Bioactive humulene derivatives from Asteriscus vogelii

Thionium Ion Initiated Medium-Sized Ring Formation: The Total Synthesis of Asteriscunolide D

“…4 More specifically, asteriscunolides A–D 5 ( 3 – 6 ) possess anti-cancer activity, with 6 being the most potent toward the A-549 (human lung carcinoma), HT-29 (human colon carcinoma), and MEL-28 (human melanoma) cell lines. 6 Recently, 3 has been found to induce apoptosis in human tumor cell lines. 7 We became interested in these targets (i.e., 3 – 6 ) because we envisioned that a dimethyl(methylthio)sulfonium tetra-fluoroborate (DMTSF)-mediated formal aldol disconnection could provide a mild and irreversible pathway to the relatively strained 11-membered ring ( 8 → 7 , Figure 2).…”

Collective Synthesis of Natural Products by Using Metathesis ­Cascade Reactions

“…For example, asteriscunolide A induces apoptosis in human cancer cell lines 32 and asteriscunolide D has be reported to be more cytotoxic than cisplatin, with good potency against HT-29 human colon carcinoma, A-549 human lung carcinoma, and MEL-28 human melanoma cell lines. 33 From a structural perspective, most of the compounds in this structural class have unique and challenging structures. Asteriscunolides A-D 34 and 6,7,9,10-tetrahydroasteriscunolide 35 contain a synthetically challenging eleven-membered ring, 36 together with a bridged cyclic butenolide moiety (Figure 2).…”

Total Synthesis of Aquatolide

“…2 There is an interesting relationship between structures 1 and 2 as they are in principle the straight and crossed [2 + 2]-photocycloaddition products from the asteriscunolides (3), of which all four geometric isomers also occur in the same plant. 3 These interesting butenolides bridged with a large ring have been found to have anticancer activity, 4 and two of the isomers, asteriscunolide C and D, have been prepared by total synthesis. 5 However, we do not know whether photochemical [2 + 2]-cycloadditions of these compounds were ever studied.…”