Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LACTONES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
PubMed1990

Formation of acids, lactones and esters through the Maillard reaction.

From a glucose/glycine reaction mixture acids, esters and lactones were isolated and identified. Sugar degradation products could also be determined as benzimidazole derivatives after reaction with o-phenylenediamine. Results derived from model systems suggested possible reaction pathways leading to some of the isolated substances. A lactic acid ester is formed as a product of an unstable beta-pyranone intermediate. A 3-deoxyhexosone serves as a precursor of two furanolactones.

Acids↗
PubMed1981

Role of lactone ring of aflatoxin B1 in toxicity and mutagenicity.

Cleavage of the lactone ring of aflatoxin B1 results in a nonfluorescent compound that has greatly reduced biological activity. Mutagenicity, as measured by the Ames test, is reduced 450-fold compared to that of B1, and toxicity, as measured by the chick embryo test, is reduced 18-fold.

Aflatoxin B1↗
PubMed1985

[Quinic acid lactone in coffee].

Quinic acid and its lactone (quinide) have been determined in coffee by capillary gas chromatography. No quinide could be detected in 14 green coffee's. After steaming of 4 green coffee's the content of quinic acid was always higher, but no quinide had been formed. During roasting, the latter can be detected when roasting loss exceed 6.5%. It increases approximately proportionally with quinic acid and amounts to 50% of the latter at 22% roasting loss. Both constituents decrease at unusual high roasting loss. In 13 commercial blends of roast coffee 2.4-6.4 g/kg quinide and 8.7-16.6 g/kg quinic acid were present. Especially high values were found in one Espresso type blend and high values in steamed and decaffeinated coffee's. In 11 commercial coffee extracts 2.0-23.2 g/kg quinide and 24.6-36.4 g/kg quinic acid were determined. At higher extraction yield, more quinic acid and quinide is formed, but at very high extraction yield the content of quinide is diminished. During holding of coffee brews at elevated temperature, quinide is slowly hydrolysed.

Chromatography, Gas↗
PubMed1996

Inhibition by hydroxyachillin, sesquiterpene lactone from Tanacetum microphyllum, of PMA-induced mouse ear oedema.

4-beta-phorbol 12-myristate 13-acetate (PMA), when administered topically to mouse ear, induces a pronounced inflammatory response mediated by protein kinase C (PKC). Activation of PKC is implicated in the pathogenesis of inflammation, with phospholipase A2-dependent arachidonic acid release and eicosanoid production. We have investigated the effects of hydroxyachillin, a sesquiterpene lactone from Tanacetum microphyllum DC., on mouse ear oedema induced by PMA. The effects of this compound on swelling and other inflammatory parameters are described. Hydroxyachillin significantly (p < or = 0.01) inhibited ear swelling in a dose-dependent manner, and was as effective as the reference drugs. The PMA-induced vascular permeability was significantly (p < or = 0.05) reduced by hydroxyachillin at the highest dose (3 mg/ear). Histologically, the signs of inflammation were greatly reduced in the hydroxyachillin-treated ear lesions. These data suggest that hydroxyachillin is an effective anti-inflammatory agent in this model, and that the inhibition of PKC may be one of the mechanisms of hydroxyachillin's effect.

Administration, Topical↗
PubMed2000

Effect of coriaria lactone on membrane potential of hippocampal neurons in rats.

Intracellular recording method of electrophysiology was used to study the effect of microinjection of coriaria lactone (CL) into hippocampus on membrane potential of hippocampal neurons in rats. The membrane potential in 34 neurons of 12 rats were recorded. The results showed that CL induced depolarization of all of 34 neurons examined. Among the 34 neurons, 15 had paroxysmal depolarization accompanied by spike discharge in cluster and spike discharge in cluster ceased when membrane was hyperpolarized, 7 showed continuous depolarization accompanied by continuous spike discharge and 12 had only depolarizing response. The results suggest that injection of CL into hippocampus may lead to an increase of excitability of local neurons accompanied by different patterns of epileptioform discharge.

Animals↗
PubMed2000

The effect of coriaria lactone on NMDA receptor mediated currents in rat hippocampal CA1 neurons.

To investigate the exact mechanism of epileptogenesis induced by coriaria lactone (CL), the effect of CL on NMDA receptor mediated current (IAsp) in rat hippocampal CA1 neurons was investigated by using nystatin perforated whole-cell patch clamp. 10(-6)-10(-4) mol/L Asp acted on NMDA receptors and elicited an inward current (IAsp) at a holding potential (VH) of -40 mV in presence of 10(-6) mol/L glycine and absence of Mg2+ extracellularly. CL enhanced NMDA receptor mediated current induced by Asp, but had no effect on threshold concentration, EC50, Hill coefficient as well as maximal-effect concentration and reversal potential of IAsp. The effect had no relationship with holding potential. These results showed that CL could enhance NMDA receptor mediated current to increase [Ca2+]i of neurons by acting on Gly site, thereby inducing epilepsy.

Animals↗
PubMed2006

Effect of coriaria lactone-activated astrocyte-conditioned medium on the cerebral TNF-alpha of normal rats.

To explore the effect of coriaria lactone (CL)-activated astrocyte-conditioned medium on the cerebral TNF-alpha of normal rats, the CL-activated astrocyte-conditioned medium (ACM) was injected into the lateral ventricle of SD rats. The rats were observed for behavioral changes, and the changes of the expression of TNF-alpha in the cerebral cortex and hippocampus were immunohistochemically examined by employing SP method. TNF-alpha level was assessed by means of radioimmunoassay in homogenate of cerebral cortex and hippocampus as well as cerebrospinal fluid. Seizure episodes were observed in ACM group 30 min after the ACM injection, but they were not observed in the control group. Immunohistochemical detection showed that the immunoreaction of TNF-alpha in hippocampus and cerebral cortex of rats were stronger than that of the control group 4 h after the ACM injection (P<0. 05). In this group, the concentrations of TNF-alpha in homogenate of cerebral cortex and hippocampus and cerebrospinal fluid were higher than those of the control group (P<0.05). It is suggested that the ACM activated by CL can enhance the expression of TNF-alpha in normal rats, and is related to epileptogenesis.

Animals↗
PubMed2006

Cytotoxic and ACAT-inhibitory sesquiterpene lactones from the root of Ixeris dentata forma albiflora.

Ixeris dentata forma albiflora was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and H2O. Eight sesquiterpenes were isolated through repeated silica gel and octadecyl silica gel (C18, ODS) column chromatography of the EtOAc and n-BuOH fractions. Physicochemical analysis using NMR, MS and IR revealed the chemical structures of the sesquiterpenes, which were zaluzanin (1), 9a-hydroxyguaian-4(15),10(14),11(13)-triene-6,12-olide (2), 3beta-O-beta-D-glucopyranosyl-8beta-hydroxyguaian-4(15),10(14)-diene-6,12-olide (3), 3-O-beta-D-glucopyranosyl-8beta-hydroxyguauan-10(14)-ene-6,12-olide (4), ixerin M (5), glucozaluzanin C (6), crepiside I (7), and ixerin D (8). This is the first time that these sesquiterpene lactones have been isolated from this plant. Compounds 1, 2 and 7 revealed relatively high cytotoxicities on human colon carcinoma cell and lung adenocarcinoma cell, while compounds 5 and 7 showed acyl-CoA: cholesterol acyltransferase (ACAT) inhibitory activity.

Adenocarcinoma↗
PubMed2005

Cytotoxic sesquiterpene lactones from Saussurea calcicola.

Seven sesquiterpene lactones were isolated by the chromatographic separation of the MeOH extract of the aerial parts of Saussurea calcicola (Compositae). Their structures were determined spectroscopically to be cynaropicrin (1), arguerin B (2), cebellin F (3), 8alpha-hydroxy-11alpha, 13-dihydrozaluzanin C (4), desacylcynaropicrin (5), 3beta-hydroxy-8alpha-epoxymethylacriloiloxy-4(15),10(14),11(13)-trien-guaian-6,12-olide (6), and kandavanolide (7). Compounds 1 and 2 showed significant cytotoxicity against five cultured human tumor cell lines with ED50 values ranging from 0.23-1.72 microg/mL.

Asteraceae↗
PubMed2004

A new sesquiterpene lactone from Artemisia rubripes nakai.

The chromatographic separation of a methylene chloride extract of Artemisia rubripes led to the isolation of a new sesquiterpene lactone (3), together with four known compounds, a coumarin (2) and three terpenes (1, 4, and 5). Their structures were characterized to be 1beta,6alpha-dihydroxy-4(15)-eudesmene (1), scopoletin (2), 1alpha,4beta-dihydroxy-8alpha-acetoxy-guaia-2,10(14), 11(13)-triene-6,12-olide (3), 1alpha,4beta-dihydroxy-8alpha-acetoxy-guaia-2,9,11(13)-triene-6,12-olide (4), and beta-sitosterol-3-O-beta-D-glycoside (5) by spectroscopic means.

Artemisia↗
PubMed2002

2,3-dibenzylbutyrolactones and 1,2,3,4-tetrahydro-2-naphthoic acid gamma-lactones: structure and activity relationship in cytotoxic activity.

Dibenzyl-g-butyrolactone and 1,2,3,4-tetrahydro-2-naphthoic acid gamma-lactone (TNL) derivatives were synthesized and evaluated for cytotoxic activity against some cancer cell lines. It was found that TNL derivatives with a shorter distance between C-4 in ring A and C'-2 in ring C were more cytotoxic, while dibenzyl-gamma-butyrolactones with a longer one were nearly inactive. In TNL series, presence of 3,4-dioxy group in ring A and 2-methoxy group in ring C was essential for the enhancement of the activity.

Antineoplastic Agents↗
PubMed2003

Cytotoxic effects of sesquiterpene lactones from the flowers of Hemisteptia lyrata B.

Four guaia-12,6-olide type sesquiterpene lactones, aguerin B (1), 8alpha-acetoxyzaluzanin C (2), cynaropicrin (3), and deacylcynaropicrin (4), were isolated from the flowers of Hemisteptia lyrata Bunge. It is the first report on the isolation of compounds 1-4 from Hemisteptia species. All the isolates (1-4) were examined for their cytotoxic activity against SK-OV-3, LOX-IMVI, A549, MCF-7, PC-3, and HCT-15 human cancer cell lines.

Antineoplastic Agents↗
PubMed2004

Saccharic acid 1.4-lactone protects against CPT-11-induced mucosa damage in rats.

PURPOSE: To evaluate the ability of D-saccharic acid 1.4-lactone (SAL), a beta-glucuronidase inhibitor, to prevent irinotecan hydrochloride (CPT-11) from inducing mucosal damage as a cause of diarrhea in rats. METHODS: Wistar rats were divided into six groups of three animals each, administered 1.0 ml isotonic solution intraperitoneally once daily for up to three consecutive days, respectively for up to six days. The series were as follows: (1) On days 1-3: saline; (2) On days 1-3: 200 mg CPT-11/m2; (3) On days -3 to -1 relative to the first administration of CPT-11: 10 mg/ml SAL; on days 1-3: 200 mg CPT-11/m2; (4) On days -3 to +3 relative to the first administration of CPT-11: 10 mg/ml SAL, and on days 1-3: additional 200 mg CPT-11/m2; (5) On days 1-3: 200 mg CPT-11/m2 (0.5 ml) + 10 mg/0.5 ml SAL; (6) On days -3 to -1 relative to the first administration of CPT-11: 3 mg/ml SAL, and on days 1-3: 200 mg CPT-11/m2. Luminal mucosa damage of the small intestine was detected by histology 24 h after the last intraperitoneal application. Peptidase activities of the proximal jejunum were measured by using an in situ perfusion model. RESULTS: Following intraperitoneal CPT-11 treatment, using conventional histology of paraffin sections, we observed severe mucosal damage. This was reflected by a decrease of the villi/crypt ratio, an increase of apoptotic cells, as well as an increase of mitotic figures in the crypt region. There was a concomitant increased lymphatic infiltration in mucosa of CPT-11 treated rats. This damage pattern could be clearly reduced by co-treatment with the beta-glucuronidase inhibitor, SAL, independent of the treatment schedule. In contrast to our expectations based on previous reports, the intraperitoneal application of CPT-11 alone or in combination with SAL did not cause significant differences in luminal enzyme liberation in comparison with controls in the in situ perfusion assay. CONCLUSIONS: The beta-glucuronidase inhibitor SAL is able to significantly reduce CPT-11-induced mucosal damage in the small intestine of rats. This observation might soon have a clinical impact for the treatment of patients with CPT-11.

Animals↗
PubMed2006

In vitro and in vivo activity of lignan lactones derivatives against Trypanosoma cruzi.

The trypanocidal effect of six lignan lactones, (-)-cubebin (1), (-)-O-methyl cubebin (2), (-)-O-benzyl cubebin (3), (-)-6,6'-dinitrohinokinin (4), (-)-hinokinin (5) and dimethoxymorelensin (6), previously synthesized by our research group, was evaluated in vitro and in vivo. The compounds with higher anti-epimastigote activity were screened against intracellular amastigote of Trypanosoma cruzi. Among these, compound 5 was selected to be assayed in vivo. It was observed that compounds 5, 6 and 2 showed higher trypanocidal activity against epimastigote forms of T. cruzi, displaying inhibitory concentration (IC(50)) values of 0.67, 3.89 and 31.35 muM, respectively. These compounds were also evaluated against intracellular amastigote forms of T. cruzi, with five displaying similar activity to benznidazole. In vivo assays showed significant reduction of parasitaemia after administration of five in mice infected.

Animals↗
PubMed2005

Microscale process evaluation of recombinant biocatalyst libraries: application to Baeyer-Villiger monooxygenase catalysed lactone synthesis.

Microscale processing techniques are rapidly emerging as a cost- effective means for parallel experimentation and hence the evaluation of large libraries of recombinant biocatalysts. In this work, the potential of an automated microscale process is demonstrated in a linked sequence of operations comprising fermentation, enzyme induction and bioconversion using three whole-cell biocatalysts each expressing cyclohexanone monoxygenase (CHMO). The biocatalysts, Escherichia coli TOP 10 [pQR239], E. coli JM107 and Acinetobacter calcoaceticus NCIMB 9871, were first produced in 96-deep square well fermentations at various carbon source concentrations (10 and 20 g L(-1) glycerol). Following induction of CHMO activity biomass concentrations of up to 6 gDCW L(-1) were obtained. Cells from each fermentation were subsequently used for the Baeyer-Villiger oxidation of bicyclo[3.2.0]hept-2-en-6-one, cyclohexanone and cyclopentanone. Each bioconversion was performed at two initial substrate concentrations (0.5 and 1.0 g L(-1)) in order to simultaneously explore both substrate specificity and inhibition. The microscale process sequences yielded quantitative and reproducible data for each biocatalyst on maximum growth rate, biomass yield, initial rate of lactone formation, specific biocatalyst activity and bioconversion yield. E. coli TOP 10 [pQR239] was demonstrated to be an efficient biocatalyst showing substrate specificities and substrate inhibition effects in line with previous studies. Finally, in order to show that the data obtained with E. coli TOP 10 [pQR239] at microwell scale (1,000 microL) could be related to larger scales of operation, the process was performed in a 2-L stirred-tank bioreactor. Using conditions designed to enable microwell kinetic measurements under none oxygen-limited conditions, the fermentation and bioconversion data obtained at the two scales showed good quantitative agreement. This study therefore confirms the potential of automated microscale experimentation for the whole-process evaluation of recombinant biocatalyst libraries and the specification of pilot and process scale operating conditions.

Acinetobacter calcoaceticus↗
PubMed2002

Sesquiterpene lactone dehydroleucodine selectively induces transient arrest in G2 in Allium cepa root meristematic cells.

Dehydroleucodine is a sesquiterpene lactone recently isolated from aerial parts of a medicinal herb, Artemisia douglasiana Besser. We have previously shown that 25 and 100 microM dehydroleucodine slowed down onion root growth by 30 and 70%, respectively, affecting neither cell viability nor cell elongation. In the present study we analyze the effect of dehydroleucodine on cell cycle phases in onion (Allium cepa L.) root meristematic cells synchronized with caffeine or caffeine and hydroxyurea. Synchronized root cells treated with 100 and 200 microM dehydroleucodine present an interphase lengthening of 5.2 h and 8.2 h, respectively. The S-phase length, estimated by [3H]thymidine incorporation assay, was 6 h for both control roots and roots that had been immersed in dehydroleucodine. The peak of [3H]leucine incorporation was observed 6 h after release from synchronization in controls and in dehydroleucodine-treated roots, indicating that protein synthesis in G2 was not affected. Thus, these results show that dose-dependently dehydroleucodine selectively induces a transient arrest of meristematic cell in G2 and that dehydroleucodine can be used experimentally as a cell cycle suppressor.

Caffeine↗
PubMed2006

Dimethylfuran-lactone pheromone from males of Galerucella calmariensis and Galerucella pusilla.

Male Galerucella calmariensis and Galerucella pusilla (Coleoptera: Chrysomelidae) emit an aggregation pheromone while feeding on host foliage. Isolation of the compound from collected volatiles was guided by comparisons of gas chromatograms of extracts from males and females and by gas chromatography-electroantennographic detection. The compound was identified by a combination of spectrometric methods and microchemical tests as the novel dimethylfuran lactone, 12,13-dimethyl-5,14-dioxabicyclo[9.2.1]tetradeca-1(13),11-dien-4-one. The structure was confirmed by synthesis, and the synthetic compound attracted males and females of both species in field bioassays. These beetles were previously introduced into North America as biological control agents for the invasive wetland weed, purple loosestrife Lythrum salicaria, and the pheromone could become a tool for monitoring populations. A new method is described for distinguishing the two species based on the tibial spurs of the males.

Animals↗