title: Metal adsorption by quasi cellulose xanthogenates derived from aquatic and terrestrial plant materials

authors: Zhou, Wenbing

subjects: cellulose xanthogenate

abstract: The FTIR spectra, SEM-EDXA and copper adsorption capacities of the raw plant materials, alkali treated straws and cellulose xanthogenate derivatives of Eichhornia crassipes shoot, rape straw and corn stalk were investigated. FTIR spectra indicated that of the three plant materials, the aquatic biomass of Eichhornia crassipes shoot contained more O-H and C=O groups which accounted for the higher Cu²⁺ adsorption capacities of the raw and alkali treated plant material. SEM-EDXA indicated the incorporation of sulphur and magnesium in the cellulose xanthogenate. The Cu²⁺ adsorption capacities of the xanthogenates increased with their magnesium and sulphur contents. However more copper was adsorbed than that can be explained by exchange of copper with magnesium. Precipitation may contribute to the enhanced uptake of copper by the cellulose xanthogenate.

text: Metal adsorption by quasi cellulose xanthogenates derived from aquatic and terrestrial plant materials The FTIR spectra, SEM-EDXA and copper adsorption capacities of the raw plant materials, alkali treated straws and cellulose xanthogenate derivatives of Eichhornia crassipes shoot, rape straw and corn stalk were investigated. FTIR spectra indicated that of the three plant materials, the aquatic biomass of Eichhornia crassipes shoot contained more O-H and C=O groups which accounted for the higher Cu²⁺ adsorption capacities of the raw and alkali treated plant material. SEM-EDXA indicated the incorporation of sulphur and magnesium in the cellulose xanthogenate. The Cu²⁺ adsorption capacities of the xanthogenates increased with their magnesium and sulphur contents. However more copper was adsorbed than that can be explained by exchange of copper with magnesium. Precipitation may contribute to the enhanced uptake of copper by the cellulose xanthogenate.

year: 2011

title: Fungal metabolite chemistry: Sporidesmin, crepidotine

authors: Ronaldson, John William

abstract: This thesis was concerned with the chemistry of two fungal products, sporidesmin and crepidotine. The structure of sporidesmin was known but aspects of its chemistry, such as how it could be modified to function as an antigen, were not. The structure of crepidotine was unknown but was elucidated in the course of this work.
Since only 50 mg of crepidotine was available, non-destructive methods were used to arrive at the structure, 2-phenyl-1,6-naphthyridin-4-one. Of these methods, ¹H nuclear magnetic resonance spectroscopy was the most important. This spectrum (¹H n.m.r.) of crepidotine was compared with known or expected spectra of possible isomers most of which were unknown.
Sporidesmin is the toxin which causes Facial Eczema. One approach for combating the problem of Facial Eczema is to develop antibodies in the animals against sporidesmin. Sporidesmin is too small a molecule per se to induce antibody formation so one of the aims of this thesis was to produce derivatives of sporidesmin and to complex them to proteins. Proteins with many molecules of sporidesmin covalently bound to them were produced to be used as antigens. When animals were treated with these antigens, antibodies were detected in their sera. The titre was low for sporidesmin complexed to albumins but four times higher when sporidesmin was complexed to bovine thyroglobulin. 
The method of complexing sporidesmin to the proteins was to open the -S-S- bridge (in sporidesmin) and alkylate the sulphur atoms with iodoacetic esters. When protein was treated with these sporidesmin derivatives the ε-amino-groups of the lysyl residues (in the protein) were transacylated yielding modified sporidesmin covalently bound to the protein, synthetic or natural.
The new compounds formed from sporidesmin in these syntheses were: diethyl and dimethyl secosporidesmin-S,S'-diacetate, ethyl and methyl 11a-mercaptosecosporidesmin-3-S-acetate, methyl 3-mercaptosecosporidesmin-11a-S-acetate; and one of the antigens was cross-linked poly(ethoxy)-poly(secosporidesmin-S,S'-diacetyl)poly-(L-lysine). Of other new derivatives of sporidesmin that were synthesized, 3,11a-dimercaptosecosporidesmin, S,S'-homosporidesmin, and sporidesmin 11-(methyl glutarate), the first was the most difficult to prepare. When attempted in the normal way (opening the -S-S- bridge as for the above esters) only sporidesmin was recovered. But the dimercapto-compound was obtained when oxygen was eliminated in the reaction. 
Because the toxicity of the sporidesmin molecule resides in the epidithiodioxopiperazine ring, means of covalently linking sporidesmin to protein without altering the -S-S- bridge were sought, e.g. acylation or diazonium coupling with suitable bridging groups. Having successfully acylated with the chloroacetyl group (forming sporidesmin di(chloroacetate) it may be possible to complex this ester to protein through the halogen atom.
In the diazonium coupling reaction, the sole aromatic hydrogen resisted coupling. Diazonium salts eliminated the epidithiodioxopiperazine ring by rupturing the pyrrolidine ring: the products were the strongly coloured substituted indoleazobenzenes, 5-chloro-2-hydroxy-6,7- dimethoxy-1-methyl-4'-nitroindole-3-azobenzene and the 2'-chloro- and 2'-nitro-analogues. From anhydrodethiosporidesmin 5-chloro-6,7-dimethoxy-8-methyl-2' ,4'-dinitropyrrolo[2,3-b]indole-2-azobenzene was obtained. These indoleazobenzenes are new compounds.
In the search for methods of diazonium coupling to o-dihydroxy-benzene, veratrole, the following new compounds were synthesized: 2-chloro-3', 4'-dimethoxy-4-nitrobiphenyl, 2-chloro-4'-hydroxy-3'-methoxy-4-nitroazobenzene, 4'-hydroxy-3'-methoxy-2, 4-dinitroazobenzene, 3', 4'-dimethoxy-2,4-dinitroazobenzene, 2-chloro-3', 4'-dimethoxy-4-nitroazobenzene and 2-chloro-4, 5-dimethoxy-2', 4'-dinitroazobenzene. 
In the ¹³C nuclear magnetic resonance spectra of sporidesmin and sporidesmin-D (dimethylthiosecosporidesmin) (decoupled and undecoupled) the peaks were assigned to the appropriate carbons. Where a resonance seemed anomalous, a reasonable explanation of the anomaly has been put forward. Comparison of the spectra of the two compounds indicated the resonances of those carbons which were involved in the strained epidithiodioxopiperazine ring system. Having assigned the peaks for sporidesmin, the structure of unknown analogues may now be more readily elucidated. 
An analogue of sporidesmin, sporidesmin-E, of comparable toxicity, having an -S-S-S- bridge was synthesized from sporidesmin for field studies. It was an unstable molecule readily decomposing to sporidesmin plus sulphur, e.g. pure sporidesmin-E always showed three spots in thin layer chromatography. The mixed melting point between these two compounds was undepressed (they melted within 3.5° of each other). That sporidesmin-E had been formed was confirmed by the M⁺ being 32 mass units greater than sporidesmin but this was still no criterion of purity. In the hydrogen-bonding investigation of the two compounds sporidesmin absorbed in the νOH region where sporidesmin-E did not so the degree that sporidesmin-E was contaminated with sporidesmin could be determined. Comparison of the infra-red spectra of sporidesmin and sporidesmin-E prepared in different ways (in KBr from MeOH or EtOEt, in nujol or in halocarbon oil) showed there were only minor differences between them. 
The hydrogen bonding analysis revealed that the C-S bonds of 3,11a-di-mercaptosecosporidesmin and sporidesmin-E were similarly orientated (i.e. diverging) and not more or less parallel as in sporidesmin-D. The mono-mercapto-derivative (methyl 11a-mercaptosecosporidesmin-3-S-acetate) showed no νSH peak: the elements of the thiol group are present (m.s.) but the hydrogen is ionic and with the adjacent amido-group is apparently in hyperconjugation.

text: Fungal metabolite chemistry: Sporidesmin, crepidotine This thesis was concerned with the chemistry of two fungal products, sporidesmin and crepidotine. The structure of sporidesmin was known but aspects of its chemistry, such as how it could be modified to function as an antigen, were not. The structure of crepidotine was unknown but was elucidated in the course of this work.
Since only 50 mg of crepidotine was available, non-destructive methods were used to arrive at the structure, 2-phenyl-1,6-naphthyridin-4-one. Of these methods, ¹H nuclear magnetic resonance spectroscopy was the most important. This spectrum (¹H n.m.r.) of crepidotine was compared with known or expected spectra of possible isomers most of which were unknown.
Sporidesmin is the toxin which causes Facial Eczema. One approach for combating the problem of Facial Eczema is to develop antibodies in the animals against sporidesmin. Sporidesmin is too small a molecule per se to induce antibody formation so one of the aims of this thesis was to produce derivatives of sporidesmin and to complex them to proteins. Proteins with many molecules of sporidesmin covalently bound to them were produced to be used as antigens. When animals were treated with these antigens, antibodies were detected in their sera. The titre was low for sporidesmin complexed to albumins but four times higher when sporidesmin was complexed to bovine thyroglobulin. 
The method of complexing sporidesmin to the proteins was to open the -S-S- bridge (in sporidesmin) and alkylate the sulphur atoms with iodoacetic esters. When protein was treated with these sporidesmin derivatives the ε-amino-groups of the lysyl residues (in the protein) were transacylated yielding modified sporidesmin covalently bound to the protein, synthetic or natural.
The new compounds formed from sporidesmin in these syntheses were: diethyl and dimethyl secosporidesmin-S,S'-diacetate, ethyl and methyl 11a-mercaptosecosporidesmin-3-S-acetate, methyl 3-mercaptosecosporidesmin-11a-S-acetate; and one of the antigens was cross-linked poly(ethoxy)-poly(secosporidesmin-S,S'-diacetyl)poly-(L-lysine). Of other new derivatives of sporidesmin that were synthesized, 3,11a-dimercaptosecosporidesmin, S,S'-homosporidesmin, and sporidesmin 11-(methyl glutarate), the first was the most difficult to prepare. When attempted in the normal way (opening the -S-S- bridge as for the above esters) only sporidesmin was recovered. But the dimercapto-compound was obtained when oxygen was eliminated in the reaction. 
Because the toxicity of the sporidesmin molecule resides in the epidithiodioxopiperazine ring, means of covalently linking sporidesmin to protein without altering the -S-S- bridge were sought, e.g. acylation or diazonium coupling with suitable bridging groups. Having successfully acylated with the chloroacetyl group (forming sporidesmin di(chloroacetate) it may be possible to complex this ester to protein through the halogen atom.
In the diazonium coupling reaction, the sole aromatic hydrogen resisted coupling. Diazonium salts eliminated the epidithiodioxopiperazine ring by rupturing the pyrrolidine ring: the products were the strongly coloured substituted indoleazobenzenes, 5-chloro-2-hydroxy-6,7- dimethoxy-1-methyl-4'-nitroindole-3-azobenzene and the 2'-chloro- and 2'-nitro-analogues. From anhydrodethiosporidesmin 5-chloro-6,7-dimethoxy-8-methyl-2' ,4'-dinitropyrrolo[2,3-b]indole-2-azobenzene was obtained. These indoleazobenzenes are new compounds.
In the search for methods of diazonium coupling to o-dihydroxy-benzene, veratrole, the following new compounds were synthesized: 2-chloro-3', 4'-dimethoxy-4-nitrobiphenyl, 2-chloro-4'-hydroxy-3'-methoxy-4-nitroazobenzene, 4'-hydroxy-3'-methoxy-2, 4-dinitroazobenzene, 3', 4'-dimethoxy-2,4-dinitroazobenzene, 2-chloro-3', 4'-dimethoxy-4-nitroazobenzene and 2-chloro-4, 5-dimethoxy-2', 4'-dinitroazobenzene. 
In the ¹³C nuclear magnetic resonance spectra of sporidesmin and sporidesmin-D (dimethylthiosecosporidesmin) (decoupled and undecoupled) the peaks were assigned to the appropriate carbons. Where a resonance seemed anomalous, a reasonable explanation of the anomaly has been put forward. Comparison of the spectra of the two compounds indicated the resonances of those carbons which were involved in the strained epidithiodioxopiperazine ring system. Having assigned the peaks for sporidesmin, the structure of unknown analogues may now be more readily elucidated. 
An analogue of sporidesmin, sporidesmin-E, of comparable toxicity, having an -S-S-S- bridge was synthesized from sporidesmin for field studies. It was an unstable molecule readily decomposing to sporidesmin plus sulphur, e.g. pure sporidesmin-E always showed three spots in thin layer chromatography. The mixed melting point between these two compounds was undepressed (they melted within 3.5° of each other). That sporidesmin-E had been formed was confirmed by the M⁺ being 32 mass units greater than sporidesmin but this was still no criterion of purity. In the hydrogen-bonding investigation of the two compounds sporidesmin absorbed in the νOH region where sporidesmin-E did not so the degree that sporidesmin-E was contaminated with sporidesmin could be determined. Comparison of the infra-red spectra of sporidesmin and sporidesmin-E prepared in different ways (in KBr from MeOH or EtOEt, in nujol or in halocarbon oil) showed there were only minor differences between them. 
The hydrogen bonding analysis revealed that the C-S bonds of 3,11a-di-mercaptosecosporidesmin and sporidesmin-E were similarly orientated (i.e. diverging) and not more or less parallel as in sporidesmin-D. The mono-mercapto-derivative (methyl 11a-mercaptosecosporidesmin-3-S-acetate) showed no νSH peak: the elements of the thiol group are present (m.s.) but the hydrogen is ionic and with the adjacent amido-group is apparently in hyperconjugation.

year: 1978

title: Physical and chemical attributes affecting survival and collection of freshwater mahinga kai species

authors: Collier, Kevin J.

abstract: Mahinga kai is one of a number of significant Māori values identified within the National Objectives Framework (NOF) for freshwater management. The Ngā Tohu o Te Taiao (NToTT) project aimed to develop knowledge, tools and processes for setting freshwater limits for mahinga kai within the NOF. Māori have raised issues and concerns about mahinga kai species due to: (i) declines in abundance, size and quality; and (ii) potential contamination from anthropogenic activities. This review provides information about the contaminants and environmental stressors likely to be affecting some important freshwater mahinga kai, with a focus on tuna (eel), īnanga (whitebait), kākahi (freshwater mussel), kōura (freshwater crayfish) and wātakirihi (watercress). In this report, we provide guidance on how to relate existing guidelines and regulations to freshwater invertebrate and fish species traditionally used for food gathering. The guidance covered includes: (i) the ANZECC (2000) water quality guidelines for physical and chemical attributes of aquatic life, which are in the process of being updated; (ii) selected international water quality guidelines (e.g., USEPA, Environment Canada, OECD) which can be used to support and supplement ANZECC water quality guidelines; (iii) human health information for collection and consumption of aquatic foods; and (iv) the National Policy Statement for Freshwater Management (NPS-FM) and the NOF (which is also under further development). It is envisaged this report will support discussion on food abundance and safety of mahinga kai, and promote steps to ensure appropriate standards are set for clean waterways and customary resources under the NPS-FM and ANZECC (2000). We highlight the complexity of issues affecting abundance and suitability of five commonly-used mahinga kai species: tuna, īnanga, kōura, kākahi and wātakirihi. Information from this report should also be of use in future freshwater habitat and species restoration projects, especially where mahinga kai species are at risk and the goal is to maintain or enhance customary resource use, and species state and condition.

text: Physical and chemical attributes affecting survival and collection of freshwater mahinga kai species Mahinga kai is one of a number of significant Māori values identified within the National Objectives Framework (NOF) for freshwater management. The Ngā Tohu o Te Taiao (NToTT) project aimed to develop knowledge, tools and processes for setting freshwater limits for mahinga kai within the NOF. Māori have raised issues and concerns about mahinga kai species due to: (i) declines in abundance, size and quality; and (ii) potential contamination from anthropogenic activities. This review provides information about the contaminants and environmental stressors likely to be affecting some important freshwater mahinga kai, with a focus on tuna (eel), īnanga (whitebait), kākahi (freshwater mussel), kōura (freshwater crayfish) and wātakirihi (watercress). In this report, we provide guidance on how to relate existing guidelines and regulations to freshwater invertebrate and fish species traditionally used for food gathering. The guidance covered includes: (i) the ANZECC (2000) water quality guidelines for physical and chemical attributes of aquatic life, which are in the process of being updated; (ii) selected international water quality guidelines (e.g., USEPA, Environment Canada, OECD) which can be used to support and supplement ANZECC water quality guidelines; (iii) human health information for collection and consumption of aquatic foods; and (iv) the National Policy Statement for Freshwater Management (NPS-FM) and the NOF (which is also under further development). It is envisaged this report will support discussion on food abundance and safety of mahinga kai, and promote steps to ensure appropriate standards are set for clean waterways and customary resources under the NPS-FM and ANZECC (2000). We highlight the complexity of issues affecting abundance and suitability of five commonly-used mahinga kai species: tuna, īnanga, kōura, kākahi and wātakirihi. Information from this report should also be of use in future freshwater habitat and species restoration projects, especially where mahinga kai species are at risk and the goal is to maintain or enhance customary resource use, and species state and condition.

year: 2017