Search results for "ALTER"

Labdane Diterpenes from Stachys plumosa

2000

Three new labdane diterpenoids were isolated from the aerial parts of Stachys plumosa. The first two (1, 2) were the dextrorotatory enantiomers of the known 6-deoxyandalusol and 13-epijabugodiol. Structures were determined using NMR and MS techniques. The absolute stereochemistry of the third compound (3) was not experimentally proved.

Biologically Active Triterpene Saponins from Callus Tissue of Polygala amarella

1999

A new bioactive saponin (1), together with a known saponin (polygalasaponin XXVIII) has been isolated from the callus tissue culture of Polygala amarella. Based on spectroscopic data, especially direct and long-range heteronuclear 2D NMR analysis and on chemical transformations, the structure of 1 was elucidated as 3-O-beta-D-glucopyranosyl presenegenin-28-O-beta-D-galactopyranosyl-(1 --> 3)-beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 3)]-beta-D-fucopyranoside. Both saponins showed significant immunological properties based on the enhancement of granulocyte phagocytosis in vitro.

Synchronized gradient elution in capillary liquid chromatography

2013

Abstract The synchronization of injection valve operation and gradient elution in capillary liquid chromatography (cHPLC) is studied. Focus is placed on the cHPLC systems which rely on the splitting of a primary flow to provide the much smaller secondary flow required at the injection device and analytical column. Owing to the tiny secondary flow rates, synchronization is necessary to achieve proper optimization of gradient elution methods. Otherwise, there is a risk of having the analytes totally or partially eluted in the initial isocratic conditions, and there is no control on the actual gradient profile reaching the column. Synchronization is first achieved by switching back the valve t…

Taxane analysis by high performance liquid chromatography-Nuclear magnetic resonance spectroscopy ofTaxus species

1998

High performance liquid chromatography–nuclear magnetic resonance spectroscopic analyses of taxane diterpenoids from three Taxus species were carried out employing a stopped-flow technique. Several taxanes have been identified from 500 mg leaf samples without prior isolation. © 1998 John Wiley & Sons, Ltd.

Nuevos actores de la no violencia

2001

La sostenibilidad, un nuevo pensamiento. Intervención de José Vidal-Beneyto

2003

Número monográfico sobre "El nuevo horizonte de la Sostenibilidad". Fundación Santander Central Hispano.

Die Lehre von der Beihilfe

1892

Eine zur Erlangung des Grades eines Magisters des Strafrechts der Juristischen Fakultät der Kaiserlichen Universität zu Dorpat vorgelegte Abhandlung

Induction of Secondary Metabolites from the Marine-Derived Fungus Aspergillus versicolor through Co-cultivation with Bacillus subtilis

2019

AbstractA new cyclic pentapeptide, cotteslosin C (1), a new aflaquinolone, 22-epi-aflaquinolone B (3), and two new anthraquinones (9 and 10), along with thirty known compounds (2, 4 – 8, 11 – 34) were isolated from a co-culture of the sponge-associated fungus Aspergillus versicolor with Bacillus subtilis. The new metabolites were only detected in the co-culture extract, but not when the fungus was grown under axenic conditions. Furthermore, the co-culture extract exhibited an enhanced accumulation of the known constituents versicolorin B (14), averufin (16), and sterigmatocyctin (19) by factors of 1.5, 2.0, and 4.7, respectively, compared to the axenic fungal culture. The structures of the …

Comparison of the activity of antifungal hexapeptides and the fungicides thiabendazole and imazalil against postharvest fungal pathogens

2003

8 pages, 2 figures, 3 tables.-- PMID: 14623382 [PubMed].-- Printed version published Dec 31, 2003.

El sistema linfático: el gran olvidado del sistema circulatorio.

2014

En el presente artículo se analizan los modelos mentales y las concepciones alternativas que tienen los estudiantes de distintos niveles educativos sobre el sistema linfático como componente del sistema circulatorio. Se establece una relación con las dificultades que se salvaron a lo largo de la historia en la adquisición de dichos conocimientos. Los resultados muestran una deficiente relación entre los sistemas linfáticos y sanguíneos, una falta de conocimientos tanto anatómicos como fisiológicos del sistema linfático y una dificultad para ampliar el modelo explicativo del transporte de nutrientes en los organismos animales, exclusivamente centrado en el sistema sanguíneo. Se termina ofrec…