Fractionation guided by immunomodulatory activity of the EtOAc extract of t
he Ascomycete Eupenicillium crustaceum has afforded two new naturally occur
ring products, 4 ' -oxomacrophorin D (1) and 4 ' -oxomacrophorin A (2), as
the immunosuppressive components of this fungus [1: 3-hydroxy-3-methylgluta
ryl (HMG) conjugate of 2]. The structures including the absolute configurat
ions of 1 and 2 have been determined on the basis of chemical correlation o
f I with macrophorin D (3). The absolute configuration of the HMG moiety in
3 has been revised from 3R to 3S.