ABSTRACT
[structure: see text] Six new antimitotic diterpenes, 2-7, have been isolated from the Caribbean octocoral Erythropodium caribaeorum. Structural variations encountered in this group of natural products test recently proposed pharmacophore models for microtubule stabilizing compounds.
Subject(s)
Antineoplastic Agents/chemistry , Cnidaria/chemistry , Diterpenes/chemistry , Microtubules/chemistry , Alkaloids/chemistry , Alkaloids/isolation & purification , Alkaloids/pharmacology , Animals , Antineoplastic Agents/isolation & purification , Cell Cycle/drug effects , Cell Death/drug effects , Diterpenes/isolation & purification , Diterpenes/pharmacology , Inhibitory Concentration 50 , Models, Molecular , Structure-Activity RelationshipABSTRACT
A marine soft coral species of the genus Heteroxenia collected from Mindoro Island, Philippines yielded two cadinene sesquiterpenes, (+)-alpha-muurolene (1) and a novel derivative (+)-6-hydroxy-alpha-muurolene (2), as well as the biologically active polyhydroxysterol, sarcoaldosterol A (3). The structure of the novel compound was unambiguously established on the basis of NMR spectroscopic (1H, 13C, COSY, 1H-detected direct and long range 13C-1H correlations) and mass spectrometric (EIMS) data. All compounds were active against the phytopathogenic fungus Cladosporium cucumerinum. The isolated terpenes were also active in the brine shrimp lethality test.
Subject(s)
Cnidaria/chemistry , Terpenes/chemistry , Terpenes/pharmacology , Animals , Artemia , Cladosporium/drug effects , Magnetic Resonance Spectroscopy , Molecular Conformation , Molecular Structure , Philippines , Sesquiterpenes/chemistry , Sesquiterpenes/pharmacology , Sesquiterpenes/toxicity , Spectrometry, Mass, Secondary Ion , Terpenes/toxicityABSTRACT
A secosterol with a gorgosterol side chain and an unusual oxygenation pattern on the A and B rings was isolated from an Indonesian soft coral Lobophytum sp. The A and B rings of the reported compound 1 have hydroxyl groups at C-3 and C-7 and an epoxide ring at C-5-C-6. The structures of 1 was solved by 2D NMR methods and by chemical shift analogy to the known secogorgosterol 2. Compound 1 was found to have activity against human ovarian tumor and human leukemia cell lines.
Subject(s)
Antineoplastic Agents/isolation & purification , Cnidaria/chemistry , Secosteroids/isolation & purification , Animals , Antineoplastic Agents/pharmacology , Drug Screening Assays, Antitumor , Female , Humans , Indonesia , Magnetic Resonance Spectroscopy , Ovarian Neoplasms/drug therapy , Secosteroids/pharmacology , Tumor Cells, CulturedABSTRACT
The marine soft coral Lobophytum pauciflorum collected from Mindoro Island, Philippines, yielded four new lobane diterpene derivatives: the acetate congeners of epoxylobatrienol and lobatrienediol (2 and 7, respectively), a methoxyl congener of lobatetraene (10), and an oxepin congener of lobatrienetriol (11), and six known derivatives (1, 3-6, and 8). The structures of the new compounds were unambiguously established on the basis of NMR spectroscopic (1H, 13C, COSY, 1H-detected direct, and long-range 13C-1H correlations) and mass spectrometric (EIMS) data. All of the compounds were active against the phytopathogenic fungus Cladosporium cucumerinum. Compound 1 was found to be active against the Gram-positive bacteria Bacillus subtilis and the yeast Saccharomyces cerevisiae. The isolated lobane diterpenes were also active in the brine shrimp lethality test. In the latter bioassay, compounds 8 and 10 were the most active congeners with LC50's of 0.64 and 4.18 micrograms/mL, respectively.
