Project description:Five new polyketides, namely, 5R-hydroxyrecifeiolide (1), 5S-hydroxyrecifeiolide (2), ent-cladospolide F (3), cladospolide G (4), and cladospolide H (5), along with two known compounds (6 and 7), were isolated from the endophytic fungal strain Cladosporium cladosporioides MA-299 that was obtained from the leaves of the mangrove plant Bruguiera gymnorrhiza. The structures of these compounds were established by extensive analysis of 1D/2D NMR data, mass spectrometric data, ECDs and optical rotations, and modified Mosher's method. The structures of 3 and 6 were confirmed by single-crystal X-ray diffraction analysis and this is the first time for reporting the crystal structures of these two compounds. All of the isolated compounds were examined for antimicrobial activities against human and aquatic bacteria and plant pathogenic fungi as well as enzymatic inhibitory activities against acetylcholinesterase. Compounds 1-4, 6, and 7 exhibited antimicrobial activity against some of the tested strains with MIC values ranging from 1.0 to 64 μg/mL, while 3 exhibited enzymatic inhibitory activity against acetylcholinesterase with the IC50 value of 40.26 μM.
Project description:The shortage of molecular information for taxol-producing fungi has greatly impeded the understanding of fungal taxol biosynthesis mechanism. In this study, the transcriptome of one taxol-producing endophytic fungus Cladosporium cladosporioides MD2 was sequenced for the first time. About 1.77 Gbp clean reads were generated and further assembled into 16,603 unigenes with an average length of 1110 bp. All of the unigenes were annotated against seven public databases to present the transcriptome characteristics of C. cladosporioides MD2. A total of 12,479 unigenes could be annotated with at least one database, and 1593 unigenes could be annotated in all queried databases. In total, 8425 and 3350 unigenes were categorized into 57 GO functional groups and 262 KEGG pathways, respectively, exhibiting the dominant GO terms and metabolic pathways in the C. cladosporioides MD2 transcriptome. One potential and partial taxol biosynthetic pathway was speculated including 9 unigenes related to terpenoid backbone biosynthesis and 40 unigenes involved in the biosynthetic steps from geranylgeranyl diphosphate to 10-deacetylbaccatin III. These results provided valuable information for the molecular mechanism research of taxol biosynthesis in C. cladosporioides MD2.