Monoperoxyphthalic Acid Research Articles

Efficient synthesis of cholic acid derivates through stereoselective C–H functionalization from hyodeoxycholic acid

Five cholic acid derivatives (including allo-ω-muricholic acid and CDCA) were synthesized from hyodeoxycholic acid via selective oxidation of C3- or C6-hydroxyl groups by IBX and NBS oxidants and stereocontrolled conversion. The hydroxyl group could be introduced through hydrolyzing α-Br keto with K2CO3 aqueous solution or through oxidizing the double bond by monoperoxyphthalic acid. The reduction of C6-O6 carbonyl to methylene could undergo with PTSH, NaBH3CN and ZnCl2 only at 5β configuration. A feasible synthetic route of CDCA from HDCA has been established to avoid the epimerization with the yield of 45% (8 steps). These strategies provided good yields, stereoselectivity and reproducibility for the preparation of cholic acid derivates and CDCA.

Investigation and Synthesis of Some Novel Spiro Heterocycles Related to Indoline Moiety

Reactions of indole-2,3-dione 1 with 2-mercaptobenzimidazole, o-phenylenediamine, 2-aminophenol, 2-aminobenzothiazole, 2-aminobenzimidazole and 3-methyl-1-phenyl-2-pyrazolin-5-one were carried out to give compounds spiroindolethiazetobenzimidazole 2, spirobenzimidazole(oxazole)indoline 3a,b, benzothiazol(imidazol) iminoindolinone 4a,b and methyloxoindolylidenepyrazolone 5 respectively. Compound 5 was reacted with 2-aminophenol as well as o-phenylenediamine to give new spirooxazepine and diazepine derivatives 6a,b respectively. Reaction of 5 with nitrogen nucleophiles as well as carbon nucleophiles was investigated to furnish new spiro heterocycles 7-11. The reaction of 2-(2-oxo-1,2-dihydroindol-3-ylidene)malononitrile compound 12 with 3-methyl-1-phenyl-2-pyrazoline-5-one was carried out to give spiroindolopyranopyrazolo derivative 13. Compounds 4a,b was reacted with thioglycolic acid to give thiazolidinone derivatives 14a,b. Epoxidation of 5 using monoperoxyphthalic acid magnesium salt hexahydrate and hydrogen peroxide were executed to afford the novel dispiro (2-pyrazolin oxiraneindoline)dione compound 15. The chemical structures of the synthesized compounds were well established by elemental and spectral analyses. Keywords: Spiroheterocycles; Epoxidation; Diazapines, Oxazepines; Spirothiazolidinone. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i2.17590 J. Sci. Res. 6 (2), 303-317 (2014)

ChemInform Abstract: Cleavage of DNA by Nickel Complexes.

Abstract The cleavage of plasmid DNA (pUB110) by several square planar nickel(II) complexes in the presence of either magnesium monoperoxyphthalic acid (MPPA) or iodosylbenzene was investigated. At 25°C and near neutral pH, Ni(salen) (100 μM) or Ni(CR) 2+ (100 μM) promoted complete conversion of supercoiled plasmid to the nicked circular form in 5 min with iodosylbenzene (0.1 g/ml) as oxidant or in 2.5 h with MPPA (1 mM) as oxidant (salen = bis(salicylaldehyde)ethylenediimine, CR = 2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca- 1(17),2,11,13,15-pentaene). No cleavage was observed under similar conditions with Ni(cyclam) 2+ , Ni(dioxocyclam), Ni(TPP) or Ni(NO 3 ) 2 (cyclam = 1,4,8,11-tetraazacyclotetradecane, dioxocyclam = 1,4,8,11-tetraazacyclotetradecane- 5,7-dione, TPP=5,10,15,20-tetraphenyl-21 H ,23 H -porphine). Possible roles for the nickel complexes in promoting DNA cleavage are discussed.

ChemInform Abstract: Regioselective Epoxidation of Allylic Alcohols with Monoperoxyphthalic Acid in Water.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Synthesis of the FR900482 Tetracyclic Ring System by Oxidation of a 2,3-Dihydro-1H-pyrrolo[1,2-a]indole Derivative.

Abstract The tetracyclic FR900482 ring skeleton has been synthesized from the 2,3-dihydro-1H-pyrrolo[1,2-a]indole derivative 5. Treatment of 5 with osmium tetraoxide, hydrogen sulfide, magnesium monoperoxyphthalic acid (MMPP), and triphenylphosphine resulted in the formation of 12.

Epoxidation and Heterocyclization of Arenesulfonamides of the Norbornene Series

Reactions of previously known and newly synthesized N-(bicyclo[2.2.1]hept-5-en-endo-2-ylmethyl)arenesulfonamides with monoperoxyphthalic acid generated in situ from phthalic anhydride and 30% hydrogen peroxide lead mostly to the corresponding N-arylsulfonyl-exo-2-hydroxy-4-azatricyclo[4.2.1.03,7]nonanes (azabrendanes). In some cases, N-(exo-5,6-epoxybicyclo[2.2.1]hept-5-en-exo-2-ylmethyl)arenesulfonamides were isolated as the only products or mixtures of alternative oxidation products were obtained. The presence of electron-acceptor nitro groups in the benzene ring and bulky substituents, primarily in the ortho position, is considered to be a structural factor preventing the primary oxidation products (epoxy derivatives) from undergoing heterocyclization.

Site-Specific Cross-Linking of Proteins through Tyrosine Hexahistidine Tags

The genetic addition of hexahistidine (H(6)) tags is widely used to isolate recombinant proteins by immobilized metal-affinity chromatography (IMAC). Addition of a tyrosine residue to H(6) tags enabled proteins to be covalently cross-linked under mild conditions in a manner similar to the natural, site-specific cross-linking of tyrosines into dityrosine. A series of seven hexahistidine tags with tyrosines placed in various positions (H(6)Y tags) were added to the amino terminus of the I28 immunoglobulin domain of the human cardiac titin. The H(6)Y-tagged I28 dimerized in the presence of excess Ni(2+) with a K(D) of 200 microM. Treatment of Ni(2+)-dimerized H(6)Y-I28 with an oxidant, monoperoxyphthalic acid (MMPP) or sodium sulfite, resulted in covalent protein multimerization through chelated Ni(2+)-catalyzed cross-linking of the Y residues engineered into the H(6) tag. The protein oligomerization was observed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The presence of dityrosine in the cross-linked proteins was confirmed by fluorescence emission at 410 nm. Proteins lacking the Y residue in the H(6) tag treated with the same oxidative conditions did not cross-link or exhibit dityrosine fluorescence, despite the presence of an endogenous Y residue. The method may have potential uses in other protein conjugation applications such as protein labeling and interfacial immobilization of proteins on artificial surfaces.

Identification of the stereoisomers of tetrahydroindene diepoxide by the 1H and 13C NMR characteristics: A combined experimental and theoretical study

The stereochemical aspects of the cis-bicyclo[4.3.0]nona-3,7-diene epoxidation reaction by monoperoxyphthalic acid were investigated. The 1H and 13C NMR spectra of the stereoisomeric diepoxides obtained in this reaction have been studied experimentally and theoretically at the CSGT-PCM/PBE1PBE/6-31G ##(II) level. The application of combined experimental and theoretical NMR studies has allowed assignments of diepoxides to the corresponding stereoisomers to be made. The established trends of the influence of the orientation of the epoxide ring and the conformation of the bicyclic skeleton could be useful for stereochemical investigations of related polycyclic epoxidic compounds.

Synthesis, Structure, and Transformations of New Endic Anhydride Derivatives.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis, Structure, and Transformations of New Endic Anhydride Derivatives

4-Azatricyclo[5.2.1.02,6]dec-8-ene and its N-phenyl derivative were synthesized by reaction of endic anhydride with amines, transformation of the amido acids thus obtained to imides, and subsequent reduction of the latter with lithium aluminum hydride. The unsubstituted tricyclic amine was brought into reactions with electrophilic reagents: p-toluenesulfonyl chloride, p-toluoyl chloride, m-tolyl isocyanate, phenyl isothiocyanate, and endic anhydride to obtain a number of new derivatives; also, the corresponding salt with 1-adamantanecarboxylic acid was isolated. N-(p-Tolylsulfonyl)- and N-(m-tolylcarbamoyl)-4-azatricyclo-[5.2.1.02,6]dec-8-enes were oxidized to the corresponding 8,9-epoxy derivatives with monoperoxyphthalic acid. The structure of the products was confirmed by the data of IR, 1H and 13C NMR, and mass spectra. The molecular structures of N-(p-iodophenyl)bicyclo[2.2.1]hept-2-ene-endo-5,endo-6-dicarboximide and N-phenyl-4-azatricyclo[5.2.1.02,6]dec-8-ene were established by X-ray analysis.

49] Mapping dynamin interdomain interactions with yeast two-hybrid and glutathione S-transferase pulldown experiments

Dynamin is a 100-kDa GTPase that contributes to the formation of clathrin-coated vesicles. Dynamin assembles into multimeric spirals at the necks of budding vesicles. The chapter investigates protein interactions that in all likelihood form the basis for dynamin self-assembly using yeast two-hybrid and glutathione S-transferase (GST) pulldown techniques. These techniques were chosen because they allowed to systematically test binding between individual dynamin protein domains and they allowed to determine the boundaries of those domains with deletion series. The binding interactions between three different domains of dynamin are discovered. The binding data support a new model that describes how dynamin and other members of the dynamin family might assemble into multimeric spirals. In addition, dimerization of the dynamin assembly domain is tested using an in vitro cross-linking protocol. This procedure is based on the ability of nickel to catalyze cross-linking by magnesium monoperoxyphthalic acid (MMPP). Nickel is kept in association with the dynamin protein fragments using the hexahistidines that were also used for protein purification.

Pernitrated metalloporphyrins as catalysts in oxidation with magnesium monoperoxophthalate: Part II. Epoxidation of linear olefins

The system composed of manganese (2,6)-dichlorotetraphenyl- or pentafluorotetraphenyl-porphyrins, bearing nitro groups at the β-pyrrolic positions as catalysts and monoperoxyphthalic acid magnesium salt (MMPP) as oxidant is an efficient model system for epoxidation of dodecene-1 and propene. A comparison with the corresponding system based on iron and cobalt complexes as well as the influence of the addition of a nitrogenous base are also described.

Synthesis of the FR900482 Tetracyclic Ring System by Oxidation of A 2,3-Dihydro-1H-Pyrrolo[1, 2-a]Indole Derivative

The tetracyclic FR900482 ring skeleton has been synthesized from the 2,3-dihydro-1H-pyrrolo[1,2-a]indole derivative 5. Treatment of 5 with osmium tetraoxide, hydrogen sulfide, magnesium monoperoxyphthalic acid (MMPP), and triphenylphosphine resulted in the formation of 12.

Facile synthesis of epoxystyrene and its copolymerisations with styrene by living free radical and atom transfer radical strategies

Epoxystyrene (ethenylphenyloxirane) has been synthesised in a single-stage process by mono-epoxidation of divinylbenzene using magnesium monoperoxyphthalic acid. Copolymers of epoxystyrene and styrene were then synthesised by living free radical polymerisation and atom transfer radical polymerisation methods. In both cases the oxirane group of epoxystyrene was found to be stable under the conditions of polymerisation, though at the temperatures required for LFRP, copolymers with bimodal molecular weight distributions resulted. In contrast, as long as the temperature used for ATRP was kept below 100°C, copolymers with narrow, monomodal distributions could be obtained.

Determining protein-protein interactions by oxidative cross-linking of a glycine-glycine-histidine fusion protein.

The Ni(II) complex of the tripeptide NH2-glycine-glycine-histidine-COOH (GGH) mediates efficient protein-protein cross-linking in the presence of oxidants such as oxone and monoperoxyphthalic acid (MMPP). Here we demonstrate that GGH fused to the amino terminus of a protein can still support cross-linking. The tripeptide was expressed at the amino terminus of ecotin, a dimeric macromolecular serine protease inhibitor found in the periplasm of Escherichia coli. In the presence of Ni(OAc)2 and MMPP, GGH-ecotin is cross-linked to give a species that has an apparent molecular mass of a GGH-ecotin dimer with no observable protein degradation. The cross-linking reaction occurs between two ecotin proteins in a dimer complex. Furthermore, GGH-ecotin can be cross-linked to a serine protease target, trypsin, and the reaction is specific for proteins that interact with ecotin. The cross-linking reaction has been carried out on small peptides, and the reaction products have been analyzed by matrix-assisted laser desorption/ionization mass spectrometry. The target of the reaction is tyrosine, and the product is bityrosyl cross-links. The yield of the cross-linking is on the order of 15%. However, the reaction efficiency can be increased 4-fold by a single amino acid substitution in the carboxy terminus of ecotin that places an engineered tyrosine within 5 A of a naturally occurring tyrosine. This cross-linking methodology allows for the protein cross-linking reagent to be encoded for at the DNA level, thus circumventing the need for posttranslational modification.

ChemInform Abstract: Highly Diastereoselective Epoxidation of Cycloalkenols with Monoperoxyphthalic Acid in Water.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reduced chlorhexidine tooth stain coverage by sequential administration of monoperoxyphthalic acid in the beagle dog.

Extrinsic tooth stain is sometimes a side-effect observed with the chronic use of chlorhexidine-containing oral care products. This chlorhexidine (CHX)-induced tooth staining is observed both in humans as well as in experimental animals. The present study tested the hypothesis that the sequential administration of monoperoxyphthalic acid (MPA) will reduce the development of chlorhexidine-induced tooth stain coverage in a beagle dog. For this study, dogs were treated with 30 mL of mouthrinse b.i.d. for 28 days. The following treatment groups ( = 12 dogs/group) were tested: water (negative control), 1.0% MPA rinse, 0.12% CHX rinse, and 1.0% MPA rinse followed by 0.12% CHX rinse. The sequential dosing of 1.0% MPA followed by 0.12+ CHX resulted in significantly (p < or = 0.05) less tooth stain than when dogs were dosed with 0.12% CHX alone. Additionally, the sequential dosing of MPA followed by chlorhexidine resulted in a 75% reduction in plaque formation in this model, which was significantly different (p < or = 0.05) from results with either treatment alone. A further study demonstrated that similar results could be obtained when MPA plus CHX treatment alone. A further study demonstrated that similar results could be obtained when MPA plus CHX treatments were separated by approximately a five-hour period in an AM and PM schedule. We conclude that the oxidizer, MPA, can significantly reduce tooth stain induced by CHX while enhancing its antiplaque and antigingivitis activity.

Probing the hydrophobic interactions in the skeletal actomyosin subfragment 1 and its nucleotide complexes by zero-length cross-linking with a nickel-peptide chelate.

The complex of Ni(II) and the tripeptide Gly-Gly-His catalyzes, in the presence of monoperoxyphthalic acid, a zero-length protein-protein cross-linking via an oxidative radical pathway involving mainly aromatic amino acids and not at all nucleophilic residues [Brown, K. C., Yang, S.-H., and Kodadek, T. (1995) Biochemistry 34, 4733-4739]. We have taken advantage of this unprecedented cross-linking system to directly and selectively probe the solution structure and functioning of the hydrophobic interface between F-actin and skeletal myosin subfragment 1 (S-1) at the level of its aromatic components, in the absence and in the presence of nucleotides (ATP and ADP) or nucleotide analogs (AMPPNP, PPi, and ADP. AlF4). Following verification of the structure of the Ni(II)-peptide chelate and of its oxidized active form by electrospray mass spectrometry, complexes of F-actin and S-1 or proteolytic S-1 derivatives and complexes of S-1 and proteolytic F-actin derivatives were readily cross-linked under various controlled conditions without apparent alteration of the acto-S-1 recognition. The covalent adducts were identified on electrophoretic gels using specific protein labeling with the oxidation-resistant fluorophor, monobromobimane, combined with immunochemical staining. Two types of actin-heavy chain conjugates were produced. One, with a mass of 180 kDa, was formed in the rigor state or with ADP bound; the other one, with a mass of 200 kDa, was generated from the ternary complexes comprising a gamma-P-containing ligand. They were accumulated with an efficiency of 8 and 6%, respectively. For each reversible complex, the 180 kDa:200 kDa band ratio was essentially as predicted from the nucleotide-dependent A to R equilibrium mechanism of the acto-S-1 interaction in solution [Geeves, A. M., and Conibear, P. B. (1995) Biosphys. J. 68, 194s-201s]. Both covalent species resulted from the cross-linking of an actin monomer to the central 50 kDa segment, and their distinct mobilities reflect gamma-P-mediated structural changes at or near the actin-50 kDa fragment interface. Peptide mapping showed the cross-linking to take place between the 506-561 S-1 segment and the 48-113 actin stretch. The localization of these regions in the atomic F-actin-S-1 model implies that nucleotide-modulated close contacts, involving aromatic residues, are operating between the C-terminal helix of the hydrophobic strong actin-binding motif of S-1 bound to the primary actin monomer and the top portion of the adjacent lower actin subunit. The specificity of the nickel-peptide cross-linking, as assessed with the acto-S-1 complex, makes it a candidate for potential general use in investigations of the hydrophobic interactions within other protein motor-based assemblies.

Highly Diastereoselective Epoxidation of Cycloalkenols with Monoperoxyphthalic Acid in Water

Highly Diastereoselective Epoxidation of Cycloalkenols with Monoperoxyphthalic Acid in Water

Partial Synthesis and Characterization of the Mono‐and Diepoxides of β‐Cryptoxanthin

Abstractβ‐Cryptoxanthin (1) was acetylated and then epoxidized with monoperoxyphthalic acid. After hydrolysis, repeated chromatography, and crystallization, (3S,5R,6S)‐5,6‐epoxy‐β‐cryptoxanthin (3), (3S,5S,6R)‐5,6‐epoxy‐β‐cryptoxanthin (4), (3R,5′R,6′R)‐5′,6′‐epoxy‐β‐cryptoxanthin (5), (3S,5R,6S,5′R,6′S)‐5,6:5′,6′‐diepoxy‐β‐cryp‐toxanthin (6), and (3S,5S,6R,5′S,6′R)‐5,6:5′,6′‐diepoxy‐β‐cryptoxanthin (7) were isolated as main products and characterized by their UV/VIS, CD, 1H‐ and 13C‐NMR, and mass spectra. The comparison of the carotenoid isolated from yellow, tomato‐shaped paprika (Capsicum annuum var. lycopersiciforme flavum) with 3–5 strongly supports the structure of 3 for the natural product.