Search results for "lactone"
showing 10 items of 335 documents
Traditional fermented sausage ‘Nem chua’ as a source of yeast biocatalysts efficient for the production of the aroma compound γ-decalactone
2013
International audience; The yeast ecosystem of Nem chua, a Vietnamese traditional fermented sausage naturally rich in medium‐chain‐length lipid‐derived flavouring compounds, was investigated to select biocatalysts able to produce the C10‐fatty acid‐derived aroma compound γ‐decalactone. The total number of yeast was about 5 × 104 to 4 × 105 CFU g−1, and eighty four different species were identified from morphological, physiological and 26S rDNA characteristics, with Candida sake and Candida haemulonii being found in all samples. Six strains able to produce γ‐decalactone from castor oil were selected, of which three Yarrowia lipolytica strains were able to produce between 1 and 2 g L−1 in our…
Modulation of acute and chronic inflammatory processes by cacospongionolide B, a novel inhibitor of human synovial phospholipase A2.
1999
1. Cacospongionolide B is a novel marine metabolite isolated from the sponge Fasciospongia cavernosa. In in vitro studies, this compound inhibited phospholipase A2 (PLA2), showing selectivity for secretory PLA2 (sPLA2) versus cytosolic PLA2 (cPLA2), and its potency on the human synovial enzyme (group II) was similar to that of manoalide. 2. This activity was confirmed in vivo in the 8 h zymosan-injected rat air pouch, on the secretory enzyme accumulating in the pouch exudate. Cacospongionolide B, that is bioavailable when is given orally, reduced the elevated levels of sPLA2 present in paw homogenates of rats with adjuvant arthritis. 3. This marine metabolite showed topical anti-inflammator…
Molecular characterization of a male-specific glycosyl hydrolase, Lma-p72, secreted on to the abdominal surface of the Madeira cockroach Leucophaea m…
2003
0264-6021 (Print) Journal Article Research Support, Non-U.S. Gov't; The epicuticular surface protein Lma-p72 is specific to the abdominal secretions of Leucophaea maderae (Madeira cockroach) adult males. Natural Lma-p72 was purified and the complete cDNA sequence determined by reverse-transcription PCR using primers based on Edman degradation fragments. Northern blot and in situ hybridization analyses showed that Lma-p72 was expressed in the tergal and sternal glands. Sequence alignment indicates that Lma-p72 is closely related to the family 1 glycosyl hydrolases (EC 3.2.1). Native Lma-p72 was proved to be active in the abdominal secretions and exhibit a beta-galactosidase-like activity. Ho…
Potassium regulates IL-1 beta processing via calcium-independent phospholipase A2.
2000
Abstract We report that potassium leakage from cells leads to activation of the Ca2+-independent phospholipase A2 (iPLA2), and the latter plays a pivotal role in regulating the cleavage of pro-IL-1β by the IL-converting enzyme caspase-1 in human monocytes. K+ efflux led to increases of cellular levels of glycerophosphocholine, an unambiguous indicator of phospholipase A2 activation. Both maturation of IL-1β and formation of glycerophosphocholine were blocked by bromoenol lactone, the specific iPLA2 inhibitor. Bromoenol lactone-dependent inhibition of IL-1β processing was not due to perturbation of the export machinery for pro-IL-1β and IL-1β or to caspase-1 suppression. Conspicuously, activ…
Near-Infrared, Light-Triggered, On-Demand Antiinflammatories and Antibiotics Release by Graphene Oxide/Elecrospun PCL Patch for Wound Healing
2019
Very recently, significant attention has been focused on the adsorption and cell adhesion properties of graphene oxide (GO), because it is expected to allow high drug loading and controlled drug release, as well as the promotion of cell adhesion and proliferation. This is particularly interesting in the promotion of wound healing, where antibiotics and anti-inflammatories should be locally released for a prolonged time to allow fibroblast proliferation. Here, we designed an implantable patch consisting of poly(caprolactone) electrospun covered with GO, henceforth named GO&ndash
Enantioselective Henry addition of methyl 4-nitrobutyrate to aldehydes. Chiral building blocks for 2-pyrrolidinones and other derivatives.
2010
A catalytic highly enantioselective Henry addition of methyl 4-nitrobutyrate to aldehydes using a Cu(II)-amino pyridine complex as catalyst is described. The products resulting from this reaction constitute a new, highly versatile family of chiral building blocks as a result of the presence of three different functional groups on the molecule. These products have been transformed into nonracemic chiral gamma-lactams, 5-hydroxy-5-substituted levulinic acid derivatives, and delta-lactones.
Effect of the remaining lanthanide catalysts on the hydrolytic and enzymatic degradation of poly-(ε-caprolactone)
2003
Poly-(e-caprolactone) is a biodegradable polymer, which can be used for both medical and environmental applications. Due to its multiple applications the synthesis of such a polymer has been attracting an increasing attention in the past few decades. In our work, the polymers were synthesised by bulk polymerisation, using different lanthanide halides as initiators. The lanthanide derivatives are known as very active catalysts in the ring-opening polymerisation of cyclic esters. Moreover, they are not toxic in comparison of catalysts, which are usually used for this synthesis. In this paper, the influence of the lanthanides on both the hydrolytic and enzymatic degradation of the PCL obtained…
Budlein A from Viguiera robusta inhibits leukocyte-endothelial cell interactions, adhesion molecule expression and inflammatory mediators release
2009
Budlein A has been reported to exert some analgesic and anti-inflammatory properties. In this study, we have evaluated its effect on LPS-induced leukocyte recruitment in vivo and the mechanisms involved in its anti-inflammatory activity. In vivo, intravital videomicroscopy was used to determine the effects of budlein A on LPS-induced leukocyte-endothelial cell interactions in the murine cremasteric microcirculation. In vitro, the effects of budlein A on LPS-induced cytokine, chemokine and nitrites release, T-cell proliferative response as well as cell adhesion molecule expression (CAM) were evaluated. In vivo, intraperitoneal administration of budlein A (2.6 mM/kg) caused a significant redu…
Inhibitory effects of cynaropicrin on human melanoma progression by targeting MAPK, NF-κB, and Nrf-2 signaling pathways in vitro
2021
Malignant melanoma is the deadliest skin cancer, due to its propensity to metastasize. MAPKs and NF-κB pathways are constitutively activated in melanoma and promote cell proliferation, cell invasion, metastasis formation, and resistance to therapeutic regimens. Thus, they represent potential targets for melanoma prevention and treatment. Phytochemicals are gaining considerable attention for the management of melanoma because of their several cellular and molecular targets. A screening of a small library of sesquiterpenes lactones selected cynaropicrin, isolated from the aerial parts of Centaurea drabifolia subsp. detonsa, for its potential anticancer effect against melanoma cells. Treatment…
Mechanisms underlying the toxicity of lactone aroma compounds towards the producing yeast cells
2003
M. A G U E D O , L. B E N E Y , Y. W A C H EA N D J. - M. B E L I N. 2003. Aims: To study the fundamental mechanisms of toxicity of the fruity aroma compound c-decalactone, that lead to alterations in cell viability during its biotechnological production by yeast cells; Yarrowia lipolytica that is able to produce high amounts of this metabolite was used here as a model. Methods and Results: Lactone concentrations above 150 mg l )1 inhibited cell growth, depolarized the living cells and increased membrane fluidity. Infrared spectroscopic measurements revealed that the introduction of the lactone into model phospholipid bilayers, decreased the phase transition temperature. Moreover, the H + -…