Search results for "Glycosides"

A comparative evaluation of NB30, NB54 and PTC124 in translational read-through efficacy for treatment of an USH1C nonsense mutation

2012

Translational read-through-inducing drugs (TRIDs) promote read-through of nonsense mutations, placing them in the spotlight of current gene-based therapeutic research. Here, we compare for the first time the relative efficacies of new-generation aminoglycosides NB30, NB54 and the chemical compound PTC124 on retinal toxicity and read-through efficacy of a nonsense mutation in the USH1C gene, which encodes the scaffold protein harmonin. This mutation causes the human Usher syndrome, the most common form of inherited deaf-blindness. We quantify read-through efficacy of the TRIDs in cell culture and show the restoration of harmonin function. We do not observe significant differences in the read…

Post-remission treatment with allogeneic stem cell transplantation in patients aged 60 years and older with acute myeloid leukaemia: a time-dependent…

2015

Summary Background Acute myeloid leukaemia mainly affects elderly people, with a median age at diagnosis of around 70 years. Although about 50–60% of patients enter first complete remission upon intensive induction chemotherapy, relapse remains high and overall outcomes are disappointing. Therefore, effective post-remission therapy is urgently needed. Although often no post-remission therapy is given to elderly patients, it might include chemotherapy or allogeneic haemopoietic stem cell transplantation (HSCT) following reduced-intensity conditioning. We aimed to assess the comparative value of allogeneic HSCT with other approaches, including no post-remission therapy, in patients with acute…

The roles of foraging environment, host species, and host diet for a generalist pupal parasitoid

2018

Even for parasitoids with a wide host range, not all host species are equally suitable, and host qualityoften depends on the plant the host feeds on. We compared oviposition choice and offspring perfor-mance of a generalist pupal parasitoid,Pteromalus apum(Retzius) (Hymenoptera: Pteromalidae), ontwo congeneric hosts reared on two plant species under field and laboratory conditions. The plantscontain defensive iridoid glycosides that are sequestered by the hosts. Sequestration at the pupal stagediffered little between host species and, although the concentrations of iridoid glycosides in the twoplant species differ, there was no effect of diet on the sequestration by host pupae. The rate of …

Hederagenin glycosides from the fruits of Blighia unijugata

2019

Abstract A phytochemical investigation of Blighia unijugata led to the isolation of eleven hederagenin glycosides. Among these compounds, six are previously undescribed, two are described in their native forms for the first time and three are known whereas firstly isolated from Blighia unijugata. The structure of the undescribed compounds was elucidated on the basis of 2D NMR and mass spectrometry analyses as 3-O-β-D-xylopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin, 3-O-β-D-xylopyranosyl-(1 → 3)-α-L-arabinopyranosyl-(1 → 4)-3-O-acetyl-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyr…

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-…

Carbohydrate Scaffolds for Combinatorial Syntheses That Allow Selective Deprotection of All Four Positions Independent of the Sequence

2004

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…

Diastereoselective synthesis of substituted 2-phenyltetrahydropyrans as useful precursors of aryl C-glycosides via selenoetherification

2004

The cyclization of several substituted 5-phenyl-pent-4-en-1-ols with selenium electrophiles along some mechanistic considerations is discussed. In particular, an efficient diastereoselective synthesis of a 2,3,5,6-tetrasubstitued tetrahydropyran is reported. These findings open an interesting approach: the use of chiral selenium electrophiles for cyclization of chiral substrates. The cyclized products are useful starting material for the synthesis of D- or L-aryl C-glycosides.