Statins (Compactin / ML-236B)

Fungal secondary metabolites produced by Penicillium citrinum as a natural chemical-competition trait, found to inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis. Endo, Kuroda & Tsujita, "ML-236A, ML-236B, and ML-236C, new inhibitors of cholesterogenesis produced by Penicillium citrinum" (J. Antibiot. 29, 1346-1348, 1976, OpenAlex W2055561625, 957 citations) -- the first published isolation, 1976, not 1973 as sometimes cited in secondary sources. ML-236B is compactin, the first statin. Directly founded the statin drug class; Lipitor (atorvastatin), a later compound in the same class, became the best-selling drug in pharmaceutical history (>$125B in lifetime sales). Classified under Chemistry/Biochemistry, not Biology, per BASIC_TAXONOMY_DRAFT.md's explicit Chemistry-Biology dual-tag framing for natural-product chemistry.