New penicillide derivatives isolated from Penicillium simpficissfinum

Two new penicillide derivatives, secopenicilides A (3) and B (4), were isolated along with penicillide (1) and purpactin A (2), and altenusin (5) and dehydroaltenusin (6), the antifungal substances of this fungus, from the extract of Penicillium simplicissimum IFM 53375. The absolute structures of 3 and 4 were determined by spectroscopic investigation and chemical correlation to penicillide (1). The absolute configuration of purpactin A (2) was determined by the chemical method.