Morpholino Derivatives Research Articles

Template-Directed Nonenzymatic Primer Extension Using 2-Methylimidazole-Activated Morpholino Derivatives of Guanosine and Cytidine.

Efforts to develop self-replicating nucleic acids have led to insights into the origin of life and have also suggested potential pathways to the design of artificial life forms based on non-natural nucleic acids. The template-directed nonenzymatic polymerization of activated ribonucleotide monomers is generally slow because of the relatively weak nucleophilicity of the primer 3′-hydroxyl. To circumvent this problem, several nucleic acids based on amino-sugar nucleotides have been studied, and as expected, the more-nucleophilic amine generally results in faster primer extension. Extending this logic, we have chosen to study morpholino nucleic acid (MoNA), because the secondary amine of the morpholino-nucleotides is expected to be highly nucleophilic. We describe the synthesis of 2-methylimidazole-activated MoNA monomers from their corresponding ribonucleoside 5′-monophosphates and the synthesis of an RNA primer with a terminal MoNA nucleotide. We show that the activated G and C MoNA monomers enable rapid and efficient extension of the morpholino-terminated primer on homopolymeric and mixed-sequenced RNA templates. Our results show that MoNA is a non-natural informational polymer that is worthy of further study as a candidate self-replicating material.

CoMFA, CoMSIA, Topomer CoMFA, HQSAR, molecular docking and molecular dynamics simulations study of triazine morpholino derivatives as mTOR inhibitors for the treatment of breast cancer

mTOR has become a promising target for many types of cancer like breast, lung and renal cell carcinoma. CoMFA, CoMSIA, Topomer CoMFA and HQSAR were performed on the series of 39 triazine morpholino derivatives. CoMFA analysis showed q2 value of 0.735, r2cv value of 0.722 and r2pred value of 0.769. CoMSIA analysis (SEHD) showed q2 value of 0.761, r2cv value of 0.775 and r2pred value of 0.651. Topomer CoMFA analysis showed q2 value of 0.693, r2 (conventional correlation coefficient) value of 0.940 and r2pred value of 0.720. HQSAR analysis showed q2,r2and r2pred values of 0.694, 0.920 and 0.750, respectively. HQSAR analysis with the combination of atomic number (A), bond type (B) and atomic connections showed q2 and r2 values of 0.655 and 0.891, respectively. Contour maps from all studies provided significant insights. Molecular docking studies with molecular dynamics simulations were carried out on the highly potent compound 36. Furthermore, four acridine derivatives were designed and docking results of these designed compounds showed the same interactions as that of the standard PI-103 which proved the efficiency of 3D-QSAR and MD/MS study. In future, this study might be useful prior to synthesis for the designing of novel mTOR inhibitors.

Synthesis, antimalarial activities and cytotoxicities of amino-artemisinin-1,2-disubstituted ferrocene hybrids

Artemisinin-ferrocene conjugates incorporating a 1,2-disubstituted ferrocene analogous to that embedded in ferroquine but attached via a piperazine linker to C10 of the artemisinin were prepared from the piperazine artemisinin derivative, and activities were evaluated against asexual blood stages of chloroquine (CQ) sensitive NF54 and CQ resistant K1 and W2 strains of Plasmodium falciparum (Pf). The most active was the morpholino derivative 5 with IC50 of 0.86 nM against Pf K1 and 1.4 nM against Pf W2. The resistance indices were superior to those of current clinical artemisinins. Notably, the compounds were active against Pf NF54 early and late blood stage gametocytes – these exerted >86% inhibition at 1 µM against both stages; they are thus appreciably more active than methylene blue (∼57% inhibition at 1 µM) against late stage gametocytes. The data portends transmission blocking activity. Cytotoxicity was determined against human embryonic kidney cells (Hek293), while human malignant melanoma cells (A375) were used to assess their antitumor activity.

Effective Synthesis of 5-Iodo Derivatives of Pyrimidine Morpholino Nucleosides

Morpholino derivatives of nucleosides are widely used in medicine and biology as monomers in the synthesis of DNA or siRNA analogues. They are considered to be promising agents for anticancer,1 ant...

New coumarin carboxylates having trifluoromethyl, diethylamino and morpholino terminal groups: Synthesis and mesomorphic characterisations

New set of trifluromethyl, diethylamino and morpholino derived coumarin compounds were prepared by reacting various coumarin 3-carboxylic acids with various phenyl esters with peripheral alkyl, ester and polar cyano moieties in the presence of EDC.HCl/DMAP as esterification agent. The chemical structures of new coumarin derivatives were confirmed by standard spectroscopic techniques and mesomorphic behaviours were established by polarised optical microscopy (POM) and differential scanning calorimetry (DSC). Trifluoromethane and morpholino derivatives show SmA/Nematic phase, while diethylamino derivatives did not show liquid crystalline property.

Ultrasonic promoted synthesis of novel s-triazine-Schiff base derivatives; molecular structure, spectroscopic studies and their preliminary anti-proliferative activities

Novel series of s-triazine-Schiff base derivatives were synthesized employing ultrasonic irradiation and characterized by NMR (1H and 13C), FT-IR, and elemental analysis. The use of ultrasonic irradiation has allowed the preparation of the target products with better yields in shorter reaction time and excellent purities compared to the conventional heating. X-ray single crystal diffraction experiments verified the molecular structure of four from the new prepared s-triaizne-Schiff base derivatives. The molecular structures of the studied compounds are computerized using DFT/B3LYP method. The effects of substituent at the triazine and phenyl ring on the electronic and spectroscopic properties of the studied compounds were also investigated. The natural atomic charges showed that pipridino-s-triazine derivatives are richer in electrons than those having morpholino derivatives. The anti-proliferative effects for the prepared compounds were tested against three different cancer cell lines.

Synthesis of a Gemcitabine Prodrug for Remote Loading into Liposomes and Improved Therapeutic Effect.

The chemotherapeutic gemcitabine was actively and stably loaded into lipid nanoparticles through the formation of a prodrug. Gemcitabine was chemically modified to increase the lipophilicity and introduce a weak base moiety for remote loading. Several derivatives were synthesized and screened for their potential to be good liposomal drug candidates for remote loading by studying their solubility, stability, cytotoxicity, and loading efficiency. Two morpholino derivatives of GEM (22 and 23) were chosen as the preferred prodrugs for this purpose as they possessed the best loading efficiencies (100% for drug-to-lipid ratio of 0.36 w/w). This is a considerable improvement over a passive loading strategy where typical loading efficiencies are on the order of ∼10-20% for a drug-to-lipid ratio of ∼0.01. Liposomes loaded with these two prodrugs were studied in an s.c. tumor model in vivo and showed improved therapeutic effect over free GEM (∼2-fold) and saline control (8- to 10-fold). This work demonstrates how chemical modification of a known hydrophilic drug can lead to improved loading, stability, and drug delivery in vivo.

Synthesis of 1,4‐Disubstituted Pyrido[1′,2′:1,5]pyrazolo[3,4‐d]pyridazines by Means of SNAr and Palladium‐Catalysed Reactions

AbstractThe first efficient synthesis of various 1,4‐disubstituted pyrido[1′,2′:1,5]pyrazolo[3,4‐d]pyridazines is reported. The reactivity toward chlorine release at the C‐1 and C‐4 positions was investigated. SNAr and palladium‐catalysed cross‐coupling reactions were carried out, and conditions were optimised for each procedure. 1,4‐Bis(het)aryl derivatives were obtained under a Suzuki cross‐coupling procedure whereas SNAr substitution was achieved mainly at C‐1 in preference to C‐4. The monosubstituted C‐4 morpholino derivative was used as a starting material to provide dissymmetrical 1,4‐diaminated or 1‐(het)aryl‐4‐morpholino products.

Myo1c is an unconventional myosin required for zebrafish glomerular development

The targeting and organization of podocyte slit diaphragm proteins nephrin and neph1 is critical for development and maintenance of a functional glomerular filtration barrier. Myo1c is a non-muscle myosin motor protein that interacts directly with nephrin and neph1 and mediates their intracellular transport to the podocyte intercellular junction. Here we investigated the necessity of Myo1c in podocyte development using zebrafish as a model system. Immunofluorescence microscopy and in situ RNA hybridization analysis of zebrafish embryos showed that Myo1c is widely expressed in various tissues including the zebrafish glomerulus. Knockdown of the Myo1c gene in zebrafish using antisense morpholino derivatives resulted in an abnormal developmental phenotype that included pericardial edema and dilated renal tubules. Ultra-structural analysis of the glomerulus in Myo1c depleted zebrafish showed abnormal podocyte morphology and absence of the slit diaphragm. Consistent with these observations, the glomerular filter permeability appeared altered in zebrafish in which Myo1c expression was attenuated. The specificity of Myo1c knockdown was confirmed by a rescue experiment in which co-injection of Myo1c morpholino derivatives with orthologous Myo1c mRNA prepared from mouse cDNA lessened phenotypic abnormalities including edema in Myo1c morphants. Thus, our results demonstrate that Myo1c is necessary for podocyte morphogenesis.

Phosphorus–Nitrogen Compounds. Part 24. Syntheses, Crystal Structures, Spectroscopic and Stereogenic Properties, Biological Activities, and DNA Interactions of Novel Spiro-ansa-spiro- and Ansa-spiro-ansa-cyclotetraphosphazenes

The reactions of octachlorocyclotetraphosphazene, N(4)P(4)Cl(8), with N(2)O(2) donor-type aminopodands (1a, 1b, 1g, and 1h) afforded two kinds of derivatives, namely, spiro-ansa-spiro (sas) (2a, 2b, 2g, and 2h) and ansa-spiro-ansa (asa) (3a and 3b) phosphazenes. The partly substituted sas phosphazenes (2a and 2b) reacted with excess pyrrolidine and morpholine in tetrahydrofuran to produce the tetrapyrrolidino (2c and 2d) and morpholino (2e and 2f) derivatives. The reactions of the asa phosphazenes (3a and 3b) with excess pyrrolidine and morpholine produced gem-2-trans-6-dichloropyrrolidinophosphazenes (3c and 3d) and -morpholinophosphazenes (3e and 3f). However, the fully substituted products were not obtained in these solvents. In addition, the expected fully substituted compound was not obtained from the reaction of 3a with excess pyrrolidine by standard or microwave-assisted methods. The reaction of the long-chain starting compound (1g) with N(4)P(4)Cl(8) gave sas (2g) and the interesting 2,6-ansa-spiro-bicyclo product (bicyclo-2,6-as; 4g), while the reaction of 1h with N(4)P(4)Cl(8) yielded only sas (2h). The structural investigations of the compounds were verified by elemental analyses, mass spectrometry, Fourier transform infrared, and DEPT, HSQC, HMBC, (1)H, (13)C, and (31)P NMR techniques. The crystal structures of 2b, 3a, 3b, 3e, and 4g were determined by X-ray crystallography. Compounds 2a-2h, 3a-3f, and 4g had two stereogenic P atoms. Compound 3b had one enantiomer according to the Flack parameter, and 3f was a racemic mixture, as shown by chiral high-performance liquid chromatography and chiral-solvating-agent, (R)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol, experiments. Furthermore, compounds 2a, 2c, and 2d exhibited weak antibacterial activity against (G+) bacterium, and 3c and 3d displayed moderate antifungal activity against Candida tropicalis. Gel electrophoresis data demonstrated that 2e, 3c, and 3e promoted the formation of DNA cleavage. The prevention of BamHI digestion by 2a-2f and 3a-3f, except 2b and 2e, disclosed binding with GG nucleotides in DNA.

Synthesis of piperazino and morpholino derivatives of aryloxypropane with potential analgesic and possible antimigraine activities

AbstractModeling studies demonstrate that aryl piperazines (I), aryloxyalkylamines (II), phenylalkykamines (III) and indolylalkylamines (VI) may interact at 5-HT receptors in a similar manner. Examination of these structures (I–VI) reveals that all possess an aromatic moiety and terminal amine binding sites (Glennon et al., J Med Chem 32(8):1921–1926, 1989). In the present investigation a new series of aryloxyalkylamines (4, 5, 8, and 9) was designed and synthesized, in which the aromatic moiety is a phenyl group substituted at the 2,3-, 2,4-, 2,5-, or 2,6-positions by halogens and the terminal amine is N-methylpiperazine, or morpholine. In addition, the alkyl side chain is ethyl, or substituted ethyl at the α- or β-carbon by a methyl group. The length of the alkyl chain that separates the terminal amine from the ether oxygen atom of the aryloxy group is of major importance, and two-carbon chain appears optimal. The structures of the new compounds were assessed by microanalyses, IR, and NMR. The analgesic activity of selected compounds was performed on experimental animals and proved to be in the range of 85–100% relative to aspirin.Graphical Abstract[IMAGE]

Tetraplex DNA specific ligands based on the fluorenone-carboxamide scaffold

A series of fluorenone-carboxamide compounds was analyzed with regard to DNA binding properties by UV spectroscopy and competition dialysis methods. The morpholino derivative 10 provided interesting results in terms of affinity and specificity toward the DNA G-tetraplex structures. Interactions against this target were evaluated by a comparative molecular modeling study in agreement with the experimental data, proposing a model for the rational design of new agents with potent and selective DNA tetraplex binding properties.

Syntheses on the basis of 4-(Oxiran-2-ylmethyl)morpholine

4-(Oxiran-2-ylmethyl)morpholine was synthesized and converted into new morpholino derivatives of propan-2-ols and butan-4-olides.

New Alkali Metal Boratabenzenes: Structures of K([18]‐Crown‐6)(C5H5BMe), of the Tetrahydropyran Solvate K(3,5‐Me2C5H3B−NMe2)(THP)2, and of Two THF Solvates of K[3,5‐Me2C5H3B−N(SiMe3)2

AbstractThe potassium salt K(C5H5BMe) (8) can be obtained from 2‐(Me3Sn)C5H5BMe (7)/KOtBu in toluene in essentially quantitative yield. Metalation of 1‐(dimethylamino)‐3‐methylene‐1,2,3,6‐tetrahydroborinine (9) with MN(SiMe3)2 (M = Na, K) in toluene afforded the unsolvated salts M(3,5‐Me2C5H3B−NMe2) (M = Na: 11; M = K: 12). Morpholino derivatives M(3,5‐Me2C5H3B−NC4H8O) (M = Li: 17; M = Na: 18) and the potassium salt K[3,5‐Me2C5H3B−N(SiMe3)2] (19) were obtained similarly. The unsolvated salts are highly air‐ and water‐sensitive, colorless powders. Crystallization with the help of auxiliary Lewis bases provided crystalline solvates K([18]‐crown‐6)(C5H5BMe) (20), K(THP)2(3,5‐Me2C5H3B−NMe2) (21), and the concomitant pseudopolymorphs K[3,5‐Me2C5H3B−N(SiMe3)2](THF)4/3 (α‐22) and K[3,5‐Me2C5H3B−N(SiMe3)2](THF)3/2 (β‐22), which were characterized structurally. The structures of α‐22 (space group C2/c) and β‐22 (space group 6122) display novel chain forms, which have no precedents in boratabenzene and cyclopentadienide chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Nuclear antisense effects of neutral, anionic and cationic oligonucleotide analogs.

The antisense activity of oligomers with 2'-O-methyl (2'-O-Me) phosphorothioate, 2'-O-methoxyethyl (2'-O-MOE) phosphorothioate, morpholino and peptide nucleic acid (PNA) backbones was investigated using a splicing assay in which the modified oligonucleotides blocked aberrant and restored correct splicing of modified enhanced green fluorescent protein (EGFP) precursor to mRNA (pre-mRNA), generating properly translated EGFP. In this approach, antisense activity of each oligomer was directly proportional to up-regulation of the EGFP reporter. This provided a positive, quantitative readout for sequence-specific antisense effects of the oligomers in the nuclei of individual cells. Nuclear localization of fluorescent labeled oligomers confirmed validity of the functional assay. The results showed that the free uptake and the antisense efficacy of neutral morpholino derivatives and cationic PNA were much higher than that of negatively charged 2'-O-Me and 2'-O-MOE congeners. The effects of the PNA oligomers were observed to be dependent on the number of L-lysine (Lys) residues at the C-terminus. The experiments suggest that the PNA containing Lys was taken up by a mechanism similar to that of cell-penetrating homeodomain proteins and that the Lys tail enhanced intracellular accumulation of PNA oligomer without affecting its ability to reach and hybridize to the target sequence.

Synthesis and in vitro and in vivo antimalarial activity of new 4-anilinoquinolines.

A new series of 4-anilinoquinolines with two proton-accepting side chains has been synthesized. Antimalarial activity and levels of cytotoxicity upon both MRC-5 cells and macrophages were found to be highly dependent upon the features of these side chains. Several compounds were found to be active in the low nanomolar range, against both chloroquine-sensitive and -resistant strains of Plasmodium falciparum in vitro. From among them, a morpholino derivative cured mice infected by Plasmodium berghei and displayed a lower toxicity than amodiaquine upon mouse macrophages.

N-Substituted 3-(arylamino)-4,5-dihydro-2 H-benz[ g]indazol-2-yl acetamides with anti-inflammatory and analgesic activities

A series of substituted 3-(arylamino)-4,5-dihydro-2 H-benz[ g]indazol-2-yl acetamides was synthesized and tested in comparison with former analogues. The title compounds showed only weak antiarrhythmic properties but good anti-inflammatory and antinociceptive activity, particularly evident in the morpholino derivative.

On the coupling of aryldiazonium salts with N,N-disubstituted 2-aminothiophenes and some of their carbocyclic and heterocyclic analogues

As exemplified with the morpholino derivatives 7, N,N-disubstituted 2-aminothiophenes couple, depending on the substitution pattern at C(5), with aryldiazonium salts 1 either at their C(3) or C(5) position yielding the corresponding 3-arylazo-2-morpholinothiophenes 9 or, under elimination of the substituent at C(5), 5-arylazo-2-morpholinothiophenes 10. This reaction contrasts to the behaviour of 5-morpholinothiazoles 8 and dimethylaniline 13 towards the same diazonium salts 1 which are unable to couple with these compounds if their C(5) or C(4) position, respectively, is not substituted by H, COOH or CHO.

Polyclonal antibodies to adenine N1-oxide: characterization and use for the measurement of DNA damage.

Adenine N1-oxide is a DNA lesion whose formation involves the specific oxidation of the adenine base by hydrogen peroxide under nonradical conditions. The damage may be measured using a HPLC/32P-postlabeling method, which however cannot be used for routine analysis. We propose herein as an alternative an immunological assay which allows a rapid evaluation of the level of adenine N1-oxide in DNA exposed to oxidative stress. Two polyclonal antibodies were raised using two different strategies for the coupling of the hapten to the protein. The first approach is based on the universal method of Erlanger and Beiser, whereas the preparation of the second antigen involves the conjugation of a morpholino derivative of adenosine N1-oxide to the carrier protein. The affinity and the specificity of those antibodies were determined by competitive enzyme-linked immunosorbent assay. The antibody obtained by the traditional method shows some cross-reactivity with normal nucleotides, whereas for the other antiserum, the selectivity was found to be higher. Therefore, this polyclonal antibody was used to quantify the level of adenine N1-oxide in calf thymus DNA oxidized either by m-chloroperbenzoic acid or by hydrogen peroxide. The detection limit of the assay is four residues of adenine N1-oxide per 10(6) normal bases. The level of adenine N1-oxide in nonmodified DNA was lower than the detection limit of the assay, whereas in mCPB- and H2O2-modified DNA, it could be up to 14 and 0.7 adenine N1-oxide residues per 10(4) normal bases, respectively.

Synthesis and evaluation of morpholino- and pyrrolidinosphingolipids as inhibitors of glucosylceramide synthase

This paper describes the new synthesis and evaluation of some morpholino- and pyrrolidinosphingolipids and mimics as inhibitors of glucosylceramide synthase. It was found that the pyrrolidino derivatives are generally more active than the morpholino derivatives and the best one was shown to be a nanomolar inhibitor.