alzheimer's disease (ad) is considered as the greatest thread to adults aged 65 and older. it stands as the most common cause of dementia, the prevalence of which is around 24 million worldwide. ad is a progressive and degenerative disorder that combats the neurons, leading to impairment of different cognitive functions. ad is characterized by an accumulation of two factors normally presen...

The chromatography fractionation of the hexane, chloroform and ethyl acetate extracts from the leaves and stems of Rourea doniana Baker, Connaraceae, resulted in the isolation of five triterpenes (lupeol, lupenone, α-amyrenone, β-amyrenone, and taraxerol), a flavonol (7,4’-dimethylkaempferol), a coumarin (scopoletin) and four phytosteroids (β-sitosterol, stigmasterol, β-sitosteryl-3-Oβ-D-glucop...

Gradients of the plant hormone auxin, which depend on its active intercellular transport, are crucial for the maintenance of root meristematic activity. This directional transport is largely orchestrated by a complex interaction of specific influx and efflux carriers that mediate the auxin flow into and out of cells, respectively. Besides these transport proteins, plant-specific polyphenolic co...

A recent meta-analysis of prospective cohort studies suggests that high dietary intakes of flavonols are associated with a significantly lower risk of coronary heart disease mortality. The major dietary sources of flavonols such as quercetin, kaempferol, and isorhamnetin are tomatoes, onions, kale, broccoli, celery, apples, and cherries, while catechins are concentrated in tea and red wine. 3 N...

13C-NMR, Apigenin, Kaempferol, Flavonoid, Biosynthesis Cell suspension cultures of parsley (Petroselinum hortense) were incubated with [l,2-13C2]acetate during a period of active flavonoid production. The flavonoid glycosides were extracted with ethanol, hydrolyzed in dilute acid, and the aglycones purified by chromatography. Apigenin, a flavone, and kaempferol, a flavonol, were analyzed at 67....

An efficient method for examining the selectivity of inhibitors on two alpha-fucosidases, one from Thermotoga maritima and the other from human, was established. The X-ray crystal structure of the former enzyme makes possible the homology modeling of the human alpha-fucosidase, indicating the major difference between both enzymes in the periphery of the catalytic site. To investigate the differ...

Glycoprotein oligosaccharides function as tags for protein quality control in the endoplasmic reticulum (ER). Since most of proteins are glycosylated and function only after they are properly folded, glycoprotein glycan profiles in the ER might be useful to analyze various cellular status including diseases. Here, we examined whether ER glycan-processing profiles in diabetic rats and osteoporot...

Tetracyclines are aromatic polyketides biosynthesized by bacterial type II polyketide synthases. The amidated tetracycline backbone is biosynthesized by the minimal polyketide synthases and an amidotransferase homologue OxyD. Biosynthesis of the key intermediate 6-methylpretetramid requires two early tailoring steps, which are cyclization of the linearly fused tetracyclic scaffold and regiosele...

Three series of thioglycosyl donors differing only in their respective aglycon substituents within each series have been prepared as representatives of typical glycosyl donors. The relative anomeric reactivities of these donors were quantified under competitive glycosylation conditions with various reaction time, promoters, solvents and acceptors. Over three orders of magnitude reactivity diffe...