Cepharatines A-D, hasubanan-type alkaloids from Stephania cepharantha

Amines with low molecular weight are usually gaseous at room temperature, while those with high molecular weight are liquid or solids in nature. Usually, low molecular weight amines have a rotten fish-like smell. Diamines typically have a pungent smell. For instance, cadaverine and putrescine, depicted in Figure 1, are two molecules responsible for decaying tissue.

Cholinergic agonists or cholinomimetics mimic the action of acetylcholine to stimulate the parasympathetic nervous system. They are categorized into direct-acting and indirect-acting agents. The direct-acting cholinergic drugs induce the parasympathetic response by directly binding to the muscarinic or nicotine receptors. In comparison, the indirect-acting cholinergic drugs prevent acetylcholine hydrolysis, indirectly contributing to the extended parasympathetic response.
The direct-acting...

Sedatives and hypnotics encompass a drug class that acts on the central nervous system (CNS) to alleviate anxiety, promote relaxation and induce sleep.These drugs function by amplifying the actions of the neurotransmitter γ-aminobutyric acid (GABA), resulting in reduced neuronal activity. Barbiturates, a subset of sedatives and hypnotics first synthesized in the late 1800s, are categorized into ultra-short, short, intermediate, and long-acting groups based on their duration of effect. A key...

Synthetic and semisynthetic opioids are pivotal in pain management and tackling opioid addiction. Semisynthetic opioids, including morphinans (morphine derivatives), oxycodone, oxymorphone, hydrocodone, and hydromorphone, have improved pharmacokinetic profiles compared to morphine. Additionally, heroin and 6-MAM (6-Monoacetylmorphine) show better CNS penetration than morphine due to heightened lipid solubility. Hydromorphone, a potent opioid, undergoes hepatic metabolism to form the active...

CNS stimulants, such as cocaine, amphetamines, and cannabinoids, have varying structures and mechanisms of action that lead to different therapeutic effects and side effects. Cocaine, with its molecular formula C17H21NO4, is a tropane alkaloid and a tertiary amino compound. It has two chemical forms: the hydrochloride salt and the "freebase." The former is in powder form, while the latter involves removing the hydrochloride salt to create a form that can be smoked. Cocaine exerts its effects by...

Indirect-acting adrenergic agonists potentiate the effects of endogenous catecholamines through different mechanisms without directly binding to adrenoceptors.
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...