Search results for "Pyrone"

Perceptual blending in odor mixtures depends on the nature of odorants and human olfactory expertise.

2012

International audience; Our olfactory system is confronted with complex mixtures of odorants, often recognized as single entities due to odor blending (e.g., coffee). In contrast, we are also able to discriminate odors from complex mixtures (e.g., off-odors). Therefore, the olfactory system is able to engage either configural or elemental processes when confronted with mixtures. However, the rules that govern the involvement of these processes during odor perception remain poorly understood. In our first experiment, we examined whether simple odorant mixtures (binary/ternary) could elicit configural perception. Twenty untrained subjects were asked to evaluate the odor typicality of mixtures…

Kavapyrone enriched extract fromPiper methysticum as modulator of the GABA binding site in different regions of rat brain

1994

Regional differences in the modulation of [3H] muscimol binding to GABAA receptor complexes by kavapyrones, compounds of the rhizome of the plant Piper methysticum which possess sedative activity, were demonstrated using membrane fractions obtained from target brain centers of kavapyrone action: hippocampus (HIP), amygdala (AMY) and medulla oblongata (MED), and from brain centers outside the main kavapyrone effects as frontal cortex (FC) and cerebellum (CER). The kava extract enhanced the binding of [3H] muscimol in a concentration-dependent manner with maximal potentiation of 358% over control in HIP followed by AMY and MED (main target brain centers). Minimal stimulation was observed in C…

Mechanisms of interference of p-diphenols with the Trinder reaction

2020

p-Diphenols, such as homogentisic acid, gentisic acid, etamsylate, and calcium dobesilate, interfere with diagnostic tests utilizing the Trinder reaction but the mechanisms of these effects are not fully understood. We observed substantial differences both in oxidation of p-diphenols by horseradish peroxidase and their influence on oxidation of 4-aminoantipyrine and various phenolic substrates. Homogentisic acid was rapidly oxidized by the enzyme and completely blocked chromophore formation. Enzymatic oxidation of the remaining p-diphenols was slow and they only moderately inhibited chromophore formation. However, in the presence of standard substrates all tested p-diphenols were rapidly co…

Design and synthesis of pironetin analogue/colchicine hybrids and study of their cytotoxic activity and mechanisms of interaction with tubulin

2014

We here report the synthesis of a series of 12 hybrid molecules composed of a colchicine moiety and a pironetin analogue fragment. The two fragments are connected through an ester-amide spacer of variable length. The cytotoxic activities of these compounds and their interactions with tubulin have been investigated. Relations between the structure and activity are discussed. Since the spacer is not long enough to permit a simultaneous binding of the hybrid molecules to the colchicine and pironetin sites on tubulin, a further feature investigated was whether these molecules would interact with the latter through the pironetin end (irreversible covalent binding) or through the colchicine end (…

Anti-Neurotoxic Effects of Tauropyrone, a Taurine Analogue

2006

Taurine and tauropyrone: Comparative neuropharmacological studies of small doses

2007

Coumarins and Related Compounds from the Medicinal Plants of Africa

2013

Coumarins (1-benzopyran-2-one) are chemical compounds in the benzopyrone class of organic compounds found in many plants. Coumarins possess a variety of biological properties, including antimicrobial, antiviral, antiinflammatory, antidiabetic, antioxidant, and enzyme inhibitory activity. This chapter gives an overview of the isolation, structural features, and pharmacological actions of variety of coumarins produced by the African plants. The biosynthetic pathway of coumarins is also discussed in this chapter. We identify 117 coumarins in African plants, of which 48 are new. The pharmacological activities of 54 of these coumarins are reported and documented in this chapter.

Production d'arôme de noix de coco (pentyl-6-alpha pyrone) par le champignon filamenteux trichoderma

1996

National audience

Semisynthesis of new tetrahydrofuranic alkyl ester and furano-pyrone derivatives as inhibitors of the mitochondrial complex I

2002

Abstract Methoxymethylation of altholactone ( 1 ) led to the corresponding O -methoxymethyl derivative ( 3 ) in addition to the unexpected 6,7-dihydro-7-methoxy analogue ( 4 ), and two original tetrahydrofuranic (THF) alkyl esters ( 5 , 6 ). Moreover, when we accomplished a new method for the preparation of the furano-pyrone goniofupyrone ( 7 ) through 7-hydroxylation of 1 in acid medium, a minor compound ( 8 ) with an identical skeleton to that of compounds 5 and 6 was identified. Careful examination of the published spectral data of the reported styryl-lactones with an heptolide skeleton reveals that those structures possess also a THF alkyl ester skeleton. The revision of those structure…

Metabolism of Linoleic Acid or Mevalonate and 6-Pentyl-α-Pyrone Biosynthesis by Trichoderma Species

1993

The understanding of the biosynthetic pathway of 6-pentyl-α-pyrone in Trichoderma species was achieved by using labelled linoleic acid or mevalonate as a tracer. Incubation of growing cultures of Trichoderma harzianum and T. viride with [U- 14 C]linoleic acid or [5- 14 C]sodium mevalonate revealed that both fungal strains were able to incorporate these labelled compounds (50 and 15%, respectively). Most intracellular radioactivity was found in the neutral lipid fraction. At the initial time of incubation, the radioactivity from [ 14 C]linoleic acid was incorporated into 6-pentyl-α-pyrone more rapidly than that from [ 14 C]mevalonate. No radioactivity incorporation was detected in 6-pentyl-…