bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability of Lycopene in Oil‐in‐Water Emulsions
Authors: Ax K. , Mayer‐Miebach E. , Link B. , Schuchmann H. , Schubert H. 
Published: March 2003

AbstractLycopene can be dissolved within the oil phase of oil‐in‐water emulsions to increase bioavailability in water‐dispersible systems. It is sensitive to oxidative conditions and easily undergoes isomerization at high temperatures. Degradation kinetics and isomerization of lycopene in oil‐in‐water‐emulsions were investigated as a function of thermal treatment and oxygen content. Lycopene degradation was found to follow a first‐order kinetics and rate constants were determined. Higher temperatures are directly correlated with increasing lycopene losses. Moreover, thermal treatment leads to a significant decrease of the concentrations of all‐trans and 13‐cis isomer, while the concentration of the 9‐cis isomer increased. Oxygen‐free conditions reduce lycopene losses significantly.
Studies on the amino acid and mineral content of buckwheat protein fractions
Authors: Wei Yi‐min , Hu Xin‐zhong , Zhang Guo‐quan , Ouyang Shao‐hui 
Published: March 2003

AbstractProtein fractions were extracted by successive extraction and analysis method in four buckwheat varieties including Japanese spring buckwheat, Japanese summer buckwheat, Yuqiao No. 1 and Yuqiao 6‐21. The amino acid and the mineral content of each protein fraction were also analyzed in this paper. The basis for the data on the experiment was the relationship between protein fractions and amino acids, and the mineral contents of protein fractions. The distribution and proportion of amino acids and the minerals in each protein fraction in the buckwheat kernel as well as the nutritional value of buckwheat kernel were discussed. The results showed that there is a high amount of soluble protein and very low amount of prolamin in the buckwheat kernel. Leucine is the first limited amino acid in buckwheat, and buckwheat protein is only a seminutritional protein. The buckwheat kernel is rich in K, Zn in the albumin, Ca, Mg and Mn in the globulin, Na in the prolamin and glutelin.
Antifungal activity of peppermint and sweet basil essential oils and their major aroma constituents on some plant pathogenic fungi from the vapor phase
Authors: Edris Amr E. , Farrag Eman S. 
Published: March 2003

AbstractThe vapors of peppermint oil and two of its major constituents (menthol and menthone( and sweet basil oil and two of its major constituents (linalool and eugenol( were tested against Sclerotinia sclerotiorum (Lib.( Rhizopus stolonifer (Ehrenb. exFr.) Vuill and Mucorsp. (Fisher) in a closed system. These fungi cause deterioration and heavy decay of peach fruit during marketing, shipping and storage. The essential oils, their major individual aroma constituents and blends of the major individual constituents at different ratios inhibited the growth of the fungi in a dose‐dependent manner. Menthol was found to be the individual aroma constituent responsible for the antifungal properties of peppermint essential oil, while menthone alone did not show any effect at all doses. In the case of basil oil, linalool alone showed a moderate antifungal activity while eugenol showed no activity at all. Mixing the two components in a ratio similar to their concentrations in the original oil was found to enhance the antifungal properties of basil oil indicating a synergistic effect.
Influence of modified atmosphere packaging on the shelf life of prebaked pizza dough with and without preservative added
Authors: Rodríguez Valle , Medina Luis , Jordano Rafael 
Published: March 2003

AbstractThe possible effect of different modified atmospheres on the shelf life of prebaked pizza dough, with and without added calcium propionate, was investigated. Three packaging atmospheres were tested: 20% CO2 : 80% N2, 50% CO2 : 50% N2, 100% CO2, and air (control). Samples were examined daily for visible mold growth and analysed after 2, 8, 17 and 31 days throughout storage (15–20°C and 54–65% relative humidity, RH) for changes in gaseous composition, pH and microbial populations (mesophilic aerobic and anaerobic bacteria, lactic acid bacteria (LAB( and yeasts and molds). Microbiological results showed that molds had a greater sensitivity to CO2 than bacteria and yeasts. Products containing calcium propionate did not show mold growth throughout storage (31 days) when packaged in air or in CO2‐enriched atmospheres (20, 50 and 100%). However, in pizza dough without preservative (calcium propionate( mold growth was evident after 7 days, except under 100% CO2 atmosphere (13 days) regardless of the packaging atmosphere. From these results we conclude that the addition of calcium propionate had more and decisive influence on the shelf life extension of prebaked pizza dough.
In vitro evaluation of antioxidant properties of Cocos nucifera Linn. water
Authors: Mantena Sudheer Kumar , Jagadish  , Badduri Sridhar Reddy , Siripurapu Kiran Babu , Unnikrishnan Mazhuvancherry Kesavan 
Published: March 2003

AbstractTender Cocos nucifera L. (Palmacea) water (CW( variety Chandrasankara, was tested for its ability to scavenge free radicals, inhibit lipid peroxidation and protect hemoglobin from nitrite‐induced oxidation. Fresh sample of CW scavenged 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH( 2,2′‐azino‐bis(3‐ethylbenz‐thiazoline‐6‐sulfonic acid) (ABTS) and superoxide radicals but promoted the production of hydroxyl radicals and increased lipid peroxidation. The activity was most significant for fresh samples of CW and diminished significantly upon heat, acid or alkali treatment or dialysis. Maturity of coconut drastically decreased the scavenging ability of CW against DPPH, ABTS and superoxide radicals. CW protected hemoglobin from nitrite‐induced oxidation to methemoglobin when added before the autocatalytic stage of the oxidation. Acid, alkali or heat treated or dialyzed CW showed a decreased ability in protecting hemoglobin from oxidation. The scavenging ability and protection of hemoglobin from oxidation may be partly attributed to the ascorbic acid, which is an important constituent of CW. As CW is a rich source of vitamins, amino acids and enzymes, etc., more than one active principle may be involved.
Rapid differentiation of new apple cultivars by headspace solid‐phase microextraction in combination with chemometrical data processing
Authors: Schulz Ines , Ulrich Detlef , Fischer Christa 
Published: March 2003

AbstractThe aim of this study was to test a combination of automated headspace solid phase‐microextraction gas chromatography (GC) with chemometrical data treatment for the rapid differentiation of enzyme‐inactivated homogenates of new apple cultivars. The four cultivars Pinova, Piflora, Renora and Florina are characterized by different volatile patterns. Differences in the contents of volatiles were especially found for butyl acetate, ethyl butanoate, 2‐methyl butanol, ethyl acetate and 6‐methyl‐5‐hepten‐2‐ol. The used sample preparation method for GC coupled with pattern recognition of chromatograms is a useful tool for rapid and reliable determination of large numbers of samples.
Comparison of the quality of some Croatian and German wheat varieties according to the German standard protocol
Authors: Unbehend Ljiljana , Unbehend G. , Lindhauer M. G. 
Published: March 2003

AbstractTen Croatian and five German wheat varieties were tested. They were carried out using the German standard testing protocol. The results demonstrated that the quality of the Croatian wheat varieties could be ranged in A–C quality groups according to the German testing protocol. Croatian wheat varieties were comparable in many parameters (protein content, hardness, water absorption, dough handling properties and volume yield) with chosen German wheat varieties. Some differences were found in falling number, sedimentation value, flour yield, and ash value number.
Protein composition of some Croatian and German wheat varieties and their influence on the loaf volume
Authors: Unbehend Ljiljana , Unbehend G. , Lindhauer M. G. 
Published: March 2003

AbstractTen Croatian and five German wheat varieties were tested. Wheat protein composition was analysed according to a modified Osborne fractionation. They were extracted in four fractions: NaCl fraction, ethanol fraction, acetic acid fraction and insoluble fraction. The influence of protein and protein composition on the loaf volume was investigated. In protein composition a difference between the Croatian and German wheat varieties were found. Protein content, glutenin content and insoluble glutenin content showed influences on the loaf volume.
Studies on dimerisation of tocopherols under the influence of methyl linoleate peroxides
Authors: Gogolewski Marek , Nogala‐Kalucka Malgorzata , Galuba Grzegorz 
Published: March 2003

AbstractThe stability of plant oils is related to the level of polyunsaturated fatty acids and the presence of native antioxidants – especially tocopherols. During storage, lipids or the fat products undergo oxidation and tocopherol dimers and trimers are formed. These compounds possess reducing and antioxidant properties and participate in oxidation clearly inhibiting this process. In the present study, the correlation between levels of peroxides formed during autoxidation of methyl linoleate and simultaneous decomposition of tocopherols was examined. The peroxide value was investigated. Quantities of decomposed tocopherols and formation of their dimers were determined by high‐performance liquid chromatography (HPLC). Mass spectrum analysis confirmed that the analysed compounds were dimers. Dimerisation of γ‐T begins at the smaller quantity of the methyl linoleate peroxides than dimerisation of δ‐T. At the beginning of methyl linoleate autoxidation dimerization of γ‐T in relation to its loss was smaller. The quantity of γ‐T dimers with ether bonds in total dimers pointed to faster binding of phenoxy radicals than transformation into the phenyl ones. δ‐T dimers with phenyl bonds constitute about 65% of the total. The quantity of peroxides in methyl linoleate, necessary for quantitative and qualitative changes of homologous tocopherols, decreased from δ‐T to α‐T.
Antioxidant properties of commercial alcoholic and nonalcoholic beverages
Authors: Lugasi Andrea , Hóvári Judit 
Published: March 2003

AbstractRecent interest in food phenolics has increased greatly, because of their antioxidant and free radical scavenging abilities. Popular beverages in the world include tea, coffee, cocoa, beer, wine and fruit/vegetable juices. All of these beverages contain phenolic compounds. In present study total polyphenol content and in vitro antioxidant properties were investigated in 16 red wines, 5 white wines, 5 lager beers, 3 dark beers, 17 fruit juices and 5 vegetable juices. High polyphenol content was measured in red wines (1 720 ± 546 mg·L–1) and in some fruit juices such as elderberry and prunes (5 680 and 1 807 mg·L–1, respectively). The concentration of polyphenols was between 159 and 5 680 mg·L–1in fruit juices and between 255 and 696 mg·L–1in vegetable ones, while low level of phenolics was observed in dark and lager beers and white wines (473, 376 and 392 mg·L–1, respectively). All samples exhibited significant antioxidant properties such as hydrogen‐donating ability, reducing power, chelating ability and total antioxidant status (TAS) value. These antioxidant properties strongly correlated with the total polyphenol content of the beverages.
In vitro study on digestion of peptides in Emmental cheese: Analytical evaluation and influence on angiotensin I converting enzyme inhibitory peptides
Authors: Parrot Sandrine , Degraeve Pascal , Curia Céline , Martial‐Gros Adèle 
Published: March 2003

AbstractA simple in vitro protocol simulating gastrointestinal digestion of proteins and peptides to investigate the effect of digestive enzymes on the biological activity of peptides present in dairy products was developed. This protocol consisted in a 30 min incubation with pepsin followed by a 4 h incubation with trypsin or pancreatin. It was applied to an Emmental cheese water‐soluble extract (WSE) and to a casein solution (as a control). Sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE) allowed to monitor the digestion of proteins. Reversed‐phase high‐performance liquid chromatography (RP‐HPLC) allowed to monitor the conversion of proteins and peptides into peptides and amino acids: it is proposed to use the mean retention time corresponding to the overall retention time distribution of molecules to assess the effect of digestive enzymes. The biological activity focused in this study was the angiotensin I converting enzyme (ACE) inhibitory activity. Digestion of Emmental WSE induced an increase of the ACE inhibition as compared to undigested WSE while a 10 kDa ultrafiltered WSE lost a part of its ACE inhibitory activity after digestion process. These results strongly suggest that digestive enzymes diminished the ACE inhibition by the peptides present in Emmental cheese WSE, while the digestion of peptides of high molecular weight would generate new ACE inhibitory peptides.
New dsDNA‐Binding Hybrid Molecules Combining an Unnatural Peptide and an Intercalating Moiety
Authors: Chaltin Patrick , Borgions Filip , Rozenski Jef , Van Aerschot Arthur , Herdewijn Piet 
Published: March 2003

AbstractIn our search for new dsDNA‐binding ligands, combinatorial chemistry was first applied to select unnatural oligopeptides with moderate affinity for dsDNA. To enhance the binding affinity of a heptapeptide lead structure, Ac‐Arg‐Ual‐Sar‐Chi‐Chi‐Tal‐Arg‐NH2 (Kd=4.9⋅10−4 M), the compound was conjugated to different heteropolyaromatic moieties by means of a variety of linker arms. Glycine, β‐alanine, glycyl‐glycine, glycyl‐β‐alanine, γ‐aminobutyric acid, and 6‐aminocaproic acid were used as spacers, representing different lengths and/or flexibilities. The intercalators coupled to the oligopeptide were acridine, fluorenone, anthracene, anthraquinone, and 3,8‐diamino‐5‐methyl‐6‐phenylphenantridinium (methidium). The binding capacities of these new hybrid molecules to dsDNA have been investigated by gel retardation and footprinting assays. The results show that, by conjugating the unnatural oligopeptide to intercalators, the affinity for dsDNA could be enhanced more than 100‐fold. For methidium‐β‐alanyl‐glycyl‐Arg‐Ual‐Sar‐Chi‐Chi‐Tal‐Arg‐NH2 (Kd of 2.1⋅10−6 M), the interaction with dsDNA was dominated by the intercalator in such a way that the sequence specificity of the heptapeptide was changed. The interaction with dsDNA of hybrid molecules of other intercalators was mainly governed by the oligopeptide, since the sequence selectivity of the heptapeptide was conserved. In general, the linker arm glycine (shortest spacer) and glycine‐β‐alanine were preferred over β‐alanine, glycyl‐glycine and the more‐flexible spacers γ‐aminobutyric acid and 6‐aminocaproic acid. This way new hybrid molecules endowed with dsDNA affinities of ca. 10−6 M and displaying different sequence selectivities have been developed. Therefore, combinations of such unnatural peptides with intercalators can be used to broaden the knowledge about the sequence‐selective recognition of dsDNA.
Functionalized 3,3′,5,5′‐Tetraaryl‐1,1′‐Biphenyls: Novel Platforms for Molecular Receptors
Authors: Welti Roger , Abel Yvonne , Gramlich Volker , Diederich François 
Published: March 2003

AbstractThis paper describes the development of novel aromatic platforms for supramolecular construction. By the Suzuki cross‐coupling protocol, a variety of functionalized m‐terphenyl derivatives were prepared (Schemes 1–4). Macrolactamization of bis(ammonium salt) (S,S)‐6 with bis(acyl halide) 7 afforded the macrocyclic receptor (S,S)‐2 (Scheme 1), which was shown by 1H‐NMR titration studies to form ‘nesting' complexes of moderate stability (Ka between 130 and 290 M−1, 300 K) with octyl glucosides 13–15 (Fig. 2) in the noncompetitive solvent CDCl3. Suzuki cross‐coupling starting from 3,3′,5,5′‐tetrabromo‐1,1′‐biphenyl provided access to a novel series of extended aromatic platforms (Scheme 5) for cleft‐type (Fig. 1) and macrotricyclic receptors such as (S,S,S,S)‐1. Although mass‐spectral evidence for the formation of (S,S,S,S)‐1 by macrolactamization between the two functionalized 3,3′,5,5′‐tetraaryl‐1,1′‐biphenyl derivatives (S,S)‐33 and 36 was obtained, the 1H‐ and 13C‐NMR spectra of purified material remained rather inconclusive with respect to both purity and constitution. The versatile access to the novel, differentially functionalized 3,3′,5,5′‐tetrabromo‐1,1′‐biphenyl platforms should ensure their wide use in future supramolecular construction.
Molecular Recognition of a Peptide by the Nickel(II) Complex of 1,4,7,10‐Tetraazacyclododecane‐2,9‐dione
Authors: Gao Jian , Reibenspies Joseph H. , Sun Yizhen , Martell Arthur E. 
Published: March 2003

AbstractThe nickel(II) complex of the macrocycle 1,4,7,10‐tetraazacyclododecane‐2,9‐dione (dota) was found to be efficient in the recognition of the dipeptide, glycyl‐glycine (Gly‐Gly) in aqueous solution. This (dota)NiII complex serves as a targeting molecule to form a stable ternary complex with the dipeptide at pH 8.3 in aqueous solution. The recognition constant (log K=19.20) and the recognition mechanism were investigated based on the potentiometric method. The single‐crystal of a six‐coordinated (dota)2NiII complex is also reported.
Total Synthesis of the Spermidine Alkaloid 13‐Hydroxyisocyclocelabenzine
Authors: Li Yi , Linden Anthony , Hesse Manfred 
Published: March 2003

AbstractA convergent total synthesis of 13‐hydroxyisocyclocelabenzine was developed. (3S)‐Methyl 3‐amino‐3‐phenylpropanoate (4) was used as the chiral building block. The 3,4‐dihydro‐4‐hydroxyisoquinolin‐1(2H)‐one derivative (5), the key fragment for the total synthesis, was prepared by a novel base‐catalyzed lactone‐lactam ring enlargement (Scheme 3). The resulting target C(13) epimers 3a/3b from macrocyclization (Scheme 4) were separated by repeated flash chromatography. The absolute configuration of the synthetic alkaloid was determined by an X‐ray crystal‐structure analysis, which enabled us to determine the absolute configuration (9S,13R) for natural 3a with positive [α]D.
Enzyme‐Mediated Preparation of Chiral 1,3‐Dioxane Odorants
Authors: Abate Agnese , Brenna Elisabetta , Fronza Giovanni , Fuganti Claudio , Ronzani Sabrina , Serra Stefano 
Published: March 2003

AbstractThe enantiomerically enriched diastereoisomers of the chiral 1,3‐dioxane odorants Floropal® (1) and Magnolan® (2) were prepared by an enzyme‐mediated approach. Their olfactory properties were evaluated to investigate differences in the odor perception for the stereoisomers.
Leptosphaeric Acid, a Metabolite with a Novel Carbon Skeleton from Leptosphaeria sp. IV403, an Endophytic Fungus in Artemisia annua
Authors: Liu Jun‐Yan , Liu Chang‐Hong , Zou Wen‐Xin , Tan Ren‐Xiang 
Published: March 2003

AbstractLeptosphaeric acid (1), a metabolite with a novel carbon skeleton, was isolated from the AcOEt extract of the culture of Leptosphaeria sp., an endophytic fungus (strain number: IV403) of Artemisia annua. The structure of acid 1 was elucidated on the basis of spectral analyses including homo‐ and heteronuclear correlation NMR experiments (HMQC and HMBC). The absolute configuration of the metabolite was determined by its CD and NOED studies.
A New Method for the Synthesis of Antihypercholesterolemic Agent Simvastatin
Authors: Dabak Kadir , Adiyaman Mustafa 
Published: March 2003

AbstractA new synthetic method for the preparation of the cholesterol‐lowering drug simvastatin from the naturally occurring lovastatin is reported. The synthesis employs first the protection of the OH group of lovastatin (1) and then the protection of the lactone CO group to prevent enolization via conversion to the orthoesters 4a and 4b. Alkylation of the 2‐methylbutyrate side chain is then successfully achieved. Removal of the protecting groups affords antihypercholesterolemic agent simvastatin (2).
Synthesis of [4.3.3]Propellanes by Carbenium‐Ion Rearrangement and Their Olfactory Characterization
Authors: Fráter Georg , Helmlinger Daniel , Kraft Philip 
Published: March 2003

AbstractTreatment of (+)‐sclareolide (1) with polyphosphoric acid or Eaton's reagent furnished, besides the anticipated cyclopentenone (−)‐12 and its isomer (−)‐15, two diastereoisomeric [4.3.3]propellanes (−)‐13 and (−)‐14, which possess interesting woody‐ambery odors. The hydrogenated derivative (−)‐17 possessed an even more‐powerful odor reminiscent of natural ambergris tincture. Mechanistic insight into this rearrangement was provided by a by‐product 24 of the reaction of sclareolide (1) with Eaton's reagent. The carbenium ion rearrangement was then employed in the synthesis of four related [4.3.3]propellanes 40–43, illustrating the utility and scope of this reaction. The olfactory properties of the synthesized [4.3.3]propellanes as well as of the original target structures 10, 33, and 34, prepared from (−)‐12 and (−)‐15, are discussed. Especially the pronounced ambra odor of (−)‐17 vividly contradicts the ‘triaxial rule of amber sensation' and provides new insight into the structural requirements for ambra odorants.
A Novel Secobetulinic Acid 3,4‐Lactone from Viburnum aboricolum
Authors: Ku Yuan‐Ling , Venkateswara Rao G. , Chen Chung‐Hsiung , Wu Chi , Guh Jih‐Hwa , Lee Shoei‐Sheng 
Published: March 2003

AbstractBio‐assay‐guided fractionation of the CHCl3‐soluble extract from the leaves of Viburnum aboricolum led to the isolation of a novel secobetulinic acid 3,4‐lactone, viburolide (=(6β)‐4,6‐dihydroxy‐3,4‐secolup‐20(29)‐ene‐3,28‐dioic acid 3,4‐lactone; 1). This is the first lupane‐type compound possessing such a lactone skeleton from natural products. Its structure was elucidated by spectral analysis and comparison with 6‐dehydroxy‐20,29‐dihydroviburolide (6) prepared from benzyl betulinate (2). Compound 6 was found to inhibit androgen‐independent human prostate cancer cells (PC‐3) with an IC50 of 12.3 μM.
A New Synthesis of Optically Active 3‐Substituted (3S)‐3,4‐Dihydro‐5‐(perfluoroalkyl)‐2H‐[1,4]oxazepin‐7‐ones
Authors: Richard Sébastien , Prié Gildas , Guignard Alain , Thibonnet Jérôme , Parrain J.‐Luc , Duchêne Alain , Abarbri Mohamed 
Published: March 2003

AbstractOptically active (perfluoroalkyl)‐oxazepin‐7‐ones were synthesized in two steps starting from ethyl perfluorobut‐2‐ynoate by direct addition of optically active amino alcohols via intermolecular Michael addition and lactone formation.
New Lignan, Benzofuran, and Sesquiterpene Derivatives from the Roots of Leontopodium alpinum and L. leontopodioides
Authors: Dobner Michael J. , Ellmerer Ernst P. , Schwaiger Stefan , Batsugkh Odonchimeg , Narantuya Samdan , Stütz Michaela , Stuppner Hermann 
Published: March 2003

AbstractThree new compounds, including a benzofuran, 1‐{(2R*,3S*)‐3‐(β‐D‐glucopyranosyloxy)‐2,3‐dihydro‐2‐[1‐(hydroxymethyl)vinyl]‐1‐benzofuran‐5‐yl}ethanone (1), a lignan, [(2S,3R,4R)‐4‐(3,4‐dimethoxybenzyl)‐2‐(3,4‐dimethoxyphenyl)tetrahydrofuran‐3‐yl]methyl (2E)‐2‐methylbut‐2‐enoate (2), and a silphiperfolene‐type sesquiterpene, [(1S,2Z,3aS,5aS,6R,8aR)‐1,3a,4,5,5a,6,7,8‐octahydro‐1,3a,6‐trimethylcyclopenta[c]pentalen‐2‐yl]methyl acetate (3), together with the known coumarins obliquin (4) and its 5‐methoxy derivative 5 were isolated from the roots of Leontopodium alpinum. Another known coumarin derivative, 5‐hydroxyobliquin (6), was isolated from the roots of L. leontopodioides. The structures of these compounds were established by spectroscopic studies.