25-Deoxycacospongionolide B and cacospongionolide C, two new terpenoids from the sponge Fasciospongia cavernosa

Stereochemistry of Antiinflammatory Marine Sesterterpenes

“…Furthermore, in order to eliminate the influence in the CD spectrum of the butenolide ring γ-carbon, 2 was reduced with NaBH 4 [15] to afford 25-deoxycacospongionolide B (11), whose relative stereochemistry was established by X-ray analysis. [16] The CD spectrum of 11 shows a single positive curve in the π-π* zone (Table 1).…”

“…The absolute configuration at C-4 in manoalide (1) was established by Amoo et al [17] to be R by reduction to manoalide diol (16) and comparison of the CD spectrum of the latter with that of the synthetic (S)-enantiomer prepared from 2-deoxy--ribose. The same result was later obtained by the Horeau method and the modified Mosher method.…”

Bioactive constituents from the green alga Caulerpa racemosa

“…These observations, combined with the 13 C NMR signals of C-1 to C-4 (d C 173.3, 168.5, 117.0, and 84.7/84.9) characteristic of an a,b-unsaturated c-lactone moiety, suggested the presence of a b-methyl-c-substituted butenolide moiety, although no direct HMBC correlation of H-4/C-1 was observed. A comparison of the remaining 1 H and 13 C NMR data for the two epimers with the corresponding data of the cooccurring known diterpenoids, cacospongionolide C (4), 16 trans-phytol (5), 17 and trans-phytyl acetate (6), 8 aided by the HMBC correlations of H 3 -16, H 3 -17/C-14, C-15; H 3 -18/C-10, C-11, C-12; and H 3 -19/C-6, C-7, C-8, readily established the rest of the molecule, namely the saturated farnesyl side chain. Moreover, the farnesyl side chain attached to C-4 (d C 84.7/84.9) was deduced from the COSY couplings of H 2 -5 (d H 1.91, m, H-5a; 1.49, m, H-5b)/ H-4.…”

“…1). By comparing their spectroscopic data with those reported in the literature, the structures of the known compounds were assigned as cacospongionolide C (4), 16 trans-phytol (5), 17 trans-phytyl acetate (6), 8 a-tocospiro A (7), 18 a-tocopherol quinone (9), 19 a-tocospirone (10), 20 (3b,24R)-stigmasta-5,28-diene-3,24-diol (12), 21 (3b,24S)-stigmasta-5,28-diene-3,24-diol (13), 21 (22E)-3b-hydroxy-cholesta-5,22-dien-24-one (14), 22 fucosterol (15), 23 24R,28S-epoxyfucosterol (16), 24 and 24S,28R-epoxyfucosterol (17). 24 Herein, the isolation, structure elucidation, as well as biological evaluation of these compounds are reported.…”

Heterocyclic terpenes: linear furano- and pyrroloterpenoids

“…106 Cacospongionolide C 145 was obtained from the Adriatic sponge Fasciospongia caverrzosa. 107 A number of acyclic diterpenoids possess a terminal furan ring, exemplified by conyzaleucolide A 146 obtained from Conyza hypoleuca (Compositae).…”