A new isochroman derivative from the marine fungus Phomopsis sp. (No. ZH-111)

new isochroman, (3 R ,4 S )-3,4-dihydro-4,5,8-trihydroxy-3-methylisocoumarin ( 1 ), and two known compounds were isolated from the marine fungus Phomopsis sp. (No. ZH-111). Their structures were determined by spectroscopic methods, mainly 1D and 2D NMR. Preliminary pharmacological test revealed that compound 1 and exumolide A ( 3 ) can accelerate the growth of subintestinal vessel plexus (SIV) branches markedly and compound 2 can inhibit the growth of subintestinal vessel plexus (SIV) branches.