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At least 55 records · Page 3Linked to original sources
PubMed1979

Molecular mechanisms of olfactory reception. IV. Some biochemical characteristics of the camphor receptor from rat olfactory epithelium.

Some parameters of the receptor element from the rat olfactory epithelium are evaluated; it is characterized by high affinity for camphor (KD = 1.5. x 10(-9) M). Triton X-100 has no marked effect on the binding of [3H]camphor. Neither RNAase nor phospholipase C affected [3H]camphor-binding activity. Pronase and trypsin abolished [3H]camphor binding activity by 65 and 40%, respectively. Sulfhydryl reagents decrease the binding of [3H]camphor by a factor of 5--8. The isoelectric point of the receptor solubilized with Triton X-100 is 4.8, as determined by isoelectric focusing. The molecular weight of the receptor as determined by gel electrophoresis is about 120 000. It is proposed that the camphor receptor is a membrane protein containing sulfhydryl groups and playing a key role in olfactory reception.

Animals↗
PubMed2006

Distribution of the UV filter 3-benzylidene camphor in rat following topical application.

A straightforward analytical method for determination of 3-benzylidene camphor (3-BC) in rat adipose tissue, brain, liver, muscle, plasma and testis following topical application was developed and validated. Three exposure levels (60, 180 and 540 mg kg(-1) day(-1)) were tested for 65 days in male Sprague-Dawley rats (24 days postnatal). Sample preparation involving homogenization and n-heptane or methanol extraction of the tissue was applied before injection into the LC-ESI-MS-MS system. The response was linear from 2 to 100 microg l(-1) for the qualifier and the quantifier MRM transitions (R(2) (quantifier) > 0.994). Detection limit of the method corresponded to 0.005 microg g(-1) tissue and 12.5 microg l(-1) plasma, respectively. Recovery was determined for all tissues (adipose tissue: 40%; all other tissues: 80-100%) at three individual levels. 3-(4-Methyl benzylidene camphor) (4-MBC) was used throughout the study as internal standard. 3-Benzylidene camphor was detected in all tissues at all exposure levels at concentrations between 0.05 microg g(-1) (liver) and 36 microg g(-1) (adipose tissue) and in plasma at 16-89 microg l(-1). The method allowed for the quantification of 3-benzylidene camphor in all tested tissues following topical application. Furthermore, it was shown that 3-benzylidene camphor can be found in various tissues in the rat following topical application. These findings may suggest that following use of 3-benzylidene camphor containing sunscreen, similar disposition and distribution may occur in humans.

Administration, Topical↗
PubMed1998

Capillary gas chromatographic assay of camphor and m-cresol in dermatological creams.

Camphor and m-cresol mixtures are used in antiseptic and anti-itching creams. No compendial method exists for these preparations. This paper reports a capillary gas chromatographic method using FID detection with 2,6-di-tert-butyl-4-methylphenol as internal standard on a 30 m x 0.32 mm Supelcowax -10 column (0.25 micron film) with helium as carrier gas. Ramped temperature programming was applied. The method allows simultaneous quantitation of camphor and m-cresol in the presence of o- and p-cresols, calamine and zinc oxide. Overall percent recoveries (+/- SD, n = 9) of camphor, o-, p- and m-cresol from spiked placebo creams, at a labeled amount of 10 (w/w)% were 96.9 +/- 0.6, 98.2 +/- 0.6, 99.2 +/- 0.5 and 101.0 +/- 0.9%, respectively, and at a labeled amount of 1% were 96.7 +/- 0.6, 97.8 +/- 0.9, 97.8 +/- 0.6, and 100.3 +/- 1.0%, respectively. The recovery studies were carried out at +/- 30% of the labeled amounts. Linear peak area or height ratios were obtained (r > 0.999) for camphor, o-, p- and m-cresol covering a concentration range of 10-200% of the labeled amount. Linearity (r > 0.999) was also obtained for m-cresol when the relative concentration of o- and p-cresol was varied from 5 to 100% of the m-cresol concentration. The resolution between the 'critical pair' of p- and m-cresol was > or = 1.1. The limit of quantitation was 23 pg for m-cresol and 9.3 pg for camphor using an injection split of 1:50. The repeatability (%RSD) for all compounds were < 2% for peak area and < 1.4% for peak height ratios. System suitability and robustness of the method were established. The method was successively applied to the assay of available commercial products and allows assay of camphor and the three cresol isomers.

Antipruritics↗
PubMed1990

Sensory characteristics of camphor.

The perceptual effects of camphor on hairy skin were measured in a psychophysical experiment. Subjects rated the intensity and quality of sensations produced when a solution of 20% camphor (in a vehicle of ethanol and deionized H2O) was applied topically to the volar forearm. Under conditions in which skin temperature was varied either from 33-43 degrees C or from 33-18 degrees C, it was found that camphor increased the perceived intensity of the cutaneous sensations produced during heating and cooling. Although camphor's effect appeared to be greater during warming, neither effect was large. Camphor also produced a significant increase in the frequency of reports of "burning." It is concluded that camphor is a relatively weak sensory irritant that may have a modest excitatory effect on thermosensitive (and perhaps nociceptive) cutaneous fibers.

Adult↗
PubMed1999

[Historical study on the moth repellent, "Fujisawa Camphor" (1)].

"Fujisawa Camphor" was introduced for sale as a moth repellent for home use in 1897. As a background that camphor was produced on a commercial basis, the following were studied: (1) Camphor was already used as a moth repellent by some people in the Endo Period. (2) With the Sino-Japanese War as a turning point, armaments were increased and they made military uniforms which were made of wool. It also made Western woolen clothes spread in general. (3) As people were in danger to catch infectious diseases in those days, they had a habit of avoiding bad odors and drifting fragrances like camphor were used in rooms to prevent the plague. (4) In those days, a technique for refining camphor was established, so white crystal-line camphor was produced on a commercial basis.

Animals↗
PubMed2004

Synchronized motion of a mobile boundary driven by a camphor fragment.

The synchronized self-motion of a camphor fragment and a mobile boundary on a water surface depending on the initial conditions and the asymmetry of the boundary was investigated. When a camphor fragment, which showed unidirectional rotation, was surrounded by a circular ring as a symmetric mobile boundary on a water surface, the circular ring also rotated but in the direction opposite to that of the camphor fragment. The velocity of the rotation of the mobile ring varied depending on the anisotropy of the shape of the ring. When a camphor fragment was placed on the inside of a circular ring floating on the water surface, the ring and camphor fragment exhibited translational motion without rotation. These characteristics of synchronized self-motion are discussed in relation to the surface tension as the driving force and convective flow due to the gradient of the surface-active camphor layer.

Journal Article↗
PubMed2006

Effect of alcohols on binding of camphor to cytochrome P450cam: spectroscopic and stopped flow transient kinetic studies.

Addition of alcohols to cytochrome P450cam (CYP101) was shown to release the substrate camphor from the heme pocket of the enzyme. The release of the substrate was found to be caused both due to increased solubility of the substrate in solution in presence of alcohol and due to change in the tertiary structure of the active site of the enzyme. The far-UV CD and near-UV CD spectra reveal that addition of alcohols to cytochrome P450cam cause a small change in the secondary structural elements but a significant change in the tertiary structural organization of this enzyme. The CD spectra at the heme region at various concentrations of alcohols indicate a substantial change in the tertiary structural organization around the heme moiety too. The equilibrium constant associated with the binding of camphor to Cyt P450cam is strongly dependent on the concentration of alcohols and the corresponding free energy associated with the binding is found to scale linearly with the concentration of alcohols. Kinetic experiments on binding of camphor to Cyt P450cam show that both k(on) and k(off) rate constants are strongly affected by addition of alcohols suggesting that alcohol expel camphor out of the heme cavity of Cyt P450cam by affecting tertiary structure of Cyt P450cam as well as by modifying the solubility properties of camphor in aqueous medium.

Alcohols↗
PubMed2000

Binding of camphor to Pseudomonas putida cytochrome p450(cam): steady-state and picosecond time-resolved fluorescence studies.

The binding of camphor to cytochrome P450(cam) has been investigated by steady-state and time-resolved tryptophan fluorescence spectroscopy to obtain information on the substrate access channel. The fluorescence quenching experiments show that some of the tryptophan residues undergo changes in their local environment on camphor binding. The time-resolved fluorescence decay profile gives four lifetime components in the range from 99 ps to 4.5 ns. The shortest lifetime component assigned to W42 lies close to the proposed camphor access channel. The results show that the fluorescence of W42 is greatly affected on binding of camphor, and supports dynamic fluctuations involved in the passage of camphor through the access channel as proposed earlier on the basis of crystallographic, molecular dynamics simulation and site-directed mutagenesis studies.

Camphor↗
PubMed2006

Chirality of camphor derivatives by density functional theory.

Infrared (IR) and vibrational circular dichroism (VCD) spectra of chiral camphor, camphorquinone and camphor-10-sulfonic acid (CSA), known as standard compounds for electronic circular dichroism (ECD) spectroscopy, are measured and their vibrational frequencies, infrared intensities, and rotational strengths are calculated using density functional theory (DFT). The observed IR and VCD spectra of chiral camphor and camphorquinone in carbon tetrachloride solution are reproduced by the DFT calculations, but those of CSA are not. DFT calculations of hydration models, where an anionic CSA specifically binds a few water molecules, are carried out. The average of the simulated VCD spectra in the hydration models is more consistent with the observed spectra. In addition, the wavelengths and dipole and rotational strengths for chiral camphor, camphorquinone, anionic CSA, and the hydration models were calculated by time-dependent DFT. In the region of 280-300 nm, the calculated wavelengths of the ECD bands for chiral camphor and camphorquinone coincide with the observed wavelengths that have been reported, and the calculated wavelengths for the hydration models are closer to the observed wavelengths reported than are those calculated for chiral anionic CSA. Consequently, the analysis combined with VCD and ECD spectroscopy using DFT calculations can elucidate the chirality of optically active molecules, even in an aqueous solution.

Camphor↗
PubMed1988

Hemoperfusion in acute camphor poisoning.

After ingestion of an unknown dose of a 10% camphor spirit (maximum dose 200 ml), a 54-year-old female was found in coma, having developed grand-mal-like seizures and respiratory failure. For detoxification, gastric lavage and hemoperfusion with amberlite XAD4 were performed. During hemoperfusion, seizures ceased, but no marked influence on the clinical course of the intoxication--especially on grade of coma--was observed. For further evaluation of the efficacy of treatment, camphor plasma elimination kinetics during hemoperfusion were compared to plasma elimination kinetics determined in a volunteer after an oral dose of 200 mg of camphor. Although the plasma compartment was almost completely (89%-95%) cleared of camphor by hemoperfusion, only a total of 35 mg of camphor was removed due to its high apparent volume of distribution (estimated 2-4 l/kg). The plasma elimination half-life was not affected by hemoperfusion, which may be explained by the saturation of metabolizing enzymes, still incomplete absorption, or metabolic interference of isopropanol. In the case presented here, neither the clinical course of the intoxication nor plasma level data gave evidence for a pronounced beneficial effect of hemoperfusion.

Acute Disease↗
PubMed1984

Metabolism of monoterpenes: lactonization of (+)-camphor and conversion of the corresponding hydroxy acid to the glucoside-glucose ester in sage (Salvia officinalis).

The bicyclic monoterpene ketone (+)-camphor is a major constituent (up to 26%) of the volatile oil of immature sage (Salvia officinalis L.) leaves; however, as the plant matures the content of this ketone declines in the fully expanded leaves (to about 65% of maximum) as does the overall yield of oil (to roughly 60% of maximum). Examination of the metabolism of (+)-[G-3H]camphor in discs prepared from mature leaves of flowering sage plants revealed that this ketone was converted to a water-soluble metabolite which on chromatographic analysis proved to be considerably more polar than a simple monoterpenyl glycoside. Mass spectral analysis of several derivatives of the terpenoid moiety of the metabolite obtained from large-scale incubations allowed identification of the aglycone, while degradative studies and detailed radiochromatographic analyses indicated that the metabolite contained two glucose residues; one glycosidically linked and the other in ester linkage. All of the evidence was consistent with the initial lactonization of camphor to 1,2-campholide followed by conversion to the beta-D-glucoside-6-O-glucose ester of the corresponding hydroxy acid (1-carboxymethyl-3-hydroxy-2,2,3-trimethyl cyclopentane). Direct evidence for the intermediacy of 1,2-campholide was also obtained through isotopic dilution experiments and by direct testing of the labeled lactone. The lactonization of camphor in sage resembles a similar step in the catabolism of camphor by microorganisms, but appears to be the first report of this reaction type in higher plants.

Camphor↗
PubMed2006

Release properties on gelatin-gum arabic microcapsules containing camphor oil with added polystyrene.

In this study, gelatin blended with arabic gum microcapsules containing camphor oil with added polystyrene were fabricated by a compound coacervation method. The parameters of oil/wall volume ratio, emulsification stirring speed, concentration of cross-linking agent, treated time and oil release properties were investigated. In order to improve the constant release effect of camphor oil, oil-soluble polystyrene (PS) was used as a sustained release agent. The camphor oil release curves were expressed by the exponential equation: psi(t)=C(eq)(1-e(-t/tau)), where psi(t) represent the variant of camphor oil concentration in the operation environment, C(eq) as the equilibrium state, t as the release time and tau as time constant. C(eq) and tau are significant factors pertaining to the camphor oil release properties. The results indicated that, for the microcapsules, the optimal oil/wall volume ratio was 0.75 to achieve the encapsulation efficiency of 99.6 wt.%. The average particle size were 294.7+/-14.2 microm, 167.2+/-11.2 microm, 85.7+/-8.7 microm at the homogenization stirring speed of 500, 1000, and 2000 rpm, respectively. The effect of sustained oil release will increase whereas the stirring speed decreases and the concentration of glutaraldehyde (GA) and treated time increases. Along with the increasing of quantity of polystyrene added, C(eq) decreased and tau increased, indicating that the sustained oil release amount and the release rate depend on the quantity of PS considerably.

Biocompatible Materials↗
PubMed2001

Influence of organic solvent on the behaviour of camphor and alpha-pinene enantiomers in reversed-phase liquid chromatography systems with alpha-cyclodextrin as chiral additive.

Reversed-phase liquid chromatography has been applied in order to gain insight into the alpha-cyclodextrin (alpha-CD)-solute complexation process, which occurs in the aqueous mobile phases containing a secondary achiral modifier. The model compounds tested were (+/-)-camphor and (+/-)-alpha-pinene. Methanol, ethanol, and 1 or 2-propanol were used as secondary modifiers. Retention factors and enantioseparation factors have been determined on a RP 18 stationary phase as a function of the alpha-CD concentration, secondary modifier content, and temperature changes. The shortest retention and the best separation of studied compounds were achieved for aqueous-methanol eluents. Apparent stability constants in various binary aqueous-organic solvent mixtures have been evaluated for alpha-CD complexes of camphor enantiomers. Using the competition concept, values for the stability constants in pure water have been calculated. It has been found that: (1) the quotient of the stability constants for both enantiomers, denoted as absolute enantioselectivity E, always remains constant at a fixed value (E approximately 1.9), which may indicate that the complex composition does not change, (2) only the first step in the complexation process is altered by changing the solvent, which does not seem to affect the separation of the enantiomers, (3) the remarkable enantioselectivity that is observed results from the second step in the complexation process, (4) enthalpy changes are much more favourable for camphor-alpha-cyclodextrin complex formation than for the transfer of camphor to the stationary phase, which means that complexation dominates over adsorption and retention is shorter at lower temperatures, (5) the difference in free energy changes of complexation (AAG) between the enantiomers of camphor is about 1.5 kJ/mol at 20 degrees C.

Bicyclic Monoterpenes↗
PubMed2004

Nucleotide sequence of a portion of the camphor-degrading gene cluster from Rhodococcus sp. NCIMB 9784.

Rhodococcus sp. NCIMB 9784 is a camphor-degrading Gram-positive organism originally isolated from activated sewage sludge. A 5.4kbp portion of a proposed camphor degradation gene cluster from this organism was cloned and its nucleotide sequence determined. Four open reading frames (ORFs) were identified encoding proteins possibly involved in camphor metabolism; sequence alignment of the translation products suggested that the ORFs encode for a ferredoxin reductase, acyl-CoA ligase, epimerase and an acyl-CoA dehydrogenase. The last three activities are thought to be involved in the poorly understood late stage of camphor degradation. Our findings are entirely consistent with the proposed formation of a branched 9-carbon acid intermediate (3,4,4-trimethyl-5-oxo-trans-2-hexenoic acid) which has been isolated from the fermentation broth of camphor-grown cells.

Amino Acid Sequence↗
PubMed2006

Camphor-related self-inflicted keratoconjunctivitis complicating delusions of parasitosis.

PURPOSE: To report a case of camphor-related self-inflicted keratoconjunctivitis secondary to delusions of parasitosis. METHODS: A 61-year-old man with delusions of parasitosis suffered from camphor-related self-inflicted ocular trauma that manifested with corneal epithelial defects and secondary anterior chamber reaction. Two episodes of exacerbation of the ocular conditions related to the use of camphor occurred. The left eye had secondary infection with Sternotrophomonas maltophilia and Staphylococcus aureus in the second episode of exacerbation. RESULTS: The right eye recovered well with the treatment of topical lubricants and corticosteroids and had best-corrected visual acuity (BCVA) of 20/25. The infection of the left eye led to corneal perforation, necessitating penetrating keratoplasty; BCVA was hand motions because of a mature cataract. Olanzapine therapy for 1 month to decrease the delusions of parasitosis and 24-hour watch to prevent the use of camphor led to the resolution of self-inflicted keratoconjunctivitis in the patient. CONCLUSIONS: Delusions of parasitosis may lead to vision-threatening self-inflicted ocular trauma. This may be the first case report of pure camphor-related self-inflicted toxic keratoconjunctivitis.

Anterior Chamber↗
PubMed1980

[Camphor preparations in the overall therapy of cerebral infarct].

The authors studied the platelet functional properties and the brain bioelectric activity in 20 patients with acute cerebrovascular diseases before and after subcutaneous injection of 2.0 ml of racemic camphor T, as well as before and after oral taking of monobromated camphor in a dose of 0.5 g 3 times a day. The platelet aggregation was examined by the method of Born (1962) with automatic recording of aggregatograms. The brain bioelectric activity was examined using an Alvar electroencephalograph. As a result, the authors discovered an inhibitory effect of camphor preparations on the platelet aggregation. Racemic camphor T and monobromated camphor were found to produce a stimulant effect on the brain.

Blood Platelets↗
PubMed2003

Manifestation of chiral recognition of camphor enantiomers by alpha-cyclodextrin in longitudinal and transverse relaxation rates of the corresponding 1:2 complexes and determination of the orientation of the guest inside the host capsule.

The 1:2 complexes of camphor enantiomers with alpha-cyclodextrin in (2)H(2)O manifest differences in longitudinal and transverse relaxation rates of camphor methyl protons owing to chiral recognition. The relaxation data obtained at two magnetic fields were quantitatively analyzed using the model of anisotropic overall tumbling with internal motion. In experimental conditions (guest-to-host ratio = 1:20, T = 300.6K), all camphor molecules are complexed. The complexes are not rigid but the rotational diffusion of camphor enantiomers embedded inside the capsules formed by two alpha-cyclodextrin hosts is well outside the extreme narrowing region. Both differences in the anisotropic overall tumbling and internal rotation of all methyl groups participate in enantiomeric differentiation of the relaxation rates. Anisotropic tumbling of camphor molecules provides information on the orientation of the guest in the host capsule that for the complex under study could not be obtained by other methods.

Journal Article↗
PubMed2006

Synthesis and application in asymmetric catalysis of camphor-based pyridine ligands.

This tutorial review deals with the synthesis and application in asymmetric catalysis of camphor-based pyridine ligands. These ligands can be roughly divided into two groups: those in which the camphor is annulated in the 2,3-positions to the beta-face of the pyridine ring and those in which the pyridine is contained as a pendant on the C2 or C3 of the camphor framework. Camphor-based pyridine ligands can also contain other donor centers located on the pyridine ring or camphor skeleton. Some of these ligands have provided interesting enantioselectivities in several asymmetric reactions, such as S(N)2' reactions, allylic oxidations, carbonyl additions with organozinc reagents and hydrogenations. This review contains a lot of chemistry on ligand synthesis and readers will find it of value and also perhaps an inspiration for the development of more active and improved versions.

Journal Article↗