Flavonoid and phenolic acid profile by LC-MS/MS and biological activity of crude extracts from Chenopodium hybridum aerial parts

Extracts from leaves and stems of Chenopodium hybridum were characterised for the presence and quantity of flavonoids and phenolic acids by LC-ESI-MS/MS. Five flavonoids and eight phenolic acids were detected for the first time in aerial parts of this plant species, the most abundant compounds being rutin (2.80 μg/g DW), 3-kaempferol rutinoside (2.91 μg/g DW), 4-OH-benzoic (1.86 μg/g DW) and syringic acids (2.31 μg/g DW). Extracts were tested for anti-inflammatory/antiarthritic, antihyaluronidase and cytotoxic activities against human prostate cancer (Du145, PC3) and melanoma cell lines (A375, HTB140 and WM793) of different malignancy. None of the extracts protected bovine serum albumin from heat-induced denaturation. Antihyaluronidase effect at the tested concentration was higher than standard naringenin. Cytotoxic activity was generally low with an exception of the extract from the leaves, which was found most effective against prostate Du145 cell line with 98.28 ± 1.13% of dead cells at 100 μg/mL.     

The influence of structural changes of the N-substituent on liquid crystalline behaviour of ester imides

Several new ester imide derivatives with different N-substituents in the imide ring were synthesized and their mesogenic properties investigated by thermal analysis, optical microscopy and X-ray diffraction. All the esters of N-4-[(4'-decyloxybiphenyl-4-yl)oxycarbonyl]phthalimideacetic acid and aliphatic alcohols exhibited monolayer SmA and SmC phases. In addition, for the ethyl and propyl esters a monotropic hexatic (F or I) phase was observed. The introduction of additional substituents at the carbon atom in the methylenemethoxycarbonyl group (in the vicinity of the nitrogen atom) substantially influenced liquid crystalline properties: the compounds with a flexible chain exhibited monotropic SmA-SmB dimorphism, but liquid crystalline properties vanished for the substituent containing the more rigid phenyl ring.     

Linear and cyclic aminomethanephosphonic acid esters derived from benzaldehyde derivatives, 3‐aminopropanol,and diethyl phosphite

A series of four diethyl {[(3‐hydroxy‐ propyl)amino](aryl)methyl}phosphonates have been prepared and characterized. In one case, the phosphonate was transformed to a seven‐membered 1,4,2‐ oxazaphosphepane heterocycle through a one‐pot intramolecular esterification. The analogous reaction with formaldehyde gave the six‐membered diethyl (1,3‐oxazinan‐3‐ylmethyl)phosphonate, which could be transformed in a posterior reaction to the corresponding aminomethanephosphonic acid. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:75–80, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20178     

Odd–even effect in biphenyl‐based symmetrical dimers with methylene spacer – evidence of the B4 phase

A series of 4‐decyloxy‐4′‐hydroxybiphenyl esters of α,ω‐alkanedicarboxylic acids containing two mesogenic units connected by a methylene spacer was synthesized. The mesogenic properties of the compounds were investigated by polarising optical microscopy, differential scanning calorimetry and X‐ray diffraction methods. A strong influence of the spacer length and its parity on the mesomorphic properties was found. A dramatic odd–even effect was observed for the clearing temperatures and entropies. Compounds with an even number of carbon atoms in the methylene spacer formed tilted smectic phases, whereas compounds with an odd number of carbon atoms in the spacer exhibited the B4 phase, characteristic of bent‐shaped molecules.     

Slippage mutation rates in 15 autosomal short tandem repeat loci for forensic purposes in a Southeastern Brazilian population

Well‐defined estimates of mutation rates in highly polymorphic tetranucleotide STR loci are a prerequisite for human identification in genetics laboratory routines useful for civil and criminal investigations. Studying 15 autosomal STR loci of forensic interest (CSF1PO, D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, FGA, TH01, TPOX, and vWA), we detected 193 slippage mutations (189 one‐step and four two‐step mutations) in 148 875 parent‐child allelic transfers from 5171 paternity cases with true biological relationship (15 096 individuals; 4754 trios and 417 duos; 9925 meiosis) from the state of São Paulo, a very representative population of Brazil. The overall mutation rate was 1.3 × 10^?3 and the highest rates were observed at loci vWA (2.8 × 10^?3), FGA and D18S51 (2.7 × 10^?3 for both), while loci TH01 and TPOX did not present any mutations. The mean slippage mutation rate of paternal origin (1.8 × 10^?3) was six times higher than that observed for maternal origin (0.3 × 10^?3).     

Die IR-Spektren einiger Arsenat-Halogen-Apatite

The infrared spectra of orthoarsenates with apatite structure, of the formulaM ₅(AsO₄)₃ X (M=Ca, Sr, Ba, Pb andX=F, Cl,Br) are measured and interpreted on the basis of a site-symmetry analysis. The influence of the different cations on the internal vibrations of the AsO₃ ⁴-ions is discussed.

     

Solvent induced cooperativity of Zn(II) complexes cleaving a phosphate diester RNA analog in methanol

The kinetics of cyclization of 2-hydroxypropyl p-nitrophenyl phosphate (1) promoted by two mononuclear Zn(II) catalytic complexes of bis(2-pyridylmethyl)benzylamine (4) and bis(2-methyl 6-pyridylmethyl)benzylamine (5) in methanol were studied under (s)(s)pH-controlled conditions (where (s)(s)pH refers to [H(+)] activity in methanol). Potentiometric titrations of the ligands in the absence and presence of Zn(2+) and a non-reactive model for 1 (2-hydroxylpropyl isopropyl phosphate (HPIPP, 6)) indicate that the phosphate is bound tightly to the 4:Zn(II) and 5:Zn(II) complexes as L:Zn(II):6(-), and that each of these undergoes an additional ionization to produce L:Zn(II):6(-):((-)OCH(3)) or a bound deprotonated form of the phosphate, L:Zn(II):6(2-). Kinetic studies as a function of [L:Zn(II)] indicate that the rate is linear in [L:Zn(II)] at concentrations well above those required for complete binding of the substrate. Plots of the second order rate constants (defined as the gradient of the rate constant vs. [complex] plot) vs. (s)(s)pH in methanol are bell-shaped with rate maxima of 23 dm mol(-1) s(-1) and 146 dm mol(-1) s(-1) for 4:Zn(II) and 5:Zn(II), respectively, at their (s)(s)pH maxima of 10.5 and 10. A mechanism is proposed that involves binding of one molecule of complex to the phosphate to yield a poorly reactive 1 : 1 complex, which associates with a second molecule of complex to produce a transient cooperative 2 : 1 complex within which the cyclization of 1 is rapid. The observations support an effect of the reduced polarity solvent that encourages the cooperative association of phosphate and two independent mononuclear complexes to give a reactive entity.     

Asymptotic results for polygonal processes related to an autoregression

We establish functional central limit theorems for polygonal process constructed from consecutive estimators of a simple AR(1) model. We consider both stationary and unit root cases. The results are applied to change segment analysis.     

(+)-Usnic Acid as a Promising Candidate for a Safe and Stable Topical Photoprotective Agent

The study aimed to examine whether usnic acid—a lichen compound with UV-absorbing properties—can be considered as a prospective photoprotective agent in cosmetic products. Moreover, a comparison of two usnic acid enantiomers was performed to preselect the more effective compound. To meet this aim, an in vitro model was created, comprising the determination of skin-penetrating properties via skin-PAMPA assay, safety assessment to normal human skin cells (keratinocytes, melanocytes, fibroblasts), and examination of photostability and photoprotective properties. Both enantiomers revealed comparable good skin-penetrating properties. Left-handed usnic acid was slightly more toxic to keratinocytes (IC₅₀ 80.82 and 40.12 µg/mL, after 48 and 72 h, respectively) than its right-handed counterpart. The latter enantiomer, in a cosmetic formulation, was characterized by good photoprotective properties and photostability, comparable to the UV filter octocrylene. Perhaps most interestingly, (+)-usnic acid combined with octocrylene in one formulation revealed enhanced photoprotection and photostability. Thus, the strategy can be considered for the potential use of (+)-usnic acid as a UV filter in cosmetic products. Moreover, the proposed model may be useful for the evaluation of candidates for UV filters.