Steroids in Newborns and Infants: Identification of 24,25‐Dihydro‐Δ⁹⁽¹¹⁾‐Lanosterol and 4α, 14α‐Dimethyl Substituted Sterols among the Esterified and Free Sterols in Human Meconium

Lipid extracts of human meconium were separated by chromatography on silicic acid and lipophilic Sephadex. Trimethylsilyl ethers of sterols in the free and ester fractions were analyzed by gas chromatography‐mass spectrometry. Cholesterol and lathosterol made up 93% of the total sterols and were the predominating sterols in the unesterified fraction (relative abundance: 96%). The remaining 4% in this fraction consisted of lanosterol, 24,25‐dihydro‐Δ⁸‐lanosterol, 24,25‐dihydro‐Δ⁹‐lanosterol, 4α,14α‐dimethyl‐5α‐cholest‐7 (and 8)‐en‐3β‐ol, and Δ⁷‐ and Δ⁸‐methostenol. The sterol ester fraction contained 4,4‐dimethyl‐5α‐cholest‐8‐en‐3β‐ol, 4,4‐dimethyl‐5α‐cholest‐8,14‐dien‐3β‐ol, β‐sitostanol, cholesterol, lathoesterol, lanosterol, 24,25‐dihydro‐Δ⁸‐lanosterol, 4α,14α‐dimethyl‐5α‐cholest‐7(and 8)‐en‐3β, and Δ⁷‐ and Δ⁸‐methostenol. However, this fraction contained a smaller proportion of Δ⁷‐sterols than the free fraction. The percentage of cholesterol and lathosterol was also relatively smaller (75%) than in the free sterol fraction.