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PubMedDate not supplied

Essential oils from micropropagated plants of Lavandula viridis.

The essential oils of Lavandula viridis were analysed by GC and GC-MS. Comparisons were made between three types of plant material from the same clone: field-grown plant, in vitro shoot cultures and micropropagated plants of the same clone. The most common components usually found in lavender oils were present in the oil samples analysed and more than 45 constituents were identified, representing more than 80% of the essential oil. The essential oils analysed consisted mainly of monoterpenes (75.4-76.3%), where oxygenated and hydrocarbons identified ranged from 41.8 to 57.3% and 18.1 to 34.2%, respectively. The major components found were 1.8-cineole (18.2-25.1%), camphor (9.1-15.7%), alpha-pinene (8.8-14.1%), borneol (4.1-4.8%), beta-pinene (1.2-5.6%), delta 3-carene (1.0-6.5%) and alpha-terpineol (0.8-4.2%). The monoterpene fraction of the in vitro shoot cultures showed different relative amounts of hydrocarbons and oxygenated components in relation to the parent plant and to micropropagated plants. In the sesquiterpene hydrocarbon fraction of the oil samples analysed (6.1-8.2%), 7-epi-alpha-selinene (1.6-4.8%) was the most important component and the oxygenated sesquiterpenes were found in small amounts (1.1-1.7%). The essential oils from field-grown plants of L. viridis, when compared with those obtained from in vitro shoot cultures or micropropagated plants of the same clone, demonstrated that the same major components were found without significant compositional variations.

Chromatography, Gas↗
PubMed1992

Substrate mobility in a deeply buried active site: analysis of norcamphor bound to cytochrome P-450cam as determined by a 201-psec molecular dynamics simulation.

While cytochrome P-450cam catalyzes the hydroxylation of camphor to 5-exo-hydroxycamphor with 100% stereospecificity, norcamphor is hydroxylated by this enzyme yielding 45% 5-exo-, 47% 6-exo-, and 8% 3-exo-hydroxynorcamphor (Atkins, W.M., Sligar, S.G., J. Am. Chem. Soc. 109:3754-3760, 1987). The present study describes a 201-psec molecular dynamics (MD) stimulation of norcamphorbound cytochrome P-450cam to elucidate the relationship between substrate conformational mobility and formation of alternative products. First, these data suggest that the product specificity is, at least partially, due to the mobility of the substrate within the active site. Second, the high mobility of norcamphor in the active site leads to an average increase in separation between the heme iron and the substrate of about 1.0 A; this increase in separation may be the cause of the uncoupling of electron transfer when norcamphor is the substrate. Third, the active site water located in the norcamphorbound crystal structure possesses mobility that correlates well with the spin-state equilibrium of this enzyme-substrate complex.

Binding Sites↗
PubMed2003

Antimicrobial activity of essential oil and methanol extracts of Achillea sintenisii Hub. Mor. (Asteraceae).

The essential oil, obtained by Clevenger distillation, and water-soluble and water-insoluble parts of the methanol extracts of Achillea sintenisii Hub. Mor. were individually assayed for their antimicrobial activities against 12 bacteria and two yeasts, Candida albicans and C. krusei. No activity was exhibited by the water-soluble subfraction, whereas both the water-insoluble subfraction of the methanol extracts and the essential oil were found to be active against some test microorganisms studied. Since the essential oil possessed stronger activity than the other extracts tested, it was further fractionated and the fractions were evaluated for their antimicrobial activity, followed by GC-MS analysis, resulting in the identification of 32 compounds which constituted 90.2% of the total oil. The GC-MS analysis of the oil and its fractions revealed that the main components of the oil, e.g. camphor and eucalyptol, possessed appreciable activity against C. albicans and Clostridium perfringens. The fi ndings presented here also suggest that the other constituents of the oil, e.g. borneol and piperitone can also be taken into account for the activity observed.

Achillea↗
PubMed2003

Composition and antimicrobial activity of Achillea clavennae L. essential oil.

The volatile constituents of Achillea clavennae L. (Asteraceae), rare plant of Europe, have been analysed using GC/MS. Twenty- five components making up 81.6% of the oil were characterized with camphor (29.5%), myrcene (5.5%), 1,8-cineole (5.3%), beta-caryophyllene (5.1%) and linalool (4.9%) being the major constituents. The essential oil was evaluated for antibacterial and antifungal activities. The screening of the antimicrobial activity of essential oil was conducted by a disc diffusion test against Gram-positive (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Streptococcus faecalis), Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis) and fungal organisms (Aspergillus niger, Aspergillus fumigatus, Candida albicans). The activity was more pronounced against Gram-negative and fungal organisms than against Gram-positive bacteria. A. clavennae oil was found to possess antimicrobial activity against Klebsiella pneumoniae, Pseudomonas aeruginosa and all fungal organisms.

Achillea↗
PubMed2001

Temperature-jump relaxation kinetics of substrate-induced spin-state transition in cytochrome P450 (comparison of the wild-type and C334A mutant P450(CAM) and P450(2B4)).

The kinetics of binding of the substrate camphor to the cytochrome P450(CAM) and the C334A mutant as well as the kinetics of binding of benzphetamine to the wild-type P450(2B4) have been studied by the temperature-jump relaxation technique in order to distinguish between the two models for substrate-induced spin-state transition. These models are the bimolecular model in which spin-state transition occurs in parallel with substrate binding, and the two-step spin-equilibrium model in which substrate binding is a separate step preceding the spin-state transition. With all three P450s, the relaxation rate versus concentration data were linear as predicted by the bimolecular model and inconsistent with the spin-equilibrium model, which predicts a curve reaching saturation. With all three P450s, the relaxation rate versus concentration data exhibited maxima. These results are considered to resolve the controversy in favor of the bimolecular model for substrate-induced spin-state transition. In addition, the results suggest that the bimolecular model may be applicable to other P450s as well.

Amino Acid Substitution↗
PubMed2001

Purification and characterization of benzoate-para-hydroxylase, a cytochrome P450 (CYP53A1), from Aspergillus niger.

Benzoate-para-hydroxylase (CYP51A or BpH) and NADPH:cytochrome P450 reductase from the filamentous fungus Aspergillus niger were purified to apparent homogeneity, using an overproducing A. niger strain. This is the first membrane-bound fungal cytochrome P450 to be isolated and characterized. Combining BpH with NADPH:cytochrome P450 oxidoreductase in the presence of the phospholipid dilauryl phosphatidylcholine restored the BpH activity, although to only a minor extent. Spectral analysis of BpH showed characteristic spectra for a cytochrome P450. Substrate binding studies with purified BpH as a function of temperature and as a function of pH were performed. Temperature-dependent studies, at pH 8.0, showed that the simplified spin equilibrium model originally proposed for camphor binding to cytochrome P450cam (M. T. Fisher and S. G. Sligar, 1987, Biochemistry 26, 4797-4803) also applies to the benzoate-BpH system. Two equilibrium constants were determined, K(1) for substrate binding without a spin change and K(2) for the spin change of the benzoate-BpH complex. pH-dependent binding studies showed that both K(1) and K(2) increase with pH, indicative of a higher affinity. As K(1) decreases more strongly with pH than K(2), we suggest that benzoate first binds to a binding site on the outside of the protein in a pH-dependent way, followed by transfer to the inside of the protein causing a spin change at the heme iron. The strong pH dependence of K(1) could be the result of the need to break salt bridges at the binding site on the outside of the protein. pH-dependent kinetic studies with microsomes showed that the apparent K(M) values followed the trend observed for benzoate binding to purified BpH, while k(cat) values were virtually constant between pH 6.6 and 8.0 and decreased above pH 8, probably due to loss of productive interaction between BpH and NADPH:cytochrome P450 oxidoreductase. Research into the substrate specificity of BpH showed that BpH can only use benzoic acid and some of its derivatives. Monosubstitution on the phenyl ring is allowed but only at certain positions with specific, not too large groups. Substitution always leads to a lower affinity of the substrate. With one exception, all substrates were converted to their 4-hydroxy derivative. The exception, 3-methoxybenzoate, was demethylated to yield 3-hydroxybenzoate only. The restricted number of substrates and the specificity in catalysis suggest that BpH is not a general-purpose hydroxylase but that its role is confined to benzoate hydroxylation in the beta-ketoadipate pathway of A. niger.

Aspergillus niger↗
PubMed2001

Spectral editing in solid-state NMR using scalar multiple quantum filters.

In this paper we describe the use of heteronuclear scalar couplings in solid-state NMR in order to generate multiple-quantum filtering (MQF) pulse sequences. These sequences can be used to edit CP/MAS spectra according to carbon multiplicity. Analytic expressions for the intensity of the MQF signals are obtained using the standard product operator formalism. Experiments that demonstrate the technique are shown in powder samples of camphor and a tripeptide.

Journal Article↗
PubMed1998

Identification of PhoP-PhoQ activated genes within a duplicated region of the Salmonella typhimurium chromosome.

Salmonellae virulence requires the PhoP-PhoQ two-component regulatory system. PhoP-PhoQ activate the transcription of genes following phagocytosis by macrophages which are necessary for survival within the phagosome environment. Thirteen previously undefined PhoP-activated gene fusions generated by MudJ and TnphoA (pag A, and E-P, respectively) were cloned and sequenced. Most pag products show no similarity to proteins in the database, while others are predicted to encode: a UDP-glucose dehydrogenase (pagA); a protein with similarity to the product of an E. coli aluminium-induced gene (pagH); a protein encoded within a Salmonella-unique region adjacent to the sinR gene (pagN); a protein similar to a product of the Yersinia virulence plasmid (pagO); and a protein with similarity to CrcA which is necessary for resistance of E. coli to camphor (pagP). Of the pag characterized, only pagK, M and O were closely linked. pagJ and pagK were shown to be unlinked but nearly identical in DNA sequence, as each was located within a 1.6 kb DNA duplication. The translations of sequences surrounding pagJ and pagK show similarity to proteins from extrachromosomal elements as well as those involved in DNA transposition and rearrangement, suggesting that this region may have been or is a mobile element. The transcriptional start sites of pagK, M, and J were determined; however, comparison to other known pag gene promoters failed to reveal a consensus sequence for PhoP-regulated activation. DNA sequences hybridizing to a Salmonella typhimurium pagK specific probe were found in S. enteritidis but absent in other Salmonella serotypes and Enterobacteriaceae tested, suggesting that these genes are specific for broad host range Salmonellae that cause diarrhoea in humans. Cumulatively, these data further demonstrate: (1) that PhoP-PhoQ is a global regulator of the production of diverse envelope or secreted proteins; (2) that PhoP-PhoQ regulate the production of proteins of redundant function; and (3) that pag are often located in regions of horizontally acquired DNA that are absent in other Enterobacteriaceae.

Artificial Gene Fusion↗
PubMed1998

Progress in the development of oxytocin antagonists for use in preterm labor.

There is currently a need for new therapeutic agents for treating preterm labor which could offer improved safety and efficacy beyond what has been achieved with the widely employed beta-mimetics. In this regard, the longstanding hypothesis of oxytocin receptor blockade as representing a potentially more selective method of tocolysis has continued to gain support from results obtained in clinical studies with the peptide oxytocin antagonist, atosiban. Our laboratory has focussed on the identification of non-peptide oxytocin antagonists with properties suitable for both oral and intravenous administration. We have previously described the development of potent, camphor-based oxytocin antagonists, including L-368,899 which entered phase I human studies. More recently we have pursued a new structural class of oxytocin antagonists based on the 1-(N-benzoylpiperidin-4-yl)-4H-3,1-benzoxazin-2(1H)-one template. L-372,662 is a new member of this structural class and in our preclinical assays possesses an attractive overall profile from the standpoint of human oxytocin receptor affinity (Ki = 4.9 nM), human oxytocin vs. vasopressin receptor selectivity (> 500-fold), potency as an antagonist of oxytocin-induced uterine contractions in late gestation pregnant rhesus monkeys (AD50 = 36 micrograms/kg), oral bioavailability (F = 90% in dogs), and aqueous solubility (10 mg/mL).

Animals↗
PubMed1990

Microbial metabolism of monoterpenes--recent developments.

Monoterpenes are important renewable resources for the perfume and flavour industry but the pathways and enzymology of their degradation by microorganisms are not well documented. Until recently the acyclic monoterpene alcohols, (+)-camphor and the isomers of limonene were the only compounds for which significant sections of catabolic pathways and associated enzymology had been reported. In this paper recent developments in our understanding of the enzymology of ring cleavage by microorganisms capable of growth with 1,8-cineole and alpha-pinene are described. 1,8-Cineole has the carbocyclic skeleton of a monocyclic monoterpene with the added complication of an internal ether linkage. Ring hydroxylation strategy and biological Baeyer-Villiger oxygenation lead to an efficient method for cleaving the ether linkage. alpha-Pinene is an unsaturated bicyclic monoterpene hydrocarbon. At least two catabolic pathways exist. Information concerning one of them, in which alpha-pinene may be initially converted into limonene, is rudimentary. The other involves attack at the double bond resulting in formation of alpha-pinene epoxide. Ring cleavage is then catalysed by a novel lyase that requires no additional components and breaks both carbocyclic rings in a concerted manner.

Bicyclic Monoterpenes↗
PubMed1979

Testing cosolvent cryoenzymology on multi-enzyme systems.

Fluid mixed solvents appear to supply an effective tool for investigation of enzyme catalysis at subzero temperatures. Labile reaction intermediates may be stabilized, characterized and separated. Cycling of reaction processes and side reactions can be slowed or stopped to permit single turnover of individual molecular events, and kinetic response to temperature and other physical parameters can provide dynamic and thermodynamic analysis of single enzyme systems. Multienzyme systems can furnish reliable probes of potential, limitations and possible procedural artefacts of the method. Amply explored examples are supplied by the studies of two components of the soluble camphor hydroxylase and the hepatic R450LM2 in solution and in the subcellular microsomal organelles, to reveal labile single enzyme compounds and multienzyme processes.

Cold Temperature↗
PubMed1985

Composition of the essential oil of Ocimum canum grown in Rwanda.

The essential oil from leaves and flowers of Ocimum canum Sims, growing wild in Rwanda, was investigated by LSC, GLC and GC-MS. All samples were characterized by a high content of linalool (60-90%). Neither camphor nor citral and methyl cinnamate, compounds reported to be characteristic for different types of O. canum, could be detected. All monoterpene hydrocarbons were present in minor amounts (less than 1.5%). The oil samples with the lowest linalool content consisted of relatively large amounts of sesquiterpene hydrocarbons such as bergamotene (about 10%) and beta-caryophyllene (about 5%). Oct-1-en-3-ol and 3-octanol were the only oxygen-containing components, besides linalool, that amounted to more than 1% in most of the oil samples.

Chemical Phenomena↗
PubMed1982

Analysis of creams. III. Application of gas--liquid chromatography. Part I.

The possibilities of the gas--liquid chromatographic analysis with flame ionization detection of creams of the o/w emulsion type were investigated. Interferences by cream base components in the determination of the active compounds were studied. It appeared to be possible to determine active compounds with a retention index lower than 1900 on ov-17 (e.g. methyl salicylate, menthol, thymol camphor) without clean-up of the cream samples; for the determination of compounds with retention indices between 1900 and 3700, a simple clean-up step suffices. The possible analysis of some of the cream base components together with the active compounds of the creams was investigated as well. Cetomacrogol emulsifying wax, lanette was sx and cetiol v could be determined easily, whether or not a sample clean-up step was incorporated.

Cetomacrogol↗
PubMed2004

(M)VOC and composting facilities. Part 2: (M)VOC dispersal in the environment.

BACKGROUND, AIMS AND SCOPE: Composting facilities are known to release odorous volatiles due to biodegradation of municipal waste and plant residues. Although odour perception and its grading is influenced by experience, attitude and adaptation, these emissions have created a lack of acceptance for residents in the vicinity of composting facilities. Enclosure of compost pile halls, ventilation systems and biofilters are often insufficient to minimise the burden of compost-derived compounds in the air. Moreover, economic considerations forced smaller communities to establish less sophisticated facilities with open storage areas and other relevant sources for wind-borne dispersal of bioaerosols. Aim of the present study was to characterise the immission and dispersal of microbial volatiles (MVOC) and, besides, to find coincidences between MVOC and compost odour. METHODS: In the course of this study, the surroundings of two composting facilities, differing in their type of process engineering, were investigated for emission of volatiles in the environment. Both microbially and plant-derived substances were assessed, several of which have low odour thresholds. Air samples were taken in distances ranging from 50 to 800 m in a downwind direction from each facility. RESULTS AND DISCUSSION: Compost-derived and microbial volatile organic compounds (MVOC) were found at distances of up to 800 m from the composting facilities. Terpenes like alpha-pinene, camphene and camphor were the dominant compounds and coincided with typical compost odour, whereas several typical MVOC were not found at greater distances. The terpenes in combination with certain MVOC may play an important role in the perception of compost odour. Exposure concentrations were not of toxicological relevance, but sensory irritation and psychohygienic effects due to an annoyance potential of such compounds should not be dismissed. RECOMMENDATIONS AND OUTLOOK: Although terpenes are generally associated with pleasant odour characteristics, they seemed to contribute to malodours in a mixture with other VOC, in this context of volatile waste from compost facilities. Malodorous emissions from biowaste have to be considered as sources of health complaints and the investigation of mixtures of compost-derived volatiles is still inevitable. Exposure levels have to be discussed taking VOC mixtures into account. Within composting facilities, technical devices have to be improved to minimise dispersal of volatiles to prevent residents from immissions eventually causing health complaints.

Aerosols↗
PubMedDate not supplied

Airborne Compositae dermatitis: monoterpenes and no parthenolide are released from flowering Tanacetum parthenium (feverfew) plants.

The air around intact feverfew (Tanacetum parthenium) plants was examined for the presence of airborne parthenolide and other potential allergens using a high-volume air sampler and a dynamic headspace technique. No particle-bound parthenolide was detected in the former. Among volatiles emitted from the aerial parts of feverfew plants and collected by the dynamic headspace technique a total of 41 compounds, mainly monoterpenes, were identified and quantified by GC and GC-MS. Alpha-Pinene, camphene, limonene, gamma-terpinene, (E)-beta-ocimene, linalool, p-cymene, (E)-chrysanthenol, camphor and (E)-chrysanthenyl acetate were the predominant monoterpenes accounting for nearly 88% of the total volatiles emitted. The average total yield of volatiles emitted over 24 h was 18,160 ng/g fresh weight of leaves and flowers, corresponding to the emission of approximately 8 mg volatiles per day from one full-grown feverfew plant. No parthenolide or other sesquiterpene lactones were detected. The present investigation does not support the theory of airborne sesquiterpene lactone-containing plant parts or of direct release of sesquiterpene lactones from living plants as the only explanations for airborne Compositae dermatitis. Potential allergens were found among the emitted monoterpenes and their importance in airborne Compositae dermatitis is discussed.

Air Pollutants↗
PubMed1999

Plant-induced seizures: reappearance of an old problem.

Several plant-derived essential oils have been known for over a century to have epileptogenic properties. We report three healthy patients, two adults and one child, who suffered from an isolated generalized tonic-clonic seizure and a generalized tonic status, respectively, related to the absorption of several of these oils for therapeutic purposes. No other cause of epilepsy was found, and outcome was good in the two adult cases, but the course has been less favorable in the child. A survey of the literature shows essential oils of 11 plants to be powerful convulsants (eucalyptus, fennel, hyssop, pennyroyal, rosemary, sage, savin, tansy, thuja, turpentine, and wormwood) due to their content of highly reactive monoterpene ketones, such as camphor, pinocamphone, thujone, cineole, pulegone, sabinylacetate, and fenchone. Our three cases strongly support the concept of plant-related toxic seizure. Nowadays the wide use of these compounds in certain unconventional medicines makes this severe complication again possible.

Epilepsy, Tonic-Clonic↗
PubMed2006

Larvicidal effects of various essential oils against Aedes, Anopheles, and Culex larvae (Diptera, Culicidae).

Mosquitoes in the larval stage are attractive targets for pesticides because mosquitoes breed in water, and thus, it is easy to deal with them in this habitat. The use of conventional pesticides in the water sources, however, introduces many risks to people and/or the environment. Natural pesticides, especially those derived from plants, are more promising in this aspect. Aromatic plants and their essential oils are very important sources of many compounds that are used in different respects. In this study, the oils of 41 plants were evaluated for their effects against third-instar larvae of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. At first, the oils were surveyed against A. aegypti using a 50-ppm solution. Thirteen oils from 41 plants (camphor, thyme, amyris, lemon, cedarwood, frankincense, dill, myrtle, juniper, black pepper, verbena, helichrysum and sandalwood) induced 100% mortality after 24 h, or even after shorter periods. The best oils were tested against third-instar larvae of the three mosquito species in concentrations of 1, 10, 50, 100 and 500 ppm. The lethal concentration 50 values of these oils ranged between 1 and 101.3 ppm against A. aegypti, between 9.7 and 101.4 ppm for A. stephensi and between 1 and 50.2 ppm for C. quinquefasciatus.

Animals↗
PubMed2006

Persistency of larvicidal effects of plant oil extracts under different storage conditions.

The persistency of larvicidal effects of 13 oils (camphor, thyme, amyris, lemon, cedarwood, frankincense, dill, myrtle, juniper, black pepper, verbena, helichrysum, and sandalwood) was examined by storage of 50-ppm solutions under different conditions (open, closed, in the light, and in the dark) for 1 month after the preparation of the solutions. The stored solutions were tested against Aedes aegypti larvae for four times during the storage period. Some oils under some conditions stayed effective until the last test, while some solutions had lost their toxicity during a short time after preparation. Thus, the mode of storage is absolutely important for the larvicidal effects. The fresh preparations were always the best.

Animals↗