Coordination Studies of Iron(II) Protoporphyrin IX and Iron(II) Hematoporphyrin IX with 4,4′-Dipyridyl and other Nitrogenous Bases

Abstract

The results of spectral studies of iron(II) protopor-phyrin IX and iron(II) hematoporphyrin IX with several substituted pyridines are reported. The existence in solution of an iron(II) porphyrin complex coordinated to a water molecule and to a substituted pyridine was shown by isolation of the complex from solution. The complex isolated was dimeric inono-4,4′-dipyridyl diaquo iron(II) hematoporphyrin. Addition of ethanol to the aqueous solvent inhibits coordination of iron(II) porphyrins with substituted pyridines. The protoporphyrin ring enhances coordination relative to the hematoporphyrin ring.     

Boronated derivatives of protohemin IX with L-amino acids as potential anticancer agents

New water-soluble conjugates of protohemin IX with an anionic 1-carba-closo-dodecaborate polyhedron and L-amino acids have been synthesized. In these compounds, the amino acid residues are bound to the porphyrin ring through the amide or ester bond. The new water-soluble amino acid derivatives of boronated protohemin IX show high antitumor activity for human tumor cell lines.     

Addition reactions of heterocycles. VI. Reactions of 1,2-dimethylpyrrole and 1-methyl-2-carbomethoxypyrrole with nitrilimines

Addition reactions of 1,2-dimethylpyrrole and 1-methyl-2-carbomethoxypyrrole with C-acetyl-N-phenylnitrilimine, have been investigated. 1,2-Dimethylpyrrole gives three different types of adducts: i.e. bis-cycloadducts (Vc) and (VIc), spirocycloadduct (IX), and non cyclic bis-adduct (XII). On the other hand, 1-methyl-2-carbomethoxypyrrole gives the bis-cycloadduct (VIb) only. Compound XII arises probably through a double 1,3-addition reaction, whereas the formation of cycloadducts Vc, VIc, and IX depends on the substituents present at C₂ of the pyrrole ring and consequentially on the intermediary occurence of mono-cycloadduct (IIIc), its methylenic tautomer VII, VIc, and XL The behaviour of the cycloadducts towards heating or acidic treatment showed a termal cleavage of the pyrazoline ring and acidic cleavage of the pyrrolidine ring.     

Syntheses of vinyl polymers with pendant porphyrin dimers and their catalytic effects on photoreductions

Vinyl copolymers with pendant porphyrin dimers were synthesized first by the dimerizations of chlorophyll-α and protoporphyrin IX via the ethylenebisamide linkage, then by copolymerization of the vinylbenzyl esters of the resulting dimers with N-vinylpyrrolidone or the esterification reaction of the dimers with chloromethylstyrene copolymers. Dimer-pendant copolymers with vinyl pyrrolidone catalyzed photoredox systems in aqueous solutions more efficiently than the corresponding monomer analogs, presumably because of the interactions exerted between the two combined porphyrin rings, which are manifested in the hypochromic effect in absorption spectra. The effect of the central Mg atom in the protoporphyrin IX ring was also considerable.     

Synthesis and structure of the N-alkyl-2,6-dimethyl-4-oxopyridine-3-carboxylic acids

A range of N-alkyl-2,6-dimethyl-4-oxopyridine-3-carboxylic acids XV have been prepared via reactions of primary alkyl amines with differing 2,6-dimethyl-4-oxopyran-3-carboxylate esters IX . The quantity of desired product formed and the character of by-products formed are determined by the natures of the amine and ester IX respectively. X-ray crystallography data for the N-ethyl analogue of XV indicates very strong intramolecular hydrogen bonding to be present, with the heterocyclic ring exhibiting considerable aromaticity.     

Neue anorganische Ringsysteme X. Die sechsgliedrigen Ringsysteme PIIISi2N3, PIIISi2N2O und PvSi2N2O

Survey on the first-time syntheses of new inorganic ring systems in our team (scheme 1). – The title ring systems were prepared according to equ. (1–5) and varied in the compounds I–IX (table 1). Introduction of a P atom into the SiN ring system gives rise to a splitting of the proton signals of the substituents in the ¹H nmr spectra (table 2), mostly in cause of coupling, partly in cause of steric effects.     

Porphyrins

The Vilsmeier formylation of Cu²⁺, Ni²⁺, Co²⁺, and Fe³⁺Cl complexes with mesoporphyrin IX dimethyl ester was investigated. It was established that the formylation takes place at all four meso positions of the porphyrin ring and that replacement of one metal by another affects only the rate of formylation (it has no effect on the orientation of electrophilic substitution). Four isomers of meso-dimethylamino-methylmesoporphyrin IX dimethyl ester were obtained by reduction of the intermediate immonium salts.See [1] for communication VII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1215–1220, September, 1978.     

Condensed Pyridazines. Part I. Synthesis of 2-Oxo-2H-pyrano[2,3-D]-pyridazine and 2-Oxo-2H-pyrano[2,3-c] pyridazine

The reaction of 4,7-diehlorofuro[2,3-d]pyridazine (1) with potassium cyanide in DMSO gave two products, (E)-3,6-diehloro-5-(2-cyanovinyl)-4-hydroxypyridazine (II) and 5,8-dichloro-2-oxo-2H-pyrano[2,3-d]pyridazine (III) as a result of ring opening or ring expansion. A new ring system, 2-oxo-2H-pyrano[2,3-c]pyridazines (IX, XII, XIII) was obtained from 5,8-dichloro-3-methyl-2-oxo-2H-pyrano[2,3-d]pyridazine (VI).     

Synthesis and antimicrobial activity of 4-aza-5α-sitostane and the 4-methyl derivative

Synthesis of 4-aza-5α-sitostane (IX), and 4-methyl-4-aza-5α-sitostane (XII) were accomplished through a set of reactions involving oxidative opening of ring A of α,β-unsaturated ketone, ring closure, followed by catalytic hydrogenation and lithium aluminum hydride reduction, respectively. The antimicrobial activity for X and XII is reported.     

Research on furan acetal compounds

The possibility of the reduction of the furan ring to a tetrahydrofuran ring under the conditions of liquid-phase hydrogenation of 2-furyl-1,3-dioxanes on Raney nickel at atmospheric pressure is demonstrated. 2-Furyl or tetrahydro-2-furyl amino derivatives of 1,3-dioxane are formed in the case of 5-nitro-2-furyl-1,3-dioxanes as a function of the structure of the starting acetals. Data from the UV and IR spectra are presented.See [1] for communication IX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1026–1029, August, 1977.     

The electrochemistry of some ferrocene derivatives: redox potential and substituent effects

Fifteen ferrocene derivatives I–IX (four of which have been prepared for the first time: II, IIIf, V and VIII) have been prepared by Friedel–Crafts acetylation, Claisen condensation, Michael reaction, and ring closure by hydrazine hydrate. The anodic behaviour of these compounds has been studied by cyclic voltammetry at a platinum electrode in an aprotic solvent. All these substituted ferrocenes exhibit a reversible one‐electron oxidation reduction centred at each iron centre, and the effect of substituents on the half‐wave oxidation potential is discussed in terms of their electronic properties. Linear correlations have been observed between these potentials and the Hammett σ_x constant for the substituents. Cyclic voltammetry has been carried out for ferrocene derivatives IIIa, V and IX. Copyright © 2003 John Wiley & Sons, Ltd.     

Electron-impact induced fragmentation of some natural products containing bis-2,2-dimethylchromene and bis-2,2-dimethylchroman ring systems

Derivatives of eriostoic and eriostemoic acids (II and III) and their tetrahydro analogs (VI and IX) which contain the bis-2,2-dimethylchromene and the bis-2,2-dimethylchroman ring systems respectively, fragment subsequent to electron-impact in characteristic fashion. The former yield mass spectra dominated by the loss of a methyl radical from their molecular ions while the latter exhibit preferential fragmentation of the heterocyclic ring system. In particular the hydrogen transfer process accompanying elemination of C₄H₇ from the parent ion of bis-2,2-dimethylchromans was investigated by deuterium labeling studies. Fragment ions containing the bis-2,2-dimethylchroman ring undergo further fragmentation by the loss of C₄H₈ rather than C₄H₇. An unusual elimination of CH₅ (accompanied by the appropriate metastable ion) from the molecular ions of the 3,5-dinitrobenzoate esters (XIV and XV) was observed in their mass spectra.     

Novel bicyclo[2.2.2]octanyl-1,4-benzodiazepinones. Their syntheses and rearrangement to bicyclooct-2-enylbenzimidazoles

The synthesis of the novel bicyclo[2.2.2]octanyl[1,4]benzodiazepinone ring system (IV) and its facile acid catalysed rearrangement to the corresponding bicyclo[2.2.2]oct-2-enylbenzirnid-azole system (IX) is described.     

Studies on the syntheses of heterocyclic compounds. part CDLV. The mass spectral investigation and synthesis of the ochotensinan skeleton

Syntheses of several 1-spiroisoquinoline derivatives (VIII, IX, X, XI, XII, XIII, and XIV) were carried out and their unique mass spectral fragmentations were reported. The presence of carbonyl groups at the C-9 and C-14 positions caused cleavage of the five membered ring through the elimination of one or two carbon monoxide groups. This led to the formation of the three membered ring system on the fragmentation pathway.     

Hyperfine Shifts of the 13C-NMR. in Protoporphyrin IX Iron (III) Dicyanide and Deuteroporphyrin IX Iron (III) Dicyanide

The ¹³C-NMR. in Zn(II) (Protoporphyrin IX), Fe(III) (Protoporphrin IX) (CN)₂, Zn(II) (Deuteroporphyrin IX dimethylester), and Fe(III) (Deuteroporphyrin IX) (CN)₂ have been identified, and the ¹³C hyperfine shifts in the iron complexes evaluated. In a partial analysis of these data the parameters Q^H, Q_CCH^H, and Q_C′CH^C, which characterize the isotropic coupling through hyperconjugation between the ¹H and ¹³C nuclei of the porphyrin side chains and the unpaired electron spin density on the aromatic ring carbon atoms, have been re-examined. This paper is part of an investigation of the electronic states in low spin ferric hemes and hemoproteins, and the relations between the electronic structures and the biological roles of these molecules.     

Preparation and O2 binding study of myoglobin having a cobalt porphycene

Sperm whale myoglobin, an oxygen-storage hemoprotein, was reconstituted with 2,7-diethyl-3,6,12,17-tetramethyl-13,16-bis(carboxyethyl)porphycenatocobalt(II) in order to investigate the reactivities of a cobalt porphycene in a protein matrix. Similar to the previously reported finding for the myoglobin with the iron porphycene, the reconstituted myoglobin with the cobalt porphycene was also found to have an O2 affinity 2 orders of magnitude greater than that of the myoglobin possessing cobalt protoporphyrin IX. The EPR spectra of the deoxy and oxy myoglobins having the cobalt porphycene at 77 K also have features similar to those of the myoglobin with cobalt protoporphyrin IX. These spectra suggest that the porphycene cobalt in the deoxy form is coordinated by one nitrogenous ligand postulated to be the imidazole ring of His93, and that the bond configuration of CoII-O2 is regarded as the CoIII-Omicron2*- species.     

New heterocyclic ring systems. XIII. 7,11-Dithiaazasteroid analogues

Synthesis of the tittle compounds has been achieved starting with the new tricyclic ring, 6-methyl-4-oxo-3,4-dihydro-2H,6H-thiopyrano[3,2-c][2,1]benzothiazine 5,5-dioxide (III). This compound was converted to the glyoxylate VI, the β-ketoester IX, a difluoride complex XIII and an enamino ketone XXIV which, by hydrazine, hydroxylamine and glycine treatment, gave 7,11-dithiaazasteroid analogues. Some unexpected products were also obtained from the ketone XVIII and the β-diketone XIX by treatment with chloroacetone and hydrazine respectively.     

Spatial structures of substituted oxiranes

Conclusions On the basis of the measurements of dipole moments and Kerr constants it can be said that the oxides of the thiophene chalcone analogues exist in s-cis and s-trans conformations, these differing in the mutual orientation of oxirane ring and carbonyl group.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1514–1518, July, 1976.The authors wish to thank V. I. Savin for having supplied the thienyl cyclopropyl ketone(IX).     

The linear dichroism spectra of free base and manganese(III) porphyrins

Linear dichroism of tetraphenylporphyrin and mesoporphyrin IX dimethyl ester are reported together with their manganese (III) derivatives, using both stretched polythene films and liquid crystals as the orienting solvents. All observed electronic transitions in the range 350–900 nm are found to be polarised in the plane of the porphyrin ring.