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PubMed1999

Lucidenic acid O and lactone, new terpene inhibitors of eukaryotic DNA polymerases from a basidiomycete, Ganoderma lucidum.

Terpenoids, 1, 2 and 3, which selectively inhibit eukaryotic DNA polymerase activities, were isolated from the fruiting body of a basidiomycete, Ganoderma lucidum, and their structures were determined by spectroscopic analyses. New terpenes, lucidenic acid O (1) and lucidenic lactone (2), prevented not only the activities of calf DNA polymerase alpha and rat DNA polymerase beta, but also these of human immunodeficiency virus type 1 reverse transcriptase. Cerevisterol (3), which was reported to be a cytotoxic steroid, inhibited only the activity of DNA polymerase alpha. Although these compounds did not influence the activities of prokaryotic DNA polymerases and other DNA metabolic enzymes such as T7 RNA polymerase and deoxyribonuclease I.

Animals↗
PubMedDate not supplied

Relationship between Debaryomyces pseudopolymorphus enzymatic extracts and release of terpenes in wine.

As a result of the interest that exists in the liberation of aromas in young wines, we obtained some different enzymatic extracts (purified extract, P; lyophilized purified extract, LP; immobilized purified extract, IP; and immobilized lyophilized purified extract, ILP) with beta-glucosidase activity from Debaryomyces pseudopolymorphus, which excreted the enzyme in the growth medium. The extracts were added to natural glycosides isolated from different grape varieties. The results were compared with the effect of seven commercial enzyme preparations (CEP), obtained from molds used in wine making. It was shown that some yeast extracts had effects similar to those of the CEP, and the next step was to use them on wine samples elaborated in the laboratory. The effect was studied at 9 and 16 days of contact, quantifying both the precursors that were retained and the liberated terpenes. The results were compared with a control wine (without any extract) and with wine treated with a commercial enzyme preparation specially indicated for the liberation of aromas. It was observed that the enzymatic extracts from Db. pseudopolymorphus hydrolyzed the precursors in wine and that they could compete with the commercial preparations since the liberation was produced in even less time.

Cell Extracts↗
PubMed2005

Measurements of secondary organic aerosol from oxidation of cycloalkenes, terpenes, and m-xylene using an Aerodyne aerosol mass spectrometer.

The Aerodyne aerosol mass spectrometer (AMS) was used to characterize physical and chemical properties of secondary organic aerosol (SOA) formed during ozonolysis of cycloalkenes and biogenic hydrocarbons and photo-oxidation of m-xylene. Comparison of mass and volume distributions from the AMS and differential mobility analyzers yielded estimates of "effective" density of the SOA in the range of 0.64-1.45 g/cm3, depending on the particular system. Increased contribution of the fragment at m/z 44, C02+ ion fragment of oxygenated organics, and higher "delta" values, based on ion series analysis of the mass spectra, in nucleation experiments of cycloalkenes suggest greater contribution of more oxygenated molecules to the SOA as compared to those formed under seeded experiments. Dominant negative "delta" values of SOA formed during ozonolysis of biogenics indicates the presence of terpene derivative structures or cyclic or unsaturated oxygenated compounds in the SOA. Evidence of acid-catalyzed heterogeneous chemistry, characterized by greater contribution of higher molecular weight fragments to the SOA and corresponding changes in "delta" patterns, is observed in the ozonolysis of alpha-pinene. Mass spectra of SOA formed during photooxidation of m-xylene exhibit features consistent with the presence of furandione compounds and nitro organics. This study demonstrates that mixtures of SOA compounds produced from similar precursors result in broadly similar AMS mass spectra. Thus, fragmentation patterns observed for biogenic versus anthropogenic SOA may be useful in determining the sources of ambient SOA.

Aerosols↗
PubMed2005

Secondary organic aerosol production from terpene ozonolysis. 1. Effect of UV radiation.

We report secondary organic aerosol (SOA) yields from the ozonolysis of alpha-pinene under both dark and UV-illuminated conditions. Exposure to UV light reduces SOA yield by 20-40%, with a maximum reduction in yield coinciding with a minimum in the amount of terpene consumed (15-30 ppb). The data are consistent with a constant absolute reduction in the yield of approximately 0.03. Gas chromatography mass spectrometry analysis of filter samples indicates that the major products found in alpha-pinene SOA include organic acids (e.g., pinic acid), keto acids (e.g., pinonic acid), and hydroxy keto acids (e.g., 10-hydroxypinonic acid). Analysis of filter-based results suggests that yield reduction is a result of the formation of a more volatile product distribution when experiments are conducted in the presence of UV light. These results implythat previous "dark bag" experiments may overestimate SOA generation from monoterpenes and also that SOA generation in the atmosphere may depend significantly on actinic flux.

Acids↗
PubMed2003

Isolation and identification of terpene chlorohydrins found in cold-pressed orange oil.

Three terpene chlorohydrins found in cold-pressed orange oil were concentrated by silica adsorption chromatography and purified by preparative HPLC. Formation of these chlorohydrins was determined to be the result of a reaction of d-limonene, the major component of cold-pressed oil, with hypochlorous acid, found in chlorinated treatment water used in the oil recovery process. NMR analyses indicated that the major chlorohydrin present was the diequatorially substituted (1R,2R,4R)-2-chloro-8-p-menthen-1-ol (1). The other two compounds were the diaxial trans stereoisomer, (1S,2S,4R)-2-chloro-8-p-menthen-1-ol (2), and the dichlorohydrin, (1R,2R,4R)-2,9-dichloro-8-p-menthen-1-ol (3).

Chlorohydrins↗
PubMed2005

Induction of de novo volatile terpene biosynthesis via cytosolic and plastidial pathways by methyl jasmonate in foliage of Vitis vinifera L.

The terpene biosynthesis in leaves of Vitis vinifera L. cv. Morio Muskat was studied using methyl jasmonate to induce defensive responses in vivo. The experiments demonstrated the strong activation of the de novo biosynthesis of terpenoids via the octadecanoid-signaling cascade and release of the compounds to the gas phase. Feeding experiments with [5,5-(2)H(2)]-1-deoxy-d-xylulose and [5,5-(2)H(2)]mevalonic acid lactone allowed the investigation of the dynamic allocation of resources via the mevalonic acid and 1-deoxy-d-xylulose/2-C-methyl-d-erythritol 4-phosphate (DOXP/MEP) pathway under induced conditions and after treatment with the specific inhibitors mevastatin and fosmidomycin. The experiments reveal that monoterpenes are almost exclusively synthesized via the DOXP/MEP pathway, whereas sesquiterpenes are generated via both pathways at approximately equal rates. The biosynthesis of the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene was not affected by mevastatine or fosmidomycin.

Acetates↗
PubMed2006

Phenol and terpene quenching of singlet- and triplet-excited states of riboflavin in relation to light-struck flavor formation in beer.

Phenolic compounds present in beer were shown by fluorescence spectroscopy and laser flash photolysis to deactivate both singlet- and triplet-excited states of riboflavin with bimolecular rate constants close to the diffusion control ranging from 2.8x10(9) to 1.1x10(10) M-1 s-1 and from 1.1x10(9) to 2.6x10(9) M-1 s-1, respectively. Enthalpies of activation were low (up to 33.2 kJ mol-1), and entropies of activation were positive, ranging from 17 to 92 J mol-1 K-1, as derived from temperature dependence, indicating a compensation effect. From a Stern-Volmer analysis of the singlet-excited riboflavin quenching by phenols it was found that high amounts of phenolic compounds (>0.3 M) would be needed to hinder triplet-excited riboflavin generation. On the other hand, a phenolic content of 0.36 mM is likely to quench 90% of the triplet-excited state. Phenol photodegradation was found to be complex, and using ESI-MS analysis it was not possible to identify specific photooxidation products of the phenolic compounds; only the photoproducts of riboflavin could be detected and structurally assigned. The rate of reaction of triplet-excited riboflavin with phenolic compounds in acetonitrile/citrate buffer (pH 4.6, 10 mM) is 550 times faster than the reaction with iso-alpha-acids from hops, indicating that triplet-excited quenchers such as phenols may be involved in the early steps in light-struck flavor formation in beer through radical formation. Terpenes present in herb-flavored beers were found to be nonreactive toward singlet- and triplet-excited-state riboflavin, and any protection depends on other mechanisms.

Beer↗
PubMed2001

Inhibition of heme detoxification processes underlies the antimalarial activity of terpene isonitrile compounds from marine sponges.

A series of terpene isonitriles, isolated from marine sponges, have previously been shown to exhibit antimalarial activities. Molecular modeling studies employing 3D-QSAR with receptor modeling methodologies performed with these isonitriles showed that the modeled molecules could be used to generate a pharmacophore hypothesis consistent with the experimentally derived biological activities. It was also shown that one of the modeled compounds, diisocyanoadociane (4), as well as axisonitrile-3 (2), both of which have potent antimalarial activity, interacts with heme (FP) by forming a coordination complex with the FP iron. Furthermore, these compounds were shown to inhibit sequestration of FP into beta-hematin and to prevent both the peroxidative and glutathione-mediated destruction of FP under conditions designed to mimic the environment within the malaria parasite. By contrast, two of the modeled diterpene isonitriles, 7-isocyanoamphilecta-11(20),15-diene (12) and 7-isocyano-15-isothiocyanatoamphilecta-11(20)-ene (13), that displayed little antimalarial activity also showed little inhibitory activity in these FP detoxification assays. These studies suggest that the active isonitrile compounds, like the quinoline antimalarials, exert their antiplasmodial activity by preventing FP detoxification. Molecular dynamics simulations performed with diisocyanoadociane (4) and axisonitrile-3 (2) allowed their different binding to FP to be distinguished.

Animals↗
PubMed2002

Biosynthesis of terpenes. Preparation of (E)-1-hydroxy-2-methyl-but-2-enyl 4-diphosphate, an intermediate of the deoxyxylulose phosphate pathway.

(E)-1-hydroxy-2-methyl-but-2-enyl 4-diphosphate (E-6) was synthesized in six reaction steps from hydroxyacetone (9) and (ethoxycarbonylmethenyl)-triphenylphosphorane (11) with an overall yield of 38%. The compound was shown to be identical with the product of IspG protein, which serves as an intermediate in the nonmevalonate terpene biosynthetic pathway.

Acetone↗
PubMed2003

Total diastereofacial selective iodofunctionalization of terpene derivatives based on Ipy2BF4.

Acetonides 1, easily obtained from simple terpenes, react with bispyridine iodonium (I) tetrafluoroborate (Ipy(2)BF(4)) and tetrafluoroboric acid in the presence of nucleophiles to give the corresponding adducts 2 with complete regio and diastereofacial control. Acetonides 1 containing a properly located phenyl or benzyloxy group easily undergo iodocyclization to furnish compounds 3 and 4.

Magnetic Resonance Spectroscopy↗
PubMed1997

Effect of menthol and related terpenes on the percutaneous absorption of propranolol across excised hairless mouse skin.

The potential use of terpenes/terpenoids as penetration enhancers in the transdermal delivery of propranolol hydrochloride (PL) was investigated. PL was chosen for the reasons of its extensive first-pass metabolism and short elimination half-life. The terpenes studied included L-menthol, (+)-limonene, (+/-)-linalool, and carvacrol at 1%, 5%, and 10% w/v concentrations. The diffusion of PL across excised hairless mouse skin was determined using side-by-side diffusion cells. Flux, permeability coefficient (Pm), and lag time (tL) were calculated. PL showed comparable lag times with menthol at all three concentration levels. At a 1% level of carvacrol, PL exhibited a 2.4- and 2.2-fold increase in lag time compared with 5 and 10% levels of enhancer, respectively. In the presence of limonene, PL had shown maximum lag time (between 3.0 and 3.3 h) at all three levels. In the case of linalool, the lag times for PL with 5 and 10% levels of enhancer were 7.0- and 5.2-fold less compared with 1% level. A significant (p < 0.05) concentration effect was observed only with linalool. Hydrogel-based patches were formulated with or without menthol as enhancer. Release profiles from the hydrogel formulations obeyed zero-order kinetics. The permeability of propranolol was significantly higher (p < 0.05) from the test patch than the control (no enhancer) patch across the mouse skin. The mechanism of permeation enhancement of menthol could involve its distribution preferentially into the intercellular spaces of stratum corneum and the possible reversible disruption of the intercellular lipid domain. The results suggest the potential use of menthol as effective penetration enhancer in the delivery of significant amounts of PL through skin.

Acyclic Monoterpenes↗
PubMed2001

Prunioside A: a new terpene glycoside from Spiraea prunifolia.

Prunioside A (1) has been isolated from an EtOAc-soluble extract of Spiraea prunifolia var. simpliciflora by a combination of chromatographic techniques. The structure was determined primarily by extensive NMR experiments. Compound 1 is a unique terpene glycoside. Its acetylated derivative (1a) inhibited nitric oxide production in murine macrophage-like RAW 264.7 cells in a dose-dependent manner.

Animals↗
PubMed2005

Reductive coupling of terpenic allylic halides catalyzed by Cp2TiCl: a short and efficient asymmetric synthesis of onocerane triterpenes.

[reaction: see text] Titanocene chloride catalyzes the regioselective alpha,alpha'-homocoupling of terpenic allylic halides. This process has been employed in the short and effective synthesis of terpenoids such as beta-onoceradiene (1), beta-onocerin (2), and squalene (3). Evidence is presented for eta1-allyltitanium species being involved in the coupling.

Allyl Compounds↗
PubMed2004

Biosynthetic pathways to isocyanides and isothiocyanates; precursor incorporation studies on terpene metabolites in the tropical marine sponges Amphimedon terpenensis and Axinyssa n.sp.

The biosynthetic origins of the isocyanide and isothiocyanate functional groups in the marine sponge metabolites diisocyanoadociane (1), 9-isocyanopupukeanane (10) and 9-isothiocyanatopupukeanane (11) are probed by the use of [(14)C]-labelled precursor experiments. Incubation of the sponge Amphimedon terpenensis with [(14)C]-labelled thiocyanate resulted in radioactive diisocyanoadociane (1) in which the radiolabel is specifically associated with the isocyanide carbons. As expected, cyanide and thiocyanate were confirmed as precursors to the pupukeananes 10 and 11 in the sponge Axinyssa n.sp.; additionally these precursors labelled 2-thiocyanatoneopupukeanane (12) in this sponge. To probe whether isocyanide-isothiocyanate interconversions take place at the secondary metabolite level, the advanced precursor bisisothiocyanate 17 was supplied to A. terpenensis, but did not result in significant labelling in the natural product isocyanide 1. In contrast, in the sponge Axinyssa n.sp., feeding of [(14)C]-9-isocyanopupukeanane (10) resulted in isolation of radiolabelled 9-isothiocyanatopupukeanane 11, while the feeding of [(14)C]-11 resulted in labelled isocyanide 10. These results show conclusively that isocyanides and isothiocyanates are interconverted in the sponge Axinyssa n.sp., and confirm the central role that thiocyanate occupies in the terpene metabolism of this sponge.

Animals↗
PubMed2001

Studies on the nonmevalonate pathway of terpene biosynthesis. The role of 2C-methyl-D-erythritol 2,4-cyclodiphosphate in plants.

2C-methyl-D-erythritol 2,4-cyclodiphosphate was recently shown to be formed from 2C-methyl-D-erythritol 4-phosphate by the consecutive action of IspD, IspE, and IspF proteins in the nonmevalonate pathway of terpenoid biosynthesis. To complement previous work with radiolabelled precursors, we have now demonstrated that [U-13C5]2C-methyl-D-erythritol 4-phosphate affords [U-13C5]2C-methyl-D-erythritol 2,4-cyclodiphosphate in isolated chromoplasts of Capsicum annuum and Narcissus pseudonarcissus. Moreover, chromoplasts are shown to efficiently convert 2C-methyl-D-erythritol 4-phosphate as well as 2C-methyl-D-erythritol 2,4-cyclodiphosphate into the carotene precursor phytoene. The bulk of the kinetic data collected in competition experiments with radiolabeled substrates is consistent with the notion that the cyclodiphosphate is an obligatory intermediate in the nonmevalonate pathway to terpenes. Studies with [2,2'-13C2]2C-methyl-D-erythritol 2,4-cyclodiphosphate afforded phytoene characterized by pairs of jointly transferred 13C atoms in the positions 17/1, 18/5, 19/9, and 20/13 and, at a lower abundance, in positions 16/1, 4/5, 8/9, and 12/13. A detailed scheme is presented for correlating the observed partial scrambling of label with the known lack of fidelity of the isopentenyl diphosphate/dimethylethyl diphosphate isomerase.

Capsicum↗
PubMed1997

Identification of cheese-associated fungi using selected ion monitoring of volatile terpenes.

The cheese-associated fungi Penicillium commune, P. roqueforti, P.solitum, P. discolor and Aspergillus versicolor have been investigated for production of volatile terpenes for chemical identification, when grown on yeast extract agar. Volatiles were collected by headspace solid-phase microextraction. Selected ion monitoring of four to seven of the most characteristic ions of mainly sesquiterpenes made it possible to identify the fungi to species level within 2 d. In a mixed culture of P. roqueforti and P. commune, inoculated in a ratio of 1000:1, volatiles from both fungi could be detected within 3 d, making identification possible.

Aspergillus↗
PubMed2004

Anti-complement activity of norlignans and terpenes from the stem bark of Styrax japonica.

A new norlignan, styraxlignolide A (1), and two new terpenes, styraxosides A (2) and B (3), were isolated from the MeOH-soluble fraction of Styrax japonica Sieb. et Zucc. (Styracaceae) stem bark, together with two known compounds, egonol (4) and masutakeside I (5). The new compounds were determined as 5-(3''-hydroxypropyl)-7-methoxy-2-(3',4'-dimethoxyphenyl)-benzofuran 3''- O-[beta-D-xylopyranoside-(1-->6)-beta- D-glucopyranoside] (1), 3beta,7beta-dihydroxy-4alpha,4beta,8beta,10beta,14alpha-pentamethyl-5alpha-gon-16-en-2-one 3-O-[beta-D-glucopyranoside-(1-->2)-beta-D-glucopyranoside] (2), and 3beta,17beta-dihydroxy-28-norolean-12-en-16-one 3-O-[alpha-L-rhamopyranoside-(1-->2)-beta-D-glucuronopyranoside] (3) by spectroscopic means including 2D-NMR. The five compounds were tested in vitro for anti-complement activity against the complement system. Compounds 1, 3, 4, and 5 displayed inhibitory activity in the anti-complement assay, with IC50 values of 123, 65, 33, and 166 microM, respectively. Compound 1a and camellenodiol (3a), obtained from acid hydrolysis of 1 and 3, respectively, did not affect the hemolytic activity of human serum against sensitized erythrocytes. This shows that a sugar seems to play a role of enhancing significantly anti-complement activity.

Complement System Proteins↗
PubMed2002

Studies on the nonmevalonate terpene biosynthetic pathway: metabolic role of IspH (LytB) protein.

Isopentenyl diphosphate and dimethylallyl diphosphate serve as the universal precursors for the biosynthesis of terpenes. Although their biosynthesis by means of mevalonate has been studied in detail, a second biosynthetic pathway for their formation by means of 1-deoxy-D-xylulose 5-phosphate has been discovered only recently in plants and certain eubacteria. Earlier in vivo experiments with recombinant Escherichia coli strains showed that exogenous 1-deoxy-D-xylulose can be converted into 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate by the consecutive action of enzymes specified by the xylB and ispCDEFG genes. This article describes the transformation of exogenous [U-(13)C(5)]1-deoxy-D-xylulose into a 5:1 mixture of [U-(13)C(5)]isopentenyl diphosphate and [U-(13)C(5)]dimethylallyl diphosphate by an E. coli strain engineered for the expression of the ispH (lytB) gene in addition to recombinant xylB and ispCDEFG genes.

Bacterial Proteins↗