Search results for "Tryptamine"

In vivo NMR at 800 MHz to monitor alkaloid metabolism in plant cell cultures without tracer labeling.

2001

Isolation and Structure Elucidation of a New Indole Alkaloid from Rauvolfia serpentina Hairy Root Culture: The First Naturally Occurring Alkaloid of …

2002

A new monoterpenoid indole alkaloid, 10-hydroxy- N(alpha)-demethyl-19,20-dehydroraumacline ( 1), was isolated as a mixture of E- and Z-isomers from hairy root culture of Rauvolfia serpentina Benth. ex Kurz (Apocynaceae) and the structure was determined by 1D and 2D NMR analyses. The new indole alkaloid represents the first naturally occurring alkaloid of the raumacline group and its putative biosynthetical pathway is discussed.

In vivo monitoring of alkaloid metabolism in hybrid plant cell cultures by 2D cryo-NMR without labelling

2003

Non-invasive measurements of alkaloid metabolism in plant cell suspension cultures of a somatic hybrid from Rauvolfia serpentina Benth. ex Kurz and Rhazya stricta Decaisne were carried out. When cell samples were taken sequentially from a stock feeding experiment, measuring times for in vivo NMR of 40 min were sufficient for following conversions of alkaloids at the natural abundance of 13C. Degradation of ajmaline added to the cells at 1.6 mM concentration to raumacline could be monitored after 96 h on a standard 800 MHz NMR instrument (Avance 800). Feeding vinorine an intermediate of ajmaline biosynthesis at 1.8 mM showed with a 500 MHz CryoProbe that the alkaloid enters two metabolic rou…

Serotonergic modulation of rat pineal gland activity: in vivo evidence for a 5-Hydroxytryptamine(2C) receptor involvement

2000

There are some suggestions that, in the pineal gland, serotonin acts not only as a precursor of melatonin but also plays a role in the modulation of the pineal biosynthetic activity. To corroborate this possible neuromodulatory role of 5-hydroxytryptamine (serotonin) (5-HT) on the pineal gland, the effects of two 5-HT(2) receptor agonists meta-chlorophenylpiperazine (m-CPP) and 1-(2, 5-dimethoxy-4-iodophenyl)-2-aminopropane were assessed in vivo on pineal N-acetyltransferase (NAT) activity and melatonin content in rats. m-CPP potentiated the enhancement of NAT activity and pineal melatonin content induced by isoproterenol administration during daytime, whereas it did not affect the diurnal …

The first report of the Italian Migraine Registry (I-GRAINE).

2022

Italian Migraine Registry (I-GRAINE) is a multicenter (n = 38), prospective, observational, non-interventional study aimed at providing big data on migraine to ensure proper clinical disease management, according to scientific, and sustainability criteria. We enrolled consecutive patients affected by episodic or chronic migraine according to the systematic random method. Information on sociodemographic characteristics, lifestyle, migraine features, patient's journey, and healthcare resource use were gathered using face-to-face interviews.On the date of 31 December 2021, we enrolled 231 patients at 12 headache centers. Most of them were women (84.4%), with high migraine frequency (9.6 +/- 6.…

c-fos expression, behavioural, endocrine and autonomic responses to acute social stress in male rats after chronic restraint: modulation by serotonin

2000

The effects in male rats of serotonin depletion (using the neurotoxin 5,7-dihydroxytryptamine) on the cross-sensitization of an acute social stress (defeat by a larger resident male) by previous repeated restraint stress (10 days, 60 min per day) was studied. Previous restraint increased freezing responses during social defeat in sham-operated rats, but this was not observed in those with depleted serotonin (83% or more in different regions of the brain). In contrast, neither heart rate (tachycardia) nor core temperature responses (hyperthermia) were accentuated in previously restrained rats (i.e. neither showed heterotypical sensitization), and neither adapted to repeated restraint (there …

Development and validation of a radioimmunoassay for serum melatonin.

1989

A radioimmunoassay using N-[3-(4-hydroxy-3-[4-hydroxy-3- [125I]iodophenylpropionyl)]-5-methoxytryptamine as tracer for determination of melatonin in the serum of different species is described. Melatonin antisera were raised in rabbits by immunization with a bovine serum albumin conjugate of N-[3-(2-aminoethyl)-5-methoxy indole] hemisuccinamide. A single high affinity, specific antiserum was obtained. In contrast to previous studies, the tracer was synthesised in one step in the absence of water, giving an excellent yield of highly pure product. No chromatographic purification step was needed. Polyethylene glycol in combination with goat antirabbit immunoglobulins was used to separate bound…

Central serotonin depletion modulates the behavioural, endocrine and physiological responses to repeated social stress and subsequent c-fos expressio…

1999

Abstract Intraspecific confrontation has been used to study effect of depleting central serotonin on the adaptation of male rats to repeated social stress (social defeat). Four groups of adult male rats were used (serotonin depletion/sham: stressed; serotonin depletion/sham: non-stressed). Central serotonin was reduced (by 59–97%) by a single infusion of the neurotoxin 5,7-dihydroxtryptamine (150 μg) into the cerebral ventricles; levels of dopamine and noradrenaline were unaltered (rats received appropriate uptake blockers prior to neurotoxic infusions). Sham-operated animals received solute only. Rats were then either exposed daily for 10 days to a second larger aggressive male in the latt…

Effects of 5-HT4 receptor stimulation on basal and electrically evoked release of acetylcholine from guinea-pig myenteric plexus

1992

The effects of 5-methoxytryptamine and 5-hydroxytryptamine (5-HT) on both basal and electrically evoked outflow of tritium were studied in guinea-pig myenteric plexus preparations preincubated with [3H]-choline. Basal outflow. 5-Methoxytryptamine caused a transient and calcium-dependent increase in basal outflow of [3H]acetylcholine that was abolished by tetrodotoxin. Ondansetron (1 μmol/1) did not affect the stimulatory response of 5-methoxytryptamine but ICS 205-930 (1 and 3 μmol/1) produced parallel rightward displacements of the concentration-response curve to 5-methoxytryptamine. The PKB value for ICS 205-930 was 6.6 suggesting an involvement of 5-HT4 receptors. 5-HT caused an increase…

Molecular Architecture of Strictosidine Glucosidase: The Gateway to the Biosynthesis of the Monoterpenoid Indole Alkaloid Family[W]

2007

Abstract Strictosidine β-d-glucosidase (SG) follows strictosidine synthase (STR1) in the production of the reactive intermediate required for the formation of the large family of monoterpenoid indole alkaloids in plants. This family is composed of ∼2000 structurally diverse compounds. SG plays an important role in the plant cell by activating the glucoside strictosidine and allowing it to enter the multiple indole alkaloid pathways. Here, we report detailed three-dimensional information describing both native SG and the complex of its inactive mutant Glu207Gln with the substrate strictosidine, thus providing a structural characterization of substrate binding and identifying the amino acids …