Showing papers on "Terpene published in 1999"
TL;DR: The minimum inhibitory concentrations (MIC) of 60 terpenoids against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Candida albicans have been determined.
Abstract: The minimum inhibitory concentrations (MIC) of 60 terpenoids against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Candida albicans have been determined. Hierarchical cluster analysis was used to group the compounds into five groups according to their activity patterns against the four microorganisms. K-Means cluster analysis was then used to confirm these groupings and to show the differences in the activity patterns of the groups. Ten molecular properties of the terpenoids, either calculated via molecular modelling or determined by direct measurement, were then used as variables in a forward stepwise discriminant analysis to identify which variables discriminated between groups. Low water solubility of Group IV compounds, mainly hydrocarbons and acetates, was found to be associated with their relative inactivity. The remaining groups, all containing oxygenated terpenoids, showed characteristic but distinct activity patterns towards the four test organisms. Hydrogen bonding parameters were found to be associated with antimicrobial activity in all cases. Activity against Gram-negative E. coli and P. aeruginosa was associated with a combination of a hydrogen bonding and size parameters. This was not found to be the case for the Gram-positive S. aureus or the yeast C. albicans. Copyright © 1999 John Wiley & Sons, Ltd.
465 citations
TL;DR: Chemical isolation of the terpene fraction resulted in the detection of ganoderic acids A, B, C and D, lucidenic acid B and ganodermanontriol as major ingredients.
Abstract: Ganoderma lucidum was studied for its antioxidative activity by bioassay guided isolation in conjunction with in vitro tests. The powdered crude drug was treated with boiling water and the aqueous extract (Ex1) was further separated to obtain terpene and polysaccharide fractions. The two fractions and Ex1 were screened for their antioxidative effect against pyrogallol induced erythrocyte membrane oxidation and Fe (II)-ascorbic acid induced lipid peroxidation. All tested samples showed antioxidative activities in a dose dependent manner and the terpene fraction was found to possess the highest effect compared with the others. Chemical isolation of the terpene fraction resulted in the detection of ganoderic acids A, B, C and D, lucidenic acid B and ganodermanontriol as major ingredients.
145 citations
TL;DR: In this paper, it was shown that some monoterpenes possess anticarcinogenic properties, acting at different cellular and molecular levels, and could be considered as effective, nontoxic dietary antitumorigenic agents that hold promise as a novel class of anticancer drugs.
Abstract: Monoterpenes are compounds found in the essential oils extracted from many plants, including fruits, vegetables, spices and herbs. These compounds contribute to the flavor and aroma of plant from which they are extracted. Monoterpenes are acyclic, monocyclic, or bicyclic C30 compounds synthesized by monoterpene synthases using geranyl pyrophosphate (GPP) as substrate. GPP is also the precursor in the synthesis of farnesyl pyrophosphate (FPP) and geranyl-geranyl pyrophosphate (GGPP), two important compounds in cell metabolism of animals, plants and yeast. Monoterpene cyclases produce cyclic monoterpenes through a multistep mechanism involving a universal intermediate, a terpinyl cation which can be transformed to several compounds. Experimental studies, using animal cancer models, have demonstrated that some monoterpenes possess anticarcinogenic properties, acting at different cellular and molecular levels. From these discoveries it seems clear that monoterpenes could be considered as effective, nontoxic dietary antitumorigenic agents that hold promise as a novel class of anticancer drugs.
104 citations
88 citations
TL;DR: A cDNA library was constructed from leaves of A. annua seedlings and target sequences were amplified by PCR using degenerate primers derived from a consensus sequence of angiosperm terpene synthases, and RT-PCR demonstrated a wound-inducible increase in QH1 and QH5 transcript abundance in both leaves and stems over a 3-day time course.
85 citations
TL;DR: A new natural product, 4-epifriedelin, and 12 known terpenoids have been isolated from the leaves of Syzygium formosanum, reported for the first time.
Abstract: A new natural product, 4-epifriedelin (1), and 12 known terpenoids have been isolated from the leaves of Syzygium formosanum. The known compounds include caryophyllene oxide, friedelin, canophyllal, glutinol, alpha-terpineol, phytol, betulinic acid, uvaol, lupeol, betulin, ursolic acid, and oleanolic acid. All of these compounds are reported for the first time from S. formosanum.
48 citations
TL;DR: More than 100 volatile compounds have been identified in the headspace of frankfurter sausages; most abundant were the terpene hydrocarbons, monoterpene alcohols, phenyl propanoids, and phenols.
Abstract: More than 100 volatile compounds have been identified in the headspace of frankfurter sausages. Most abundant were the terpene hydrocarbons, monoterpene alcohols, phenyl propanoids, and phenols. Separate analyses of solutions of spices and smoke demonstrated that most of the terpenes were derived from the spices, whereas the phenols originated mostly from the smoke ingredients. Many of the compounds contributing to the overall odor of the frankfurters have been identified. Some odors, characteristic of the smokiness and spiciness of frankfurters, were caused by phenols and terpenes, whereas others were due to compounds derived from the meat fraction; these compounds included aldehydes, ketones, furanthiols, and alicyclic sulfur compounds.
44 citations
TL;DR: In this paper, the alisols H, 1, J-23-acetate, K-23 -acetate and N-23acetate were isolated from Alismatis rhizoma, the rhizome of Alisma orientale JUZEP.
Abstract: New protostane-type triterpenes termed alisols H, 1, J-23-acetate, K-23-acetate, L-23-acetate, M-23-acetate, and N-23-acetate were isolated from Alismatis Rhizoma, the rhizome of Alisma orientale JUZEP. Their stereostructures were determined on the basis of physicochemical evidence.
29 citations
TL;DR: Parents and hybrid populations of big sagebrush in Salt Creek Canyon, Utah, show clinal variation in terpene composition across a hybrid zone, and several terpenes produced by both parental taxa were not produced by hybrids.
26 citations
TL;DR: Attempts to obtain rapid growing roots or even hairy-roots did not succeed but the possibility to transform Ginkgo cell strains has been demonstrated.
Abstract: The accumulation of the terpenes ginkgolides and bilobalide in Ginkgo biloba was reported in plants as well as in plant cell cultures. Several hundred plants cultivated under controlled conditions in the field have been analyzed for their terpene production over many years. Cross-pollination experiments were performed with mature trees and the terpene content of the progeny was analyzed. The age of the tree is the main factor influencing the terpene content of the leaves as the level always decreases dramatically between young and old trees. 80 cell culture strains have been established and ginkgolides analyzed by GC/MS. These cell cultures reveal very low amounts of terpenes (1 microgram g-1 D.W. or less). On the contrary, isolated in vitro root cultures accumulate terpenes at the same concentration as the young plant leaves (4 mg g-1 D.W.). Attempts to obtain rapid growing roots or even hairy-roots did not succeed but the possibility to transform Ginkgo cell strains has been demonstrated.
24 citations
TL;DR: Two novel sesterpenes, bilosespens A and B were isolated from the Red Sea sponge Dysidea cinerea collected in the Dahlak archipelago, Eritrea, and the structure of the mixture was established by spectroscopic analysis.
TL;DR: In this paper, reversed phase liquid chromatography was used to demonstrate that some terpenes can form inclusion complexes with β-cyclodextrin, and the stability of these complexes was studied for aromatic, aliphatic, or acyclic terpene derivatives with various mobile phases.
Abstract: Terpene compounds include a wide variety of molecules with very different structures and physico-chemical properties. Monoterpenes are of interest because of their volatility and aromatic properties. Inclusion complexation of these molecules with cyclodextrins will lead to chemical and volatility protection and to a possible controlled release. In this study, reversed phase liquid chromatography was used to demonstrate that some terpenes can form inclusion complexes with β-cyclodextrin. The stability of these complexes was studied for aromatic, aliphatic, or acyclic terpenes with various mobile phases. It is confirmed that mobile phase composition plays a major role in the complex stability. Moreover, in terms of separation, it was observed that mobile phase characteristics could modify inclusion selectivity, with retention inversions for some terpene derivatives when β-cyclodextrin was added to the mobile phase. It was also demonstrated that “rough” molecular modelling can qualitatively predict stoichiom...
TL;DR: In this article, the seasonal change of volatile components in Citrus sudachi was monitored by headspace gas-chromatographic analyses, and the authors determined that these increase and decrease of odor active terpenes during maturation are determined to contribute to the change of the characteristic aroma and the generation of sudachichi-like aroma.
Abstract: Seasonal change of volatile components in Citrus sudachi was monitored by headspace gas-chromatographic analyses. The limonene content increased sharply from 50.87% (unripe sudachi) to 87.23% (over-ripe sudachi) in accordance with maturation of the fruit, while α-thujene, sabinene, α-phellandrene, β-ocimene and γ-terpinene decreased. Linalool decreased particularly sharply during maturation from 5.20% to 0.55%. Other oxygenated compounds such as cis- and trans-limonen-1,2-oxide, citronellal, decanal, terpinen-4-ol and carvone were not detected in unripe sudachi but appeared in the volatiles during the ripening progress. These oxygenated terpenes had larger log Uo values (>1). Furthermore, as limonene, α-pinene, decanal, citronellal, linalool are the characteristic odor chemicals in sudachi, these increase and decrease of odor active terpenes during maturation are determined to contribute to the change of the characteristic aroma and the generation of sudachi-like aroma.
01 Jan 1999
TL;DR: The chemical study of Baccharis calliprinos Griseb.
Abstract: The chemical study of Baccharis calliprinos Griseb. yielded 2a,3a-dihydroxycativic acid (1) together with the flavonoids luteolin-7,3'-dimethylether (II), homoeriodictyol (110 and eriodictyol-3',4'dimethylether (IV). On the other hand, from the aerial parts of B. rhetinodes Meyen & Walp bacchotricuneatin A (V), oleanolic acid (VI) and the flavone (11) were isolated. The three isolated flavonoids were subjected to the antiinflammatory test using the carrageenan-induced mouse paw edema test. RESUMEN. "Flavonas y Terpenos Bioactivos a partir de Baccharis calliprinos y B. rhetinodes (Asteraceae)". El estudio fitoquímico de Baccharis calliprinos Griseb. permitió el aislamiento del ácido 2a,3a-dihidroxicativico (1) y de los flavonoides luteolina-7,3'-dimetiléter (11); homoenodictyol (m) y eriodictyol-3',4'-dimetiléter (IV). Por otra parte, de las partes aéreas de B. rhetinodes Meyen & Walp fueron aislados bacchotricuneatina A (V), ácido oleanólico (VI) y la flavona (II). Los tres flavonoides informados, fueron sometidos al bioensayo de actividad antiinflamatoria utilizando el método del edema inducido por carragenina en pata de ratón.
TL;DR: The present study deals with the microbial oxidation of a bicyclic monoterpene hydrocarbon, a-pinene, by the yeast Candida tropicalis MTCC 230 to (+)a terpineol, a .potent flavor compound (Scheme I), which was characteriied by TLC, FTIR, I H NMR, Uc NMR and GC-MS spectroscopy.
Patent•
05 Feb 1999
TL;DR: In this paper, a process for producing unsaturated cyclic compounds, comprising the steps of hydrochlorinating a terpene to produce a hydrochlorinated terpenes, and subjecting the hydrochlorinate terpeni to elimination of hydrogen chloride, is described.
Abstract: A process for producing an unsaturated cyclic compound, comprising the steps of hydrochlorinating a terpene to produce a hydrochlorinated terpene, and subjecting the hydrochlorinate terpene to elimination of hydrogen chloride to form an unsaturated cyclic compound. The terpene is preferably α-pinene, β-pinene, camphene or suitable turpentine fraction. The cyclic compounds can be used as monomers and by means of the invention it is thus possible to produce plastics from renewable raw material sources.
TL;DR: A hexane extract of the fruits of Dysoxylum cauliflorum Hiern. (Meliaceae) has afforded a triterpenoid with a novel abeo -dammarane carbon skeleton as mentioned in this paper.
Abstract: A hexane extract of the fruits of Dysoxylum cauliflorum Hiern. (Meliaceae) has afforded a triterpenoid with a novel abeo -dammarane carbon skeleton. Extensive NMR studies ( 1 H, 13 C, HMQC, HMBC, difference NOE) enabled its identification as 23(24→25) abeo -20 R ,24-dihydroxydammaran-3-one.
TL;DR: In this paper, a new and efficient strategy was described for carrying out the enantiospecific synthesis of monocarbocyclic terpenoids from (−)-sclareol.
Abstract: A new and efficient strategy is described for carrying out the enantiospecific synthesis of monocarbocyclic terpenoids from (−)-sclareol ( 1 ). The key steps are the Grob scission of 11- p -toluenesulphonyloxydriman-7α-ol ( 2 ) to give the tobacco seco-sesquiterpene 3 and the Baeyer-Villiger oxidation of 4-[( 1′S, 2′S )-2′-formyl-2′,6′,6′-trimethylcyclohexyl]-2-butanone ( 4 ), derived from 3 . The first enantiospecific synthesis of (−)-caparrapi oxide ( 8 ) based on this methodology is reported.
TL;DR: The first total synthesis of the title compound has been accomplished using an intramolecular Diels-Alder reaction of a masked o-benzoquinone, anionic [1, 3]-rearrangement of a vinylbicyclo[2.2]octenol and intramerolecular hetero-Michael addition of a hydroxy enone as the key steps as discussed by the authors.
Abstract: The first total synthesis of the title compound has been accomplished using an intramolecular Diels–Alder reaction of a masked o-benzoquinone, anionic [1,3]-rearrangement of a vinylbicyclo[2.2.2]octenol and intramolecular hetero-Michael addition of a hydroxy enone as the key steps.
Journal Article•