Lergosterolo

Lergosterolo, commonly referred to in English as ergosterol, is the principal sterol found in the membranes of fungi and many yeasts. It is a steroid alcohol with a structure that distinguishes it from cholesterol, providing the necessary membrane rigidity and organization in fungal cells. Ergosterol helps maintain membrane fluidity and permeability, contributing to fungal growth and viability.

Biosynthesis and biology: Ergosterol is produced in the fungal mevalonate pathway from acetyl-CoA, undergoing several enzymatic steps to form ergosterol from lanosterol. The process involves enzymes such as lanosterol 14-demethylase (CYP51); this enzyme is a common target of azole antifungal drugs, which inhibit ergosterol synthesis and disrupt the fungal membrane.

Vitamin D2 precursor: Exposure of ergosterol to ultraviolet light converts it to previtamin D2, which thermally isomerizes to ergocalciferol (vitamin D2). This property underpins the use of ergosterol-derived compounds as sources of vitamin D2 in certain mushrooms and fortified foods.

Applications and uses: Ergosterol serves as a useful biomarker for fungal biomass in soils, foods, and environmental samples, because it is predominantly associated with fungi. In medicine and pharmacology, the pathway that produces ergosterol is a well-established target for antifungal drugs. Additionally, ergosterol-derived vitamin D2 is utilized in dietary supplements and fortification strategies.

Occurrence and distribution: Ergosterol is widespread in fungi and yeasts but is not a major component of animal membranes. Its presence is often used in mycological analyses and food quality assessments to indicate fungal material.