Difference between revisions of "Lignan Project"

From MC Chem Wiki
Jump to navigation Jump to search
Line 4: Line 4:
 
Lignin is an abundant, complex organic polymer that acts as one of the principle components of plants. Lignin plays a role in the structure of plant cell walls, works to move water through the plant to critical areas and helps to prevent water evaporation.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> Lignins account for a large percentage of overall plant mass, at around 20-25%.<ref>[[:Media:Lignan and Lignan Biosynthesis.pdf|Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. ''American Chemical Society Symposium Series'', 1-27.]]</ref> We know that lignin does not act alone in it’s structural duties, commonly forming complexes with polymeric carbohydrates.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> Difficulty in isolating lignin from these lignin-carbohydrate complexes means that synthetic lignins are commonly used for research purposes. The basic monomers that make up the lignin polymer are p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol (Figure 1.). These three monomers are phenylpropane units that differ in their substitutions at the 3 and 5 positions.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> In the case of lignin nomenclature, the side chain attachment to the aromatic ring is considered position C-1 and the phenol group considered to be position C-4. These monomeric alcohols undergo oxidative coupling with each other and with a growing polymer end unit.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> This oxidation process results in radicals delocalized at positions C-1, C-3, C-5, C-β, and O-4.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> The most frequently formed bonds are β-O-4 bonds.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref>
 
Lignin is an abundant, complex organic polymer that acts as one of the principle components of plants. Lignin plays a role in the structure of plant cell walls, works to move water through the plant to critical areas and helps to prevent water evaporation.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> Lignins account for a large percentage of overall plant mass, at around 20-25%.<ref>[[:Media:Lignan and Lignan Biosynthesis.pdf|Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. ''American Chemical Society Symposium Series'', 1-27.]]</ref> We know that lignin does not act alone in it’s structural duties, commonly forming complexes with polymeric carbohydrates.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> Difficulty in isolating lignin from these lignin-carbohydrate complexes means that synthetic lignins are commonly used for research purposes. The basic monomers that make up the lignin polymer are p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol (Figure 1.). These three monomers are phenylpropane units that differ in their substitutions at the 3 and 5 positions.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> In the case of lignin nomenclature, the side chain attachment to the aromatic ring is considered position C-1 and the phenol group considered to be position C-4. These monomeric alcohols undergo oxidative coupling with each other and with a growing polymer end unit.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> This oxidation process results in radicals delocalized at positions C-1, C-3, C-5, C-β, and O-4.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref> The most frequently formed bonds are β-O-4 bonds.<ref>[[:Media:Dimmel Overview.pdf|Dimmel, D. (2010). Overview. ''Lignin and Lignans Advances in Chemistry.'' Taylor & Francis Group.]]</ref>
  
−
The coupling of two lignin monomers, usually at their β carbons, results in lignan, a nonstructural component of plants that play a role in plant defense.<ref>[[:Media:Lignan and Lignan Biosynthesis.pdf|Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. ''American Chemical Society Symposium Series'', 1-27.]]</ref> These lignans show important biological activity that the lignin polymer does not.<ref>[[:Media:Lignan and Lignan Biosynthesis.pdf|Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. ''American Chemical Society Symposium Series'', 1-27.]]</ref> One interesting medical application of lignan is found in its interactions with breast cancer. It has been shown that both flaxseed and sesame seed lignans and their metabolites have the potential to act as competitive inhibitors of estrogen and prevent the binding of estrogen to estrogen receptors on breast cancer tumors.<ref>[[:Media:naturally lignan-rich foods.pdf|Rodríguez-García et al. (2019). Naturally Lignan-Rich Foods: A Dietary Tool for Health Promotion. ''Molecules, 24''(917), 1-25.]]</ref><ref>[[:Media:Estrogenic Activities of Sesame Lignans and Their Metabolites.pdf|Pianjing, P., Thiantanawat, A., Rangkadilok, N., Watcharasit, P., Mahidol, C., Satayavivad, J. (2001) Pianjing, P.; Thiantanawat, A.; Rangkadilok, N.; Watcharasit, P.; Mahidol, C.; Satayavivad, J. ''Journal of Agricultural and Food Chemistry'', 59, 212–221]]</ref>. These effects are possible on the basis that many lignans share structural features with the human estrogen estradiol, including hydrophobic benzene rings and alcohol groups that are capable of interaction with the binding site of the estrogen receptor.<ref>[[:Media:Estrogenic Activities of Sesame Lignans and Their Metabolites.pdf|Pianjing, P., Thiantanawat, A., Rangkadilok, N., Watcharasit, P., Mahidol, C., Satayavivad, J. (2001) Pianjing, P.; Thiantanawat, A.; Rangkadilok, N.; Watcharasit, P.; Mahidol, C.; Satayavivad, J. ''Journal of Agricultural and Food Chemistry'', 59, 212–221]]</ref><ref>[[:Media:Molecular basis of agonism and antagonism in the oestrogen receptor.pdf]]|Brzozowski, A. M., Pike, A. C., Dauter, Z., Hubbard, R. E., Bonn, T., Engström, O., Ohman, L., Greene, G. L., Gustafsson, J. A., Carlquist, M. (1997). Molecular basis of agonism and antagonism in the oestrogen receptor. ''Nature'' 389 (6652), 753–758.]]</ref> Lignan also displays antioxidant properties, showing the ability to scavenge hydroxyl radicals.<ref>[[:Media:naturally lignan-rich foods.pdf|Rodríguez-García et al. (2019). Naturally Lignan-Rich Foods: A Dietary Tool for Health Promotion. ''Molecules, 24''(917), 1-25.]]</ref>,6 Lignan’s medical applications make it an interesting topic for further study, but an issue lies within the commercial availability of lignan. Lignan itself is not commercially available except as an analytical standard, and analytical standards can range upwards of $300 USD for 10 mg of product. For an undergraduate research lab, this presents serious problems in terms of budget and funding. In order to study the chemistry of lignans, we need a way to isolate and purify lignans in a cost effective manner.
+
The coupling of two lignin monomers, usually at their β carbons, results in lignan, a nonstructural component of plants that play a role in plant defense.<ref>[[:Media:Lignan and Lignan Biosynthesis.pdf|Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. ''American Chemical Society Symposium Series'', 1-27.]]</ref> These lignans show important biological activity that the lignin polymer does not.<ref>[[:Media:Lignan and Lignan Biosynthesis.pdf|Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. ''American Chemical Society Symposium Series'', 1-27.]]</ref> One interesting medical application of lignan is found in its interactions with breast cancer. It has been shown that both flaxseed and sesame seed lignans and their metabolites have the potential to act as competitive inhibitors of estrogen and prevent the binding of estrogen to estrogen receptors on breast cancer tumors.<ref>[[:Media:naturally lignan-rich foods.pdf|Rodríguez-García et al. (2019). Naturally Lignan-Rich Foods: A Dietary Tool for Health Promotion. ''Molecules, 24''(917), 1-25.]]</ref><ref>[[:Media:Estrogenic Activities of Sesame Lignans and Their Metabolites.pdf|Pianjing, P., Thiantanawat, A., Rangkadilok, N., Watcharasit, P., Mahidol, C., Satayavivad, J. (2001) Pianjing, P.; Thiantanawat, A.; Rangkadilok, N.; Watcharasit, P.; Mahidol, C.; Satayavivad, J. ''Journal of Agricultural and Food Chemistry'', 59, 212–221]]</ref>. These effects are possible on the basis that many lignans share structural features with the human estrogen estradiol, including hydrophobic benzene rings and alcohol groups that are capable of interaction with the binding site of the estrogen receptor.<ref>[[:Media:Estrogenic Activities of Sesame Lignans and Their Metabolites.pdf|Pianjing, P., Thiantanawat, A., Rangkadilok, N., Watcharasit, P., Mahidol, C., Satayavivad, J. (2001) Pianjing, P.; Thiantanawat, A.; Rangkadilok, N.; Watcharasit, P.; Mahidol, C.; Satayavivad, J. ''Journal of Agricultural and Food Chemistry'', 59, 212–221]]</ref><ref>[[:Media:Molecular basis of agonism and antagonism in the oestrogen receptor.pdf]]|Brzozowski, A. M., Pike, A. C., Dauter, Z., Hubbard, R. E., Bonn, T., Engström, O., Ohman, L., Greene, G. L., Gustafsson, J. A., Carlquist, M. (1997). Molecular basis of agonism and antagonism in the oestrogen receptor. ''Nature'' 389 (6652), 753–758.]]</ref> Lignan also displays antioxidant properties, showing the ability to scavenge hydroxyl radicals.<ref>[[:Media:naturally lignan-rich foods.pdf|Rodríguez-García et al. (2019). Naturally Lignan-Rich Foods: A Dietary Tool for Health Promotion. ''Molecules, 24''(917), 1-25.]]</ref><ref>[[:Media:Flaxseed Lignans.pdf|Touré A., Xu X.]]. (2010). Flaxseed Lignans: Source, Biosynthesis, Metabolism, Antioxidant Activity, Bio-Active Components, Health Benefits. ''Comprehensive Reviews in Food Science and Food Safety'' 9:261–269.]]</ref> Lignan’s medical applications make it an interesting topic for further study, but an issue lies within the commercial availability of lignan. Lignan itself is not commercially available except as an analytical standard, and analytical standards can range upwards of $300 USD for 10 mg of product. For an undergraduate research lab, this presents serious problems in terms of budget and funding. In order to study the chemistry of lignans, we need a way to isolate and purify lignans in a cost effective manner.
  
 
==Experimental Methods==
 
==Experimental Methods==

Revision as of 00:48, 12 April 2021

Abstract

Introduction

Lignin is an abundant, complex organic polymer that acts as one of the principle components of plants. Lignin plays a role in the structure of plant cell walls, works to move water through the plant to critical areas and helps to prevent water evaporation.[1] Lignins account for a large percentage of overall plant mass, at around 20-25%.[2] We know that lignin does not act alone in it’s structural duties, commonly forming complexes with polymeric carbohydrates.[3] Difficulty in isolating lignin from these lignin-carbohydrate complexes means that synthetic lignins are commonly used for research purposes. The basic monomers that make up the lignin polymer are p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol (Figure 1.). These three monomers are phenylpropane units that differ in their substitutions at the 3 and 5 positions.[4] In the case of lignin nomenclature, the side chain attachment to the aromatic ring is considered position C-1 and the phenol group considered to be position C-4. These monomeric alcohols undergo oxidative coupling with each other and with a growing polymer end unit.[5] This oxidation process results in radicals delocalized at positions C-1, C-3, C-5, C-β, and O-4.[6] The most frequently formed bonds are β-O-4 bonds.[7]

The coupling of two lignin monomers, usually at their β carbons, results in lignan, a nonstructural component of plants that play a role in plant defense.[8] These lignans show important biological activity that the lignin polymer does not.[9] One interesting medical application of lignan is found in its interactions with breast cancer. It has been shown that both flaxseed and sesame seed lignans and their metabolites have the potential to act as competitive inhibitors of estrogen and prevent the binding of estrogen to estrogen receptors on breast cancer tumors.[10][11]. These effects are possible on the basis that many lignans share structural features with the human estrogen estradiol, including hydrophobic benzene rings and alcohol groups that are capable of interaction with the binding site of the estrogen receptor.[12][13] Lignan also displays antioxidant properties, showing the ability to scavenge hydroxyl radicals.[14][15] Lignan’s medical applications make it an interesting topic for further study, but an issue lies within the commercial availability of lignan. Lignan itself is not commercially available except as an analytical standard, and analytical standards can range upwards of $300 USD for 10 mg of product. For an undergraduate research lab, this presents serious problems in terms of budget and funding. In order to study the chemistry of lignans, we need a way to isolate and purify lignans in a cost effective manner.

Experimental Methods

Results

Discussion

Conclusion

References

  1. ↑ Dimmel, D. (2010). Overview. Lignin and Lignans Advances in Chemistry. Taylor & Francis Group.
  2. ↑ Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. American Chemical Society Symposium Series, 1-27.
  3. ↑ Dimmel, D. (2010). Overview. Lignin and Lignans Advances in Chemistry. Taylor & Francis Group.
  4. ↑ Dimmel, D. (2010). Overview. Lignin and Lignans Advances in Chemistry. Taylor & Francis Group.
  5. ↑ Dimmel, D. (2010). Overview. Lignin and Lignans Advances in Chemistry. Taylor & Francis Group.
  6. ↑ Dimmel, D. (2010). Overview. Lignin and Lignans Advances in Chemistry. Taylor & Francis Group.
  7. ↑ Dimmel, D. (2010). Overview. Lignin and Lignans Advances in Chemistry. Taylor & Francis Group.
  8. ↑ Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. American Chemical Society Symposium Series, 1-27.
  9. ↑ Lewis, N. G., Davin, L. B., & Sarkanen, S. (1998) Lignan and Lignan Biosynthesis: Distinctions and Reconciliations. American Chemical Society Symposium Series, 1-27.
  10. ↑ Rodríguez-García et al. (2019). Naturally Lignan-Rich Foods: A Dietary Tool for Health Promotion. Molecules, 24(917), 1-25.
  11. ↑ Pianjing, P., Thiantanawat, A., Rangkadilok, N., Watcharasit, P., Mahidol, C., Satayavivad, J. (2001) Pianjing, P.; Thiantanawat, A.; Rangkadilok, N.; Watcharasit, P.; Mahidol, C.; Satayavivad, J. Journal of Agricultural and Food Chemistry, 59, 212–221
  12. ↑ Pianjing, P., Thiantanawat, A., Rangkadilok, N., Watcharasit, P., Mahidol, C., Satayavivad, J. (2001) Pianjing, P.; Thiantanawat, A.; Rangkadilok, N.; Watcharasit, P.; Mahidol, C.; Satayavivad, J. Journal of Agricultural and Food Chemistry, 59, 212–221
  13. ↑ Media:Molecular basis of agonism and antagonism in the oestrogen receptor.pdf|Brzozowski, A. M., Pike, A. C., Dauter, Z., Hubbard, R. E., Bonn, T., Engström, O., Ohman, L., Greene, G. L., Gustafsson, J. A., Carlquist, M. (1997). Molecular basis of agonism and antagonism in the oestrogen receptor. Nature 389 (6652), 753–758.]]
  14. ↑ Rodríguez-García et al. (2019). Naturally Lignan-Rich Foods: A Dietary Tool for Health Promotion. Molecules, 24(917), 1-25.
  15. ↑ Touré A., Xu X.. (2010). Flaxseed Lignans: Source, Biosynthesis, Metabolism, Antioxidant Activity, Bio-Active Components, Health Benefits. Comprehensive Reviews in Food Science and Food Safety 9:261–269.]]
Retrieved from "http://205.166.159.208/wiki/index.php?title=Lignan_Project&oldid=16610"