From methanolic extract of aerial parts of Peucedanum ruthenicum M. Bieb (Apiaceae) collected from Mazandaran province of Iran, four flavonoids namely Isorhamnetin 3-0-rutinoside 1, rutin 2, quercetin 3, morin 4 and two phenolic acids namely caffeic acid 5 and p-coumaric acid 6 have been isolated by Paper Chromatography (PC) and crystallization. Their structures were elucidated by MS, 1H, 13C N...

The local structure of carbon spheres obtained via the hydrothermal carbonization process is characterized by using a combination of advanced solid-state 13C NMR techniques. Glucose was chosen as the starting product because it offers the possibility of 13C isotopic enrichment and is regarded as a model compound for more complex polysaccharides and biomass, as reported in recent studies. A numb...

The metabolism of glutamine, a physiological substrate of the human kidney, plays a major role in systemic acid-base homoeostasis. Not only because of the limited availability of human renal tissue but also in part due to the lack of adequate cellular models, the mechanisms regulating the renal metabolism of this amino acid in humans have been poorly characterized. Therefore given the renewed i...

Pyoluteorin (1) is an antibiotic and phytotoxic metabolite of several Pseudomonas spp. [1 — 3]. Its biosynthesis had not been studied previously but consideration of its structure suggested that it is a tetraketide with proline (or equivalent) as the starter unit. This has now been confirmed by an incorpora­ tion experiment employing [l,2 -13C2]acetate as pre­ cursor and analysis of the isolate...

Adopting new s-process nucleosynthesis scenario and branch s-process path, we calculate the heavy-element abundances of solar metallicity 3M thermal pulse asymptotic giant branch (hereafter TP-AGB) stars, and then discuss the correlation between heavy-element abundances and C/O ratio. 13C(α, n)16O reaction is the major neutron source, which is released in radiative condition during the interpul...

The hepatic metabolism of 1,omega-dodecanedioic acid, a physiologically relevant representative of the medium-chain dicarboxylic acid family, has been studied by a combination of in vivo and in vitro 13C and 1H NMR spectroscopic techniques. Rats in different nutritional or hormonal situations were infused with [1,12-13C2]- or [1,2,11,12-13C4]dodecanedioic acid, and the kinetics of 13C label app...

Two types of 3D MAS NMR experiments are introduced, which combine standard (NC,CC) transfer schemes with (1H,1H) mixing to simultaneously detect connectivities and structural constraints of uniformly 15N,13C-labeled proteins with high spectral resolution. The homonuclear CCHHC and CCC experiments are recorded with one double-quantum evolution dimension in order to avoid a cubic diagonal in the ...