Bismuth ion (Bi³⁺)

Bismuth ion typically refers to the trivalent cation **Bi³⁺**, which is the biologically and pharmacologically relevant form of bismuth in medicinal chemistry. Bismuth is a heavy post-transition metal found in Group 15 of the periodic table, with a stable oxidation state of +3 in most of its compounds. **Bismuth ions themselves are not recognized as a bona fide therapeutic target such as a receptor, enzyme, transporter, or signal transduction molecule.** There are no canonical abbreviations for bismuth as a drug target because it is not a macromolecular target; rather, it is an inorganic ion with chemical, antimicrobial, and physicochemical properties. **Bismuth compounds** (not the free ion) are of therapeutic interest, particularly for their antimicrobial effects (notably against *Helicobacter pylori*) and have some applications in gastrointestinal treatments through a range of formulated salts (e.g., bismuth subsalicylate, bismuth subnitrate, bismuth subcitrate). The mechanism of action of these compounds is due to **direct chemical effects, including inhibition of bacterial enzymes, interference with microbial membranes, and anti-inflammatory properties**—but these act via **biochemical or toxic chemical mechanisms**, and not via selective action at a defined molecular target/receptor. **As an ion, bismuth has no known physiological function or established biological role** in human biochemistry. It is generally considered nontoxic in the forms used in pharmaceuticals, though accumulation or improper use can cause rare but serious toxicity. **Correction/clarification on "is_target" and "is_incorrect":** - The **bismuth ion** is not classified as a therapeutic target in the context of molecular pharmacology or drug discovery, such as GPCRs, enzymes, or ion channels; rather, it is an inorganic ion used in medicinal chemistry. - The entry is **considered "incorrect" for modern target annotation frameworks**, as it describes an inorganic chemical ion rather than a molecular target as customarily defined in pharmacology and drug discovery. **Summary of conventions/fields:** - Full canonical name: "Bismuth ion" (more specifically, "Bismuth(III) ion" or "Bi³⁺") - No standard abbreviation (Bi³⁺ is IUPAC, not target-specific) - Not a molecular target; rather, a pharmacologically active chemical species - No relevant molecular family (not a receptor, enzyme, channel, etc.) - No direct disease roles as a *target*; however, some bismuth compounds are clinically relevant drugs - No known function as a biomarker or drug-interacting target; discussion of mechanism pertains to physiochemical interaction projects, not target-driven MOA.

Other names

Bismuth(III) ionBi³⁺Bismuth cationBismuth ion (general; includes Bi⁺ and Bi³⁺ formal oxidation states)

The mechanism of action of these compounds is due to direct chemical effects, including inhibition of bacterial enzymes, interference with microbial membranes, and anti-inflammatory properties—but these act via biochemical or toxic chemical mechanisms, and not via selective action at a defined molecular target/receptor.