Synthesis and antifolate activity of new pyrrolo[2,3‐d]pyrimidine and thieno[2,3‐d]pyrimidine inhibitors of dihydrofolate reductase

Three previously undescribed dihydrofolate reductase (DHFR) inhibitors, N^α‐[4‐[N‐[(2,4‐diaminopyrrolo[2,3‐d]pyrimidin‐5‐yl)methyl]amino]benzoyl]‐N^δ‐hemiphthaloyl‐L‐ornithine (7) , N^α‐ [4‐ [N‐[(2,4‐diaminothieno[2,3‐d]pyrimidin‐5‐yl)methyl]amino]benzoyl]‐ N^δ‐hemiphthaloyl‐L‐ornithine (8) , and N‐[4‐[N‐[(2,4‐diaminothieno[2,3‐d]pyrimidin‐5‐yl)methyl]amino]benzoyl]‐L‐glutamic acid (12) , were synthesized and their antifolate activity was assessed. The ability of 7 and 8 to bind to DHFR and inhibit the growth of CCRF‐CEM human lymphoblastic leukemia cells in culture were dramatically reduced in comparison with the corresponding pteridine analogue, N^α‐(4‐amino‐4‐deoxypteroyl)‐N^δ‐hemiphmaloyl‐L‐ornithine ( 1 , PT523). In a similar manner, the antifolate activity of 12 was markedly reduced in comparison with that of the corresponding glutamate analogue, aminopterin ( 5 , AMT). In contrast, 7, 8 , and 12 all displayed excellent affinity for the reduced folate carrier (RFC) of CCRF‐CEM cells as measured by a standard competitive influx assay. Lack of a consistent correlation between the results of the growth inhibition assays and those of the DHFR and RFC binding assays results suggest that additional factors also play a role in the antifolate activity of these compounds.     

Synthesis and Cytotoxic Activity of Some Novel Dihyrobenzo[h]pyrano[3,2‐c]chromene Derivatives

Three‐component reaction of 4‐hydroxy‐2H‐benzo[h]chromen‐2‐one, aromatic aldehydes, and malononitrile in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in ethanol at room temperature affords good yields of novel dihyrobenzo[h]pyrano[3,2‐c]chromene derivatives. The synthesized compounds examined by MTT assays for cytotoxic activity in two human cancer cell lines (MOLT‐4, HL‐60). Most of the evaluated compounds showed low inhibitory activity against tumor cell line at micromolar concentrations.     

4-Aminobicyclo[2.2.2]octan-2-ones and -ols <Emphasis Type="Italic">via</Emphasis> Enamine Intermediates

Summary. The synthesis of new bicyclo[2.2.2]octane derivatives is described and their structures were established by NMR experiments. All compounds were tested in in vitro assays for their activities against causative organisms of malaria and African sleeping sickness and compared to those of former synthesized compounds.     

4-Aminobicyclo[2.2.2]octan-2-ones and -ols via Enamine Intermediates

The synthesis of new bicyclo[2.2.2]octane derivatives is described and their structures were established by NMR experiments. All compounds were tested in in vitro assays for their activities against causative organisms of malaria and African sleeping sickness and compared to those of former synthesized compounds.     

Synthesis of Deuterium Labeled Tryptamine Derivatives

The synthesis of deuterium labeled tryptamine derivatives, [2‐(1H‐indol‐3‐yl)‐[²H₄]‐ethyl]‐dimethylamine (DMT), [²H₁₀]‐diethyl‐[2‐(1H‐indol‐3‐yl)‐ethyl]‐amine (DET), [2‐(1H‐indol‐3‐yl)‐ethyl]‐[²H₆]‐dipropyl‐amine (DPT) and [²H₂]‐alpha‐methyltryptamine (AMT) is described. The isotopically labeled compounds are used as internal standards in gas chromatography‐mass spectrometry (GC‐MS) assays.     

The 14‐Alkyl‐ and 14‐Alkenyl‐5β‐methylindolomorphinan Series Provide δ‐Selective Partial Opioid Agonists

A series of 14β‐alkyl‐ and 14β‐alkenyl‐5β‐methylindolomorphinans was synthesized and evaluated in opioid binding and functional assays. While being relatively nonselective in binding assays, the 14‐cinnamyl and 14‐isopentyl members showed selective opioid δ‐receptor partial agonist activity in [³⁵S]GTPγS assays.     

Synthesis of a new series of 8-substituted-2,8-diazaspiro[4.5]decan-3-ones

A new series of 8-substituted-2,8-diazaspiro[4.5]decan-3-ones has been synthesized and tested in in vitro and in vivo assays predictive for cholinergic activity, in comparison with the muscarinic agent RS-86. Preliminary pharmacological data indicate that the compounds are devoid of significant cholinergic properties.     

Assessment of the in vitro toxicity of calixarenes and a metal-seamed calixarene: a chemical pathway for clinical application

Calixarenes are known to form host–guest complexes and supramolecular nanoassemblies with well-defined architectures. However, the use of these materials in conjunction with drug moieties is still under explored. One reason is the insufficient biocompatibility studies. Our present study represents a systematic in vitro investigation of the cytotoxicity associated with C-methylresorcin[4]arene, C-methylpyrogallol[4]arene, p-phosphonated calix[8]arene and a metal-seamed calixarene–copper(II) complex, using human HEK293 and rat C6G cell lines and two different cell viability assays (MTT and CellTiter-Glo) to avoid species-biased results. All compounds showed low to moderate toxicity. The trend in the CC₅₀ values indicated that the suppression of the coordination ability and the presence of phosphonate groups decrease the overall cytotoxicity of the compounds. The results of this study not only establish calixarenes and their immediate families as potential drug carriers and drug modifiers, but also reveal a pathway for fine-tuning their toxicological behaviour by appropriate chemical modification.     

Synthesis of Aza‐Rocaglates via ESIPT‐Mediated (3+2) Photocycloaddition

Synthesis of aza‐rocaglates, nitrogen‐containing analogues of the rocaglate natural products, is reported. The route features ESIPT‐mediated (3+2) photocycloaddition of 1‐alkyl‐2‐aryl‐3‐hydroxyquinolinones with the dipolarophile methyl cinnamate. A continuous photoflow reactor was utilized for photocycloadditions. An array of compounds bearing the hexahydrocyclopenta[b]indole core structure was synthesized and evaluated in translation inhibition assays.     

Polycyclic N-Heterocyclic compounds. 50. Synthesis and pharmacological evaluation of 2,3,6,7-Tetrahydrothieno[2,3-H]-imidazo[2,1-f][1,6]naphthyridines,3,4,7,8-Tetrahydro-2H-thieno-[2,3-h]pyrimido[2,1-f][1,6]naphthyridines and their precursor

Some novel 5-hydroxyalkylamino-1,2-dihydrothieno[2,3-h][1,6]naphthyridines were prepared by the reaction of 5-chloro-1,2-dihydrothieno[2,3-h][1,6]naphthyridine derivatives with some aminoalcohols in the presence of base. These derivatives were cyclized to the corresponding imidazo or pyrimido derivatives. The bronchodilatory activity of these compounds was evaluated on the basis of their relaxation activity to tracheal contraction induced by carbamylcholine chloride as a primary in vitro assays. Effect of some naphthyridines on carbamylcholine chloride-induced contractions of trachea in the presence or absence of milrinone or 4-(3-butoxy-4-methoxyphenyl)imidazolidin-2-one, which is inhibitor of phosphodiesterase III or IV, were also evaluated.     

Glyco‐pseudopolyrotaxanes: Carbohydrate Wheels Threaded on a Polymer String and Their Inhibition of Bacterial Adhesion

We report glyco‐pseudopolyrotaxanes composed of cucurbit[6]uril‐based mannose wheels (ManCB[6]) threaded on polyviologen (PV), which not only effectively induce bacterial aggregation, but also exhibit high inhibitory activity against bacterial binding to host cells. Three glyco‐pseudopolyrotaxanes ( 1 – 3 ), which have 10, 5, and 3 ManCB[6] wheels, respectively, on a PV string, were prepared and characterized. Bacterial aggregation assays and hemagglutination inhibition assays illustrated the specific and multivalent interaction between the glyco‐pseudopolyrotaxanes and E. coli ORN178. Compound 3 was especially effective at inducing bacterial aggregation and showed 300 times higher inhibitory potency than monomeric methyl‐α‐mannoside (Me‐αMan) for ORN178‐induced hemagglutination. Furthermore, we demonstrated their inhibitory activities for the adhesion of ORN178 bacteria to urinary epithelial cells as a model of urinary tract infection. Our findings suggest that these supramolecular carbohydrate clusters are potentially useful in antiadhesion therapy.     

In Vitro and In Vivo Sequestration of Phencyclidine by Me4Cucurbit[8]uril**

We report investigations of the use of cucurbit[8]uril (CB[8]) macrocycles as an antidote to counteract the in vivo biological effects of phencyclidine. We investigate the binding of CB[8] and its derivative Me₄CB[8] toward ten drugs of abuse ( 3 – 9 , 12 – 14 ) by a combination of ¹H NMR spectroscopy and isothermal titration calorimetry in phosphate buffered water. We find that the cavity of CB[8] and Me₄CB[8] are able to encapsulate the 1-amino-1-aryl-cyclohexane ring system of phencyclidine (PCP) and ketamine as well as the morphinan skeleton of morphine and hydromorphone with K_d values ≤50 nm . In vitro cytotoxicity (MTS metabolic and adenylate kinase cell death assays in HEK293 and HEPG2 cells) and in vivo maximum tolerated dose studies (Swiss Webster mice) which were performed for Me₄CB[8] indicated good tolerability. The tightest host⋅guest pair (Me₄CB[8]⋅PCP; K_d=2 nm ) was advanced to in vivo efficacy studies. The results of open field tests demonstrate that pretreatment of mice with Me₄CB[8] prevents subsequent hyperlocomotion induction by PCP and also that treatment of animals previously dosed with PCP with Me₄CB[8] significantly reduces the locomotion levels.     

Synthesis of novel 5H‐Pyrimido[5,4‐b]mdole‐(1H,3H)2,4‐diones as potential ligands for the cloned α1‐adrenoceptor subtypes

A new series of 3‐[ω‐[4‐(4‐substituted phenyl)piperazin‐1‐yl]alkyl]‐5H‐pyrimido[5,4‐b]indole‐(1H,3H)‐2,4‐diones ( 3–10 and 12–13 ) were synthesized from the N‐(2‐chloroethyl)‐N'‐[3‐(2‐ethoxycarbonyl)indolyl] urea ( 1 ) or the N‐(3‐chloropropyl)‐N'‐[3‐(2‐ethoxycarbonyl)indolyl] urea ( 2 ) and a number of 1‐(4‐substi‐tuted‐phenyl)piperazines. 3‐[2‐[4‐(4‐Aminophenyl)piperazin‐1‐yl]ethyl]‐5H‐pyrimido[5,4‐b]indole‐(1H,3H)2,4‐dione ( 14 ) was obtained by reduction of the parent nitro compound 8 . The obtained 5H‐pyrimido[5,4‐b]indole‐(1H,3H)2,4‐dione derivatives were tested towards cloned α_1A, α_1B and α_1D adrenergic receptors subtypes in binding assays. Some compounds showed good affinity and selectivity for the α_1D‐adrenoceptor subtype.     

Synthesis ofO-methyloximes and nitrones of a series of substituted 4-[2-hydroxy-2-(1H-1,2,4-triazol-1-ylmethyl)cyclohexylidenemethyl]-benzaldehydes and their fungicidal activity

O-Methyloximes and nitrones of a series of substituted 4-[2-hydroxy-2-(1H-1,2,4-triazol-1-ylmethyl)cyclohexylidenemethyl]benzaldehydes have been synthesized, and their fungicidal activity has been assayed. All of them exhibit low fungicidal activity in thein vitro assays and high activity in thein vivo assays; theO-methyl oximes are more active than the corresponding nitrones.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2082–2087, December, 1993.     

Synthesis of new 1,2,3-triazolo[1,2-a]benzotriazole derivatives or substituted 2,3-benzo-1,3a,6,6a-tetraazapentalenes. II

This paper continues the synthesis of new 1,2,3-triazolo[1,2-a]benzotriazoles or 2,3-benzo-1,3a,6,6a-tetrazapentalenes to submit to biological assays. The derivatives were obtained by deoxycyclization reactions of appropriate nitrophenyl-1,2,3-triazole derivatives and by thermal decomposition of appropriate azidophenyl-1,2,3-triazoles (Schemes 1 and 2). Some attempts to extend these synthetic routes to the preparation of 1,2,4-triazolo[1,2-a]benzotriazoles (Scheme 3) and 1,2,3-triazolo[1,2-b]-4H-1,2,3-benzo-triazines (Scheme 4) completely failed.     

Novel 3‐(2‐Oxo‐2H‐benzo[b][1,4]oxazin‐3‐yl)propanoates from Dimethyl‐2‐oxoglutarate and Test of Their Biological Activity

Five novel 3‐(2‐oxo‐2H‐benzo[b][1,4]oxazin‐3‐yl)propanoates were synthesized under mild conditions from 2‐aminophenols and dimethyl‐2‐oxoglutarate. Biological assays of these 1,4‐benzoxazinones were conducted with three bacterial strains and one yeast. All compounds were active against a Candida albicans ATCC 10231, whereas only methyl 3‐(6‐methyl‐2‐oxo‐2H‐benzo[b][1,4]oxazin‐3‐yl)propanoate showed a general moderate activity against the bacterial strains tested.     

Tunable Electrochemical C−N versus N−N Bond Formation of Nitrogen‐Centered Radicals Enabled by Dehydrogenative Dearomatization: Biological Applications

Herein, an environmentally friendly electrochemical approach is reported that takes advantage of the captodative effect and delocalization effect to generate nitrogen‐centered radicals (NCRs). By changing the reaction parameters of the electrode material and feedstock solubility, dearomatization enabled a selective dehydrogenative C?N versus N?N bond formation reaction. Hence, pyrido[1,2‐a]benzimidazole and tetraarylhydrazine frameworks were prepared through a sustainable transition‐metal‐ and exogenous oxidant‐free strategy with broad generality. Bioactivity assays demonstrated that pyrido[1,2‐a]benzimidazoles displayed antimicrobial activity and cytotoxicity against human cancer cells. Compound 21 exhibited good photochemical properties with a large Stokes shift (approximately 130 nm) and was successfully applied to subcellular imaging. A preliminary mechanism investigation and density functional theory (DFT) calculations revealed the possible reaction pathway.     

Synthesis of 2-methylcarbamazepine,a new internal standard for chromatographic assays of carbamazepine (tegretol®)

The synthesis of 2-methyl-5H-dibenz[b,f]azepine-5-carboxamide (2-methylcarbamazepine, 2-MCBZ, 8), a promising internal standard for chromatographic assays of the antiepileptic agent carbamazepine (CBZ, 1), is described. N-(p-Tolyl)anthranilic acid (2) was utilized as a starting material for the synthesis of a key compound, 2,9-dimethylacridine (4), which was converted in two steps to 2-methyl-9-hydroxymethylacridan (6). The acridan 6, in the presence of poly-phosphoric acid, was ring-expanded to form 2-methyl-5H-dibenz[b,f]azepine (7), this latter compound being converted by conventional reactions to its 5-carbamyl derivative, 2-MCBZ (8).     

Tunable Electrochemical C−N versus N−N Bond Formation of Nitrogen-Centered Radicals Enabled by Dehydrogenative Dearomatization: Biological Applications

Herein, an environmentally friendly electrochemical approach is reported that takes advantage of the captodative effect and delocalization effect to generate nitrogen-centered radicals (NCRs). By changing the reaction parameters of the electrode material and feedstock solubility, dearomatization enabled a selective dehydrogenative C−N versus N−N bond formation reaction. Hence, pyrido[1,2-a]benzimidazole and tetraarylhydrazine frameworks were prepared through a sustainable transition-metal- and exogenous oxidant-free strategy with broad generality. Bioactivity assays demonstrated that pyrido[1,2-a]benzimidazoles displayed antimicrobial activity and cytotoxicity against human cancer cells. Compound 21 exhibited good photochemical properties with a large Stokes shift (approximately 130 nm) and was successfully applied to subcellular imaging. A preliminary mechanism investigation and density functional theory (DFT) calculations revealed the possible reaction pathway.     

CHEMICAL BEHAVIOR OF SOME BENZ[b] INDENO[1,2-e] [1,4] THIAZINE DERIVATIVES

Abstract

The study of the chemical behavior of some benz[b] indeno[1,2-e] [1,4] thiazine derivatives was accomplished. Different reactivities were observed for 4b,5-dihydrobenz[b]-indeno[1,2-e] [1,4] thiazine-10α(11H)-ol (3) and 5-ethyl-4b,5-dihydrobenz[b] indeno[1,2-e]-[1,4] thiazine-10α(11H)-ol (5); 3 is reoxidated to benz[b] indeno[1,2-e] [1,4] thiazine-10α(11H)-ol (2), while 5 undergoes transposition and oxidation to spiro[3-ethylbenzo-thiazol-2(3H), 1′-indan-2′-one] (6). Possible pathways for these transformations are discussed.