100632-37-9 Hygrolidin, 21-de((3-carboxy-1-oxo-2-propenyl)oxy)-19,23-deepoxy-23-deethyl-20,21-didehydro-2-demethyl-19-deoxy-23-hydroxy-2-methoxy-23-methyl-19-oxo- PD 118576 PD-118,576