Synthesis, toxicological, and pharmacological assessment of derivatives of 2-aryl-4-(3-arylpropyl)morpholines

Pharmacological and Toxicological Screening of Novel Benzimidazole-Morpholine Derivatives as Dual-Acting Inhibitors

The aim of this study was to investigate acetylcholinesterase (AChE), monoamine oxidase A (MAO-A), monoamine oxidase B (MAO-B), cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzyme inhibitory, and antimicrobial activities of a new series of 2-(4-substituted phenyl)-1-[2-(morpholin-4-yl)ethyl]-1H-benzimidazole derivatives, for their possible use as multi-action therapeutic agents. Target compounds (n = 15) were synthesized under microwave irradiation conditions in two steps, and their structures were elucidated by FT-IR, ¹H-NMR, ¹³C-NMR and high resolution mass spectroscopic analyses. Pharmacological screening studies revealed that two of the compounds (2b and 2j) have inhibitory potential on both COX-1 and COX-2 enzymes. In addition, cytotoxic and genotoxic properties of the compounds 2b, 2j and 2m were investigated via the well-known MTT and Ames tests, which revealed that the mentioned compounds are non-cytotoxic and non-genotoxic. As a concise conclusion, two novel compounds were characterized as potential candidates for treatment of frequently encountered inflammatory diseases.

Synthesis and biological evaluation of some novel thiazole compounds as potential anti-inflammatory agents

In the present investigation, furo[2,3-d]thiazol-5(2H)-one 5 was obtained from reaction of thiosemicarbazone derivative 2 with diethyl acetylene dicarboxylate. A series of newly synthesized 2-(hydrazinyl)thiazol-4(5H)-one 6, 7 &8 and 2-(4-(substituted)-thiazol-2-yl)hydrazono derivatives 9a, b &10 were synthesized from treatment of thiosemicarbazone derivative 2 with appropriate α-halogenated compounds. Also, a one pot synthesis of thiazole derivatives 13 &15 was achieved from three components reaction of hydrazone derivative 11 with phenyl isothiocyanate and α-halogenated compounds catalyzed by DMF/KOH. 4-(4-Morpholino phenyl) thiazol-2-amino 17 was obtained via the reaction of acetophenone derivative 1 with thiourea in presence of iodine. The reactivity of 2-aminothiazole 17 toward some electrophilic reagents was investigated. The structure of the newly compounds was confirmed on the basis of elemental analysis and spectral data. The antibacterial activity towards two Gram negative (Proteus mirabilis &Serratia marcesens) and two Gram positive (Staphylococcus aureus &Bacillus cereus) bacteria was investigated. The anti-inflammatory activity was also investigated and the inhibition of the carrageenin-induced oedema by these compounds was established.

Synthesis, FT-IR, ¹H, ¹³CNMR, ESI MS and PM5 studies of a new Mannich base of polyether antibiotic - Lasalocid acid and its complexes with Li⁺, Na⁺ and K⁺ cations

The polyether antibiotic Lasalocid acid has been converted to its Mannich base derivative by a chemoselective one-pot reaction with formaldehyde and morpholine through the decarboxylation process. Spectroscopic studies of the structure of this new derivative have shown that in this ortho-phenol Mannich base the O-H⋯N intarmolecular hydrogen bond is present. The compound forms complexes with Li(+), Na(+) and K(+) cations of exclusively 1:1 stoichiometry. The structures of these complexes have been studied and visualized by semi-empirical calculation based on results of spectrometric and spectroscopic investigation. It is demonstrated that in contrast to Lasalocid acid the novel Mannich type derivative forms preferential complexes with Li(+) cation.

Ab initio, density functional computations, FT-IR, FT-Raman and molecular geometry of 4-morpholine carbonitrile

The 4-morpholine carbonitrile (4MC) was investigated by vibrational spectroscopy and quantum chemical methods. The solid phase FT-IR and FT-Raman spectra were recorded in the region 4000-400 cm(-1) and 3500-50 cm(-1), respectively. The molecular geometry and vibrational frequencies of 4MC have been calculated in the ground state by using the ab initio Hartree-Fock and density functional method (B3LYP) with 6-311++G(d, p) basis set. The observed and calculated frequencies are found to be in good agreement. The calculated HOMO and LUMO energies show the charge transfer occurs within the molecule. Stability of the molecule arising from hyper conjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The theoretical FT-IR and FT-Raman spectra for the title compound have also been constructed.

Diastereoselective synthesis of enantiopure morpholines by electrophilic selenium-induced 6-exo cyclizations on chiral 3-allyl-2-hydroxymethylperhydro-1,3-benzoxazine derivatives

Enantiopure morpholine derivatives have been prepared by selenocyclofunctionalization of chiral 3-allyl-2-hydroxymethyl-substituted perhydro-1,3-benzoxazine derivatives. The cyclization occurs in high yields and diastereoselection, although the temperature of the reaction and the structure of the substituent at C-2 and the substitution pattern of the double bond can modify the regio- and stereochemistry of the final products.

Synthesis, stereochemistry and antimicrobial evaluation of some N-morpholinoacetyl-2,6-diarylpiperidin-4-ones

In a search for new leads towards potent antimicrobial agents, an array of novel N-morpholinoacetyl-2,6-diarylpiperidin-4-ones has been synthesized and their in vitro antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi and antifungal activity against Candida albicans, Rhizopus sp., Aspergillus niger and Aspergillus flavus were evaluated. Structure and stereochemistry of all the N-morpholinoacetyl-2,6-diarylpiperidin-4-ones have been analyzed using (1)H and (13)C NMR spectroscopic techniques. In all the cases, amide N-CO group is preferentially in coplanar orientation with respect to the dynamically averaged plane of the piperidone ring. Further, all the symmetrically substituted compounds 19, 23, 24, 26 and 27 are expected to adopt half boat conformations while other compounds 20-22 and 25 adopt twist-boat conformations. Structure-activity relationship results for these nine compounds have shown that compounds 26 and 27 exerted excellent antibacterial activity against all the bacterial strains used except 27 against S. aureus. Against C. albicans and A. flavus, compound 24 recorded excellent antifungal activities while against Rhizopus sp., compound 25 showed potent activities. The obtained results may be used as key step for the building of novel chemical compounds with interesting antimicrobial profiles comparable to that of the standard drugs.

1H and 13C NMR spectra of N-substituted morpholines

(1)H and (13)C NMR data for N-substituted morpholines 1-20 were measured using 1D (DEPT, 1D NOE difference) and 2D NMR spectroscopic methods including (1)H-(1)H COSY, long-range (1)H-(1)H COSY, NOESY, gHMBC and gHMQC experiments. At room temperature the (1)H NMR spectra of protonated compounds 2 and 9 show the chair conformation for the morpholine ring. Spin-spin coupling constants were deduced from the resolution-enhanced proton spectra.