Alkaloids

N-Demethyl-α-obscurine, a lycodine-type Lycopodium alkaloid, is isolated from Lycopodii Herba.

Atherosperminine (Atherospermine) is a phosphodiesterase inhibitor. Atherosperminine inhibits growth of chloroquine-resistant Plasmodium falciparum. Atherosperminine scavenges DPPH free radicals, exhibits ferric reducing power, and chelates metal ions. Atherosperminine can be used for the research of malaria.

Humantenine is a highly toxic indole alkaloid from Gelsemium elegans (Gardn. & Champ.) Benth. that binds to RNA m6A modification regulatory proteins (ALKBH5, METTL). Humantenine stably binds via hydrogen bonding and hydrophobic interactions and disrupts the m6A methylation level of target genes, thereby impairing the expression of intestinal epithelial cell tight junction and cytoskeleton-related genes, causing intestinal barrier dysfunction and significant intestinal cytotoxicity. The intraperitoneal injection LD₅₀ values of Humantenine are <1 mg/kg in mice, 1.2 mg/kg in male rats and 1.5 mg/kg in female rats, respectively. Species differences exist in the metabolism of Humantenine in human, porcine, goat and rat liver microsomes, and demethylation, dehydrogenation and oxidation occur in liver microsomes.

(±)-Coniine (2-Propylpiperidine) is a piperidine alkaloid and nAChR agonist (EC₅₀=0.3 mM). (±)-Coniine is acutely toxic to mice with an LD50 value of 7.7 mg/kg.

Magnocurarine is a neuromuscular junction blocker that inhibits muscle contraction by functionally blocking signal transmission without directly damaging nerve or muscle tissues. In frog, mouse and rabbit models, Magnocurarine exerts a dose-dependent paralytic effect, which progresses gradually from limb weakness and loss of righting reflex to respiratory depression and even cardiac arrest. Although high doses cause complete cessation of movement, Magnocurarine does not affect the spinal multineuronal reflex in frogs. Magnocurarine exhibits biological activity similar to that of tubocurarine (HY-125901) in various animal models.

Quinidine sulfate dihydrate is an orally active antiarrhythmic agent. Quinidine sulfate dihydrate reduces the expression level of P-gp, inhibits P-gp-mediated efflux, increases the intracellular accumulation of P-gp substrates, induces PARP cleavage and Caspase-3 activation, and elevates the proportion of Apoptotic cells at the sub-G1 phase. Quinidine sulfate dihydrate exerts sustained block and open-channel block effects on I_K(f). Quinidine sulfate dihydrate alters the urinary metabolic ratio of Amphetamine, modulates the Pentylenetetrazol-induced seizure threshold, and regulates the anticonvulsant effect of Dextromethorphan. Quinidine sulfate dihydrate can be used in studies related to uterine sarcoma and seizures.

Tabersonine hydrochloride is a selective, orally active NLRP3 inhibitor. Tabersonine hydrochloride directly binds to the NACHT domain of NLRP3, inhibiting its ATPase activity and oligomerization, thereby blocking ASC spot formation and caspase-1 activation, and reducing the release of pro-inflammatory cytokines such as IL-1β. Tabersonine hydrochloride also inhibits K63-linked ubiquitination of TRAF6, blocking NF-κB, PI3K/Akt, and p38 MAPK signaling pathways. Tabersonine hydrochloride can inhibit inflammatory responses, induce apoptosis of liver cancer cells through mitochondrial pathways and death receptor pathways, reduce mitochondrial membrane potential, promote cytochrome c release, and activate caspase proteins. Tabersonine hydrochloride is mainly used in the study of NLRP3-driven inflammatory diseases (such as acute lung injury, sepsis, peritonitis) and tumors such as liver cancer.

Denudatine, is primarily isolated from plants of the genera Aconitum and Delphinium. Denudatine has effects on action potential of ventricular fibers and inhibits arrhythmogenic action of aconitine.

Berberine (Natural Yellow 18) is an alkaloid isolated from the Chinese herbal medicine Huanglian, as an antibiotic. Berberine (Natural Yellow 18) induces reactive oxygen species (ROS) generation and inhibits DNA topoisomerase. Berberine (Natural Yellow 18) has antineoplastic properties. The sulfate form (HY-N0716B) improves bioavailability.

Methyldopa hydrochloride (L-(-)-α-Methyldopa hydrochloride) hydrochloride, a potent antihyoertensive agent, is an alpha-adrenergic agonist (selective for α2-adrenergic receptors). Methyldopa hydrochloride is a proagent and is metabolized (α-Methylepinephrine) in the central nervous system.

Pyranonigrin A is isolated and identified from Penicillium brocae MA-231. Pyranonigrin A shows potent activity against a broad spectrum of human-, aqua-, and plant-pathogens.

Pyridoxatin is a free radical scavenger of microbial origin. Pyridoxatin is isolated from a fungus culture identified as Acremonium sp. BX86. Pyridoxatin inhibits lipid peroxidation induced by free radicals in rat liver microsomes free from vitamin E.

epi-Aszonalenin A is a benzodiazepine fungal metabolite originally isolated from Aspergillus novofumigatus. epi-Aszonalenin A can be used as a psychoactive agent.

7-Acetylintermedine is a hepatotoxic botanical pyrrolizidine alkaloid.