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PubMed1979

Decreased pentobarbital sleeptime following a single intraperitoneal injection of cedar-derived sesquiterpenes.

Within one day after a single IP injection of cedar sesquiterpenes into mice, pentobarbital sleeptime was reduced by 40%. The estimated ED50 is 50 mg terpenes/kg body weight. The mice recovered from this terpene-induced reduction in the strength of hypnosis within 6 days after the terpene injection. The potency of the terpenes, the rapidity of their action, and the duration of their effectiveness in modulating a drug response suggest their usefulness as a pharmacological tool.

Animals↗
PubMed2025

A multifunctional sesquiterpene synthase integrates with cytochrome P450s to reinforce the terpenoid defense network in maize.

Terpenoids, the largest and most structurally diverse class of plant natural products, play essential roles in maize defense and ecological interactions. In this study, we identified and functionally characterized a sesquiterpenoid-based defense pathway in maize centered on α-santalenoic acid, a pathogen-inducible sesquiterpenoid antibiotic. Using a combination of metabolite-based genome-wide association studies (mGWAS), linkage mapping, and heterologous expression assays, we identified ZmTPS9 as a multiproduct terpene synthase that primarily produces α-santalene and β-bisabolene. Sequence analysis and site-directed mutagenesis revealed that threonine at position 413 is critical for enzyme activity, with its deletion resulting in a complete loss of enzyme activity. The sesquiterpene hydrocarbons produced by ZmTPS9 are further oxidized by three cytochrome P450 monooxygenases, ZmCYP71Z16, ZmCYP71Z18, and ZmCYP71Z19, to yield antimicrobial metabolites including α-santalenoic acid, zealexin D1 (ZD1), and zealexin D2 (ZD2). Together, these findings demonstrate a convergent biosynthetic strategy in maize, where multiproduct terpene synthases and promiscuous P450s collaboratively generate a flexible and robust terpenoid defense network.

Zea mays↗
PubMed1965

BIOCHEMICAL POLYMORPHISM IN ANTS.

Ants of different sexes and castes produce different odorous compounds. In Pheidole fallax Mayr, soldier ants produce an indole base, probably skatole, whereas minor workers produce a trial substance, Males of certain species of Lasius and Acanthomyops produce mixtures of terpenes and an indole base. These mixtures are discharged during mating pheromones. The terpene mixtures are qualitatively similar, but each species produces a blend of distinctive proportions. Citronellol and 2,6-dimethyl-5-hepten-1-ol have been identified in the mixtures by gas chromatography and mass spectrometry.

Animals↗
PubMed1985

Microbial transformations of some monoterpenoids and sesquiterpenoids.

The absolute configurations of fragrances, flavours and drugs are often important for their special properties. The growing interest of organic chemists in chiral synthons has stimulated work on biotransformations, for which readily available and inexpensive compounds can be used as substrates. Microbial transformations of 1-menthenes like gamma-terpinene, alpha-terpinene, limonene and alpha-phellandrene give the corresponding 1,2-trans-diols with high stereospecificity. Because of the volatility and toxicity of these substrates, and their low solubility in aqueous solutions, a special fermentation technique has been developed in which the terpenes are fed continuously to extended cultures of Corynespora cassiicola or Diplodia gossypina. (4R)-Limonene is transformed by Gibberella cyanea to (1S,2S,4R)-p-menth-8-en-1,2-diol, but 3,3,5,5-tetramethyl-limonene yields a 6-monohydroxylated product and a 6,10-dihydroxylated product with a 6-hydroxy-8,10-epoxy structure as the main metabolite. Vicinal diols are also formed from aliphatic terpenes, by reaction at the terminal isoprenoid groups. Some oxirane structures are found as intermediates. Acyclic sesquiterpenes often form complex mixtures when they are metabolized further. The products of the transformation of trans-nerolidol by several fungi are given as examples. Cyclic sesquiterpenes, with less flexible structures, are oxidized more specifically. Whereas longifolene is a very poor substrate for Corynespora cassiicola, isolongifolene is always hydroxylated at one of the methyl groups attached to C-7. The 14- or 15-hydroxy compounds are further oxidized, very fast, in the 3 position or 4 position.

Bacteria↗
PubMed1995

Modulation of membrane fluidity and lipidic metabolism in transformed rat fibroblasts induced by the sesquiterpenic hormone farnesylacetone.

Farnesylacetone is a natural terpene extracted from androgenic glands of the crustacean Carcinus maenas and is capable of inhibiting proliferation, notably in transformed mammalian cells. Flow cytometry with three lipophilic probes, diphenylhexatriene, trimethylammonium-diphenylhexatriene, and Nile red, has revealed modifications of the lipidic metabolism in transformed FR3T3-mTT4 rat fibroblasts treated by farnesylacetone, including changes in membrane fluidity. Farnesylacetone strongly increased the number of neutral lipidic droplets in the cytoplasm. Moreover, after prolonged terpene treatment, the membrane fraction of cells contained a substantial level of triglycerides. Farnesylacetone provoked an immediate but transitory increase in membrane fluidity of the cell membrane. The change in measured lipid fluidity appears to be due to these triglycerides rather than to the phospholipids.

Animals↗
PubMed1988

Structure-activity relationship of 1-alkyl- or 1-alkenylazacycloalkanone derivatives as percutaneous penetration enhancers.

Nine azacycloalkanone (5-, 6-, or 7-member ring) derivatives with an alkyl or alkenyl (terpene) chain (10, 15, or 20 carbons) were compared with 1-dodecylazacycloheptan-2-one (azone, 1) for their effects on the percutaneous penetration of 6-mercaptopurine (6-MP) through excised guinea pig skin. Pretreatment of skin with an enhancer markedly increased penetration and skin accumulation of 6-MP. Superior enhancing effects were observed for enhancers having a terpene chain of 10 carbons and an azacyclo ring with one carbonyl group. Enhancers with a C20 tail chain were less effective. Enhancer ring size had little effect on enhancing activity, whereas the increase in the number of carbonyl groups in the ring caused a decrease. Computer fitting of a penetration profile to Fick's diffusion equation gave two parameters corresponding to diffusion and partitioning of 6-MP. The diffusion parameter was little affected by pretreatment with an enhancer, whereas the partition parameter was markedly increased. This suggests that enhancement is determined by the ability to increase the drug partitioning into the skin and to enlarge the drug concentration gradient in the skin barrier. The primary skin irritation was examined with rabbit dorsal skin in vivo. The enhancers with an alkyl chain induced severer primary irritation (erythema and edema) than those with an alkenyl chain. From the balance between enhancing and irritating activities, it is concluded that 1-geranylazacycloheptan-2-one, 1-farnesylazacycloheptan-2-one and 1-farnesylazacyclopentan-2-one are favorable enhancers.

Animals↗
PubMed1997

Cardioprotective and anti-oxidant effects of the terpenoid constituents of Ginkgo biloba extract (EGb 761).

Hemodynamic and electron spin resonance analyses were used to assess the in vivo and in vitro cardioprotective and antioxidant effects of therapeutically relevant doses of Ginkgo biloba extract (EGb 761) and its terpenoid constituents (ginkgolides A and B, bilobalide) in the rat. Significant anti-ischemic effects, indicating improved myocardial functional recovery, were observed after repeated (15-day) oral treatments with both EGb 761 (60 mg/kg/day) and ginkgolide A (4 mg/kg/day), as compared to placebo. In vitro pre- and post-ischemic perfusion of hearts in the presence of the ginkgolides A and B (both at 0.05 microgram/ml) or bilobalide (0.15 microgram/ml), but not EGb 761 (5 micrograms/ml), significantly improved all hemodynamic parameters. Post-ischemic levels of the 5,5-dimethyl-1-pyrroline N-oxide (DMPO)/hydroxyl radical spin-adduct (DMPO-OH) in coronary effluents were significantly decreased after in vivo oral treatments or after in vitro perfusion with EGb 761 or the terpenes, the most effective compound being ginkgolide A. As the presence of the terpenes did not influence the formation of the superoxide/DMPO adduct or DMPO-OH in acellular tests with superoxide and hydroxyl radical generators, their cardioprotective effects appear to involve an inhibition of free radical formation rather than direct free radical scavenging.

Animals↗
PubMed2006

Marine mollusks from Australia and New Zealand: chemical and ecological studies.

Marine mollusks contain structurally diverse terpenes, polyketides, polypropionates and nitrogenous metabolites that may confer an ecological advantage on the host organism. From a chemical perspective, the most studied Australian taxa include representatives of the nudibranchs and sea hares, which are characterised by terpenes acquired from their specialised diets of sponges and algae, respectively. In contrast, siphonariid limpets that are prevalent on temperate seashores carry out de novo biosynthesis of polypropionate metabolites. Nitrogenous compounds isolated from Australian marine mollusks include precursors to the first commercially significant marine bioproduct, Tyrian Purple, and metabolites that are characteristic of ingested cyanobacteria.

Animals↗
PubMed1990

Catabolism of geraniol by cell suspension cultures of Citrus limon.

The addition of geraniol to cell suspension cultures of Citrus limon resulted in the rapid formation of nerol, citronellol, geranic acid and citronellic acid. Concurrently, a transient accumulation of bound forms of branched chain fatty acids, and, with a few hours delay, of regular chain C2 to C12 fatty acids was elicited. A concerted action of combined alpha/beta-oxidation enzymes on the terpenic acids, followed by an enlarged acetyl CoA pool is suggested. Terpene catabolism in plants and in vitro plant cells is discussed.

Acyclic Monoterpenes↗
PubMed2004

Characterization of three agave species by gas chromatography and solid-phase microextraction-gas chromatography-mass spectrometry.

Steam distillation (SD) extraction-solid-phase microextraction coupled to GC-MS was developed for the determination of terpenes and Bligh-Dyer extraction-derivatization coupled with GC for the determination of fatty acids such as ethyl esters were used. It was found that the three different Agave species have the same profile of fatty acids; the quantity of these compounds is different in each Agave variety. On the other hand, different terpenes were identified in the three Agave plants studied: nine in A. salmiana, eight in A. angustifolia and 32 in A. tequilana Weber var. azul.

Agave↗
PubMed2006

Long-term exposure to enhanced UV-B radiation has no significant effects on growth or secondary compounds of outdoor-grown Scots pine and Norway spruce seedlings.

The effects of long-term enhanced UV-B radiation on growth and secondary compounds of two conifer species were studied in an outdoor experiment. Scots pine (Pinus sylvestris) seedlings were exposed for two growing seasons and Norway spruce (Picea abies) seedlings for three growing seasons to supplemental UV-B radiation, corresponding to a 30% increase in ambient UV-B radiation. The experiment also included appropriate controls for ambient and increased UV-A radiation. Enhanced UV-B did not affect the growth of the conifer seedlings. In addition, neither the concentrations of terpenes and phenolics in the needles nor the concentrations of terpenes in the wood were affected. However, in the UV-A control treatment the concentrations of diterpenes in the wood of Scots pine decreased significantly compared to the ambient control. Apparently, a small increase in UV-B radiation has no significant effects on the secondary compounds and growth of Scots pine and Norway spruce seedlings.

Environmental Monitoring↗
PubMed2005

Structural characterization of phytotoxic terpenoids from Cestrum parqui.

Isolation, chemical characterization and phytotoxicity of nine polyhydroxylated terpenes (five C13nor-isoprenoids, two sesquiterpenes, a spirostane and a pseudosapogenin) from Cestrum parqui L'Herr are reported. In this work we completed the phytochemical investigation of the terpenic fraction of the plant and described the structural elucidation of polar isoprenoids using NMR methods. All the configurations of the compounds have been assigned by NOESY experiments. Four new structures have been identified as (3S,5R,6R,7E,9R)-5,6,9-trihydroxy-3-isopropyloxy-7-megastigmene, 5alpha-spirostan-3beta,12beta,15alpha-triol, and 26-O-(3'-isopentanoyl)-beta-d-glucopyranosyl-5alpha-furost-20(22)-ene-3beta,26-diol, and as an unusual tricyclic sesquiterpene. The compounds have been assayed for their phytotoxicity on lettuce at the concentrations ranging between 10(-4) and 10(-7)M. The activities of some compounds were similar to that of the herbicide pendimethalin.

Cestrum↗
PubMed2006

5-O-glucosyldihydroflavones from the leaves of Helicia cochinchinensis.

From the leaves of Helicia cochinchinensis, collected on Okinawa Island, seven phenolic glucosides and two terpenic glucosides were isolated. Five of the phenolic glucosides were previously known, being identified with p-coumaric and ferulic acids glucosyl esters, rhodioloside, helicidiol, and naringenin 5-O-beta-D-glucopyranoside. The structures of two other phenolic glucosides, named heliciosides A and B, were elucidated to be 5-O-beta-D-glucosides of 3-hydroxyflavanone, namely aromadendrin and taxifolin, by means of spectroscopic analyses. The two terpenic glucosides were identified with ampelopsisionoside and icariside C1.

Fatty Alcohols↗
PubMed2005

The effect on human eye blink frequency of exposure to limonene oxidation products and methacrolein.

Oxidation products of terpenes (e.g. limonene) contain unidentified irritants, which may be responsible for a fraction of the reported eye and airway complaints in indoor environments. Here we report exposure to parts per billion (ppb) levels of limonene oxidation products (LOPs) and the terpene oxidation product methacrolein using blink frequency (BF) as a measure of trigeminal stimulation of the human eye. Ten male subjects averaging 43 (standard deviation 10.5) years were exposed for 20 min to LOPs, methacrolein, and clean air, respectively. A baseline BF was measured prior to and following each exposure (8 min and 4 min, respectively). The subjects were exposed locally in the non-dominant eye and single blind at 20% relative humidity (RH), while viewing an educational film. Blinking was video recorded and evaluated for full sessions of 36 min. Mean BF increased significantly during exposure to LOPs and methacrolein compared to the baseline of clean air, and the findings coincided with weak eye irritation symptoms. Lowest observed effect levels were 286 ppb methacrolein and a 10-min-old LOPs mixture of initially 92 ppb limonene and 101 ppb ozone (O3), which increased the BF comparably by 18% (p=0.001) and 17% (p=0.003), respectively. The increase in BF was smaller, although not significantly different, during exposure to LOPs at 50% RH to 20% RH in mixtures prepared from ca. 350 ppb limonene and 300 ppb O3. LOPs may cause trigeminal stimulation and possibly eye irritation at O3 and limonene concentrations, which are close to high-end values measured in indoor settings. The effects may be exacerbated by low RH.

Acrolein↗
PubMed2001

Techniques for gas chromatography of volatile terpenoids from a range of matrices.

The commercial importance of the volatile mono- and sesqui-terpenoids has resulted in a wide range of techiques being used for extraction, concentration, chromatography, and characterisation of constituents. The major chromatographic technique is gas chromatography, and tandem techniques of chromatography linked to further chromatography and spectroscopy, allow much increased resolution, and greater ease of characterisation of terpenes. A wide range of extraction techniques are discussed, and suitability for particular matrices and sample sizes outlined. Chromatography operating conditions and stationary phases, and techniques for solute identification are laid out. A number of applications of terpene analysis in many different matrices are discussed.

Chromatography, Gas↗
PubMed2000

Monoterpenes in grape juice and wines.

The importance of monoterpenes on varietal flavour of wines has been reviewed. These compounds were mainly found linked to sugar moieties in the grape juice and wines, showing no olfactive characteristics. In this way, mechanisms to liberate terpenes were studied, making a comparative study between acidic and enzymic hydrolysis of terpene glycosides. Finally, analytical techniques developed to study these compounds, in both free or glycosidically forms, and also to fractionate glycosidic precursors, have been discussed.

Beverages↗
PubMed2000

Antioxidative activity of natural products from plants.

A variety of flavonoids, lignans, an alkaloid, a bisbenzyl, coumarins and terpenes isolated from Chinese herbs was tested for antioxidant activity as reflected in the ability to inhibit lipid peroxidation in rat brain and kidney homogenates and rat erythrocyte hemolysis. The pro-oxidant activities of the aforementioned compounds were assessed by their effects on bleomycin-induced DNA damage. The flavonoids baicalin and luteolin-7-glucuronide-6'-methyl ester, the lignan 4'-demethyldeoxypodophyllotoxin, the alkaloid tetrahydropalmatine, the bisbenzyl erianin and the coumarin xanthotoxol exhibited potent antioxidative activity in both lipid peroxidation and hemolysis assays. The flavonoid rutin and the terpene tanshinone I manifested potent antioxidative activity in the lipid peroxidation assay but no inhibitory activity in the hemolysis assay. The lignan deoxypodophyllotoxin, the flavonoid naringin and the coumarins columbianetin, bergapten and angelicin slightly inhibited lipid peroxidation in brain and kidney homogenates. It is worth stressing that the compounds with antioxidant effects in this assay, with the exception of tetrahydropalmatin and tanshinone I, have at least one free aromatic hydroxyl group in structure. Obviously, the aromatic hydroxyl group is very important for antioxidative effects of the compounds. None of the compounds tested exerted an obvious pro-oxidant effect.

Animals↗
PubMed2003

Volatile constituents of Aristolochia argentina.

The essential oils from leaves, aerial stems and underground organs of Aristolochia argentina Gris., a medicinal plant popularly known as "charrúa", were obtained by hydrodistillation and analyzed by GC and GC/MS. Forty-three components were identified in the oils. All parts of the plant afforded volatile oils characterized by high levels of argentilactone (57-89%) and the presence of undecatriene isomers (0.3-4.0%), these latter compounds providing the essential oils and extracts with an intense particular odor. Terpenes account for the remaining portion of the essential oils (5-29%). Bicyclogermacrene predominates in the aerial parts of the plant, whereas ishwarane is the main terpene of the subterranean organs. Argentilactone, a suspected carcinogenic compound, was also identified in a medicinal commercial tincture of A. argentina.

Alkenes↗