The adsorption of the helically shaped polyaromatic hydrocarbon heptahelicene (C30H18) on Ni(1 1 1) was studied by means of STM, TPD, LEED, ToF–SIMS, XPS, and AES at temperatures between 130 and 1000 K. The molecule in the monolayer remains intact up to 500 K. Above that temperature a stepwise ...

Using quantum chemistry methods, structure⿿NLO property relationships are investigated for families of 7-ring helicenes built from thiophene and benzene rings. In absence of donor or acceptor substituents, the first hyperpolarizability (β) is small. On the other hand, with NO2 groups in termina...

A convenient synthetic method is described for 3-substituted aromatic trifluoromethyl ethers through an oxidative desulfurization–fluorination reaction. Upon addition to liquid crystalline materials, these ethers lower birefringence (Δn) of the host liquid crystals.

The R-(−) isomer of methyl 1-(2,2-dimethylindan-1-yl) imidazole-5-carboxylate (CGA 214372; 2) strongly inhibited P450-dependent obtusifoliol 14α-demethylase (P450OBT.14DM) (I50 = 8 × 10−9M, I50Km = 5 × 10−5) in a maize (Zea mays) microsomal preparation. Kinetic studies indicated uncompetitive...

Microsomes isolated from corn embryos (Zea mays) can demethylate the 14α-methyl group of obtusifoliol 2. An enzymatic assay has been developped for obtusifoliol 14α-methyl-demethylase in higher plants. The enzymatic reaction was shown to occur sequentially, converting obtusifoliol 2 to 4α-met...

Obtusifoliol-[2,2,4-3H3] was synthesised and incubated with the chrysophyte alga Ochromonas malhamensis which converted it into poriferasterol. A reaction sequence applied to poriferasterol showed that the tritium retained at C-4 occupied the 4α-position. This demonstrates that biological C-4 d...

Obtusifoliol 14α-demethylase is a plant orthologue of sterol 14α-demethylase (CYP51) essential in sterol biosynthesis. We have prepared CYP51 antisense Arabidopsis in order to shed light on the sterol and steroid hormone biosynthesis in plants. Arabidopsis putative CYP51 cDNA (AtCYP51) was obt...

A series of 7-oxo-obtusifoliol analogues have been synthetized and investigated as potential inhibitors of cytochrome P-450 dependent obtusifoliol 14α-demethylase (P-450OBT.14DM) from higher plant microsomes. 7-Oxo-24ξ(24')-dihydro-obtusifoliol and 7-oxo-24(25)-dihydro-29-nor-lanosterol w...

Two new ergostane-type steroids were isolated together with two known compounds, obtusifoliol and 4α,14α-dimethyl-5α-ergosta-7,9(11),24(28)-trine-3β-ol, from the whole herb of Euphorbia chamaesyce. The structures of the new compounds were established as 3β-hydroxy-4α,14α-dimethyl-5α-ergo...

For understanding the effects of phytosterols on the development of cotton (Gossypium hirsutum L.) fibers and the molecular basic of sterol signaling in cotton fiber growth, a gene encoding a homologue of obtusifoliol 14α-demethylase from developing fibers of upland cotton cultivar Xuzhou 142 w...

From the aerial parts of Euphorbia sogdiana Popov, obtusifoliol (1) and two related steroids (2–3) have been isolated and characterized along with a known cycloartane derivative (4). The chemical structure of the obtusifoliol-related compounds, obtained by 1D and 2D NMR, and MS measurements, ha...

m- and p-Chlorinated ω-phenoxyalcohols 1, were transformed into the corresponding lithium ω-(m- and p-lithiophenoxy)alkoxides 4, respectively, by successive deprotonation with n-butyllithium and subsequent chlorine–lithium exchange by lithium naphthalene radical anion in THF–methylcyclohexan...

Ethnopharmacological relevanceChicory (Cichorium intybus L.) is an indigenous vegetable widely cultivated in Europe, America and Asia. In ancient times, the leaves, flowers, seeds, and roots have been used as a wealth of health benefits including its tonic effects, the ability to ease digestive ...

There is increasing evidence that consumption of polyphenol and phenolic-rich foods and beverages have the potential to reduce the risk of developing diabetes type 2, with coffee a dominant example according to epidemiological evidence. One of the proposed mechanisms of action is the inhibition ...

3,5-Dimethoxyhomophthalic acid was synthesized in four steps from 3,5-dimethoxycinnamic acid via a series of reactions including cyclization of 3-(3′,5′-dimethoxyphenyl) propionic acid to 5,7-dimethoxy-1-indanone and oxidative decomposition of methyl-2-hydroxy-2-[5, 7-dimethyoxy-1-oxo-1H-inden...

The standard (po =  0.1 MPa) molar enthalpies of formation for 2,3-, 2,4-, 2,5-, 3,4- and 3,5- trans -dimethoxycinnamic acids, in the gaseous phase, were derived from the standard molar enthalpies of combustion in oxygen, of the crystalline compounds, determined by static bomb combustion calorim...

In our previous paper, we reported that rosmarinic acid (1) of Argusia argentea could neutralize snake venom induced hemorrhagic action. Rosmarinic acid (1) consists of two phenylpropanoids: caffeic acid (2) and 3-(3,4-dihydroxyphenyl)lactic acid (3). In this study, we investigated the structura...

Background: The traditional method to determine the binding sites of inhibitors bound to nucleoside transporters on cell membrane is the radioactive assay. This method suffers from radiolabel instability and the need to dispose of reactive materials. Fluorescence spectroscopy has been increasing...

The N-heterocycles quinaldic acid (quinoline 2-carboxylic acid), kynurenic acid (4-hydroxyquinoline 2-carboxylic acid), 2-oxo-1,2-dihydroquinoline, and xanthine care utilized by Alcaligenes sp. F-2 as sole source of carbon and energy. Although quinoline did not serve as growth substrate, 8-hydro...

BackgroundPreviously, we have demonstrated that kynurenic acid (KYNA), an endogenous metabolite of tryptophan formed along kynurenine pathway, is present in synovial fluid of rheumatoid arthritis (RA) and osteoarthritis (OA) patients. In this study, the goal was to investigate the presence of qu...