Thesis (Ph. D.)--Institute of Paper Chemistry, 1975. / Includes bibliographical references (leaves 122-125).

Thesis (Ph. D.)--Institute of Paper Chemistry, 1967. / Bibliography: leaves 71-74.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1967. / Bibliography: leaves 66-67.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / abstract / toc / Zoology / Master / Master of Philosophy

Artemisia Sphaerocephala Krasch (ASK) polysaccharide, extracted from the outer layer of ASK seeds, it has attracted attention due to its reported bioactivities. In the present study, extraction and fractionation methods for ASKP were developed. Two different Mw fractions 60P (MW: 551 KDa) and 60S (MW: 39 KDa) were obtained using ammonium sulphate precipitation. The physicochemical properties, in terms of rheological properties, chemical compositions and surface activities, of both fractions were elucidated. Using high performance anion exchange chromatography (HPAEC), partial acid hydrolysis, methylation analysis, 1D & 2D NMR spectroscopy and MALDI-TOF-MS methods, the detailed structural features of 60P and 60S were obtained, which were confirmed to be arabino(glucurono)xylan and (galacto)glucomannan, respectively Using light scattering and HPSEC techniques, the conformational properties of 60P were investigated. 0.5 M NaOH solution exhibited better ability to eliminate aggregates of 60P compared to water, NaCl solution and urea solution. The molecule of 60P exhibited a random coil conformation and semi-flexible structure in 0.5 M NaOH solution. In addition, the dependence of conformation of 60P on the molecular weight was also revealed by HPSEC analysis. The computer modeling technique using RIS-Metropolis Monte Carlo (RMMC) method was also applied. The conformational properties of 60P with different T-GlcpA ratio and various distribution patterns (random, alternative and block) along the xylan chain were determined. Results indicated that: the more regular the side chain distribution, the more extended the structure. The conformational properties of 60S with different molecular weights and various ratios of O-acetyl group to mannose were also considered. Results indicated that the radius of gyration (Rg) demonstrated an increasing trend with Mw and the data was comparable with that obtained from HPSEC; the insertion of O-acetyl group increased the chain extension at low ratio while showing a decrease it at a high ratio. The present study provides fundamental information regarding the physicochemical properties, structural and conformational properties of polysaccharides from the seeds of Artemisia sphaerocephala Krasch (ASK). Such information is essential to the understanding of the structure-conformation- functionality relationships of ASKP, thus promotes their potential food and industry applications.

No description available.

Young developing fruits of nasturtium (Tropaeolum majus L.) accumulate large deposits of non-fucosylated "storage" XG in periplasmic spaces of cotyledon cells. The only XG that is clearly fucosylated in these fruits Is the structural fraction (approx. 1% total) integrated into growing primary walk. Storage XG can be fucosylated by a nasturtium transferase in vitro, but this does not happen in vivo, even as a transitory signal required for secretion which would subsequently be cleaved to produce mature non-fucosylated storage XG in the periplasmic space. The two fucosylated subunits that are formed in vitro are identical to those found in structural XG in vivo. A block appears to develop in the secretory machinery of young cotyledon cells resulting in extended galactosylation and diversion of XG traffic to the periplasm without fucosylation. The primary walls buried beneath accretions of storage XG eventually swell and lose cohesion, probably because they continue to extend without incorporating components like fucosylated XG that are needed for maintaining wall integrity.