Fumigaclavine B is an ergoline compound made in fungi including Aspergillus fumigatus.

Both 8α and 8β diastereomers (epimers) were named fumigaclavine B in scientific literature.

See also Fumigaclavine A Fumigaclavine C Fumigaclavine B O-acetyltransferase

References https://pubchem.ncbi.nlm.nih.gov/compound/46173120#section=Top