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Alstonine
Alstonine is a pentacyclic alkaloid and putative antipsychotic constituent of various plant species including ''Alstonia boonei'', ''Catharanthus roseus'', ''Picralima nitida'', ''Rauvolfia afra'' and ''Rauvolfia vomitoria''. In preclinical studies alstonine attenuates MK-801-induced hyperlocomotion, working memory deficit and social withdrawal. It also possesses anxiolytic-like effects in preclinical studies, attenuates amphetamine-induced lethality and stereotypy as well as apomorphine-induced stereotypy, and attenuates haloperidol-induced catalepsy. These effects appear to be mediated by stimulation of the 5-HT2C receptor, 5-HT2C receptor. In addition, alstonine, similarly to clozapine, indirectly inhibits the reuptake of glutamate in hippocampus, hippocampal slices. Unlike clozapine however, the effect of which is abolished by the D2 receptor, D2 receptor agonist apomorphine, alstonine requires 5-HT2A receptor, 5-HT2A and 5-HT2C receptors to produce this effect, as it is abolis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rauwolscine
Rauwolscine, also known as isoyohimbine, α-yohimbine, and corynanthidine, is an alkaloid found in various species within the genera ''Rauvolfia'' and '' Corynanthe'' (including ''Pausinystalia''). It is a stereoisomer of yohimbine. Rauwolscine is a central nervous system stimulant, a local anesthetic and a vague aphrodisiac. Rauwolscine acts predominantly as a α2-adrenergic receptor antagonist. It has also been shown to function as a 5-HT1A receptor partial agonist and 5-HT2A and 5-HT2B receptor antagonist. See also * Ajmalicine * Corynanthine Corynanthine, also known as rauhimbine, is an alkaloid found in the ''Rauvolfia'' and ''Corynanthe'' (including ''Pausinystalia'') genera of plants. It is one of the two diastereoisomers of yohimbine, the other being rauwolscine. It is also relat ... * Spegatrine References {{Tryptamines Indoloquinolizines Tryptamine alkaloids Quinolizidine alkaloids Alkaloids found in Rauvolfia Alpha-2 blockers 5-HT1A agonists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitragynine
Mitragynine is an indole-based alkaloid and is one of the main Psychoactive drug, psychoactive constituents in the Southeast Asian plant ''Mitragyna speciosa'', commonly known as kratom. It is an atypical opioid that is typically consumed as a part of kratom for its Analgesic, pain-relieving and Euphoria, euphoric effects. It has also been researched for its use to potentially manage symptoms of opioid withdrawal. Mitragynine is the most abundant active alkaloid in kratom. In Thai varieties of kratom, mitragynine is the most abundant component (up to 66% of total alkaloids), while 7-Hydroxymitragynine, 7-hydroxymitragynine (7-OH) is a minor constituent (up to 2% of total alkaloid content). In Malaysian kratom varieties, mitragynine is present at lower concentration (12% of total alkaloids). Total alkaloid concentration in dried leaves ranges from 0.5 to 1.5%. Such preparations are Oral administration, orally consumed and typically involve dried kratom leaves which are brewed into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deserpidine
Deserpidine (INN) or reserpidine (USAN) is an antihypertensive drug structurally related to reserpine differing only by the absence of a methoxy group on the indole ring. It is a naturally occurring alkaloid from ''Rauvolfia ''Rauvolfia'' (sometimes spelled ''Rauwolfia'') is a genus of evergreen trees and shrubs, commonly known as devil peppers, in the family Apocynaceae. The genus is named to honor Leonhard Rauwolf. The genus can mainly be found in Tropics, trop ...'' spp. References Alkaloids found in Rauvolfia Antihypertensive agents Benzoate esters Tryptamine alkaloids Indoloquinolizines Quinolizidine alkaloids Monoamine-depleting agents Pyrogallol ethers VMAT inhibitors Methoxy compounds Methyl esters Heterocyclic compounds with 5 rings {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corynanthine
Corynanthine, also known as rauhimbine, is an alkaloid found in the ''Rauvolfia'' and ''Corynanthe'' (including ''Pausinystalia'') genera of plants. It is one of the two diastereoisomers of yohimbine, the other being rauwolscine. It is also related to ajmalicine. Corynanthine acts as an alpha-1 adrenergic receptor, α1-adrenergic and alpha-2 adrenergic receptor, α2-adrenergic receptor receptor antagonist, antagonist with approximately 10-fold binding selectivity, selectivity for the former site over the latter. This is in contrast to yohimbine and rauwolscine which have around 30-fold higher affinity for the α2-adrenergic receptor over the α1-adrenergic receptor. As a result, corynanthine is not a stimulant (or an aphrodisiac for that matter), but a depressant, and likely plays a role in the antihypertensive properties of ''Rauvolfia'' extracts. Like yohimbine and rauwolscine, corynanthine has also been shown to possess some activity at serotonin receptors. See also * Ajmalici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ajmalicine
Ajmalicine, also known as δ-yohimbine or raubasine, is an antihypertensive drug used in the treatment of high blood pressure. It has been marketed under numerous brand names including Card-Lamuran, Circolene, Cristanyl, Duxil, Duxor, Hydroxysarpon, Iskedyl, Isosarpan, Isquebral, Lamuran, Melanex, Raunatin, Saltucin Co, Salvalion, and Sarpan. It is an alkaloid found naturally in various plants such as ''Rauvolfia'' spp., '' Catharanthus roseus'', and '' Mitragyna speciosa''. Ajmalicine is structurally related to yohimbine, rauwolscine, and other yohimban derivatives. Like corynanthine, it acts as a α1-adrenergic receptor antagonist with preferential actions over α2-adrenergic receptors, underlying its hypotensive rather than hypertensive effects. Additionally, it is a very strong inhibitor of the CYP2D6 liver enzyme, which is responsible for the breakdown of many drugs. Its binding affinity at this receptor is 3.30 nM. Biosynthesis Two moieties are involved in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convulsant
A convulsant is a drug which induces convulsions or epileptic seizures, the opposite of an anticonvulsant. These drugs generally act as stimulants at low doses, but are not used for this purpose due to poor therapeutic indices. Most convulsants are antagonists (or inverse agonists) at either the GABAA or/and glycine receptors (e.g the pesticide fipronil), or ionotropic glutamate receptor agonists (e.g the marine toxin domoic acid). Many other drugs may cause convulsions as a side effect at high doses (e.g. bupropion, tramadol, pethidine, dextropropoxyphene, clomipramine) but only drugs whose primary action is to cause convulsions are known as convulsants. Nerve agents such as sarin, which were developed as chemical weapons, produce convulsions as a major part of their toxidrome, but also produce a number of other effects in the body and are usually classified separately. Dieldrin which was developed as an insecticide blocks chloride influx into the neurons causin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Antagonist
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins.Pharmacology Guide: In vitro pharmacology: concentration-response curves ." '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include alpha blockers, beta b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT2A Receptor
The 5-HT2A receptor is a subtype of the 5-HT2 receptor, 5-HT2 receptor that belongs to the serotonin receptor family and functions as a GPCR, G protein-coupled receptor (GPCR). It is a cell surface receptor that activates multiple intracellular signalling cascades. Like all 5-HT2 receptors, the 5-HT2A receptor is coupled to the Gq protein, Gq/G11 signaling pathway. It is the primary excitatory receptor subtype among the serotonin-responsive GPCRs. The 5-HT2A receptor was initially noted for its central role as the primary target of serotonergic psychedelic drugs such as LSD and psilocybin mushrooms. It later regained research prominence when found to mediate, at least in part, the effects of many antipsychotic drugs, particularly atypical antipsychotic, atypical antipsychotics. Downregulation of post-synaptic 5-HT2A receptors is an adaptive response triggered by chronic administration of selective serotonin reuptake inhibitors (SSRIs) and atypical antipsychotics. Elevated 5-HT2A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonist
An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an Receptor antagonist, antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology The word originates from the Ancient Greek, Greek word (''agōnistēs''), "contestant; champion; rival" < (''agōn''), "contest, combat; exertion, struggle" < (''agō''), "I lead, lead towards, conduct; drive." Types of agonists Receptor (biochemistry), Receptors can be activated by either endogenous agonists (such as hormones and neurotransmitters) or exogenous agonists (such as medication, drugs), resulting in a biological response. A physiological agonism an ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D2 Receptor
Dopamine receptor D2, also known as D2R, is a protein that, in humans, is encoded by the ''DRD2'' gene. After work from Paul Greengard's lab had suggested that dopamine receptors were the site of action of antipsychotic drugs, several groups, including those of Solomon H. Snyder and Philip Seeman used a radiolabeled antipsychotic drug to identify what is now known as the dopamine D2 receptor. The dopamine D2 receptor is the main receptor for most antipsychotic drugs. The structure of DRD2 in complex with the atypical antipsychotic risperidone has been determined. Function D2 receptors are coupled to Gi subtype of G protein. This G protein-coupled receptor inhibits adenylyl cyclase activity. In mice, regulation of D2R surface expression by the neuronal calcium sensor-1 (NCS-1) in the dentate gyrus is involved in exploration, synaptic plasticity and memory formation. Studies have shown potential roles for D2R in retrieval of fear memories in the prelimbic cortex and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
