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PubMed1990

Protein components of a cytochrome P-450 linalool 8-methyl hydroxylase.

The cytochrome P-450 heme-thiolate monooxygenases that hydroxylate monoterpene hydrocarbon groups are effective models for the cytochrome P-450 family. We have purified and characterized the three proteins from a P-450-dependent linalool 8-methyl hydroxylase in Pseudomonas putida (incognita) strain PpG777. The proteins resemble the camphor 5-exohydroxylase components in chemical and physical properties; however, they show neither immunological cross-reactivity nor catalytic activity in heterogenous recombination. These two systems provide an excellent model to probe more deeply the heme-thiolate reaction center, molecular domains of substrate specificity, redox-pair interactions, and the regulation of the reaction cycle.

Acyclic Monoterpenes↗

PubMed1989

[Fundamental study on photocured resin for crown and bridge].

The purpose of this study is to clarify the superiority of five polyfunctional acrylates to composite filler and comonomer system, and the reasonable concentration of catalyst, Camphor quinone/Dimethylamino-ethylmethacrylate (CQ/DMAEMA), in the photocured resin for crown and bridge. The results are summarized as follows: 1. The influence of acrylate resin matrix of composite fillers was found in the elastic modulus (Em), Knoop hardness (Hk) and the wear resistance (Rw) of the photocured resin. Two photocured resins including Dipentaerythrytol hexaacrylate (DPHA) or DPHA-4(3-acryloxy propyl) tetramethylol methane (DPHA-APTM) composite fillers showed a higher Em, Hk and Rw but slightly lower tensile strength (Ts) and bending strength (Bs) than the one which included Bis-2-methacryloxyethyl 2, 2, 4-trymethyl hexamethylene diurethane (UDMA) or Trimethylolpropane trimethacrylate (TMPTMA) under a wet condition. And these two resins showed as a high water sorption value (Ws) as that of the photocured resin of UDMA. 2. The conversion of polymerization, cured depth and physical properties (Em, Hk and Rw) of the photocured resins were examined. They increased up to 0.5/1.0 or 1.0/1.0 in proportion to the increase of the concentration of the catalysts (CQ/DMAEMA). 3. When DPHA was added into the photocured resins consisted with UDMA monomer and DPHA or DPHA-APTM composite fillers, these resins showed a higher Em, Hk and Rw than the photocured resin with only UDMA as monomer. No significant difference of Ts and Bs between the photocured resins with and without DPHA was observed under a dry condition, but the values of Ts and Bs decreased in proportion to the increase of DPHA monomer under the wet condition. The residual monomer of the photocured resins was less than 1.2 per cent.

Acrylic Resins↗

PubMed1989

[Formulation of photocurable bonding liner and adhesion to dentin. Effect of photoinitiator, monomer and photoirradiation].

An investigation was undertaken to evaluate the effect of both photoinitiators (camphor-quinone-amine systems) and the adhesion promoting monomer (4-MET) on photopolymerization of bonding liners and their adhesion to dentin. Photopolymerization of bonding liners was measured with differential scanning calorimetry (DSC). The bonding liner containing 2-(dimethylamino)ethyl methacrylate (DMAEMA) as a reducing agent decreased the rate of polymerization in the presence of 4-MET. On the other hand, the bonding liners containing N-phenylglycine (NPG) and N,N-dimethylaniline derivatives as a reducing agent showed good polymerization in the presence of 4-MET. The results of the tensile bond test suggested that bonding liners containing NPG and 4-(dimethylamino)benzoic acid (DMABA), one of the N,N-dimethylaniline derivatives, with or without 4-MET bonded well to dentin treated with EDTA 3-2. NPG and DMABA are recommended not only as reducing agents but also as aids in the diffusion of monomers into the dentin substrate. The relationship between the strength of the bond to dentin and photoirradiation of the bonding liner and composite resin was studied. Elongation of photoirradiation of both the bonding liner and composite resin was effective in impacting the strength of the bond to dentin. Furthermore, sufficient photoirradiation of the bonding liner prior to any filling of composite resin was especially important to obtain high bond strengths. SEM and TEM observations supported good adhesion being achieved by hybrid formations between photocurable bonding liners and dentin.

Composite Resins↗

PubMedDate not supplied

[Problems in the root canal treatment of premature teeth with open apex].

The root canal treatment of pulpless teeth with open apex was always a problem in the field of endodontics. On occasions, various techniques have been used for the hermetic sealing of these teeth, and finally, the method of root canal filling with calcium hydroxide and CMCP (camphorous para mono chlorophenol) was adopted. This method was considered to be the most biological, and as it was proved the influence of calcium hydroxide, closing of the apex was achieved by various types of tissues. In this study we describe the problems that arise in such cases, as well as the various treatments. Finally cases of children who came for therapy in the clinic of Endodontics will be presented.

Calcium Hydroxide↗

PubMed1988

[Photoallergic and allergic contact eczema caused by dibenzoylmethane compounds and other sunscreening agents].

Dibenzoylmethanes are widely used in Europe in UV-A-absorbing sunscreens. We report on 21 patients with (photo)allergic contact dermatitis from 4-isopropyl-dibenzoylmethane. Six subjects revealed, in addition, (photo)allergic reactions to 4-tert.butyl-4'-methoxy-dibenzoylmethane, seven to 3-(4-methylbenzylidene)-camphor, two to 2-phenyl-benzimidazole-5-sulfonic acid and one to 2-phenyl-5-methylbenzoxazole. Allergic contact dermatitis from 2-phenyl-benzimidazole-5-sulfonic acid has not been reported previously. The relevance of sunscreens as a cause of (photo-)allergic contact dermatitis is discussed.

Adolescent↗

PubMed1986

Nucleotide sequence of the Pseudomonas putida cytochrome P-450cam gene and its expression in Escherichia coli.

Cytochrome P-450cam catalyzes the stereospecific methylene hydroxylation of camphor to form 5-exohydroxycamphor and is encoded by the camC gene on the CAM plasmid of Pseudomonas putida, ATCC 17453. The cytochrome P-450cam structural gene has been cloned by mutant complementation in P. putida (Koga, H., Rauchfuss, B., and Gunsalus, I. C. (1985) Biochem. Biophys. Res. Commun. 130, 412-417). We report the complete nucleotide sequence of the camC gene along with 155 base pairs of 5' and 175 base pairs of 3' flanking sequence. Upon comparison of the amino acid sequence derived from the gene sequence to the one obtained from the purified protein (Haniu, M., Armes, L. G., Yasunobu, K. T., Shastry, B. A., and Gunsalus, I. C. (1982) J. Biol. Chem. 257, 12664-12671), five differences were found. The most significant was the addition of a Trp and a Thr residue between Val-54 and Arg-55, thereby increasing the amino acid numbering scheme by 2 after Val-54, bringing the total number of amino acids to 414. Other differences were: Gln-274----Glu-276, Ser-359----His-361, and Asn-405----Asp-407. N-terminal amino acid sequence analysis of the cloned cytochrome P-450cam enzyme expressed in Escherichia coli under the lac promoter showed a faithful translation of the hemo-protein, with the N-terminal Met removed by processing as found in P. putida. Purification to homogeneity of the cloned protein was accomplished by the method used for the CAM plasmid-encoded enzyme of P. putida. The G + C content of the camC gene was found to be 59.0%, caused by a preferred usage of G and C terminated codons. The gene encoding putidaredoxin reductase, camA, was located 22 nucleotides downstream from the cytochrome P-450cam gene. The camA gene initiated with a novel GUG codon, the first such initiator documented in Pseudomonas.

Amino Acid Sequence↗

PubMed1988

Ureas and amides derived from N-(5-norbornen-2-ylmethyl) bornan-2-exo-amine with antiarrhythmic and other activities.

The synthesis of title compounds by reaction of camphor nitrimine with (5-norbornen-2-yl)methylamine, followed by NaBH4 reduction of the resulting imine to N-substituted isobornylamine (IV) and reaction of (IV) with alkyl and aryl isocyanates or acyl chlorides, is described. Some ureas and amides are endowed with antiarrhythmic activity in rats superior or comparable to that of quinidine, whereas benzamide (V o) showed an appreciable hypoglycemic activity in mice. Moreover, compounds (V) exhibited in general moderate hypotensive, bradycardic and antiinflammatory activities in rats, as well as a weak infiltration anesthesia in mice.

Amides↗

PubMed1987

[Inactivation of sodium dithionite reduced cytochromes P-450 of different origins].

The inactivation of five dithionite reduced soluble cytochrome P-450 isoforms has been studied. The inactivation of microsomal rabbit liver isoform LM2 and bacterial linalool cytochrome P-450 is followed by its conversion into cytochrome P-420. Microsomal rabbit liver isoform LM4, bacterial camphor and p-cymene cytochromes P-450 were not inactivated under these conditions. The inactivation of linalool cytochrome P-450 and LM2 isoform is a first order reaction; the rate constants for linalool cytochrome P-450 and LM2 are 0.3 and 0.1 min-1, respectively. In the case of linalool cytochrome P-450 its carboxycomplex (Fe2+-CO) is inactivated, while in the case of LM2 the inactivation affects its oxycomplex (Fe2+-O2). The amino acid residues of linalool cytochrome P-450 are probably modified due to a direct electron transfer in its carboxycomplex. The amino acid residues of LM2 isoform are modified, presumably due to oxidation by oxygen active species which are released during the oxycomplex decay.

Animals↗

PubMed1987

Esters of N-(2-hydroxy-1,1-dimethylethyl)-1,7,7-trimethylbicyclo[2.2.1] heptan-2-exo-amine with hypotensive activity.

The synthesis of title compounds by reaction of camphor nitrimine with 2-amino-2-methylpropanol, followed by NaBH4 reduction of the resulting imine to the aminoalcohol (III) and esterification of (III) with aliphatic and aromatic acyl chlorides in pyridine solution, is described. Phenyl carbamate (V) was also prepared by reaction of (III) with phenyl isocyanate. Some esters and (V) showed a moderate hypotensive activity in rats. Effects on heart rate and antiarrhythmic activity in rats, as well as infiltration anesthesia in mice, are also reported.

Amines↗

PubMed1986

Biosynthesis of monoterpenes. Enantioselectivity in the enzymatic cyclization of (+)- and (-)-linalyl pyrophosphate to (+)- and (-)-bornyl pyrophosphate.

Enzymes from Salvia officinalis and Tanacetum vulgare leaf epidermis catalyze the conversion of the acyclic precursor geranyl pyrophosphate to the cyclic monoterpenes (+)- and (-)-bornyl pyrophosphate, respectively. The antipodal cyclizations are considered to proceed by the initial isomerization of the substrate to the respective bound tertiary allylic intermediates (-)-(3R)- and (+)-(3S)-linalyl pyrophosphate. [(3R)-8,9-14C,(3RS)-1E-3H] Linalyl pyrophosphate (3H:14C = 5.22) was tested as a substrate with the cyclases from both sources to determine the configuration of the cyclizing intermediate. This substrate yielded (-)-bornyl pyrophosphate with 3H:14C ratio greater than 31, indicating specific utilization of (+)-(3S)-linalyl pyrophosphate as predicted. With the (+)-bornyl pyrophosphate cyclase, the 3H:14C ratio of the product was about 4.16, indicating a preference for the (-)-(3R)-enantiomer, but the ability also to utilize (+)-(3S)-linalyl pyrophosphate. (3R)- and (3S)-[1Z-3H]Linalyl pyrophosphate were separately compared to the achiral precursors [1-3H] geranyl pyrophosphate and [1-3H]neryl pyrophosphate (cis-isomer) as substrates for the cyclizations. All functional precursors afforded optically pure (-)-(1S,4S)-bornyl pyrophosphate with the T. vulgare-derived cyclase (as determined by chromatographic separation of diastereomeric ketals of the derived ketone camphor), and (+)-(3S)-linalyl pyrophosphate was the preferred substrate. With the (+)-bornyl pyrophosphate cyclase from S. officinalis, geranyl, neryl, and (-)-(3R)-linalyl pyrophosphates gave the expected (+)-(1R,4R)-stereoisomer as the sole product, and (-)-(3R)-linalyl pyrophosphate was the preferred substrate. However, (3S)-linalyl pyrophosphate yielded (-)-(1S,4S)-bornyl pyrophosphate, albeit at lower rates, indicating the ability of this enzyme to catalyze the anomalous enantiomeric cyclization.

Acyclic Monoterpenes↗

PubMed1986

Theoretical studies of cytochrome P-450. Characterization of stable and transient active states, reaction mechanisms and substrate-enzyme interactions.

The techniques of theoretical chemistry embodied in ab initio and semiempirical quantum mechanical and empirical energy methods have been used to elucidate the relationship between structure, spectra and function of the oxidative metabolizing heme proteins, the cytochrome P-450s, using a recent X-ray structure of a P-450cam-camphor complex. Specifically, the origin of the spin state changes when substrate binds to the oxidized resting state and the nature of the transient biologically active oxygen transfer state have been described. Mechanisms of hydroxylation and epoxidation, the two fundamental oxidative reactions performed by these enzymes, have been deduced and the role of substrate binding and orientation on product distribution investigated.

Binding Sites↗

PubMed1985

Neural and environmental influences on neoplasia and conditioning of NK activity.

The effects of physical restraint and poly I:C treatment on the growth of MOPC 104E myeloma and murine osteosarcoma and survival of animals bearing such tumors were investigated. Our studies show that in the Balb/c mice with MOPC 104E myeloma the effects of restraint stress were detrimental and lead to early death of the mice. When the restraint was combined with poly I:C, during the early course of the disease, restraint stress neutralized the beneficial effects of the poly I:C treatment. These studies show that under certain circumstances, restraint stress can negate the effects of therapy. On the other hand, restraint stress produced an opposite effect in C3H/He mice with murine osteosarcoma tumor treated in the same fashion. In mice with osteosarcoma, restraint stress delayed tumor growth and increased the median survival time. When restraint stress was combined with poly I:C treatment, the mean tumor size was smaller and median survival was substantially increased over the control group. Because poly I:C therapy delayed tumor growth and increased survival in both models, efforts to strengthen this response were tested by conditioning. Our studies show the response to poly I:C as measured by elevation of the NK activity could be conditioned with camphor smell. Conditioning of the host to raise immune activity to alter the outcome of disease is a new area yet to be explored and has important clinical significance. These studies, we believe, are important because they explore the connection between mind and body and resistance to disease.

Animals↗

PubMed1986

Peripheral nerve conduction studies in passively addicted neonates.

Neurologic signs dominate the manifestations of the neonatal abstinence syndrome (NAS). To help delineate this dysfunction, peripheral nerve conduction studies (NCS) were made in 25 neonates born to methadone-maintained mothers; 12 of the mothers abused other controlled substances concomitantly. Median and common peroneal motor nerve conduction velocities (NCV) in these infants were normal, both at three to seven days and three to four weeks of age, and were unaffected by maternal drug intake pattern, severity of neonatal abstinence symptoms, treatment with either camphorated tincture of opium or phenobarbital, intrauterine growth retardation, or abstinence-associated seizurer. Electromyographic findings were normal in 21/23 infants; two others showed minimal partial denervation, characterized by fibrillations and positive sharp waves. NCV in the NAS may enhance gestational age assessment and therefore increase validity of neurobehavioral follow-up. Our studies continue to point to a central rather than a peripheral motor dysfunction exhibited by passively addicted infants at birth, which may persist on two-to-five-year follow-up.

Electromyography↗

PubMed1985

N-substituted 4,7,7-trimethyl-3-(1-piperidinyl)bicyclo-[2.2.1]hept-2-ene 2-carboxamides and 2-carbothioamides with hypotensive activity.

The synthesis of two series of N-substituted 4,7,7-trimethyl-3-(1-piperidinyl)bicyclo[2.2.1]hept-2-ene 2-carboxamides (I d-h) and 2-carbothioamides (I i-o), as well as of some N-aryl 4,7,7-trimethyl-3-(1-pyrrolidinyl)bicyclo[2.2.1]hept-2-ene 2-carboxamides (I a-c), by reaction of camphor piperidinoenamine and pyrrolidinoenamine with aryl isocyanates and isothiocyanates is described. On the whole compounds (I d-h) showed a weak hypotensive activity in rats.

Animals↗

PubMed1985

Stereochemistry at C-1 of geranyl pyrophosphate and neryl pyrophosphate in the cyclization to (+)- and (-)-bornyl pyrophosphate.

(1R)-1-3H-labeled and (1S)-1-3H-labeled geranyl pyrophosphate and neryl pyrophosphate were prepared from the corresponding 1-3H-labeled aldehydes by a combination of enzymatic and synthetic procedures. Following admixture with the corresponding 2-14C-labeled internal standard, each substrate was converted to (+)-bornyl pyrophosphate and (-)-bornyl pyrophosphate by cell-free enzyme preparations from sage (Salvia officinalis) and tansy (Tanacetum vulgare), respectively. Each pyrophosphate ester was hydrolyzed, and the resulting borneol was oxidized to camphor. The stereochemistry of labeling at C-3 of the derived ketone was determined by base-catalyzed exchange, taking advantage of the known selective exchange of the exo-alpha-protons. By comparison of such exchange rates to those of product generated from (1RS)-2-14C,1-3H2-labeled substrate, it was demonstrated that geranyl pyrophosphate was cyclized to bornyl pyrophosphate with net retention of configuration at C-1 of the acyclic precursor, whereas neryl pyrophosphate was cyclized to product with inversion of configuration at C-1. The observed stereochemistry is consistent with a reaction mechanism whereby geranyl pyrophosphate is first stereospecifically isomerized to linalyl pyrophosphate which, following rotation about C-2-C-3 to the cisoid conformer, cyclizes from the anti-endo configuration. Neryl pyrophosphate cyclizes either directly or via the linalyl intermediate without the attendant rotation.

Plants↗

PubMed1985

[Spectrophotometric study of cytochrome P-450 (11 beta) interaction with physiological effectors].

Using the optical absorbance spectroscopy method, the interaction of a number of biospecific ligands (steroids, adrenodoxin) with homogeneous cytochrome P-450 (11 beta) from bovine adrenal mitochondria was investigated. The parameters of the steroid-protein interaction in a number of substrates and products of the 11 beta- and 18 (19)-hydroxylation with the active site of cytochrome P-450 (11 beta) were determined. A sharp decrease in the cytochrome affinity for steroids upon the insertion of the first hydroxy group was observed, which provides for a predominant formation of monohydroxylated products from the substrate and minimum amounts of dihydroxylated ones, despite the presence of more than one position for the substrate hydroxylation by cytochrome P-450 (11 beta). Some structural elements of the steroid molecule were determined as any alterations in these strongly affect the enzyme affinity for the steroid. These structures are: 1) delta 4-3-oxo structure; 2) either 21-hydroxy group of pregnen steroids or the one fulfilling its functions, 17 beta-hydroxy or 17-oxo group of androsten steroids, and 3) the 11th position of all the substrates under study. It was shown that the binding of various substrates into stoichiometric (1:1) steroid-protein complexes provides a transition to high spin state from 30-40% (cortisol, corticosterone) to 90-95% (11-deoxycorticosterone) of hemoprotein iron. Using the experimental system containing individual cytochrome P-450 (11 beta) and adrenodoxin, as well as the steroid and nonionic detergent Tween 20, it was shown that the parameters of substrate binding and hemoprotein spin equilibrium did not differ from the corresponding parameters of the cytochrome-adrenodoxin dienzyme complex. The peculiarities of the multiligand interactions in the 11 beta-hydroxylase system, involving cytochrome, substrates and ferredoxin demonstrate some analogy with a bacterial camphor hydroxylase system and some differences from the mitochondrial system for the side chain cleavage of cholesterol.

Adrenal Glands↗

PubMed1984

[Asymmetrical synthesis of (R)(-) and (S)(+)-etilefrine by enantioselective hydrogenation and the effects of enantiomers in an animal experiment].

The enantiomers of etilefrine (Effortil) were produced by enantioselective hydrogenation. The optical purity was determined by conversion with (+)-[(R)-tetrahydrofurfuryl-(1S)-camphor-10-sulfonate] to N-[(R)-tetrahydrofurfuryl]-etilefrine and subsequent separation of the diastereomers by HPLC. An animal experiment showed that the (R)(-)-enantiomer is more effective.

Animals↗

PubMedDate not supplied

[A strain of Pseudomonas aeruginosa growing on petroleum hydrocarbons].

The strain Pseudomonas aeruginosa BS313 was used to isolate mutants that are capable to utilize octane as the sole carbon source. By means of conjugation plasmids of camphor (CAM) and naphthalene (pBS2) biodegradation were inserted into one of the mutant strains P. aeruginosa BS316. The resultant strain P. aeruginosa BS315 shows the capacity to degrade aliphatic, aromatic and cyclic oil hydrocarbons.

Biodegradation, Environmental↗