marine microorganisms such as bacteria , fungi , and microalgae have proven to be a rich source of structurally novel and biologically active secondary metabolites . in our search for new substances from marine microorganisms , two new cytotoxic twelve - membered macrolides , sporiolides a ( 1 ) and b ( 2 ) , were isolated from the cultured broth of a fungus cladosporium sp . , which was separated from an okinawan marine brown alga actinotrichia fragilis . in this paper ( l037 ) was separated from the brown alga collected off seragaki beach , okinawa island , and grown in sc broth [ starch ( 1% ) and casein ( 0.1% ) in 50% sea water , ph 7.4 ] at 28c for 14 days . the filtrate of the cultured broth ( 10 l ) was extracted with etoac ( 1 l  2 ) . the etoac - soluble portions ( 58 mg ) were subjected to a silica gel column ( hexane / etoac , 70:30 ) followed by c18 reversed - phase hplc ( develosil ods-5 , nomura chemical , 1.0  25 cm : flow rate 2.5 ml / min ; uv detection at 254 nm ; eluent : meoh / h2o , 70:30 ) to give sporiolides a ( 1 , 2.7 mg ) and b ( 2 , 11.5 mg ) together with a known related macrolide , cladospolide d   ( 7.0 mg ) . on the other hand , other known compounds , cladospolide a [ 46 ] ( 5.0 mg ) , iso - cladospolide b   ( 2.0 mg ) , and seco - patulolide c   ( 3.0 mg ) , were isolated from the etoac extract of the mycelium . sporiolide a ( 1 ) { [ ]d 14 ( c 0.2 , meoh ) } was obtained as colorless amorphous solid . the molecular weight of 1 was elucidated to be 348 dalton on the basis of fabms data that showed the pseudomolecular ion at m / z 371 ( m+na ) . the molecular formula , c19h24o6 , of 1 was established by hrfabms data [ m / z 371.1483 , ( m+na ) ,  + 1.2 mmu ] . the ir spectrum suggested the presence of hydroxy ( 3426 cm ) , unsaturated ester and/or ketone carbonyl ( 1724 cm ) groups . the uv absorptions at 237 ( 9200 ) and 209 ( 11700 ) nm indicated the presence of benzoyl chromophore . the h nmr ( table 1 ) spectrum of 1 showed proton signals due to a benzoyl group [ h 8.05 ( 2h , m ) , 7.56 ( 1h , m ) , and 7.43 ( 2h , m ) ] . analysis of the h - h cosy spectrum ( figure 1 ) revealed connectivities of c-2 to c-3 and c-5 to c-12 . hmbc correlations of h-3 ( h 5.90 ) to c-1 ( c 168.8 ) , c-4 ( c 207.1 ) , and c-5 ( c 76.0 ) and h-11 ( h 4.89 ) to c-1 indicated that 1 possessed a twelve - membered macrocyclic lactone with a ketone group at c-4 and a hydroxy at c-5 . an hmbc correlation between h-3 to c-13 ( c 165.5 ) revealed that the benzoyl group was attached to c-3 . thus , the structure of sporiolide a was assigned as 1 , which corresponded to be a 3-o - benzoyl form of pandangolide 1 . sporiolide b ( 2 ) { [ ]d 33 ( c 0.3 , meoh ) } was obtained as colorless amorphous solid . the molecular weight of 2 was elucidated by m / z 281(m+na ) in the positive mode fabms . the molecular formula , c13h22o5 , of 2 was established by hrfabms data ( m / z 281.1367 [ m+na ] , + 0.2mmu ) . the ir spectrum suggested the presence of hydroxy ( 3429 cm ) , unsaturated ester and/or ketone carbonyl ( 1710 cm ) groups . detailed analysis of h , c , and 2d nmr data revealed that the structure of 2 was similar to that of 1 , except for functional group at c-3 . an hmbc correlation of h-3 ( h 4.46 ) to c-13 ( c 58.2 , meo ) indicated the presence of a methoxy group at c-3 . thus , the structure of sporiolide b ( 2 ) was elucidated to be a 3-o - methoxy form of pandangolide 1 . sporiolides a ( 1 ) and b ( 2 ) were new twelve - membered macrocyclic lactones from the cultured broth of a marine - derived fungus cladosporium sp . , although similar twelve - membered macrocyclic lactone such as cladospolide a has been obtained from a terrestrial fungus cladosporium sp . and more recently , cladospolide d , iso - cladospolide b , seco - patulolide c , and pandangolides 1 and 2 have been isolated from an unidentified marine fungus , while pandagolides 2 and 3 were isolated from a marine - derived fungus cladosporium herbarum . sporiolides a ( 1 ) and b ( 2 ) exhibited cytotoxicity against murine lymphoma l1210 cells with ic50 values of 0.13 and 0.81 g / ml , respectively . sporiolide a ( 1 ) showed antifungal activity against candida albicans , cryptococcus neoformans , aspergillus niger , and neurospora crassa and antibacterial activity against micrococcus luteus , while sporiolide b ( 2 ) had antibacterial activity against micrococcus luteus ( table 2 ) . the ir and uv spectra were recorded on a jasco ft / ir-5300 and a shimadzu uv-1600pc spectrophotometer , respectively . fab mass spectrum was obtained on a jeol hx-110 spectrometer using nitrobenzyl alcohol as a matrix . ( l037 ) was separated from the brown alga actinotrichia fragilis , which was collected off seragaki beach at okinawa island . subcultures of the organism are deposited at graduate school of pharmaceutical sciences , hokkaido university . the fungus was grown in sc broth [ starch ( 1% ) and casein ( 0.1% ) in 50% sea water , ph 7.4 ] at 28c for 14 days . the filtrate of the cultured broth ( 10 l ) was extracted with etoac ( 1 l  2 ) . the etoac - soluble portions ( 58 mg ) were subjected to a silica gel column ( hexane / etoac , 70:30 ) followed by c18 reversed - phase hplc [ develosil ods-5 , nomura chemical , 1.0  25 cm : flow rate 2.5 ml / min ; uv detection at 254 nm ; eluent : meoh / h2o , 70:30 ] to give sporiolides a ( 1 , 2.7 mg ) and b ( 2 , 11.5 mg ) together with cladospolide d ( 7.0 mg ) . on the other hand , cladospolide a , isocladospolide b , and seco - patulolide c were isolated from the etoac extract of the mycelium . sporiolide a ( 1 ) : colorless amorphous solid ; [ ]d 14 ( c 0.2 , meoh ) } ; uv ( meoh )  237 ( 9200 ) and 209 ( 11700 ) nm ; ir ( kbr )  3426 , 1724 , and 1633 cmh and c nmr ( table 1 ) ; fabms m / z 371 [ m+na ] ; hrfabms m / z 371.1483 [ m+na ] ( calcd for c19h24o6na , 371.1471 ) . sporiolide b ( 2 ) : colorless amorphous solid ; [ ]d 33 ( c 0.3 , meoh ) ; ir ( kbr )  3429 , 1710 , and 1646 cmh and c nmr ( table 1 ) ; fabms m / z 281 [ m+na ] ; hrfabms m / z 281.1367 [ m+na ] ( calcd for c13h22o5na , 281.1365 ) . the ir and uv spectra were recorded on a jasco ft / ir-5300 and a shimadzu uv-1600pc spectrophotometer , respectively . fab mass spectrum was obtained on a jeol hx-110 spectrometer using nitrobenzyl alcohol as a matrix . ( l037 ) was separated from the brown alga actinotrichia fragilis , which was collected off seragaki beach at okinawa island . subcultures of the organism are deposited at graduate school of pharmaceutical sciences , hokkaido university . the fungus was grown in sc broth [ starch ( 1% ) and casein ( 0.1% ) in 50% sea water , ph 7.4 ] at 28c for 14 days . the filtrate of the cultured broth ( 10 l ) was extracted with etoac ( 1 l  2 ) . the etoac - soluble portions ( 58 mg ) were subjected to a silica gel column ( hexane / etoac , 70:30 ) followed by c18 reversed - phase hplc [ develosil ods-5 , nomura chemical , 1.0  25 cm : flow rate 2.5 ml / min ; uv detection at 254 nm ; eluent : meoh / h2o , 70:30 ] to give sporiolides a ( 1 , 2.7 mg ) and b ( 2 , 11.5 mg ) together with cladospolide d ( 7.0 mg ) . on the other hand , cladospolide a , isocladospolide b , and seco - patulolide c were isolated from the etoac extract of the mycelium . sporiolide a ( 1 ) : colorless amorphous solid ; [ ]d 14 ( c 0.2 , meoh ) } ; uv ( meoh )  237 ( 9200 ) and 209 ( 11700 ) nm ; ir ( kbr )  3426 , 1724 , and 1633 cmh and c nmr ( table 1 ) ; fabms m / z 371 [ m+na ] ; hrfabms m / z 371.1483 [ m+na ] ( calcd for c19h24o6na , 371.1471 ) . sporiolide b ( 2 ) : colorless amorphous solid ; [ ]d 33 ( c 0.3 , meoh ) ; ir ( kbr )  3429 , 1710 , and 1646 cmh and c nmr ( table 1 ) ; fabms m / z 281 [ m+na ] ; hrfabms m / z 281.1367 [ m+na ] ( calcd for c13h22o5na , 281.1365 ) .
two new cytotoxic twelve - membered macrolides , sporiolides a ( 1 ) and b ( 2 ) , were isolated from the cultured broth of a fungus cladosporium sp . , 
 which was separated from an okinawan marine brown alga actinotrichia fragilis , and the structures were elucidated by spectroscopic data . sporiolides a ( 1 ) and b ( 2 ) exhibited cytotoxicity against murine lymphoma l1210 cells . 
 spoliolide a ( 1 ) showed antifungal activity against cryptococcus neoformans and neurospora crassa .