Trazodone (brand name Oleptro, Desyrel, etc) is a serotonin uptake inhibitor that is used as an antidepressive agent. Trazodone binds to the 5-HT2 receptor, it acts as a serotonin agonist at high doses and a serotonin antagonist at low doses. Like fluoxetine, trazodone's antidepressant activity likely results from blockage of serotonin reuptake by inhibiting serotonin reuptake pump at the presynaptic neuronal membrane. If used for long time periods, postsynaptic neuronal receptor binding sites may also be affected. The sedative effect of trazodone is likely the result of alpha-adrenergic blocking action and modest histamine blockade at the H1 receptor. It weakly blocks presynaptic alpha2-adrenergic receptors and strongly inhibits postsynaptic alpha1 receptors. Trazodone does not affect the reuptake of norepinephrine or dopamine within the CNS. Because of its lack of anticholinergic side effects, trazodone is especially useful in situations in which antimuscarinic effects are particularly problematic (e.g., in patients with benign prostatic hyperplasia, closed-angle glaucoma, or severe constipation). Trazodone's propensity to cause sedation is a dual-edged sword. For many patients, the relief from agitation, anxiety, and insomnia can be rapid; for other patients, including those individuals with considerable psychomotor retardation and feelings of low energy, therapeutic doses of trazodone may not be tolerable because of sedation. Trazodone elicits orthostatic hypotension in some patients, probably as a consequence of α1-adrenergic receptor blockade. Mania has been observed in association with trazodone treatment, including in patients with bipolar disorder, as well as in patients with previous diagnoses of major depression. Compared to the reversible MAOI antidepressant drug moclobemide, significantly more impairment of vigilance occurs with trazodone.

N,N-Dimethyl-5-Methoxytryptamine (aka 5-MeO-DMT) is a psychedelic of the tryptamine class. It is found in a wide variety of plant species, and a single psychoactive toad species, the Colorado River toad. Like its close relatives DMT and bufotenin (5-HO-DMT), it has been used as an entheogen in South America. It can also be found in the dart poison traditionally used by the Yanoama Indians of Upper Orinoco. It acts as a non-selective serotonin (5-HT) agonist. -MeO-DMT is O-demethylated by polymorphic cytochrome P450 2D6 (CYP2D6) to an active metabolite, bufotenine. 5-MeO-DMT is classified as a controlled substance in China, Australia, Sweden, Turkey, and the USA.

Ergocornine is an ergot alkaloid. Ergocornine can inhibit prolactin release by a direct action on the anterior pituitary. It can modulate activity at both dopamine and serotonin receptors.

Chlorprothixene (Taractan, Tarasan, Truxal) is a thioxanthine derivative developed by Lundbeck for the treatment of psychotic disorders. The drug exerts its activity by binding to and inhibiting serotonin receptors, dopamine receptors, muscarinic acetylcholine receptor, histamine H1 receptor and alpha1-adrenergic receptor.

Ergonovine (also known as ergometrine) is the active water soluble component of ergot of rye. Ergonovine is being used as a maleate salt to prevent or treate postpartum haemorrhage and postabortion haemorrhage. Ergonovine stimulates alpha-adrenergic and serotonin receptors, thus activating contractions of uterine and vascular smooth muscle. Ergonovine may have depressant effect on CNS system as it binds to dopamine receptors.

Dihydroergocristine is an ergot alkaloid that has an partial agonist activity on dopaminergic and alpha-adrenergic receptors and antagonist activity on serotonin receptors. The drug was approved by FDA in combination with other alkaloids (dihydroergocornine, dihydro-alpha-ergocryptine and dihydro-beta-ergocryptine mesylate salts) under the name Hydergine for the treatment of dimentia and cerebrovascular insufficiency.

Isorhynchophylline is a plant alkaloid isolated from Uncaria species with therapeutic potential for cardiovascular and central nervous system diseases. The antihypertensive effect of isorhynchophylline was firstly observed in 1989, which was strongly linked to the traditional use of Uncaria species (Gouteng in Chinese). Isorhynchophylline and rhynchophylline were the main hypotensive constituents in Uncaria rhynchophylla. In rat isolated mesenteric arteries and tail artery, isorhynchophylline inhibited the increased infusion pressure induced by high K+ and norepinephrine in a concentration-dependent manner. The potency of isorhynchophylline and rhynchophylline was similar in mesenteric arteries, but in the tail artery, the effect of isorhynchophylline on high K+ induced infusion pressure increase was stronger than that of rhynchophylline, and there was a similar trend in the contractile response induced by norepinephrine. Isorhynchophylline also inhibited the hypertensive effect of angiotensin II. The results indicate that in small blood vessels of rat, isorhynchophylline can directly inhibit the contractile responses induced by several agonists. In vivo, ouabain and CaCl2 were used to establish experimental arrhythmic models in guinea pigs and rats. In vitro, the whole-cell patch-clamp technique was used to study the effect of isorhynchophylline on action potential duration and calcium channels in acutely isolated guinea pig and rat cardiomyocytes. Isorhynchophylline, infusion 0–16 mg/kg at a constant rate, dose-dependently decreased heart rate, prolonged sinus node recovery time, and PR, AH, HV intervals. Isorhynchophylline significantly inhibited the heart rate and atrioventricular conduction. These inhibitory effects of isorhynchophylline were partially antagonized by isoprenaline, but not by atropine. Isorhynchophylline inhibited the automaticity and contractile force of isolated guinea pig atrium in a concentration-dependent manner. Isorhynchophylline significantly depressed adrenaline-induced automaticity, and prolonged functional refractory period and decreased excitability. Furthermore, 10 μmol/L of isorhynchophylline reduced the effect of ouabain on the contractile force in the left atrium and significantly inhibited the response to paired stimulation. In anesthetized dogs, isorhynchophylline markedly reduced the tension-time index which indicated myocardial oxygen consumption. The result indicates that the decrease of myocardial oxygen consumption by isorhynchophylline would protect the heart against ischemia induced by hypertension. Isorhynchophylline showed a mild central depressive effect in mice. Isorhynchophylline significantly decreased locomotor activity after oral administration to mice. The depression of locomotor activity upon administration of the alkaloid appears to be due to mediating of the central dopaminergic system. Isorhynchophylline dose-dependently inhibited 5-hydroxytryptamine (5-HT)2A receptor-mediated head-twitch but not 5-HT1A receptor-mediated head-weaving responses evoked by 5-methoxy-N, N-dimethyltryptamine. Isorhynchophylline attenuated the in vitro ischemia-induced neuronal damage in a dose-dependent manner. Isorhynchophylline protects against glutamate-induced neuronal death in cultured cerebellar granule cells by inhibition of Ca2+ influx. Pretreatment with isorhynchophylline significantly elevated cell viability, decreased the levels of intracellular reactive oxygen species and malondialdehyde, increased the level of glutathione, and stabilized mitochondrial membrane potential in β- amyloid(25–35)-induced neurotoxicity in rat pheochromocytoma cells. In unthoracotomized dogs, isorhynchophylline (5 mg/kg, iv) reduced the mean arterial pressure but did not affect renal blood flow. Isorhynchophylline did not block nictitating membrane contraction induced by stimulating collum sympathetic nerve and did not decrease blood pressure after injected in the cerebral ventricle.

2,4-Dichlorophenoxyacetic acid (2,4-D) was the first synthetic herbicide to be commercially developed and has commonly been used as a broadleaf herbicide for over 60 years. It is a selective herbicide that kills dicots without affecting monocots and mimics natural auxin at the molecular level. 2,4-D was developed during World War II as one of many so-called phenoxy herbicides by aiming to increase crop yields for a nation at war. It was commercially released in 1946 becoming the first successful selective herbicide and allowed for greatly enhanced weed control in wheat, maize, rice, and other similar cereal crops because it specifically targets dicots. This herbicide family is said to have “initiated an agricultural revolution and laid the corner stone of present-day weed science” when it was first marketed in the 1940s.

Serotonin (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter produced by serotonergic neurons in the CNS and enterochromaffin cells in the gastrointestinal tract. Pharmacologic action of serotonin is mediated by a large and diverse range of 5-HT receptors. Serotonin plays an important part in the biochemistry of depression, migraine, bipolar disorder, and anxiety. It is also believed to be influential on sexuality and appetite. Creatinine is a product of the metabolic breakdown of creatine phosphate in muscle. Creatinine is filtered by healthy kidneys. Serotonin creatinine sulfate complex was the first isolated salt form of serotonin.