Steroids in newborns and infants. Identification of 24,25-dihydro-delta-9(ll)-lanosterol and 4 alpha, 14 alpha-dimethyl substituted sterols among the esterified and free sterols in human meconium.

TLDR: In this paper, the trimethylsilyl ethers of sterols in the free and ester fractions were analyzed by gas chromatography-mass spectrometry and showed that cholesterol and lathosterol made up 93% of the total sterols and were the predominating sterols.

Abstract: 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.