ABSTRACT
Several prenylflavonoids have been synthesised and tested against human tumour cell lines. The prenyl unit has been geranyl or a labdane diterpene. These labdane-flavonoids have been synthesised for the first time. The antitumour activity increase with the prenylation at C-8 position. Twenty-three C and O-prenylated acylphloroglucinols have been synthesised as well. In this case the C-alkylation products have resulted, in general, more active.
Subject(s)
Acetophenones/chemical synthesis , Acetophenones/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Flavonoids/chemical synthesis , Flavonoids/pharmacology , Acetophenones/chemistry , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Flavonoids/chemistry , Humans , Inhibitory Concentration 50 , Spectrum AnalysisABSTRACT
[Reaction: see text]. The synthesis of three marine sponge metabolites, luffolide (4), 5, and 6, are described for the first time, establishing the absolute configuration of these compounds. The key intermediate, aldehyde 17, was obtained from methyl isoanticopalate, 11. The addition of 3-furyllithium to 17 and subsequent photochemical oxidation give the gamma-hydroxybutenolide 5 and its epimer at C-16. Sesterterpenolide 6 is obtained by dehydration of 5. From the key aldehyde 17, luffolide (4) was obtained in six steps.
Subject(s)
Porifera/chemistry , Sesquiterpenes/chemical synthesis , Terpenes/chemical synthesis , Aldehydes/chemistry , Animals , Diterpenes/chemistry , Molecular Conformation , Molecular Structure , Oxidation-Reduction , Photochemistry , Stereoisomerism , Terpenes/chemistryABSTRACT
The simultaneous determination of NH(4)(+) and K(+) in solution has been attempted using a potentiometric sensor array and multivariate calibration. The sensors used are rather non-specific and of all-solid-state type, employing polymeric (PVC) membranes. The subsequent data processing is based on the use of a multilayer artificial neural network (ANN). This approach is given the name "electronic tongue" because it mimics the sense of taste in animals. The sensors incorporate, as recognition elements, neutral carriers belonging to the family of the ionophoric antibiotics. In this work the ANN type is optimized by studying its topology, the training algorithm, and the transfer functions. Also, different pretreatments of the starting data are evaluated. The chosen ANN is formed by 8 input neurons, 20 neurons in the hidden layer and 2 neurons in the output layer. The transfer function selected for the hidden layer was sigmoidal and linear for the output layer. It is also recommended to scale the starting data before training. A correct fit for the test data set is obtained when it is trained with the Bayesian regularization algorithm. The viability for the determination of ammonium and potassium ions in synthetic samples was evaluated; cumulative prediction errors of approximately 1% (relative values) were obtained. These results were comparable with those obtained with a generalized regression ANN as a reference algorithm. In a final application, results close to the expected values were obtained for the two considered ions, with concentrations between 0 and 40 mmol L(-1).
ABSTRACT
An intermediate moisture food (IMF), has been developed in our laboratory for elder people, over 60 years. The IMF is based on a cereal: legume mixture with calcium and flavour, it supplies proteins, carbohydrates and vegetable oils; as well as, high energetic density (3.22 cal/g) and covers up to 51% of calcium needed. It can be easily consumed as a tasty and soft food. It has a water activity of 0.80, for it can be stored at room conditions. It is very likely that IMF becomes a good alternative to improve and vary elder peoples diet.