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Comparisons of methods for quantification of phlorotannins in brown seaweed

Najibi, Azizollah LU (2024) KEMR10 20232
Department of Chemistry
Abstract
Introduction: Phlorotannins, bioactive natural phenolic polymer, existing in mostly brown seaweeds have been commonly quantified through colorimetric methods.
Background: Colorimetric methods such as Folin-Ciocalteu (F-C) and 2,4-
dimethoxybenzaldehyde (DMBA) assays have been widely used for total phlorotannins
content (TPC) estimation.
Aim(s): The aim of this study was to compare two different colorimetric methods, being Folin-Ciocalteu and DMBA assays in terms of their bias and selectivity in quantification of phlorotannin in brown seaweed.
Methods: Supercritical fluid extraction (SFE) was used for extraction of phlorotannins from brown seaweeds. F-C and DMBA with the help of UV/Vis spectrophotometer were utilized for... (More)
Introduction: Phlorotannins, bioactive natural phenolic polymer, existing in mostly brown seaweeds have been commonly quantified through colorimetric methods.
Background: Colorimetric methods such as Folin-Ciocalteu (F-C) and 2,4-
dimethoxybenzaldehyde (DMBA) assays have been widely used for total phlorotannins
content (TPC) estimation.
Aim(s): The aim of this study was to compare two different colorimetric methods, being Folin-Ciocalteu and DMBA assays in terms of their bias and selectivity in quantification of phlorotannin in brown seaweed.
Methods: Supercritical fluid extraction (SFE) was used for extraction of phlorotannins from brown seaweeds. F-C and DMBA with the help of UV/Vis spectrophotometer were utilized for phlorotannins quantification. SFE method was optimized by exploring different composition of carbon dioxide, ethanol and water, which ranged between 0-100%. Reduced cubic Scheffe model was used to find the optimum with the highest total phlorotannins amount in Fucus vesiculosus.
Results: The optimization of extraction of phlorotannin with SFE demonstrated the
importance of utilizing high content of polar solvent such as ethanol and water, while the use of CO2 generally was needed in very minor amount. Nonetheless, the quantification of TPC in Fucus vesiculosus with two assays showed different amounts, where FC showed TPC of 12.7 ± 0.6 mg PGE/ g DW with the ideal solvents’ composition of CO2/EtOH/H2O 15/60/25 v/v/v, while DMBA resulted in a TPC of 3.7 ± 0.5 mg PGE/g DW with solvents’ composition of CO2/EtOH/H2O 0/45/55 v/v/v both at 300 bar, 70 °C and 3 mL/min flow rate. However, when assessing the bias between the two methods using spiked Ulva lactuca extract, the F-C and DMBA assays exhibited biases of 4.2 ± 1.0 % and -3.04 ± 1.1 %, respectively.
Conclusion: DMBA assay showed more selectivity towards phlorotannins than F-C.
Although both assays showed good trueness in phlorotannin’s quantification, a big difference in TPC acquired by these assays was observed. (Less)
Popular Abstract
Have you ever thought about benefits of the plants which stack on the feet when you are planning to swim in the sea or ocean?
Seaweeds are those plants which contain beneficial compounds called phlorotannins.
However, the studies in algal science have shown that brown seaweeds among others, green and red, contain phlorotannins. Phlorotannins have been used in pharmaceutical industry to produce medicine due to their bioactive properties. So, scientists try to take these compounds out from brown seaweeds. However, this task is difficult due to the existence of other compounds in seaweeds which are structurally similar to phlorotannins. Moreover, measuring the amounts of taken phlorotannins is also difficult in analytical chemistry since... (More)
Have you ever thought about benefits of the plants which stack on the feet when you are planning to swim in the sea or ocean?
Seaweeds are those plants which contain beneficial compounds called phlorotannins.
However, the studies in algal science have shown that brown seaweeds among others, green and red, contain phlorotannins. Phlorotannins have been used in pharmaceutical industry to produce medicine due to their bioactive properties. So, scientists try to take these compounds out from brown seaweeds. However, this task is difficult due to the existence of other compounds in seaweeds which are structurally similar to phlorotannins. Moreover, measuring the amounts of taken phlorotannins is also difficult in analytical chemistry since there are no
standards for phlorotannins with high molecular mass. Hence, there is a try to approach the best way to measure these taken phlorotannins from brown seaweeds.
Several techniques have been employed to take phlorotannins out from brown seaweeds. In this study, green extraction method employing supercritical CO2 was utilized, taking advantage of its less burden to the environment. Different methods employing ultra-violet light detection techniques are used to estimate the content of phlorotannins, however, their accuracy has not been examined in detail. So, in this project, two methods applied for phlorotannin’s measurement and the associated bias to each method is calculated.
To conclude, the solvents’ composition in supercritical CO2 extraction was optimized to achieve the highest amount of phlorotannins measured through two quantification assays. Although both methods showed low bias, the difference between the amount of phlorotannins acquired through two assays was high. Hence, the reason of this difference should be studied in the future. (Less)
Please use this url to cite or link to this publication:
author
Najibi, Azizollah LU
supervisor
organization
course
KEMR10 20232
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Analytical chemistry, Phlorotannin, brown seaweed, Fucus vesiculosus, Ulva lactuca, Folin-Ciocalteu (F-C) assay, 2, 4-dimethoxybenzaldehyde (DMBA) assay
language
English
id
9149432
date added to LUP
2024-03-08 08:44:39
date last changed
2024-03-08 08:44:39
@misc{9149432,
  abstract     = {{Introduction: Phlorotannins, bioactive natural phenolic polymer, existing in mostly brown seaweeds have been commonly quantified through colorimetric methods.
Background: Colorimetric methods such as Folin-Ciocalteu (F-C) and 2,4-
dimethoxybenzaldehyde (DMBA) assays have been widely used for total phlorotannins 
content (TPC) estimation. 
Aim(s): The aim of this study was to compare two different colorimetric methods, being Folin-Ciocalteu and DMBA assays in terms of their bias and selectivity in quantification of phlorotannin in brown seaweed.
Methods: Supercritical fluid extraction (SFE) was used for extraction of phlorotannins from brown seaweeds. F-C and DMBA with the help of UV/Vis spectrophotometer were utilized for phlorotannins quantification. SFE method was optimized by exploring different composition of carbon dioxide, ethanol and water, which ranged between 0-100%. Reduced cubic Scheffe model was used to find the optimum with the highest total phlorotannins amount in Fucus vesiculosus.
Results: The optimization of extraction of phlorotannin with SFE demonstrated the 
importance of utilizing high content of polar solvent such as ethanol and water, while the use of CO2 generally was needed in very minor amount. Nonetheless, the quantification of TPC in Fucus vesiculosus with two assays showed different amounts, where FC showed TPC of 12.7 ± 0.6 mg PGE/ g DW with the ideal solvents’ composition of CO2/EtOH/H2O 15/60/25 v/v/v, while DMBA resulted in a TPC of 3.7 ± 0.5 mg PGE/g DW with solvents’ composition of CO2/EtOH/H2O 0/45/55 v/v/v both at 300 bar, 70 °C and 3 mL/min flow rate. However, when assessing the bias between the two methods using spiked Ulva lactuca extract, the F-C and DMBA assays exhibited biases of 4.2 ± 1.0 % and -3.04 ± 1.1 %, respectively.
Conclusion: DMBA assay showed more selectivity towards phlorotannins than F-C. 
Although both assays showed good trueness in phlorotannin’s quantification, a big difference in TPC acquired by these assays was observed.}},
  author       = {{Najibi, Azizollah}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Comparisons of methods for quantification of phlorotannins in brown seaweed}},
  year         = {{2024}},
}