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Determination of changes in sugar composition during the aging of honey by HPLC, FTIR and NMR spectroscopy
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Abstracts immune disease implicated with H. pylori strains carry Lewis blood-group epitopes.
which
Diastereoselective Inter- and Intramolecular Cycloaddition Reactions of Nitrilimines Derived From Sugars Pi1 Herczegh”, Attila A&s’,
Attila Wnyei’ and Gyula Batta’
‘Research Group of Antibiotics of the Hungarian Academy of Sciences, H-4010 Debrecen, Hungary and ‘Department of Physical Chemistry, L. Kossuth University, H-4010 Debrecen, Hungary
A chiral nitrilimine was generated from D-galactose phenylhydrazone and it was allowed to react with acrylate ester dipolarophiles to give pyrazolines. Intramolecular cycloaddition of an unsaturated nitrilimine prepared from D-xylose led to the formation of a chiral cyclopentanopyrazoline as a single isomer.
Determination of Changes in Sugar Composition During the Aging of Honey by HPLC, FTIR and NMR Spectroscopy Licinia G. Jut&o*, Madalena Caldeira*, Victor MS. Gil*, Maria Teresa Baptista**, Ant&i0 Proenqa da Cunha** and Ana Maria Gil# ‘Chemistry Department, University of Coimbra, Portugal; ‘*Pharmacy Faculty, University of Coimbra, Portugal and #Chemistry Department, Univesity of Aveiro, Portugal
Honey is a complex mixture of different carbohydrates in which fructose and glucose are the most abundant. The quantities of these monosaccharides are believed to vary during the aging of honey according to the chromatographic studies reported. Since the effects of heating are similar to those induced by natural aging, two types of unifloral honeys (heather Calluna vulgaris and rosemary Rosmarinus officinalis L.) were each heated at 45°C and 6O”C, for specified lengths of time. Quantification of glucose and fructose, as well as the ratio glucose/fructose, was attempted by HPLC, liquid state NMR and FTIR-ATR (attenuated total reflectance) and the results compared. All three techniques showed glucose and fructose as the major components in honey and NMR and HPLC showed that the latter is the most abundant in both varieties. NMR enabled the identification of the major anomers of the two monosaccharides along with some oligosaccharides present in small quantities. The oligosaccharides detected by HPLC were: turanose, maltose, trehalose and isomaltose, as well as melizitose in rosemary honey. Quantification of these oligosaccharides could only be carried out by HPLC. The effects of heating on the sugar composition were clear in the NMR spectra, indicating that the decrease in fructose content is accompanied by a slight increase in glucose content. This change was more pronounced in the rosemary honey. HPLC results showed a significant increase of the oligosaccharides. The use of ATR cell enabled good quality FTIR spectra to be obtained for all samples. Due to the strong signal overlap observed in the region of interest (1500-800 cm-‘), no individual signals were assigned but one particular intensity ratio was found to depend, particularly for the rosemary variety, on the temperature and time of heating. Studies are currently under way to explore the use of such ratio measure-
ments as an indicator samples.
of glucose/fructose
ratios in honey
D-glucose Bound Dienes in Diels-Alder Reactions A.M. Freitas’, A. Gil Fortes” and R.J. Stoodleyb ‘Departamento de Quimica, Universidade do Minho, Campus de Gualtar, 4710 Braga, Portugal and bDepartment of Chemistry, UMIST, PO Box 88, Manchester M60 lQD, UK
The fact that 2,3,4,6-tetra-0-acetyl-fl-D-glucopyranosyl auxiliary confers a useful diastereofacial reactivity on anomerically bound dienes in their reaction with dienophiles and heterodienophiles lead us to further studies on cycloaddition reactions to glucose bound systems. In the sequence of our earlier studies, cyclic dienes were prepared and their diastereofacial reactivity is being studied. The reaction with cyclic dienophiles afforded bridged structures with moderate diastereoselectivity. Further studies on Diels-Alder type reactions are under investigation and will be presented in this communication.
Chemical Synthesis and Structural Study of Lincomycin Sulfoxides and Sulfone Ferenc Sztaricskai’*, Z&b Dinya’, G a Batta’, An&6 MocsPri’, Miklbs Hollbsi’, Zsuzsa Maje 5”, Rokuro Masuma’ and Satoshi 0mura3* ‘Research Group of Antibiotics of the Hungarian Academy of Sciences, L., Kossuth University, P.O. Box 70, 4010 Debrecen, Hungary; 2Department of Organic Chemistry, L. Eijtviis University, P.O. Box 32, 1518 Budapest, Hungary and ‘The Kitasato Institute, Tokyo 108, Japan
Oxidation of lincomycin with dimethyldioxirane resulted in two sulfoxide-glycosides, whose treatment with osmium tetraoxide and N-methylmorpholine-N-oxide afforded the same sulfone. According to FAB-MS and CD investigations, the absolute configuration of the sulfur atom is R and S. A new, unsaturated antibiotic analog derived from clindamycin exists in the 4C1 conformation. The antibiotic activities of the synthesized compounds were also studied.
Chemical Characterisation of Water Soluble Arabinoxylansbranan Ferulates Isolated From Maize Bran Pawadee Methacanon’, John F. Kennedy*‘, Linda L. Lloyd*, Marion Paterson’ and Charles J. KniU’ ‘Birmingham Carbohydrate and Protein Technology Group, School of Chemistry, The University of Birmingham, BI.5 2TT, UK and ‘Birmingham Carbohydrate and Protein Technology Group, Chembiotech Laboratories, University of Birmingham Research Park, Birmingham, B1.5 ZSQ, UK
A novel polysaccharide material, Sterigel@ (Seton Healthcare), has been used as a wound management aid. The composition and carbohydrate structure of plant cell wall polysaccharide isolated from maize bran as starting material of the Sterigel@ have been determined. The polysaccharide was shown to be arabinoxylans with an arabinose and xylose ratio of 1.0:1.2 but small proportions of other monosaccharides (galactose, glucose and glucuronic acid) were also present. Methylation analysis and ‘H and 13C NMR spectroscopy revealed the carbohydrate structure to be composed of a highly substituted (1 ---) 4)-/I-D-xylan. The polysaccharide backbone is substi-
Abstracts immune disease implicated with H. pylori strains carry Lewis blood-group epitopes.
which
Diastereoselective Inter- and Intramolecular Cycloaddition Reactions of Nitrilimines Derived From Sugars Pi1 Herczegh”, Attila A&s’,
Attila Wnyei’ and Gyula Batta’
‘Research Group of Antibiotics of the Hungarian Academy of Sciences, H-4010 Debrecen, Hungary and ‘Department of Physical Chemistry, L. Kossuth University, H-4010 Debrecen, Hungary
A chiral nitrilimine was generated from D-galactose phenylhydrazone and it was allowed to react with acrylate ester dipolarophiles to give pyrazolines. Intramolecular cycloaddition of an unsaturated nitrilimine prepared from D-xylose led to the formation of a chiral cyclopentanopyrazoline as a single isomer.
Determination of Changes in Sugar Composition During the Aging of Honey by HPLC, FTIR and NMR Spectroscopy Licinia G. Jut&o*, Madalena Caldeira*, Victor MS. Gil*, Maria Teresa Baptista**, Ant&i0 Proenqa da Cunha** and Ana Maria Gil# ‘Chemistry Department, University of Coimbra, Portugal; ‘*Pharmacy Faculty, University of Coimbra, Portugal and #Chemistry Department, Univesity of Aveiro, Portugal
Honey is a complex mixture of different carbohydrates in which fructose and glucose are the most abundant. The quantities of these monosaccharides are believed to vary during the aging of honey according to the chromatographic studies reported. Since the effects of heating are similar to those induced by natural aging, two types of unifloral honeys (heather Calluna vulgaris and rosemary Rosmarinus officinalis L.) were each heated at 45°C and 6O”C, for specified lengths of time. Quantification of glucose and fructose, as well as the ratio glucose/fructose, was attempted by HPLC, liquid state NMR and FTIR-ATR (attenuated total reflectance) and the results compared. All three techniques showed glucose and fructose as the major components in honey and NMR and HPLC showed that the latter is the most abundant in both varieties. NMR enabled the identification of the major anomers of the two monosaccharides along with some oligosaccharides present in small quantities. The oligosaccharides detected by HPLC were: turanose, maltose, trehalose and isomaltose, as well as melizitose in rosemary honey. Quantification of these oligosaccharides could only be carried out by HPLC. The effects of heating on the sugar composition were clear in the NMR spectra, indicating that the decrease in fructose content is accompanied by a slight increase in glucose content. This change was more pronounced in the rosemary honey. HPLC results showed a significant increase of the oligosaccharides. The use of ATR cell enabled good quality FTIR spectra to be obtained for all samples. Due to the strong signal overlap observed in the region of interest (1500-800 cm-‘), no individual signals were assigned but one particular intensity ratio was found to depend, particularly for the rosemary variety, on the temperature and time of heating. Studies are currently under way to explore the use of such ratio measure-
ments as an indicator samples.
of glucose/fructose
ratios in honey
D-glucose Bound Dienes in Diels-Alder Reactions A.M. Freitas’, A. Gil Fortes” and R.J. Stoodleyb ‘Departamento de Quimica, Universidade do Minho, Campus de Gualtar, 4710 Braga, Portugal and bDepartment of Chemistry, UMIST, PO Box 88, Manchester M60 lQD, UK
The fact that 2,3,4,6-tetra-0-acetyl-fl-D-glucopyranosyl auxiliary confers a useful diastereofacial reactivity on anomerically bound dienes in their reaction with dienophiles and heterodienophiles lead us to further studies on cycloaddition reactions to glucose bound systems. In the sequence of our earlier studies, cyclic dienes were prepared and their diastereofacial reactivity is being studied. The reaction with cyclic dienophiles afforded bridged structures with moderate diastereoselectivity. Further studies on Diels-Alder type reactions are under investigation and will be presented in this communication.
Chemical Synthesis and Structural Study of Lincomycin Sulfoxides and Sulfone Ferenc Sztaricskai’*, Z&b Dinya’, G a Batta’, An&6 MocsPri’, Miklbs Hollbsi’, Zsuzsa Maje 5”, Rokuro Masuma’ and Satoshi 0mura3* ‘Research Group of Antibiotics of the Hungarian Academy of Sciences, L., Kossuth University, P.O. Box 70, 4010 Debrecen, Hungary; 2Department of Organic Chemistry, L. Eijtviis University, P.O. Box 32, 1518 Budapest, Hungary and ‘The Kitasato Institute, Tokyo 108, Japan
Oxidation of lincomycin with dimethyldioxirane resulted in two sulfoxide-glycosides, whose treatment with osmium tetraoxide and N-methylmorpholine-N-oxide afforded the same sulfone. According to FAB-MS and CD investigations, the absolute configuration of the sulfur atom is R and S. A new, unsaturated antibiotic analog derived from clindamycin exists in the 4C1 conformation. The antibiotic activities of the synthesized compounds were also studied.
Chemical Characterisation of Water Soluble Arabinoxylansbranan Ferulates Isolated From Maize Bran Pawadee Methacanon’, John F. Kennedy*‘, Linda L. Lloyd*, Marion Paterson’ and Charles J. KniU’ ‘Birmingham Carbohydrate and Protein Technology Group, School of Chemistry, The University of Birmingham, BI.5 2TT, UK and ‘Birmingham Carbohydrate and Protein Technology Group, Chembiotech Laboratories, University of Birmingham Research Park, Birmingham, B1.5 ZSQ, UK
A novel polysaccharide material, Sterigel@ (Seton Healthcare), has been used as a wound management aid. The composition and carbohydrate structure of plant cell wall polysaccharide isolated from maize bran as starting material of the Sterigel@ have been determined. The polysaccharide was shown to be arabinoxylans with an arabinose and xylose ratio of 1.0:1.2 but small proportions of other monosaccharides (galactose, glucose and glucuronic acid) were also present. Methylation analysis and ‘H and 13C NMR spectroscopy revealed the carbohydrate structure to be composed of a highly substituted (1 ---) 4)-/I-D-xylan. The polysaccharide backbone is substi-