Esters of para-aminobenzoic acid in cosmetics. Identification and dosage within sun-creams

A method is presented for the identification and determination by T.L.C. and G.L.C. of esters of para-aminobenzoic acid with a free amine function and of local anaesthetics, prohibited in cosmetic products, in accordance with the cosmetic directive 76/768/EEC. In a commercial product, nominally supplied as para-aminobenzoic monoglyceryl ester (authorised in sun-creams in accordance with the EEC directive) other phenyl groups with para substitution were identified by means of T.L.C. and N.M.R. spectroscopy; among them, the para-aminobenzoic ethyl ester. G.L.C. enables a quantitative determination of these substances. Les esters de l'acide para-amino benzoique dans les produits cosmétiques. Identification et dosage dans les crémes solaires     

The distribution of anthocyanins in grape skin extracts of port wine cultivars as determined by high performance liquid chromatography

The distribution of anthocyanins in methanolic skin extracts of 16 grape cultivars used for port wine production and grown at five sites in the Douro Valley in Northern Portugal has been assessed by high performance liquid chromatography. Results are confined to the seven most readily separated and identified anthocyanins and are expressed as percentages of their total (88–99% of the total integrated area). Anthocyanins based on malvidin (Mv) predominated. Of these, Mv 3-glucoside was the major pigment (33–60%), being exceeded by Mv 3-p-coumarylglucoside (2–51%) in only two cultivars; Mv 3-acetylglucoside (1–15%) was consistently the lowest. Peonidin 3-glucoside (1–27%) was prominent in four cultivars, but delphinidin 3-glucoside (1–11%), petunidin 3-glucoside (2–11%) and cyanidin 3-glucoside (trace-6%) were of low proportions throughout. The ratio Mv 3-acetylglucoside/total Mv glucosides appeared characteristic of cultivar, independent of site, and a useful aid to identification of grape cultivars. The coloured pulp of some cultivars contained peonidin 3-glucoside as a major component, present in greater proportions than in the skin; the percentage of Mv 3-p-coumarylglucoside was lower in pulp than in skin. The identities of six of the seven anthocyanins were confirmed by fast atom bombardment mass spectrometry and the structures of the Mv derivatives were determined by nuclear magnetic resonance. The formation of formyl and acetyl anthocyanin artefacts is described.     

葡萄叶片中单宁,木质素,PPO活性与抗黑痘病的关系

本研究以野生种葡萄（华东葡萄、掌裂草葡萄，秋葡萄）、栽培葡萄（红富士）的健全和病叶为试材，调查了４个种或品种的病情指数，测定了单宁与木质的含量和ＰＰＯ活性，结果表明，野生种葡萄经载培葡萄抗病；单宁和木素含量、ＰＰＯ活性与葡萄的抗黑痘病能力呈正相关。这些酚类物质在葡萄抗病研究中具有重要意义，可作为葡萄抗病性鉴定的指标。     

The determination of bitter principles in zucchinis

A method using reverse phase thin layer and high performance liquid chromatography was developed to determine the level of the bitter principle occasionally found in zucchini (Cucurbita pepo L.). The system gave excellent separation with recovery rates of about 90% from spiked fruit. The bitter principle was confirmed by C¹³ NMR and mass spectrometry as cucurbitacin E glycoside which was present in concentrations in the order of 600mg kg^?1 in bitter fruits. Bitterness was detected by a taste panel at cucurbitacin E glycoside concentrations of 1 mg kg^?1 in aqueous solutions and 2 mg kg^?1 in zucchini pulp. The method described should assist the screening for bitterness in commercial and breeding populations of zucchini.     

Wine phenolics—analysis of low molecular weight components by high performance liquid chromatography

Low molecular weight phenolic compounds were separated by high performance liquid chromatography on hydrocarbon-bonded reverse phase packings, with a water-methanol elution gradient. Phenolic compounds were extracted from wine with ethyl acetate. A first extraction at pH 7 enabled isolation of neutral molecules (catechins, procyanidins, flavonols, aromatic alcohols); a second extraction at pH 2 was performed to extract phenolic acids. Successive injections of these two extracts in the chromatograph gave the distribution of the different phenolic compounds in the wine under analysis. Analytical data are given for low molecular weight phenolic compounds present in young red Bordeaux wines from different vine cultivars.     

argR基因对钝齿棒杆菌发酵过程中产精氨酸特性的影响

本文测定了一株钝齿棒杆菌（Corynebacterium crenatum）诱变菌和二株基因工程菌发酵过程中产arginine曲线、生长曲线以及发酵液中碳源消耗量和pH值的变化。实验结果显示Arg产量最高的菌株为C．crenatumA．S．M2.sp，其产量达到9mg／ml，据此认为钝齿棒杆菌中的argR基因可能为Arg代谢中的一个正调控因子。     

Presence of quercetin-3-O-glucuronoside in Spanish table wines

Quercetin-3-O-glucuronoside has been identified in several Spanish table wines by thin-layer (t.l.c.) and high-performance liquid (h.p.l.c.) chromatographic methods. This is thought to be the first report of its occurrence in wine.     

Prediction of moisture and bulk density in milled peat by near infrared reflectance

Calibrations have been developed for the prediction of moisture (34–71% w/w) and bulk density (193–402 g litre^?1) in milled peat. Predictive accuracy was satisfactory in the case of moisture (residual standard deviation (r.s.d.)=1.1) but less so for bulk density (r.s.d.=15.1); values for precision (pooled standard deviation between duplicates) were 0.7 and 12.1 respectively. Variations in milled peat colour had no effect on the accuracy of either calibration although variation in sample temperature (+6 to +27°C) resulted in an increased residual standard deviation and the appearance of a small mean bias; precision was also affected.     

The effect of grain stability on damage caused by Prostephanus truncatus (Horn) and three other beetle pests of stored maize

In an experiment where grain was presented to Prostephanus truncatus (Horn), Rhyzopertha dominica (F), Sitophilus zeamais Motsch, and Tribolium castaneum (Herbst) in four different ways, it was found that on simulated maize cobs P. truncatus caused much more damage than on loose maize, whereas the reverse was true for the other species. Damage was measured as percentage weight loss over a 6 week period, starting with adult beetles. It is suggested that such differences in the biology of the pests should be taken into account when investigating the inherent susceptibility to infestation of different maize varieties.     

Analysis of sugars and organic acids in ripening mango fruits (Mangifera indica L. var Keitt) by high performance liquid chromatography

The sugars and organic acids present in the pulp of Keitt mangoes at various stages of ripeness were analysed by h.p.l.c. Ripening was associated with a loss in firmness, peel chlorophyll and pulp acidity, with increasing soluble solids and total sugars. The major sugars were identified as glucose, fructose and sucrose. All three increased during ripening; sucrose was found to be in the greatest concentration throughout, with fructose the predominant reducing sugar. Acidity loss was shown by decreasing titratable acidity and increasing pH values. Citric and malic acids were found to be the major organic acids. A large decrease in citric acid and a small reduction in malic acid were responsible for the loss of acidity. Tartaric, ascorbic, oxalic and α-ketoglutaric acids were also shown to be present at low concentrations.