Theme Leader: Assoc Prof Dhanjay Jhurry
Researchers from the Departments of Chemistry and Biosciences at the University of Mauritius have developed independently over the past 10 years research themes in the broad area of indigenous renewable resources – land and marine. While chemists have been investigating the elaboration of high value-added materials/chemicals from sugars and marine seaweeds and algae, biologists have been focusing on the phytochemical and biological screening and conservation of endemic and medicinal plants. A brief on the research achievements of each group is given at 1, 2 & 3 below:
1. Development of materials/chemicals based on indigenous land and marine renewable resources.
Research in this area is motivated by a desire to address basic problems (synthetic, structural and mechanistic aspects of polymer chemistry) as well as issues of a more developmental nature. Our efforts have been targeted towards the development of value-added materials taking into account available local land and marine resources such as sugars and their derivatives (lactic acid, amino acids) and algae and seaweeds. The objectives of the research theme aim at helping Mauritius to reduce its dependency on petroleum-based products through the enhanced exploitation of renewable feedstocks. The research work undertaken can be placed under the following headings:
(1) Controlled synthesis of biodegradable/bioresorbable polyesters (polylactides, polydioxanone, polycaprolactone) and polypeptides by ring-opening polymerisation of the cyclic monomers (lactides, dioxanone, caprolactone, N-carboxyanhydrides) using novel coordination or anionic initiators.
(2) Polymer-sucrochemistry: synthesis and characterization of polymers containing sugar moieties as side groups (polyvinylsaccharides) or in the main chain (polyurethanes and polyethers).
(3) Biopolymer extraction and derivatization: (i) Synthesis and characterization of environmentally-friendly materials derived from cellulose. (ii) Extraction and characterization of biopolymers (agarose and carrageenans) from red algae (eucheuma, hypnea) and seaweeds (gracilaria).
A few highlights of research achievements:
Working in a team, we have developed:
• tailored polylactides for commodity and high-tech applications. Local expertise is now available in this area and should be beneficial to the industrial production of these polymers in Mauritius.
• polyethers and polyvinylsugars based on sucrose using novel, facile and eco-friendly synthetic methods. The polyvinylsugars have proved to be very efficient in colour removal of effluent textile wastewater.
• copolypeptides for use as wound dressings.
• an extraction process at laboratory scale (100 g) to isolate carrageenans and agarose from algae and seaweeds around Mauritius.
5 relevant Publications
1. D. Jhurry, A. Bhaw-Luximon, T. Mardamootoo, A. Ramajooloo
Biopolymers from the mauritian marine environment
Macromolecular Symposia, in press (2005)
2. Goury V, Jhurry D, Bhaw-Luximon A, Novak B, Belleney J.
Synthesis and characterization of random and block copolypeptides derived from ?-Methylglutamate and Leucine N-Carboxyanhydrides
BioMacromolecules 6(4), 1987-1991 (2005)
3. Bhaw-Luximon A, Jhurry D, Belleney J, Goury V.
Polymerization of ?-methylglutamateNCA using Al-Schiff’s base complexes as initiators.
Macromolecules (2003), Vol 36, Issue 4, 977-982
4. Narain R, Jhurry D.
Synthesis and polymerization of novel vinylgluconamides
Polymer International (2002) 51, 85
5. Narain R, Jhurry D, Wulff G.
Synthesis and characterization of polymers based on 4-vinylphenylglucitol
European Polymer Journal (2002) 38, 273
2 Biodiversity and bioprospection
The natural biodiversity of Mauritius is currently subject of serious concern and has become one important priority, both in terms of conservation and bioprospection. There is no well-defined national programme oriented towards biodiversity bioprospection and in this regards we are currently working in collaboration with a number of institutions on the propagation and phytochemical and biological screening of endemic plant species and the analysis of food based plants.
The main development objectives are to inventorize our biodiversity and maintain its sustainable and equitable development, to promote capacity building for taxonomy, extraction, analyses and biological activity assays and to strengthen traditional knowledge systems. This would lead to market link objectives such as the screening for bioactive extracts or molecules, establishing lead molecules and extracts for selected therapeutic targets, genetic engineering for economic size matching, scaling-up for cost effectivity and eventually benefit sharing.
In our line of study concerning the production of biologically active secondary metabolites, we have initiated and oriented our research activities towards both the in vivo and in vitro production of prophylactic polyphenolic compounds from native and introduced traditional plants. In this respect for the past few years we have concentrated our efforts on the establishment of a specialised framework with appropriate infrastructure for free-radical biochemistry and antioxidant research on Mauritian medicinal and endemic plant species. We are currently publishing data on the phytochemical composition, chemotaxonomic surveys and antioxidant potential of introduced species, endemic species, traditionally used plants and food based plants. We have already initiated work on more than 75 plant species using a wide range of assaying systems.
The use of cell cultures as a biotechnological tool for conservation and the production of bioactive natural products is an important component of our research activity. In this line of study we have initiated a number of projects aimed to enhance the production of prophylactic antioxidants.
Recently we have completed a Mauritius Research Council funded food research project where we have evaluated the polyphenolic composition, the vitamin contents and the antioxidant capacity of our local fruits, vegetables and teas. Besides providing a base for an epidemiological evaluation of the potential antioxidant effects of polyphenols and vitamins, the collective data are being used to determine the Mauritian daily intake of dietary polyphenolics.
Established links and Ongoing collaboration :
Professor Okezie Aruoma
The Food and Research Centre, Dept of applied Science, London South Bank University, 103 Bourough Road, London SEI OAA, UK
Professor Kyung-Sun Kang
Laboratory of stem cell and Tumor Biology, Dept of Veterinary Public Health, College of veterinary Medicine, Seoul National University, Seoul, KoreaProfessor Alan Crozier
Plant Products and Human Nutrition Group, Bower Building, Department of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, UK.
Professeur Francis Trotin
Faculté des Sciences Pharmaceutiques et Biologiques, 3 Rue du Professeur Laguesse-BP 83, 59006 Lille, CEDEX
Dr Shinya Toyokuni
Associate professor, Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
Recent selected publications :
1. Luximon-Ramma, T. Bahorun, A. Crozier, V. Zbarsky, K.K. Datla, D.T. Dexter and O.I. Aruoma. Assessment of the total phenol, proanthocyanidin, flavonoid, Catechin and gallic acid contents and antioxidant activities of Mauritian commercial black teas: Important contributor to their medicinal properties. Food Research International, 2005 38 , 357-367 V.S.
2. M.A. Soobrattee, V.S. Neergheen, A.Luximon-Ramma, O.I. Aruoma and T. Bahorun, Phenolics as potential antioxidant therapeutic agents : Mechanisms and actions. Mutation Research/fundamental and Molecular Mechanisms of Mutagenesis, 2005, 579, 200-213
3. V.S. Neergheen, T. Bahorun, M.A Soobrattee, and O.I. Aruoma. Characterisation of phenolic contents of selected Mauritian endemic plants from the Rubiaceae and Myrtaceae families and assessment of their antioxidant activities Journal of Plant Physiology, 2005, in press
4. Neergheen, M.A Soobrattee, T. Bahorun and O.I. Aruoma. Phenol contents and antioxidant activities of some Mauritian endemic plants from the Ebenaceae and Myrtaceae Families, In Biodiversity towards drug Development. 2005 1-15 ISBN : 99903/73/16/7
5. T. Bahorun, A. Luximon-Ramma, A. Crozier and O.I. Aruoma, Total phenol, flavonoid, proanthocyanidin, vitamin C levels and antioxidant activities of commonly consumed Mauritian vegetables. Journal of the Science of Food and Agriculture. 2004, 84: 1553-1561.
6. S.Toyokuni, T. Tanaka, W. Kawaguchi, N.R Lai Fang, M. Ozeki, S. Akatsuka, H. Hiai, O.I. Aruoma and T. Bahorun. Effects of the phenolic contents of Mauritian Endemic plant extracts on promoter activities of antioxidant enzymes. Free Radical Research. 2003, 37 (11): 1215-1224.
7. O I. Aruoma, T. Bahorun and L-J Jen, Neuroprotection by bioactive components in medicinal and food plant extracts. Mutation Research. 2003, 544: 203-215.
8. T. Bahorun, E. Aumjaud, H. Ramphul, M. Rycha, A. Luximon-Ramma, F. Trotin and O.I. Aruoma. Phenolic constituents and antioxidant capacities of Crataegus monogyna (Hawthorn) callus extracts. Nahrung Food. 2003, 3 : 191-198
9. A. Luximon-Ramma, T. Bahorun and A. Crozier. Antioxidant actions, phenolic and vitamin C composition of common Mauritian exotic fruits. Journal of the Science of Food and Agriculture. 2003, 83: 496-502
The native forest of Mauritius is now a mere fraction of what it was when the first settlers arrived some 400 years ago. Indeed less than 2% of the luxuriant forest that once covered the island now survives as small pockets in an ocean of sugar cane and an advancing wave of concrete. Unless a sustainable effort is urgently made to develop a conservation and restoration strategy, there will be no future for the native plant species and this will be an incalculable loss indeed.
Historical records have shown that the Diospyros (ebony trees) were the dominant species of the Mauritian indigenous forest. It is not known how many Diospyros species existed before the large scale exploitation of these species for the quality of their timber. To date 11 species prevail, some of which are represented by only a few individuals. We are currently examining their biogeography, phylogeny and reproductive biology with a view to understand their survival and colonisation patterns. Information gathered from these studies will be invaluable for proper reforestation strategies.
Phylogenetic analysis based on morphology has enabled us to establish a hypothesis of the evolution and adaptive radiation of these species in Mauritius. We are now finalising DNA analysis which will enable us to compare DNA based with morphology based phylogenies. This comparison will not only enhance our understanding of island biology but will also lay down the ground work for a more global study of most if not all the endemic plant species. Our findings will also be an important contribution to the world wide effort to determine the historical biogeography of well established plant families and provide a data bank for restoration work in the fragile island ecosystems.
1. Olesen JM, Eskildsen LI, Venkatasamy S: Invasion of pollination networks on oceanic islands: Importance of invader complexes and endemic super generalists. Journal of Diversity and Distribution. 2002;8:181-192.
2. Venkatasamy S, Khittoo G, Nowbuth P, Vencatasamy DR: Phylogenetic relationships among the Diospyros (Ebenaceae) species endemic to the Mascarene Islands based on morphology. Botanical Journal of the Linnean Society. 2005. In press.
3. Nowbuth P, Khittoo G, Bahorun T, Venkatasamy S: Assessing genetic diversity of some Anthurium andraeanum Hort. cut-flower cultivars using RAPD Markers. African Journal of Biotechnology. 2005; 4:1189-1194.
4. Venkatasamy S, Khittoo G, Vencatasamy DR: Leaky dioecy in Diospyros egrettarum (Ebenaceae) endemic to the island of Mauritius. Submitted to Plant Ecology.
In support of the University’s recent initiative to foster multi-disciplinary research in order to address more efficiently national priority needs, researchers from both Departments have naturally pooled together and have identified as common theme the “Exploitation and Conservation of indigenous renewable resources”.
Assoc Prof Theeshan Bahorun (co-team leader)
Assoc Prof Dhanjay Jhurry (co-team leader)
Dr. Govindranathsing Khittoo
Dr. Archana Bhaw-Luximon
Dr. Shailendra Oree
Dr. Shobha Jawaheer
Mrs S.Venkatasamy, Farm Manager
Supporting MPhil/PhD students: 11