Search results for "glycoside"
showing 10 items of 296 documents
Steroidal glycosides from Ornithogalum dubium Houtt
2018
The phytochemical study of Ornithogalum dubium Houtt. (Asparagaceae) led to the isolation of five undescribed steroidal glycosides together with two known ones. Their structures were established by using NMR analysis and mass spectrometry as (25R)-3β-hydroxyspirost-5-en-1β-yl O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranoside, (25S)-3β-hydroxyspirost-5-en-1β-yl O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside, (22S)-16β-[(α-L-rhamnopyranosyl)oxy]-22-hydroxycholest-5-en-3β-yl O-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranoside, (22S,23S)-1β,3β,11α,16β,23-pentahydroxy-5α-cholest-24-en-22β-yl β-D-glucopyranoside, (22S,23S)-3β-[(β-D-glucopyranosyl)oxy]-22,23-dihydroxy-5α-cholest-24-en-16β-yl O-α-…
Digitalis purpurea P5 beta R2, encoding steroid 5 beta-reductase, is a novel defense-related gene involved in cardenolide biosynthesis.
2009
The stereospecific 5 beta-reduction of progesterone is a required step for cardiac glycoside biosynthesis in foxglove plants. Recently, we have isolated the gene P5 beta R, and here we investigate the function and regulation of P5 beta R2, a new progesterone 5 beta-reductase gene from Digitalis purpurea. P5 beta R2 cDNA was isolated from a D. purpurea cDNA library and further characterized at the biochemical, structural and physiological levels. Like P5 beta R, P5 beta R2 catalyzes the 5 beta-reduction of the Delta(4) double bond of several steroids and is present in all plant organs. Under stress conditions or on treatment with chemical elicitors, P5 beta R expression does not vary, wherea…
Carbohydrate Scaffolds for Combinatorial Syntheses That Allow Selective Deprotection of All Four Positions Independent of the Sequence
2004
Saponins from the Roots of Nylandtia spinosa
2007
From the roots of Nylandtia spinosa, four new triterpene saponins, 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-galactopyranosyl-(1-->4)-[alpha- l-arabinopyranosyl-(1-->3)]-beta- d-xylopyranosyl-(1-->4)-[beta- d-apiofuranosyl-(1-->3)]-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 1), 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-galactopyranosyl-(1-->4)-[alpha- l-arabinopyranosyl-(1-->3)]-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-beta- d-fucopyranosyl ester ( 2), 3- O-beta- d-glucopyranosylpresenegenin 28- O-beta- d-apiofuranosyl-(1-->4)-[beta- d-galactopyranosyl-(1-->2)]-beta- d-xylopyranosyl-(1-->4)-alpha- l-rhamnopyranosyl-(1-->2)-be…
PSA Depletion Induces the Differentiation of Immature Neurons in the Piriform Cortex of Adult Mice
2021
Immature neurons are maintained in cortical regions of the adult mammalian brain. In rodents, many of these immature neurons can be identified in the piriform cortex based on their high expression of early neuronal markers, such as doublecortin (DCX) and the polysialylated form of the neural cell adhesion molecule (PSA-NCAM). This molecule plays critical roles in different neurodevelopmental events. Taking advantage of a DCX-CreERT2/Flox-EGFP reporter mice, we investigated the impact of targeted PSA enzymatic depletion in the piriform cortex on the fate of immature neurons. We report here that the removal of PSA accelerated the final development of immature neurons. This was revealed by a h…
Experimental techniques for testing the sensitivity of bladder tumours to antineoplastic drugs
1973
A number of laboratory tests can be employed to examine the sensitivity of human bladder tumour cells to various chemotherapeutic agents.-Their principles and methods, and some preliminary results, are described with special reference to certain in vitro and in vivo cytotoxicity tests and to heterotransplantation in the hamster. Satisfactory agreement has sometimes been observed between experimental results and clinical responses, but our experience is still very limited.-The employment of several such tests would probably lead to a greater degree of reliability in the laboratory assessment of the sensitivity of bladder tumours to cytotoxic drugs.
Activation of a Sweet Taste Receptor by Oleanane-Type Glycosides from Wisteria sinensis
2022
The phytochemical study of Wisteria sinensis (Sims) DC. (Fabaceae), commonly known as the Chinese Wisteria, led to the isolation of seven oleanane-type glycosides from an aqueous-ethanolic extract of the roots. After successive purifications by various chromatographic methods, like solid/liquid chromatographic methods, vacuum liquid chromatography (VLC), medium pressure liquid chromatography (MPLC), on normal and reverse phase (RP-18 silica gel), and size exclusion chromatography on Sephadex L, their structures were elucidated by an extensive 600 MHz NMR analysis including 1D and 2D NMR experiments as well as ESI-MS. Among the seven isolated saponins, two have never been reported before : 3…
Beneficial Read-Through of aUSH1CNonsense Mutation by Designed Aminoglycoside NB30 in the Retina
2010
PURPOSE. The human Usher syndrome (USH) is the most frequent cause of inherited combined deaf-blindness. USH is clinically and genetically heterogeneous, assigned to three clinical types. The most severe type is USH1, characterized by profound inner ear defects and retinitis pigmentosa. Thus far, no effective treatment for the ophthalmic component of USH exists. The p.R31X nonsense mutation in USH1C leads to a disease causing premature termination of gene translation. Here, we investigated the capability of the novel synthetic aminoglycoside NB30 for the translational read-through of the USH1C-p.R31X nonsense mutation as a retinal therapy option. METHODS. Read-through of p.R31X by three com…
Neurochemical and morphological studies on demyelination in multiple sclerosis with special reference to etiological aspects.
1972
Light microscopic studies were used as control for neurochemical studies and these showed that some micro plaques could be found also in areas which were normal on visual inspection. Also foreign cell infiltrates were found outside any clear plaque material. The number of these cells did not correlate with other findings like lipid or enzyme chemistry. In electronmicroscopic studies astrocytes demonstrated most lysosomes and phagocytosis of myelin. This increased lysosomal reaction was demonstrated also in biochemical analyses performed on MS biopsy specimens. Occasional nuclear changes like inclusion bodies and protrusion of inner nuclear membrane were observed suggesting some exogenous, p…