title: The Molecular Weight Characterisation of Pinus radiata Bark Condensed Tannins

authors: Bogun, Ben Rowan

subjects: condensed tannins

abstract: Crude condensed tannins extracted from Pinus radiata bark (sourced from Tokoroa) with various solvents (Hot water (HW), methanol/water/acetic acid (MWA), acetone/water (AW) and hot aqueous 2% sulphite/urea solution (SFU)) were subjected to Sephadex LH-20 column chromatography to purify the condensed tannins by removing carbohydrate and flavonoid components (crude extracts were approximately 70% condensed tannins). The condensed tannins from the HW and MWA extractions were then fractionated on a Sephadex LH-20 column using a stepwise gradient of methanol, water and acetone to separate the condensed tannins according to molecular weight (MW).  Fractions were collected and pooled to give eight final fractions (HW 1-8 and MWA 1-8). Purified and fractionated condensed tannin fractions were then analysed with a range of techniques including 1H nuclear magnetic resonance (NMR) spectroscopy, acid/phloroglucinol depolymerisation coupled with high performance liquid chromatography (HPLC) with UV and MS detection, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionisation mass spectrometry (ESI-MS) and gel permeation chromatography (GPC).
 
In the MALDI-TOF MS spectrum of the crude extracts the most intense signal was typically the tetramer peak and the decamer was typically the largest oligomer detected.  In the spectra of late-eluting column fractions (i.e. HW and MWA 5-7) oligomers greater than the nonamer (DP up to 14) were detected and the most intense signal was shifted from the tetramer to higher MW oligomers. ESI MS showed itself to be better at analysing small MW condensed tannins. The MS results demonstrated that prior separation of the condensed tannins was effective in improving MS detection of higher MW oligomers. 

The mDP of the crude and fractionated fractions was obtained by depolymerisation/HPLC. The mean degree of polymerisation (mDP) of the purified condensed tannins ranged between 7.3 (AW) and 9.2 (SFU).  The mDP of the fractionated condensed tannins ranged between 2 and 18. The depolymerisation/HPLC results of the fractionated condensed tannins were used to construct a GPC calibration curve of condensed tannin MW versus GPC retention time. To identify the GPC dimer peak a procyanidin dimer was synthesised by reacting condensed tannins with catechin under acidic conditions. Through the use of various NMR techniques (DEPT135, COSY, HSQC and HMBC experiments) the synthetic dimer was characterised and the 1H and 13C NMR spectra fully assigned.  The GPC calibration curve enabled MW profiles for the HW and MWA 2-8 fractions and crude extracts to be obtained. GPC analysis confirmed the presence of larger oligomers that were not detected by MALDI-TOF MS and ESI MS.  GPC number average MW results were in agreement with the average MW results obtained from depolymerisation/HPLC results.

Pinus radiata bark condensed tannins from two different geographical locations (Golden Downs (Nelson) and Waimate (South Canterbury)) and different tree heights (0, 10 and 20 m) were analysed using the techniques described above to discover if there was any variability between samples.  Trends that were observed between the different condensed tannins were decreases in condensed tannin yield and mDP as bark was obtained from higher up a tree.  Extracts from New Zealand native bark (totara, rimu and kauri) were also analysed, showing that Rimu was the only bark of these species that contained significant amounts of condensed tannins. Overall this research has provided additional information on the structure and MW of P. radiata condensed tannins.

text: The Molecular Weight Characterisation of Pinus radiata Bark Condensed Tannins Crude condensed tannins extracted from Pinus radiata bark (sourced from Tokoroa) with various solvents (Hot water (HW), methanol/water/acetic acid (MWA), acetone/water (AW) and hot aqueous 2% sulphite/urea solution (SFU)) were subjected to Sephadex LH-20 column chromatography to purify the condensed tannins by removing carbohydrate and flavonoid components (crude extracts were approximately 70% condensed tannins). The condensed tannins from the HW and MWA extractions were then fractionated on a Sephadex LH-20 column using a stepwise gradient of methanol, water and acetone to separate the condensed tannins according to molecular weight (MW).  Fractions were collected and pooled to give eight final fractions (HW 1-8 and MWA 1-8). Purified and fractionated condensed tannin fractions were then analysed with a range of techniques including 1H nuclear magnetic resonance (NMR) spectroscopy, acid/phloroglucinol depolymerisation coupled with high performance liquid chromatography (HPLC) with UV and MS detection, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionisation mass spectrometry (ESI-MS) and gel permeation chromatography (GPC).
 
In the MALDI-TOF MS spectrum of the crude extracts the most intense signal was typically the tetramer peak and the decamer was typically the largest oligomer detected.  In the spectra of late-eluting column fractions (i.e. HW and MWA 5-7) oligomers greater than the nonamer (DP up to 14) were detected and the most intense signal was shifted from the tetramer to higher MW oligomers. ESI MS showed itself to be better at analysing small MW condensed tannins. The MS results demonstrated that prior separation of the condensed tannins was effective in improving MS detection of higher MW oligomers. 

The mDP of the crude and fractionated fractions was obtained by depolymerisation/HPLC. The mean degree of polymerisation (mDP) of the purified condensed tannins ranged between 7.3 (AW) and 9.2 (SFU).  The mDP of the fractionated condensed tannins ranged between 2 and 18. The depolymerisation/HPLC results of the fractionated condensed tannins were used to construct a GPC calibration curve of condensed tannin MW versus GPC retention time. To identify the GPC dimer peak a procyanidin dimer was synthesised by reacting condensed tannins with catechin under acidic conditions. Through the use of various NMR techniques (DEPT135, COSY, HSQC and HMBC experiments) the synthetic dimer was characterised and the 1H and 13C NMR spectra fully assigned.  The GPC calibration curve enabled MW profiles for the HW and MWA 2-8 fractions and crude extracts to be obtained. GPC analysis confirmed the presence of larger oligomers that were not detected by MALDI-TOF MS and ESI MS.  GPC number average MW results were in agreement with the average MW results obtained from depolymerisation/HPLC results.

Pinus radiata bark condensed tannins from two different geographical locations (Golden Downs (Nelson) and Waimate (South Canterbury)) and different tree heights (0, 10 and 20 m) were analysed using the techniques described above to discover if there was any variability between samples.  Trends that were observed between the different condensed tannins were decreases in condensed tannin yield and mDP as bark was obtained from higher up a tree.  Extracts from New Zealand native bark (totara, rimu and kauri) were also analysed, showing that Rimu was the only bark of these species that contained significant amounts of condensed tannins. Overall this research has provided additional information on the structure and MW of P. radiata condensed tannins.

year: 2007

title: Award of damages to part-subsistence villagers in Papua New Guinea

authors: Tennent, Douglas

abstract: One of the great challenges to Courts in civil claims is to award damages in an appropriate manner which as far as possible places the plaintiff in the position that he or she would be in but for the injury. The awarding of appropriate damages to a person leading a part-subsistence village lifestyle presents the Courts with a special challenge.
This article considers the attempts that the Courts in Papua New Guinea have made to award appropriate damages to people living this lifestyle. The article attempts to bring together the common principles that emerge through the cases. It also outlines some of the important issues that still need to be addressed by the Courts to ensure that the actual needs of plaintiffs living in a village lifestyle are addressed.

text: Award of damages to part-subsistence villagers in Papua New Guinea One of the great challenges to Courts in civil claims is to award damages in an appropriate manner which as far as possible places the plaintiff in the position that he or she would be in but for the injury. The awarding of appropriate damages to a person leading a part-subsistence village lifestyle presents the Courts with a special challenge.
This article considers the attempts that the Courts in Papua New Guinea have made to award appropriate damages to people living this lifestyle. The article attempts to bring together the common principles that emerge through the cases. It also outlines some of the important issues that still need to be addressed by the Courts to ensure that the actual needs of plaintiffs living in a village lifestyle are addressed.

year: 2002-01-01

title: Using inclusive research with participants with learning (intellectual) disability to better inform adult literacy policies in Aotearoa New Zealand

authors: Newcombe, Nicolina

abstract: Western ideas about disability and literacy were developed in tandem during the Industrial Revolution and subsequently brought to Aotearoa New Zealand via colonisation. These ideas inform and reinforce educator attitudes, which are the leading factor impeding adults with learning [intellectual] disability from their educational pathways of choice. People without learning disability need to hear the voices of people with learning disability to counteract these attitudes and move towards transformational equality.

There is a paucity of information about the access to and accessibility of adult literacy education for people with learning disability in Aotearoa New Zealand. However, anecdotal evidence reports their exclusion, even from foundational adult learning. There was a gap in knowledge where collaborative research that conveys the experiences of adults with learning disability was needed to gain greater insight to these issues in our bicultural context. My original contribution to knowledge is to present the voices of adults with learning disability as they discuss and demonstrate their literacy practices, and to use their perspectives to make recommendations for adult literacy policies in Aotearoa New Zealand.

I undertook a thematic analysis of current adult literacy policies in Aotearoa New Zealand and found that they target “most” adult learners, while positioning disabled people as needing specialised, and by inference optional to provide, education and resources. These policies also prescribe a linear and progressive andragogy that may not meet the needs of all adults with learning disability, while measuring literacy skills in a way that does not foreground their strengths or value their purposes for engagement.

Then, I conducted Inclusive Participatory Action Research with five adults with learning disability to gather information about their literacy practices and perspectives. Participants in this research decided to call themselves the Passioners. We met for 10 research meetings, preceded by at least two home visits, and interspersed by reflective meetings with individual participants. All research information was presented in easy read and key information was distributed audiovisually.

The Passioners added value to this research by providing unique opportunities that are only available through doing inclusive research with them, prompting research improvements, innovation, and my efforts towards acculturation in their worlds. I evaluated my inclusive approach in this research to learn more about how people with learning disability do research as people with learning disability, and what dispositions, resources, and skills people without learning disability need to do research with them.

Using reflexive thematic analysis, I constructed six themes from our research meetings data: learning disability cultural literacies, Māori (Indigenous peoples of Aotearoa New Zealand) cultural literacies, Pākehā (New Zealanders of European descent) cultural literacies, encoding, decoding, and social media, which extends the narrow definition of literacy in our adult literacy policies. These findings, and those from my policy analysis, were used to inform policy recommendations. Policy recommendations in this research may support implementation of the United Nations Convention on the Rights of Persons with Disabilities, particularly access to lifelong learning on an equal basis with others.

text: Using inclusive research with participants with learning (intellectual) disability to better inform adult literacy policies in Aotearoa New Zealand Western ideas about disability and literacy were developed in tandem during the Industrial Revolution and subsequently brought to Aotearoa New Zealand via colonisation. These ideas inform and reinforce educator attitudes, which are the leading factor impeding adults with learning [intellectual] disability from their educational pathways of choice. People without learning disability need to hear the voices of people with learning disability to counteract these attitudes and move towards transformational equality.

There is a paucity of information about the access to and accessibility of adult literacy education for people with learning disability in Aotearoa New Zealand. However, anecdotal evidence reports their exclusion, even from foundational adult learning. There was a gap in knowledge where collaborative research that conveys the experiences of adults with learning disability was needed to gain greater insight to these issues in our bicultural context. My original contribution to knowledge is to present the voices of adults with learning disability as they discuss and demonstrate their literacy practices, and to use their perspectives to make recommendations for adult literacy policies in Aotearoa New Zealand.

I undertook a thematic analysis of current adult literacy policies in Aotearoa New Zealand and found that they target “most” adult learners, while positioning disabled people as needing specialised, and by inference optional to provide, education and resources. These policies also prescribe a linear and progressive andragogy that may not meet the needs of all adults with learning disability, while measuring literacy skills in a way that does not foreground their strengths or value their purposes for engagement.

Then, I conducted Inclusive Participatory Action Research with five adults with learning disability to gather information about their literacy practices and perspectives. Participants in this research decided to call themselves the Passioners. We met for 10 research meetings, preceded by at least two home visits, and interspersed by reflective meetings with individual participants. All research information was presented in easy read and key information was distributed audiovisually.

The Passioners added value to this research by providing unique opportunities that are only available through doing inclusive research with them, prompting research improvements, innovation, and my efforts towards acculturation in their worlds. I evaluated my inclusive approach in this research to learn more about how people with learning disability do research as people with learning disability, and what dispositions, resources, and skills people without learning disability need to do research with them.

Using reflexive thematic analysis, I constructed six themes from our research meetings data: learning disability cultural literacies, Māori (Indigenous peoples of Aotearoa New Zealand) cultural literacies, Pākehā (New Zealanders of European descent) cultural literacies, encoding, decoding, and social media, which extends the narrow definition of literacy in our adult literacy policies. These findings, and those from my policy analysis, were used to inform policy recommendations. Policy recommendations in this research may support implementation of the United Nations Convention on the Rights of Persons with Disabilities, particularly access to lifelong learning on an equal basis with others.

year: 2024-09