161 research outputs found
The first occurrence of Pplyhydroxylated steroids with phosphate conjugation from the starfish Tremaster novaecaledoniae
Neuroprotective effects of quercetin 4'-O-β-d-diglucoside on human striatal precursor cells in nutrient deprivation condition
Marine sterols side-chain-oxygenated sterols possibly of abiotic origin from the new Caledonian sponge Stelodoryx chlorophylla
Phosphated and sulphated marine polyhydroxylated steroids from the starfish Tremaster novaecaledoniae
The gymnochromes : novel marine brominated phenanthroperylenequinone pigments from the stalked crinoid Gymnocrinus richeri
A novel group of polyhydroxycholanic acid derivatives from the deep water starfish Styracaster caroli
Three novel polyhydroxysteroid constituents have been isolated from the starfish #Stracaster caroli$ collected at a depht of 2000 m off New Caledonia. These, designated carolisterols A - C (1 - 3), are characterized by a polyhydroxycholanic acid moiety, in which the 24-carboxylic acid function is found as an amide derivative ofD-cysteinolic acid. (Résumé d'auteur
Ptilomycalin A, crambescidin 800 and related new highly cytotoxic guanidine alkaloids from the starfishes Fromia monilis and Celerina heffernani
Two novel pentacyclic guanidine alkaloids, celeromycalin 3 and fromiamycalin 4, have been isolated from the New Caledonian starfishes Celerina heffernani and Fromia monilis, respectively. The new compounds exhibited an high cytotoxic activity like the previous crambescidins. These complex pentacyclic guanidines are typical sponges metabolites and their occurence in starfishes is noteworthy. Fromia monilis also contained the less active component 5, made up from an hydroxyspermidine residue linked to a long chain omega-hydroxyacid
Phenolic compounds from Achillea millefolium L. and their bioactivity
Since antiquity, Achillea millefolium L. (Asteraceae) has been used in traditional medicine of several cultures, from Europe to Asia. Its richness in bioactive compounds contributes to a wide range of medicinal properties. In this study, we assessed A. millefolium methanolic extract and its isolated components for free radical scavenging activity against 2,2-diphenyl-pycrilhydrazyl, total antioxidant capacity (based on the reduction of Cu ++ to Cu +), and ability to inhibit lipid peroxidation. The activity against chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum was also tested. Chlorogenic acid, its derivatives and some flavonoids isolated by semipreparative HPLC and identified by NMR and spectrometric techniques were the major bioactive constituents of the methanolic extract. The latter exhibited significant antioxidant properties, as well as its flavonol glycosides and chlorogenic acids. With regard to the antiplasmodial activity, apigenin 7-glucoside was the most effective compound, followed by luteolin 7-glucoside, whereas chlorogenic acids were completely inactive. On the whole, our results confirmed A. millefolium as an important source of bioactive metabolites, justifying its pharmaceutical and ethnobotanical use
Ação repelente, inseticida e fagoinibidora de extratos de pimenta dedo-de-moça sobre o gorgulho do milho
- âŠ