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The first and convergent total syntheses of polyketide natural products dechlorogreensporones A and D have been accomplished in 17 longest linear steps with 2.8% and 5.4% overall yields, respectively, starting from known methyl 2-(2-formyl-3,5-dihydroxyphenyl)acetate and commercially available R-(+)-propylene oxide and 1,2-epoxy-5-hexene. Our synthesis exploited key Mitsunobu esterification and (E)-selective ring-closing metathesis (RCM) to assemble the macrocycles as well as a Jacobsen hydrolytic kinetic resolution to install the stereogenic centers. Both synthetic compounds were found to display significant cytotoxic activity against seven human cancer cell lines with the IC50 ranges of 6.66–17.25 μM.

The first total synthesis of greensporone C, a cytotoxic 14-membered resorcylic acid lactone, has been accomplished via a longest linear sequence of 16 steps in 3.3% overall yield. The key features of the synthesis include Mitsunobu esterification and ring-closing metathesis to construct the macrocycle and establish the ( E )-olefin geometry, respectively. Our synthesis also confirmed the absolute stereochemistry of the natural product.

A chiron approach to the synthesis of the proposed structure of pestalotioprolide A, a 14-membered unsaturated macrolide isolated from the mangrove-derived fungus Pestalotiopsis sp. PSU-MA119, starting from d -(+)-gluconic acid δ-lactone is described. The key strategies to assemble the macrolactone include Yamaguchi esterification and ring-closing metathesis.

A new naphthoquinone, solaninaphthoquione (1), and a new succinate ester derivative, 4-(4-hydroxyphenethoxy)-4-oxobutanoic acid (2), were isolated from the soil fungus Fusarium solani PSU-RSPG227 together with five previously reported compounds; javanicin (3), monaspilosin (4), aspergillol B (5), tyrosol (6) and 4-hydroxyphenylacetic acid (7). Their structures were elucidated primarily by NMR spectroscopic data. Due to paucity of materials, compounds 2, 4 and 5 as well as analogues of 5 were prepared for biological activity evaluation. Compound 1 showed significant cytotoxic activity against breast cancer (MCF-7) cells and mild cytotoxic activity against oral human carcinoma (KB) cells (IC50 values of 21.3 and 22.6 μM, respectively) compared to standard compounds. Compound 1 also displayed weak antimalarial activity (IC50 of 26.1 μM).

An asymmetric total synthesis of (I) is performed starting from D-(+)-gluconic acid δ-lactone via Yamaguchi esterification and ring-closing metathesis as the key steps.