RESUMO
IN THE CRYSTAL STRUCTURE OF KALLOLIDE A ACETATE PYRAZOLINE [SYSTEMATIC NAME: 7-methyl-16-oxo-4,10-bis-(prop-1-en-2-yl)-17,18-dioxa-14,15-diaza-tetra-cyclo-[9.4.2.1(6,9).0(1,12)]octa-deca-6,8,14-trien-5-yl acetate], C(23)H(28)N(2)O(5), there is a 12-member-ed carbon macrocyclic structure. In addition, there is a tris-ubstituted furan ring, an approximately planar γ-lactone ring [maximum deviation of 0.057â (3)â Å] and a pyraz-oline ring, the latter in an envelope conformation. The pyrazoline and the γ-lactone rings are fused in a cis configuration. In the crystal, mol-ecules are linked by weak C-Hâ¯O inter-actions, forming a two-dimensional network parallel to (001). An intra-molecular C-Hâ¯O hydrogen bond is also present.
RESUMO
An extensive chemical study of the secondary metabolites found in the crude organic extract of the gorgonian octocoral Pseudopterogorgia kallos has led to the isolation of seven new cembranolides, bipinnatins K-Q ( 2- 8), and one known compound, bipinnatin E ( 9). The molecular structures of compounds 2- 8, many of which contain unusual structural features, were assigned mainly by 2D NMR spectroscopic methods and X-ray crystallographic analysis. The discovery of compounds 2- 8 may lend support to previously proposed mechanisms for the biosynthesis of recently isolated bioactive natural products from the same gorgonian specimen. The in vitro cytotoxicity of bipinnatins 4, 6, and 7 against the NCI tumor cells MCF breast cancer, NCI-H460 non-small cell lung cancer, and SF-268 CNS cancer was evaluated. However, only bipinnatin Q ( 6) displayed significant cytotoxic activity. Some of the compounds isolated proved to be inhibitors of acetylcholine receptors.
Assuntos
Antozoários/química , Antineoplásicos , Diterpenos , Bloqueadores Neuromusculares , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Região do Caribe , Cristalografia por Raios X , Diterpenos/química , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Conformação Molecular , Estrutura Molecular , Bloqueadores Neuromusculares/química , Bloqueadores Neuromusculares/isolamento & purificação , Bloqueadores Neuromusculares/farmacologiaRESUMO
[structure: see text] A novel trispiropentacyclic diterpene, intricarene (1), was isolated from the hexane extract of the Caribbean gorgonian octocoral Pseudopterogorgia kallos. Its highly entangled structure was established by interpretation of NMR, IR, UV, and HREIMS data and subsequently confirmed by X-ray diffraction analysis. The unprecedented carbon skeleton of 1 constitutes a new addition to the already impressive architectural diversity of the diterpene class of marine secondary metabolites.
Assuntos
Antozoários/química , Diterpenos , Compostos Heterocíclicos de Anel em Ponte , Animais , Cristalografia por Raios X , Diterpenos/química , Diterpenos/isolamento & purificação , Compostos Heterocíclicos de Anel em Ponte/química , Compostos Heterocíclicos de Anel em Ponte/isolamento & purificação , Conformação Molecular , TriterpenosRESUMO
Bielschowskysin is a naturally occurring diterpene isolated from the Caribbean gorgonian octocoral Pseudopterogorgia kallos. Its highly oxygenated hexacyclic structure is based on a previously undescribed tricyclo[9.3.0.0(2,10)]tetradecane ring system that was established through spectroscopic analysis and X-ray crystallographic analysis. Bielschowskysin was shown to exhibit antimalarial activity against Plasmodium falciparum as well as strong anticancer activity against two human cancer cell lines.
Assuntos
Antozoários/química , Diterpenos/isolamento & purificação , Animais , Antimaláricos/química , Antimaláricos/isolamento & purificação , Antimaláricos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Diterpenos/química , Diterpenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Conformação Molecular , Plasmodium falciparum/efeitos dos fármacosRESUMO
[structure: see text] Providencin (1) is a naturally occurring cytotoxin isolated from the Caribbean gorgonian octocoral Pseudopterogorgia kallos. Its highly oxygenated hexacyclic structure is based on a previously undescribed bicyclo[12.2.0]hexadecane ring system and was established through spectroscopic analysis and X-ray crystallographic analysis. Providencin (1) was shown to exhibit modest anticancer activity against human breast (MCF7), lung (NCI-H460), and CNS (SF-268) cancer cell lines.
Assuntos
Antineoplásicos/isolamento & purificação , Diterpenos/isolamento & purificação , Antozoários/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Cristalografia por Raios X , Diterpenos/química , Diterpenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Células Tumorais CultivadasRESUMO
The Caribbean alcyonacean Pseudopterogorgia kallos is shown to contain a novel rearranged pseudopterane diterpene, kallosin A (1), possessing several unusual structural features. In addition to having two distinct 2(3H)- and 2(5H)-furanone moieties, kallosin A is based on a new carbon skeleton. The structural assignment of 1 was based mainly on 1D and 2D NMR spectral data and was further supported by accurate mass measurement and single-crystal X-ray diffraction analysis.