New cytotoxic spongian-class rearranged diterpenes from a marine sponge

Marine natural products

“…708 Chromodorolide D 833, a heavily rearranged spongian diterpene, was reported along with 834 from an unidentied sponge (Cape Manza, Okinawa). 709 Chromodorolide D was also reported as chromodorolide E from an Australian Dysidea sp., along with a second structure 835 that was also called chromodorolide D. 710 Given the order in which the reports were accepted and published, 835 should be renamed chromodorolide E to reconcile the two separate papers.…”

Total Synthesis of (−)-Chromodorolide B

“…This product showed 1 H and 13 C NMR data and optical rotation in close accord to those reported for a natural sample. 1b,c In addition, synthetic 1 provided single crystals, which allowed the structure of chromodorolide B to be unambiguously confirmed by X-ray analysis. 20c …”

“…5 In the chromodorolides, these dioxabicyclic rings are appended to an additional oxygenated cyclopentane ring. Although modest in vitro antitumor, nematocidal and antimicrobial activities have been reported, 1b,c,e the chromodorolides and analogues are of most interest for their potential effects on the Golgi apparatus. 5c We report herein the first total synthesis of a chromodorolide, (−)-chromodorolide B ( 1 ), by a concise sequence that features a bimolecular radical addition/cyclization/fragmentation (ACF) cascade.…”

“…Further simplification of acid 9 leads to intermediate 10 having the C 12 hydrocarbon and the highly oxidized fragment joined at a vinylic carbon of the hydrophobic fragment. 6 On the basis of our recent experience showing that fragment couplings of nucleophilic tertiary radicals with alkenes can be high yielding, 5b we envisioned a cascade sequence in which trisubstituted carbon radical B , generated by visible-light photoredox fragmentation of the N -acyloxyphthalimide substituent of intermediate 12 , 7 would couple with ( R )-4-methoxybutenolide ( 11 ) 8 to generate α-acyloxy-radical intermediate A , which was hoped would undergo intramolecular 5- exo cyclization from a conformation such as A ′ depicted in Scheme 1 that minimizes destabilizing allylic A 1,3 interactions. The cascade would then be terminated by β-fragmentation of the adjacent C–X (X = halide) bond to deliver the desired coupled product 10 .…”

Metabólitos secundários das esponjas Aiolochroia crassa e Dysidea robusta e do fungo Aspergillus sydowii

“…A tiocoralina (8), isolada inicialmente da bactéria Micromonospora marina (ROMERO et al 1997) apresentou potente atividade citotóxica contra câncer renal, de pulmão, do colo e melanoma, também se encontra em fase de testes clínicos. ABED et al 2011;BERBER et al 2011;HITORA et al 2011;MANZO et al 2011;KHALIL e CAPON, 2011;ANKISETTY e SLATTERY, 2012;LIU et al 2012;TAKAHASHI et al 2012;TANG et al 2012;UDDIN et al 2012;WILLIAMS et al 2012 …”