RESUMO
Three new alkaloids, designated isohalitulin (4), haliclorensin B (5), and haliclorensin C (6), were isolated from two specimens of the Madagascan sponge Haliclona tulearensis, collected at two locations in Salary Bay, north of Tulear. Their structures were elucidated by extensive spectroscopic means. Alkaloids 4-6 exhibited mild toxicity in the brine shrimp test.
Assuntos
Alcaloides/isolamento & purificação , Haliclona/química , Alcaloides/química , Alcaloides/farmacologia , Animais , Artemia/efeitos dos fármacos , Biologia Marinha , Estrutura Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
Two new dibromo proaporphine alkaloids, designated saldedines A (1) and B (2), were isolated from an unidentified tunicate collected at Salary Bay, Madagascar. Saldedines A and B are the first marine proaporphine alkaloids. Their structures were elucidated by extensive spectroscopic means, and the structure of 1 was confirmed by single-crystal X-ray diffraction analysis. Both saldedines A and B were tested for toxicity to brine shrimp and showed moderate activity.
Assuntos
Alcaloides/isolamento & purificação , Aporfinas/isolamento & purificação , Artemia/efeitos dos fármacos , Urocordados/química , Alcaloides/química , Alcaloides/farmacologia , Animais , Aporfinas/química , Aporfinas/farmacologia , Cristalografia por Raios X , Biologia Marinha , Estrutura MolecularRESUMO
Three novel nitrogenous macrolides designated salarin A and B (1 and 2) and tulearin A (3) were isolated from the Madagascar Fascaplysinopsis sp. sponge. The structures of the compounds were elucidated by interpretation of MS and 1D and 2D NMR spectra. Both salarins carry an acetylcarbamate moiety, and in addition, 1 contains a triacylamine group and 2 a methoxymethylketone lactam. Tulearin A carries the naturally rare carbamate ester. The compounds were found to be toxic to brine shrimp larvae, and salarin A and tulearin A were also cytotoxic to leukemia cells.
Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Macrolídeos/isolamento & purificação , Macrolídeos/farmacologia , Poríferos/química , Animais , Antineoplásicos/química , Artemia/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Larva/efeitos dos fármacos , Macrolídeos/química , Madagáscar , Estrutura MolecularRESUMO
Three new cembranes, flexusines A (1) and B (2) and an epimukulol (3), were isolated from the soft coral Sarcophyton flexuosum collected near Reunion Island, Indian Ocean. Their structures were elucidated using 1D and 2D NMR spectral analyses.
Assuntos
Antozoários/química , Diterpenos/isolamento & purificação , Animais , Diterpenos/química , Humanos , Oceano Índico , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , EstereoisomerismoRESUMO
Nine novel compounds designated negombins A-I (1-9) were isolated, together with latrunculin, from the Tanzanian sponge Negombata sp. The nine are sacculatane type diterpenes, previously only known from liverworts. The structures of the compounds were elucidated by interpretation of MS and 1D and 2D NMR spectra. A possible biogenesis initiated by the naturally rare chloronium ion is suggested, possibly hinting to a guest microorganism as the source of the compounds. Compound 4 is toxic to brine shrimp larvae.
Assuntos
Diterpenos/química , Poríferos/química , Poríferos/classificação , Animais , Diterpenos/isolamento & purificação , Conformação Molecular , Especificidade da Espécie , EstereoisomerismoRESUMO
OBJECTIVES: Assessment of antifungal activity of a compound isolated from the marine sponge Dysidea herbacea against the fungal pathogens Candida (primarily C. albicans) and Aspergillus (primarily A. fumigatus) species, and investigations of the possible mode of activity of the compound. METHODS: Freeze dried sponges were extracted with EtOAc-MeOH. Bioassay guided separation was used to identify the active compound. Antifungal activity was assessed in vitro by a modified NCCLS technique. For determination of the possible mode of activity of the compound we tested the effect on fungal cellular morphology (light, scanning and transmission electron microscopy) and possible site of activity in the fungal cells, such as cell membrane (ion leakage kinetics) as well as toxicity (cytotoxicity tests). RESULTS AND CONCLUSIONS: The active compound was determined to be 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy) phenol. This compound exhibited in vitro activity against the tested fungal pathogens. The experiments on the mode of activity revealed that there are significant changes in fungal cell morphology, as demonstrated by scanning and transmission electron microscopy. The compound, apparently, affects the fungal cell membrane, expressed primarily in leakage of potassium ions from the fungal cells. Two other bromo diphenyl ethers were also found to be active. Further experiments in in vivo models are planned.
Assuntos
Aspergillus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Biologia Marinha , Fenóis/farmacologia , Poríferos/química , Extratos de Tecidos/farmacologia , Animais , Aspergillus/ultraestrutura , Candida albicans/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão e Varredura , Extratos de Tecidos/química , Extratos de Tecidos/isolamento & purificaçãoRESUMO
[structure: see text] Two novel ansa farnesyl quinols, designated likonides A and B, were isolated together with avarone from the Kenyan sponge Hyatella sp. The compounds are of a unique ansa structure. The structures and stereochemistry of the compounds were elucidated by interpretation of MS, two-dimensional NMR, and CD experiments.
Assuntos
Hidroquinonas/síntese química , Poríferos/química , Animais , Cicloexenos , Farneseno Álcool/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Quinonas/química , Sesquiterpenos/químicaRESUMO
[structure: see text] A novel cyclic peptide, callynormine A, was isolated from the Kenyan marine sponge Callyspongia abnormis and its structure elucidated by interpretation of its NMR data and X-ray diffraction analysis. Callynormine A represents a new class of heterodetic cyclic peptides (designated endiamino peptides) possessing an alpha-amido-beta-aminoacrylamide cyclization functionality.
Assuntos
Callyspongia/química , Peptídeos Cíclicos/isolamento & purificação , Animais , Cristalografia por Raios X , Ciclização , Quênia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Peptídeos Cíclicos/química , Peptídeos Cíclicos/classificação , EstereoisomerismoRESUMO
Three novel compounds, designated kitungolides A (1), B (2), and C (3), were isolated from a soft coral of a new genus collected at Kitungamwe, Kenya. The three new compounds are of a unique heterotricyclic skeleton. The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, COSY, HMQC, HMBC, and NOESY experiments. [structure: see text]
Assuntos
Antozoários/química , Diterpenos/isolamento & purificação , Pironas/isolamento & purificação , Animais , Antozoários/classificação , Conformação MolecularRESUMO
A new steroidal alkaloid, plakinamine L (1) with an unprecedented acyclic side chain, was isolated from the marine sponge Corticium sp. collected near Salary (south-west of Madagascar). The structure was elucidated by combined spectroscopic methods.
Assuntos
Alcaloides/isolamento & purificação , Poríferos/química , Esteroides/isolamento & purificação , Animais , Estrutura MolecularRESUMO
A new sterol glycoside, auroside (1) and two new hydroxylated sterols, patusterol A and B (2, 3) have been isolated from the South African soft coral Eleutherobia aurea and from the Kenyan soft coral Lobophytum patulum. The structure elucidation was achieved from extensive 1D- and 2D- NMR and MS data, and in the case of auroside also by chemical reactions. In addition, from Lobophytum patulum, was also isolated a known nitrogen containing compound (Z)-N-[2-(4-hydroxyphenyl)ethyl]-3-methyldodec-2-enamide, and from Eleutherobia aurea several, earlier reported, diterpenoids. Compound 2 was found to be toxic to brine shrimp embryos with an LC50 value of 2.30 microM.
Assuntos
Antozoários/química , Esteróis/química , AnimaisRESUMO
Two novel alpha-oxoamides, salaramide A (1) and its homologue salaramide B (2), were isolated from the Madagascar marine sponge, Hippospongia sp., collected in Salary Bay, north of Tulear. The structures of 1 and 2 were elucidated by interpretation of mass spectra, 1D and 2D NMR spectra, and confirmed by chemical transformation.
Assuntos
Amidas/química , Óxidos/química , Poríferos/química , Piridinas/química , Amidas/farmacologia , Animais , Estrutura Molecular , Óxidos/farmacologia , Piridinas/farmacologiaRESUMO
A novel nitrogenous bismacrolide, designated tausalarin C (1), was isolated from the Madagascar sponge Fascaplysinopsis sp. The structure of the compound was elucidated by interpretation of MS and 1D and 2D NMR spectra. It is suggested that tausalarin C is assembled from salarin A (2) and pretaumycin A. The relative configuration of the chiral centers of salarin A was determined by X-ray diffraction. Tausalarin C was found to inhibit proliferation of K562 leukemia cells. A possible biogenesis is discussed.
Assuntos
Antineoplásicos/isolamento & purificação , Macrolídeos/isolamento & purificação , Poríferos/química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células K562 , Macrolídeos/química , Macrolídeos/metabolismo , Macrolídeos/farmacologia , Conformação Molecular , Estrutura Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
Ten new sesquiterpenes, nardosinanols A-I ( 1- 9) and lemnafricanol ( 10), have been isolated from several Kenyan soft corals, i.e., from Lemnalia sp., Paralemnalia clavata, Lemnalia africana, and Rhytisma fulvum fulvum. The structures and relative stereochemistry of these compounds were elucidated by interpretation of MS, COSY ( (1)H- (1)H correlations), HSQC, HMBC, and NOESY NMR spectroscopic experiments and in the case of 5 also by chemical transformation to compounds 11 and 12. Nine compounds ( 1- 9) are based on the nardosinane skeleton ( 1- 6 are nardosinanes and 7- 9 nornardosinanes). Lemnafricanol ( 10) possesses a novel tricyclic skeleton. Compounds 3, 7, and 10 were found to be toxic to brine shrimp with LC 50 values of 4.0, 0.35, and 0.32 microM, respectively.
Assuntos
Antozoários/química , Sesquiterpenos/isolamento & purificação , Animais , Artemia/efeitos dos fármacos , Quênia , Estrutura Molecular , Sesquiterpenos/química , Sesquiterpenos/farmacologiaRESUMO
Two closely related lipodepsipeptides, taumycins A and B (1 and 2) have been isolated from the Madagascar sponge Fascaplysinopsis sp. The two compounds have the same 12-membered oxodepsipeptide ring system in common. Both were toxic to brine shrimp larvae, and taumycin A (1 microM), but not taumycin B, inhibited growth of the human UT-7 leukemic cell line. The structure of the two compounds, likely to be derived from microorganisms, was established by MS and 1D and 2D NMR data.
Assuntos
Depsipeptídeos/química , Peptídeos/química , Poríferos/química , Animais , Artemia/crescimento & desenvolvimento , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Depsipeptídeos/farmacologia , Depsipeptídeos/toxicidade , Humanos , Larva/efeitos dos fármacos , Madagáscar , Peptídeos/farmacologia , Peptídeos/toxicidadeRESUMO
Two new cembranoids, methyl tetrahydrosarcoate ( 1) and methyl tetrahydroisosarcoate ( 2), were isolated from the soft coral Sarcophyton elegans, collected at Kitangambwe Kenya, together with four biscembranoids, the known nyalolide ( 3) and the unprecedented desacetylnyalolide ( 4), diepoxynyalolide ( 5), and dioxanyalolide ( 6). The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, 1D NMR, COSY, HSQC, HMBC, and NOESY experiments. Compound 1 is most likely the dienophile affording, by a Diels-Alder reaction, the four biscembranoids. Dioxanyalolide ( 6) possesses antibacterial activity against Escherichia coli at a concentration of 1.25 microg/mL. Methyl tetrahydrosarcoate ( 1) and diepoxynyalolide ( 5) exhibited LC 50 values of 1.5 microM in a brine shrimp bioassay, while desacetylnyalolide ( 4) was only mildly active.
Assuntos
Antozoários/química , Diterpenos/isolamento & purificação , Animais , Artemia/efeitos dos fármacos , Diterpenos/química , Diterpenos/farmacologia , Quênia , Estrutura Molecular , Terpenos/química , Terpenos/isolamento & purificaçãoRESUMO
Six new tetraprenylated purine alkaloids, designated nuttingins A-F (1-6), were isolated together with three known malonganenones, A-C (12-14), and five new closely related malonganenones, D-H (7-11), from the gorgonian Euplexaura nuttingi collected in Pemba Island, Tanzania. The structures of the compounds were elucidated by interpretation of 1D and 2D NMR data including 15N chemical shifts obtained from 1H-15N HMBC spectra. Nuttingins A-E (1-5) and malonganenones D-G (7-10) displayed inhibitory activity against both K562 and UT7 tumor cell lines, compounds 3-5 being the most active ones, approximately 3-fold more potent than the others. Compounds 1-5 and 7-11 also induce apoptosis in transformed mammalian cells at a concentration of 1.25 microg/mL.
Assuntos
Alcaloides/isolamento & purificação , Antineoplásicos/isolamento & purificação , Cnidários/química , Alcaloides/química , Alcaloides/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células K562 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , TanzâniaRESUMO
Mycgranol, a new isocopalane diterpene (methyl 1beta-hydroxy-2-oxoisocopalanoate) was isolated from the Kenyan sponge Mycale (Aegogropila) aff. graveleyi. The structure of the compound was elucidated by interpretation of MS, COSY, HMQC, HMBC, and ROESY data. The absolute configuration of mycgranol was determined to be the same as that of the nudibranch isocopalane diterpenes rather than that of the ent-compounds known from sponges of the genus Spongia.
Assuntos
Diterpenos , Diterpenos/isolamento & purificação , Poríferos/química , Animais , Diterpenos/química , Diterpenos/classificação , Quênia , Estrutura Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
Lemnaflavoside (1) and three monoacetates (2-4) have been isolated from the Indo-Pacific soft coral Lemnalia flava, collected off Mombasa, Kenya. The structure of the new glycoside was elucidated by interpretation of MS and 2D NMR data. The sugar of the diterpene glycoside was found to be D-xylose.
Assuntos
Antozoários/química , Diterpenos/isolamento & purificação , Glicosídeos/isolamento & purificação , Acetilação , Animais , Diterpenos/química , Glicosídeos/química , Hidrólise , Quênia , Espectrometria de Massas , Conformação Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Five asmarines, the known A and F and three new ones, I, J, and K, and four diterpenes, the known chelodane, barekoxide, and zaatirin and a new one, nosyberkol, were isolated from the Nosy Be Islands (Madagascar) sponge Raspailia sp. The structures of all these compounds were established on the basis of MS and NMR data. A biogenesis for the various Raspailia sp. diterpenes is suggested.