Produced in fungi, including yeast, and invertebrates from ergosterol in response to ultraviolet radiation; metabolized first to 25-hydroxyvitamin D2 and subsequently to the active 1,25-dihydroxyvitamin D2.

A benzothiazole derivative with anti-excitotoxic effects that acts by blocking the presynaptic release of glutamate, indirectly antagonizing glutamate receptors, and inactivating neuronal voltage-gated Na+ channels (ED50 = 2.3 μM); suppresses glutamate-induced seizures in rats (ED₅₀ =…

A tricyclic antidepressant that inhibits the reuptake of serotonin and norepinephrine and acts as an antagonist at histamine, serotonin, adrenergic, and muscarinic receptors with Ki values in the nanomolar range.

An analog of wortmannin; irreversibly binds PI3K; inhibits recombinant PI3K and mTOR (IC₅₀ = 2.7 and 193 nM, respectively) and prevents the growth of LNCap cells (IC₅₀ = 1.46 μM).

A dihydropyridine L-type calcium channel antagonist that displays antihypertensive and antianginal activity; selectively inhibits adenosine A3 receptors (Ki = 3.25 µM) and CYP3A4 catalytic activity (IC₅₀ = 0.148 µM); activates TRPA1 channels, producing an increase in Ca2+…

A neuroexcitatory amino acid that functions as a NMDA and metabotropic glutamate receptor agonist; used to induce brain lesions in animal models of cognitive dysfunction.

An NSAID commonly used in animals to combat pain and inflammation, particularly as associated with osteoarthritis; inhibits both COX-1 and COX-2 (IC₅₀s = 22.3 and 3.9 µM, respectively) and also FAAH (IC₅₀ = 74 µM).

A hepatotoxic monocylic pentapeptide that acts as a potent inhibitor of protein phosphatase types 1 (PP1) and 2A (PP2A), exhibiting IC50 values of 1.8 and 0.026 nM, respectively.

An intermediate produced from vitamin D2 by cytochrome P450 isoforms in vertebrates; subsequently metabolized to 1,25-dihydroxy vitamin D2, which is an agonist for the vitamin D receptor.

A selective non-peptide inhibitor of CXCR2, inhibiting IL-8 binding to CXCR2 (IC₅₀ = 22 nM).

A cyclic polypeptide-containing anticancer antibiotic that binds to DNA and blocks transcription by interfering with RNA synthesis; ~10 nM promotes cell death in a variety of tumors.

A natural fungal metabolite which reversibly interferes with protein trafficking and secretion mediated by the Golgi apparatus and endoplasmic reticulum; directly and reversibly inhibits Sec7 domain-containing GEFs which are necessary for Arf activation associated with vesicular transport (IC50 =…

A potent, reversible, ATP-competitive, and selective inhibitor of the Src family of protein tyrosine kinases: p56lck (IC₅₀ = 4 nM), p59fynT (IC₅₀ = 5 nM), Hck (IC₅₀ = 5 nM).

An analog of 1,24-dihydroxy vitamin D3 which, when used in a 4 μg/g ointment, suppresses psoriasis; inhibits the growth of both normal and psoriatic human keratinocytes (IC50 ~ 10 nM) via the vitamin D receptor; suppresses the production of RANTES and IL-8 by human dermal fibroblasts.

A cyclododecadepsipeptide potassium-selective ionophore antibotic; induces apoptosis in several cell tyes, including CHO cells, by stimulating potassium efflux.

A dipyridinyl compound that demonstrates high in vitro and ex vivo selectivity for COX-2 over COX-1.

An orally active broad spectrum antifungal agent that blocks ergosterol biosynthesis by inhibiting the fungal CYP isoform CYP51; potently inhibits the mammalian analog CYP51A1 (IC₅₀ = 63.5 nM), as well as a variety of other CYP isoforms.

An agonist of α2 adrenergic receptors (Ki = 194 nM); used for sedation, anesthesia, and analgesia in non-human mammals.

A noncompetitive nicotinic acetylcholine receptor antagonist with preferential activity at the α3β4 subtype (IC₅₀ = 90-640 nM) compared to α4β2, α3β2, and α7 subtypes (IC₅₀s range from 1-7 μM).

A CYP2C9 metabolite of the NSAID diclofenac that demonstrates anti-inflammatory and analgesic properties by inhibiting COX and suppressing PGE2 synthesis.

PGE1 is the theoretical COX metabolite of DGLA, but it is virtually undetectable in the plasma of normal humans or other animals. Its pharmacology includes vasodilation, hypotension, and anti-platelet activities. The IC₅₀ of PGE1 for the inhibition of ADP-induced human platelet…

An amino-amide anesthetic that binds to the intracellular portion of voltage-gated sodium channels and blocks sodium influx into nerve cells, preventing the generation of an action potential; inhibits the uptake of dopamine in striatal synaptosomes by 47% at 100 µM.

Myriocin is an amino fatty acid antibiotic derived from certain thermophylic fungi, in this case Mycelia sterilia. It is a potent immunosuppressant having 10- to 100-fold more activity than cyclosporin A. Myriocin is a potent inhibitor of serine palmitoyltransferase (Ki = 0.28 nM), the enzyme that…

A polymethoxylated flavone that has been shown to enhance adipogenesis and lipolysis, to inhibit α-glucosidase and α-amylase activity, and to suppress the expression of genes associated with inflammation by regulating IκBα.

A cell-permeable, stable free radical that is commonly used to evaluate the ability of compounds to act as free radical scavengers or hydrogen donors and to measure the antioxidant activity of tissue extracts; followed by color change from purple (absorbance at 515-528 nm) to yellow.

An indole diterpene which potently and reversibly inhibits large conductance Ca2+-activated K+ (BKCa) channels, as shown in patch clamp (Ki = 1.9 nM) and whole smooth muscle cell studies (Ki = 35.7 nM).

A natural type B trichothecene produced by certain species of the fungus Fusarium; inhibits protein biosynthesis, binds to peptidyl transferase, and inhibits the synthesis of RNA and DNA; passes the blood-brain barrier at different rates in different animals.

A flavonoid compound found in the bark and rinds of many plants and fruits.

A thio analog of the purine base guanine that incorporates into DNA during replication, inducing double-strand breaks that destabilize its structure and result in cytotoxicity; used as a chemotherapeutic for acute leukemia and other types of cancer, including BRCA2-mutated tumors.

A DNA alkylating agents that induces DNA interstrand and intrastrand crosslinks, cytotoxicity, and apoptosis; inhibits the growth of PC-3 prostate cancer cells with IC₅₀ values of 0.074 or 0.77 μM for sequential dosing or single dosing, respectively.

A nitrogen mustard β-chloro-nitrosourea compound used as an alkylating agent to form interstrand crosslinks in DNA, which leads to cancer cell cytotoxity and apoptosis; also reported to inhibit glutathione reductase, thioredoxin reductase, and lipoamide dehydrogenase.

A cyanobacterial toxin that targets protein and glutathione synthesis in hepatocytes (IC50s = 1.3 and 2.4 µM, respectively), inhibits uridine monophosphate synthase complex activity (Ki = 10 µM), and induces DNA damage.