia and lymphomas, acute monocytic leukemia, and HeLa S 3 uterine carcinoma. The brominated compounds were more selective in inhibiting the growth of tumors derived from human selective in inhibiting the growth of tumors derived from human solid tumors. Nevertheless, activity with some of the derivatives occurred in the human KB nasopharynx, SW-480 colon, and HCT ileum adenocarcinoma, and lung A549 carcinoma screens. In Tmolt 4 T cell leukemia cells DNA synthesis was reduced over 60 min from 25 to 100 μM followed by RNA synthesis reduction. De novo purine synthesis was retarded with the regulatory enzyme PRPP-amido transferase being markedly inhibited with less effects on the activities of IMP dehydrogenase, dihydrofolate reductase, and the nucleoside kinases. After 60 min incubations d[TTP] and d[GTP] pools were marginally reduced. In vitro ct-DNA studies suggest that the agents may affect the DNA molecule itself with increased DNA viscosity and the Tmolt 4 studies suggest that DNA cross-linking of DNA strands may be present.

Synthesis and biological evaluation of 1,2,5-oxadiazole N-oxide derivatives as potential hypoxic cytotoxins and DNA-binders.

Abstract: Several new 1,2,5-oxadiazole N-oxide derivatives were synthesized to be tested both as potential selective hypoxic cell cytotoxins and as DNA-binding agents. The compounds prepared included bis(1,2,5-oxadiazole N-oxide) derivatives and oxadiazole rings linked to naphthyl residues. The compounds were tested for their cytotoxicity in oxia and hypoxia and they proved to be non-selective and less active than the parent compounds 3-formyl-4-phenyl-1,2,5-oxadiazole N2-oxide (3) and 3-chloromethyl-4-phenyl-1,2,5-oxadiazole N2-oxide (4). The DNA-affinity assays showed that the compounds tested have poor affinity for this biomolecule.

Pyridazine N-oxides. III. Synthesis and "in vitro" antimicrobial properties of N-oxide derivatives based on tricyclic indeno[2,1-c]pyridazine and benzo[f]cinnoline systems.

Abstract: A number of 9H-indeno[2,1-c]pyridazine N-oxides (3a-c) and benzo[f]cinnoline N-oxides (4,5a-c) have been synthesized and tested for antimicrobial activity. All new products were inactive against Gram negative bacteria and fungi. In contrast, among the compounds synthesized, 3b, 4b and 5b showed a moderate activity against Gram positive Staphylococcus aureus and Staphylococcus epidermidis. Of the present series, the 9-nitro-benzo[f]cinnoline N-oxide 5b possessed the highest activity especially against Trichomonas vaginalis (MIC = 3.9 micrograms/ml).

New Nonsteroidal Steroid 5α‐Reductase Inhibitors. Syntheses and Structure‐Activity Studies on Carboxamide Phenylalkyl‐Substituted Pyridones and Piperidones

Abstract: In the search for nonsteroidal inhibitors of 5 alpha-reductase for the treatment of benign prostatic hyperplasia (BPH), we synthesized diisopropyl (1a-8a) and tert-butyl (1b-8b) benzamides, as well as ethyl benzoates (1c, 3c), which were substituted in 4 position via variable alkyl spacer (n = 0: 1-4, n = 1: 5, 7 and n = 3: 6, 8) with a 1-methyl-2-pyridone (1, 2, 5, 6) or a 1-methyl-2-piperidone (3, 4, 7, 8) moiety mimicking steroidal ring A. The directly connected benzamides (1a-4a, 1b-4b) and benzoates (1c, 3c) were obtained by palladium-catalysed coupling reaction of diethyl(3-pyridyl)-borane with 4-bromobenzoic acid derivatives, followed by alpha-oxidation of the 1-methyl-pyridinium salt and subsequent separation of the regioisomers. Catalytic hydrogenation of the pyridones (1, 2) led to the piperidones (3, 4). The preparation of the benzamides with a methylene (5, 7) and a propylene spacer (6, 8), respectively, started with the reduction of the keto group of 5-benzoyl-1,2-dihydro-1-methyl-2(1H)-pyridone and catalytic hydrogenation of the alkene obtained by Wittig reaction of 5-formyl-1,2-dihydro-1-methyl-2(1H)-pyridone with (2-phenylethyl)triphenylphosphonium bromide, respectively. The phenyl ring was functionalized by Friedel-Crafts reaction, haloform cleavage to give the acid, formation of the acid chloride, and subsequent treatment with the appropriate amines. Again, catalytic hydrogenation of the pyridones (5, 6) led to the piperidones (7, 8). The 5 alpha-reductase inhibitory properties were determined using rat ventral prostate, as well as human BPH tissue as enzyme source, 1 beta-2 beta-[3H]testosterone as substrate and a HPLC procedure for the separation of dihydrotestosterone (DHT). Tested at a concentration of 100 microM, the inhibition values of 1-8 ranged from 0-79%. Significant differences were observed between rat and human enzyme. The most active compound was ethyl 4-(1-methyl-2-oxopiperid-5-yl)benzoate 3c (68%) for the human enzyme and N,N-bis(1-methylethyl)-4-[3-(1,2-dihydro-1-methyl-2-oxopyrid-5-yl) propyl] benzamide 6a (79%) for the rat enzyme.

Synthesis and antitumour activity of new derivatives of flavone-8-acetic acid (FAA). Part 41) : Variation of the basic structure

Abstract: A range of 11 derivatives of flavone-8-acetic acid (FAA) in which the structure has been substantially altered in different ways have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. The generally poor activity observed shows that the basic structure cannot be altered much without destroying the activity.

Synthesis, structure, and binding of some 2-imidazolines to rat brain alfa-1 and alfa-2-adrenergic receptors.

Abstract: A series of novel 2-[(2-aminophenyl)imino]imidazolinium salts 3a-d and N-benzyl-N-(4,5-dihydro-imidazol-2-yl)-O-methylhydroxylamine hydrochloride 7a-c were prepared and their structure was determined by IR and NMR spectroscopic data as well as X-ray analysis of the imidazolinium azide salt 3e. Binding evaluation for both alpha 1- and alpha 2-adrenergic receptors in rat brain preparations of these compounds and the previously described alpha-hydroxy-2-aryliminoimidazolines 11a-d, N-(4,5-dihydroimidazol-2-yl)-1,3-2-oxodihydrobenzimidazoles 12a-b, 2-amino-N-(4,5-dihydroimidazol-2-yl)-benzimidazoles 13a-b, and N-(4,5-dihydroimidazol-2-yl)-indoles 14a-b was performed. Among the compounds tested, 2-[(2-amino-4,5-dichlorophenyl)imino]imidazolinium chloride 3c showed highest binding affinity to alpha 2-adrenoreceptors (Ki = 30 nM).

Synthesis, antitumor activity, and anti-HIV-1 testing of certain heterocyclic systems containing an adamantane nucleus.

Abstract: A new series of substituted 2-(1-adamantyl)-4H-3,1-benzoxazin-4-ones and 2-(1-adamantyl)-3-amino or alkyl-3,4-dihydroquinazolin-4-ones have been synthesized and tested for their antitumor and antiviral activities. Among the tested compounds, compounds 5a and 5b exhibited a broad spectrum antitumor activity with full panel (MG-MID) median growth inhibition (GI50) values of 3.2 and 4.9 microM respectively. Meanwhile, compounds 5c, 5d, 5h, 5i, and 5j showed moderate selectivity towards leukemia cell lines. On the other hand, compounds 4a and 4b possessed moderate Anti-HIV-1 potency with EC50 values of 50.3 and 69.2 microM respectively. Detailed synthesis, spectroscopic, and biological data are reported.

Studies on the Chemistry of Thienoannelated O,N- and S,N-Containing Heterocycles. Part 19[1]: Thieno[2,3-b][1,4]thiazines with Calcium Antagonistic and Potassium Opening Activities

Abstract: In this study novel substituted 6-benzyl-thieno[2,3-b][1,4]thiazines with an urea moiety were synthesized. Structural modifications of the amino side chain were carried out with the aim of finding tissue specific compounds. The effects on papillary muscles, right atria, aortic strips, and terminal ilea were investigated. Compounds 10c and 10d showed the most potent negative inotropic effect. The calcium antagonism of all derivatives occurred in a non-competitive manner, which may indicate that they also have potassium channel opening activities.

Synthesis and antioxidant activity of flavanoid derivatives containing a 1,4-benzodioxane moiety.

Abstract: Flavanoids bearing a 1,4-benzodioxane moiety [rac-15a, -16a, -17, -18, (-)-15a, (-)-16a] were prepared from protocatechualdehyde (5) and τested for inhibitory activity on the superoxide anion (O 2 .- ) release by human polymorphonuclear leukocytes (PMNLs).