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 775 records · Page 43Linked to original sources
PubMed1998

Novel lactone compounds from Mortierella verticillata that induce the human low density lipoprotein receptor gene: fermentation, isolation, structural elucidation and biological activities.

Among methods of controlling hypercholesterolemia and hyperlipidemia is the direct stimulation of hepatic low density lipoprotein (LDL) receptors. Two novel lactone compounds, CJ-12,950 and CJ-13,357, containing and unusual oxime moiety, were isolated from a zygomycete Mortierella verticillata. These lactones are potent inducers of the LDL receptor gene in vitro, that enhanced LDL receptor expression in human hepatocytes 2-fold at 100 nM.

Cell Culture Techniques↗
PubMed1999

Structure elucidation of Sch 20561, a cyclic dehydropeptide lactone--a major component of W-10 antifungal antibiotic.

Antibiotic W-10 is a fermentation complex produced by the bacterium Aeromonas sp. W-10. The cyclic dehydropeptide lactones Sch 20562 (1) and Sch 20561 (2) are the major components of this fermentation complex and are of biological interest in view of their unique structural features and potent antifungal activity. The chemical degradation studies that were utilized in the assignment of structure 2 for Sch 20561 are described here. The structure determination of 2 made use of the ozonolytic cleavage of the dehydropeptide units to form fragments that were sequenced by mass spectrometry. The cyclic dehydropeptide lactone Sch 20561 (2) was found to be the aglycone of Sch 20562 (1) and these two natural products were correlated by a chemical transformation involving the deglucosidation of 1 to form 2.

Aeromonas↗
PubMed2000

Feigrisolides A, B, C and D, new lactones with antibacterial activities from Streptomyces griseus.

Four new lactone compounds, named feigrisolides A to D (1 to 4), have been isolated from Streptomyces griseus. The chemical structures were determined by detail analysis of their spectroscopic data and chemical transformations. Structurally, the feigrisolides A (1) and B (2) are hepta-lactones, feigrisolide C (3) and D (4) are 16-membered macrodiolides. Biological studies showed that feigrisolide B (2) exhibited strong antibacterial, as well as medium cyctotoxic, and antiviral activities. Feigrisolides A (1), C (3) and D (4) are medium inhibitors of 3alpha-hydroxysteroid-dehydrogenase (3alpha-HSD) inhibiting activity.

Anti-Bacterial Agents↗
PubMed2001

Novel macrolactins as antibiotic lactones from a marine bacterium.

Seven new macrolactins (named G~M) and known macrolactins A and F were isolated from a culture broth of Bacillus sp. PP19-H3. The strain had been isolated from the macroalga, Schizymenia dubyi. Macrolactin A, which was 24-membered lactone, had previously been reported to show antibacterial, cytotoxic and antiviral activities. The new macrolactins include 22-membered ring or dicyclic lactone in addition to geometric isomers of known macrolactins A and F. The antibacterial activities of all the macrolactins examined in this study were relatively weak.

Anti-Bacterial Agents↗
PubMed1999

Oxidative bioactivation of the lactol prodrug of a lactone cyclooxygenase-2 inhibitor.

The lactol derivative of a lactone cyclooxygenase-2 inhibitor (DFU) was evaluated in vivo and in vitro for its potential suitability as a prodrug. DFU-lactol was found to be 10 to 20 times more soluble than DFU in a variety of aqueous vehicles. After administration of DFU-lactol at 20 mg kg-1 p.o. in rats, a Cmax of 7.5 microM DFU was reached in the plasma. After oral administration, the ED50s of DFU-lactol in the carrageenan-induced paw edema and lipopolysaccharide-induced pyresis assays in rats are comparable with the ED50s observed when dosing with DFU. Incubations of DFU-lactol with rat and human hepatocytes demonstrated that the oxidation of DFU-lactol can be mediated by liver enzymes and that a competing pathway is direct glucuronidation of the DFU-lactol hydroxyl group. Assays with subcellular fractions from rat liver indicated that most of the oxidation of DFU-lactol occurs in the cytosolic fraction and requires NAD(P)+. Human liver cytosol can also support the oxidation of DFU-lactol to DFU when NAD(P)+ is added to the incubations. Fractionation of human liver cytosolic proteins showed that at least three enzymes are capable of efficiently effecting the oxidation of DFU-lactol to DFU. Incubations with commercially available dehydrogenases suggest that alcohol and hydroxysteroid dehydrogenases are involved in this oxidative process. These data together suggest that lactols may represent useful prodrugs for lactone-containing drugs.

Animals↗
PubMed1975

Ascorbate-synthesizing system in rat liver microsomes. II. A peptide-bound flavin as the prosthetic group of L-gulono-gamma-lactone oxidase.

L-Gulono-gamma-lactone oxidase [EC 1.1.3.8] was purified 80-fold from rat liver microsomes. In confirmation of our previous finding with a cruder preparation, the purified enzyme was shown to contain an L-gulono-gamma-lactone-reducible pigment as a prosthetic group. This pigment was not liberated from the protein by acid ammonium sulfate, 10% trichloroacetic acid or 2 M area, but was effectively released by proteolytic digestion. The pigment thus released showed a reduced-minus-oxidized difference spectrum characteristic of a flavin compound. The pigment was liberated from a trichloroacetic acid-treated preparation of the enzyme by pronase digestion and purified by Florisil column chromatography and paper chromatography. The absorption spectrum as well as the fluorescence emission and excitation spectra of the purified pigment indicated that it was actually a flavin peptide. It was, however, different not only from FMN but also from flavin peptides isolated from other sources such as succinate dehydrogenase [EC 1.3.99.1] and monoamine oxidase [EC 1.4.3.4] as regards the pH dependence of fluorescence intensity and the Rf value on thin-layer chromatography. A preliminary analysis showed that the purified flavin compound contained several amino acid residues. Alkaline photolysis of the purified flavin peptide suggested that the isoalloxazine ring of the flavin is involved in its binding to the peptide. The hypsochromic shift of the absorption peak in the near-ultraviolet region suggested further that the linkage between the flavin and the peptide may be mediated by the 8-methyl group of the isoalloxazine nucleus. It can be concluded that the prosthetic group of gulonolactone oxidase is a flavin which is covalently bound to the enzyme protein.

Alcohol Oxidoreductases↗
PubMed1997

[An observation of the percutaneous absorption of total alkaloids and terpenoid lactones of Tripterygium wilfordii].

The main ingredients of Tripterygium wilfordii are total alkaloids and terpenoid lactones. The authors studied the percutaneous absorption of these compounds on mice by means of ultravillet spectrophotometry. The results showed that these alksloids and lactones could pass through the skin of the mice. The rate of 12-hour percutaneous absorption was 13.40% for the former and 17.60% for the latter. After the application of Tripterygium wilfordii adhesive plaster to the human skin for 12 hours, the two ingredients were absorbed 17.34% and 22.13% respectively. This suggests that Tripterygium wilfordii can really be administered through the skin.

Administration, Topical↗
PubMedDate not supplied

Camptothecin conjugated with DNA minor-groove binder netropsin: enhanced lactone stability, inhibition of human DNA topoisomerase I and antiproliferative activity.

BACKGROUND: The conjugates of camptothecin (CPT) with ligands possessing different DNA selectivity could be promising agents in cancer therapy affecting expression of specific genes by trapping DNA topoisomerase I (top I)-DNA complexes in a sequence-selective manner. Our recent data show that minor-groove binder netropsin (Nt) and its derivatives modulate the CPT-induced pattern of top I-mediated DNA cleavage. In an effort to develop a new molecule with good biological activity we have linked CPT with Nt and report here the first results of in vitro examination of the new compound. MATERIALS AND METHODS: CPT-Nt conjugate linked with flexible spacer through position 7 of CPT chromophore was synthesized and analyzed for lactone stability, the ability to modulate a top I-mediated DNA cleavage and antiproliferative activity within a panel of six tumor cell lines. RESULTS: CPT-Nt conjugate demonstrates enhanced lactone stability and concentration-dependent top I poisoning or suppression in vitro. The rate of conjugate hydrolysis in a water solution displays a 20-fold enhancement of stability compared with CPT. The cytotoxicity of the conjugate against acute promyelocytic leukaemia (HL60), chronic myelogenous leukaemia (K562), breast adenocarcinoma (MCF7), colorectal adenocarcinoma (HT29), lung carcinoma(A549) and ovarian adenocarcinoma (CaOV3) tumor cell lines was evaluated. The lowest IC50 value (0.08 microM) indicated its selective toxicity towards the ovarian adenocarcinoma cell line. CONCLUSION: The enhanced stability of CPT-Nt conjugate and its selective toxicity against the CaOV3 cell line may indicate its utility as an antitumor agent against ovarian adenocarcinoma.

Antineoplastic Agents↗
PubMed1992

[Noradrenaline fluorescence histochemical study on the locus coeruleus of kindling rat induced by coriaria lactone].

Fourteen male Wistar rats were divided into two groups. The experimental rats were injected with subconvulsive dosage of coriaria lactone (1 mg/kg) intramuscularly per 3.5 days. The controls were injected with normal saline. After 26 injections, the loci coeruleus of kindling rats were studied with the noradrenaline (NA) fluorescence histochemical technique at the time between seizures. The NA fluorescence could be clearly visualized under fluorescent microscope. The intensity of fluorescence was reflected by autoexposure-meter of the fluorescent microscope. The brighter the fluorescence, the shorter the autoexposure time. The intensity of NA fluorescence in the locus coeruleus of experimental animals was weaker than that of the controls. Since NA plays an inhibitory role in cerebral cortex, the decrease of NA, either induced by repeated injections of coriaria lactone or due to the time of sample taken after seizure, needs further study.

Animals↗
PubMed2003

Consistent antibody response against ganglioside GD2 induced in patients with melanoma by a GD2 lactone-keyhole limpet hemocyanin conjugate vaccine plus immunological adjuvant QS-21.

PURPOSE: Melanomas, sarcomas, and neuroblastomas abundantly express the ganglioside GD2 on the cell surface where it is susceptible to immune attack by antibodies. Overexpression of GD2 on these tumors is striking, as is the frequency of clinical responses after treatment of neuroblastoma with monoclonal antibodies against GD2. In addition, preclinical models have demonstrated the ability of a GD2-keyhole limpet hemocyanin (KLH) conjugate vaccine to induce antibodies that eliminate micrometastases. However, vaccination of patients with GD2-KLH has previously failed to induce a consistent relevant antibody response. We test here whether the use of GD2 lactone-KLH can overcome the low immunogenicity of GD2-KLH. EXPERIMENTAL DESIGN: Eighteen patients with melanoma were vaccinated s.c. in the adjuvant setting on weeks 0, 1, 2, 3, 10, and 24. Groups of 6 patients were entered at three dose levels (3, 10, or 30 micro g) of GD2 lactone (GD2L) in vaccines containing GD2L-KLH plus the immunological adjuvant QS-21. Blood was drawn at regular intervals to assess the antibody response. RESULTS: The vaccine was well tolerated. The majority of patients in all three dose levels produced anti-GD2 antibodies detectable by ELISA assay. Specificity for GD2 was also confirmed by immune thin-layer chromatography. Although there was no statistical difference in terms of titers between the three groups, patients at the 30- micro g dose level had higher titers and longer lasting antibody responses overall by ELISA (median IgM/IgG peak titer 1:640/1:80) and generated the strongest cell surface reactivity by fluorescence-activated cell sorting (median IgM peak percentage positive cells/mean fluorescence intensity for pre- and postvaccination sera is 10%/63 and 70%/135). Patients vaccinated with the 30- micro g GD2 dose also had the most potent complement dependent cytotoxicity using human complement, with 5 of 6 patients showing strong cell surface reactivity by fluorescence-activated cell sorting and >30% cytotoxicity by chromium release with a serum dilution of 1/100. CONCLUSIONS: GD2L-KLH conjugate vaccine plus adjuvant QS-21 induces antibodies against GD2 that bind to the cell surface and induce complement-dependent cytotoxicity in the majority of patients with melanoma.

Adjuvants, Immunologic↗
PubMed1992

The cytotoxicity of helenalin, its mono and difunctional esters, and related sesquiterpene lactones in murine and human tumor cells.

Naturally occurring sesquiterpene lactones and their semisynthetic derivatives, such as the O = C-C = CH-bearing helenalin and its esters, have been shown to demonstrate potent cytotoxicity against the growth of murine L1210 lymphoid leukemia and human Tmolt3 leukemia, colon adenocarcinoma, HeLaS3, lung bronchogenic, KB, osteosarcoma, and glioma cells. The modes of action of helenalin in L1210 cells are the inhibition of DNA, RNA, and protein syntheses. This study confirms that thiol bearing enzymes of nucleic acid metabolism were significantly inhibited, e.g. DNA polymerase alpha, IMP hydrogenase, and ribonucleoside reductase. The addition of GSH to the reaction medium demonstrated total recovery of L1210 ribonucleoside reductase activity. Helenalin reduced cellular GSH levels in L1210 cells. Helenalin also reduced all four pool levels of d(NTP)s which would account for part of the observed inhibition of DNA synthesis. Reductions in the ribonucleotide pool levels were also generally evident after drug treatment. Thus, the sesquiterpene lactones appear to have more than one mode of action in L1210 cells. All of the modes of actions of helenalin are feasible mechanisms to lower nucleic acid synthesis and cause cell death of the L1210 leukemia cells.

Animals↗
PubMed2005

[Effects of lactone I from Atractylodes macrocephala Koidz on cytokines and proteolysis-inducing factors in cachectic cancer patients].

OBJECTIVE: To observe the effect of lactone I from Atractylodes macrocephala Koidz (LAMK I) on the cytokines and proteolysis-inducing factors (PIF) in cachectic cancer patients. METHOD: Sixty-four cachectic cancer patients were randomized into two groups, namely LAMK I group and FOE (fish oil-enriched nutritional supplementation) treatment group. The appetite, body weight changes, mid-arm muscle circumference (MAMC), and KPS scores were recorded 3 and 7 weeks after the treatment. Immunohistochemistry was used to analyze the changes in the cytokines interleukin (IL)-1, IL-6 and tumor necrosis factor (TNF)-alpha and Western blotting employed to examine the changes of PIF after the treatment. RESULTS: The patients' appetite and MAMC in LAMKI group was better than those of patients in FOE group, and the serum IL-1 and TNF-alpha levels and urine PIF level were significantly lower than those of FOE group. Body weight and serum IL-6 level were not significantly different between the two groups. CONCLUSION: Lactone I from Atractylodes macrocephala Koidz can be beneficial for treating cancer cachexia.

Adult↗
PubMed2005

[Expression of metabotropic glutamate receptor 1alpha in different brain areas of the kindled epilepsia models of rats by Coriaria lactone].

OBJECTIVE: To detect the expression of Metabotropic Glutamate Receptor 1alpha (MGLUR1alpha) in the different brain areas of the kindled epilepsia models of rats by Coriaria Lactone (CL). METHODS: Thirty male SD rats were divided into 3 groups and were given intramuscular injections of 0.75, 1.0 and 1.25 ml/kg Coriaria Lactone respectively. 5 rats in the control group were given intramuscular injection of 1.0 ml/kg saline. After the kindling models were completed, the EcoG of all groups were recorded with the multi-electrophysiology recorder to view whether the EcoG of kindled rats accord with their seizures and to know whether there are differencees in EcoG among the kindled, non-kindled and control groups. The coronary sections of brain tissue were HE stained and MGLUR1alpha immunohistochemistry stained, and were observed under light microscope. RESULTS: The kindled rats had all grade (Simialowski scale) seizures after CL injection and their seizures accorded with their EcoG features. The MGLUR1alpha expression of kindled rats in hippocampus and temporal cortex outside hippocampus was stronger than that of non-kindled and control rats (P < 0.05); the strong expression was noted to be of no obvious difference between neuron and glia. CONCLUSION: The MGLUR1alpha expression of kindled rats in hippocampus and temporal cortex outside hippocampus is stronger than that of non-kindled and control. It is possible that MGLUR1alpha participates in epileptic seizures.

Animals↗
PubMed2006

Antitumor activities of the four sesquiterpene lactones from Elephantopus scaber L.

AIM: To evaluate antitumor activity of sesquiterpene lactones (scabertopin (ES-2), isoscabertopin (ES-3), deoxyelephantopin (ES-4), isodeoxyelephantopin (ES-5)) isolated from Elephantopus scaber L. in vitro and in vivo. METHODS: SMMC-7721, Caco-2 and HeLa cell lines were treated with ES-2,3,4,5. Cell viability was determined by MTT assay. Agarose gel electrophoresis was used to detect DNA fragmentation. To evaluate in vivo antitumor activity of ES-4, experimental murine tumor model was used. RESULTS: It was shown that ES-2, ES-4, ES-5 exhibited significant antitumor effect in vitro in a concentration-dependent manner. However, the effect of ES-3 on the growth of tested cell lines was relatively weak. In HeLa cells exposed to ES-4 for 48 h, morphological changes and DNA ladder pattern evidencing on apoptosis were detected. ES-4 revealed in vivo antitumor activity. CONCLUSION: Antitumor activity of studied sesquiterpene lactones may be due, at least in part, to induction of apoptosis in vitro. ES-4 possesses also antitumor activity in vivo.

Antineoplastic Agents, Phytogenic↗
PubMed1990

Treatment of dermatitis caused by the sesquiterpene lactone helenin.

Many sesquiterpene lactones, terpenoid compounds present in members of the Compositae (Asteraceae) family of plants, are known to cause allergic contact dermatitis. There is no treatment of this skin disease. We report on the use of an amino acid, L-cysteine, to control dermatitis in guinea pigs sensitized to the sesquiterpene lactone, helenin. The cysteine treatment of allergic reactions induced by helenin reduced the recovery time of the animals by about 50%. The effect of cysteine treatment might be explained by: cysteine reaction with free helenin, and substitution of skin proteins from the protein-helenin complex by cysteine through competitive reactions. Cysteine treatment present a new promising way for control of this type of allergy in humans.

Animals↗
PubMedDate not supplied

Immunosuppressive activity of two plant steroidal lactones withaferin A and withanolide E.

Withaferin A and withanolide E, two steroidal lactones of plant origin were demonstrated to have specific immunosuppressive effects on human B and T lymphocytes as well as on mice thymocytes. E rosettes and EAC rosette formation by normal human T and B lymphocytes were inhibited by the two compounds at very low concentrations. The formation of mouse red blood rosettes by chronic lymphatic leukemic cells were only inhibited by withaferin A. The functional activity of normal human T lymphocytes as assessed by a local xenogeneic graft versus host reaction was also affected by these two plant steroidal lactones. These experiments demonstrate a specific action of the compound on antigen recognition as well as proliferative capacity of T lymphocytes as well as B lymphocytes.

Animals↗
PubMed1987

The development of an ELISA-assay for semi-quantitative detection of dihydrogriesenin, a sesquiterpene lactone from Geigeria.

Certain species of Geigeria contain sesquiterpene lactones which cause vomiting disease in sheep. Dihydrogriesenin (DHG), a sesquiterpene lactone from G. asperta, contains an alpha-methylene function which can spontaneously react with thiol groups on proteins to form a covalent adduct. A specific antiserum against a DHG-protein adduct can be used to determine the fate of DHG in poisoned animals. The preparation of such an antiserum is reported in this paper. DHG was reacted with cysteine and subsequently coupled to serum albumin using the carbodiimide reaction. When rabbits were immunized with one such conjugate (DHG-bovine serum albumin), it was found that the carrier determinants were immunodominant. A DHG-specific anti-serum of sufficient (ELISA) titre could, however, be obtained by alternating serum albumin carriers for DHG in booster immunizations. The ELISA antigen-antibody reaction could be inhibited by prior reaction of the antisera with cysteinyl-DHG in solution.

Animals↗