Structure of Fucoidan

Fucoidan is chemically a high molecular polysaccharide consisting mainly of sugar called "sulfated fucose". Fucoidan is mainly found in the cell wall matrix and is a resistant and barrier component. The structure of fucoidan is complex, and the components and ratios of fucoidan extracted from different brown algae by different extraction methods are different. After research, it was found that the main constituent unit of fucoidan is 1, 2-α-fucose or 1, 3-α-fucose. Research shows that fucoidan has a variety of biological activities. For example, anticoagulant, antitumor, antiviral, hypolipidemic, and immunity-enhancing pharmacological activities.

Fig.1 The metabolic pathway of fucoidan. (Chao, et al., 2018)

Fucoidan Analysis Service at CD BioGlyco

CD BioGlyco has been involved in Polysaccharide Analysis for many years, so we offer our clients a full range of fucoidan analysis services. The analytical testing services we provide for fucoidan are:

• Polysaccharide content. We provide two determination methods: the phenol-sulfuric acid method and the anthrone-sulfuric acid method. According to the client's requirements, we will choose the suitable method.
• Sulfate content. The barium sulfate turbidimetric method is an effective method to determine sulfate content.
• Monosaccharide composition. For monosaccharide composition, we offer gas chromatography (GC), high-performance liquid chromatography (HPLC), and ion exchange resin methods.
• Molecular weight. For molecular weight analysis, we provide gel permeation chromatography (GPC) and provide detailed analysis reports for clients.
• Structure and conformation of polysaccharides. For the structure of polysaccharides, we provide infrared, multi-dimensional nuclear magnetic and ultraviolet testing means, and provide detailed data analysis.
• Heavy metal content. Pb, Cd: dry digestion, graphite furnace method; Hg: alumina pentoxide method; As: silver salt method.

Fig.2 Analysis procedure of fucoidan. (CD BioGlyco)

Case Study: High-Resolution MS Fingerprinting for Authenticity Verification and Algal Source Identification of Fucoidan Extracts

• Introduction & Background

Fucoidan is a complex, sulfur-containing polysaccharide found abundantly in the cell walls of brown seaweeds (Phaeophyceae). Renowned for its diverse biological properties, including immunomodulatory, anti-inflammatory, and anti-tumor activities—fucoidan has become a highly sought-after ingredient in the pharmaceutical, nutraceutical, and cosmetic industries.

However, the structural architecture, molecular weight, degree of sulfation, and ultimate bioactivity of fucoidan vary significantly depending on the specific brown algae species from which it is harvested (such as Cladosiphon okamurasaki, Fucus vesiculosus, or Undaria pinnatifida). Because these differences directly dictate market value and clinical efficacy, validating the botanical authenticity and specific algal origin of raw materials is a critical bottleneck for quality control and regulatory compliance.

To address this challenge, CD BioGlyco offers an advanced fucoidan analysis service platform. In this project, our team was commissioned to perform precision metabolomic chemical fingerprinting using high-resolution mass spectrometry to accurately verify the algal sources of three commercial seaweed extract lots.

• The Challenge & Client Requirement

Traditional crude polysaccharide assays (such as basic total carbohydrate or barium chloride sulfate tests) are unable to differentiate between different species of brown algae once the fucoidan has been extracted and processed into powder form. The client required an ultra-sensitive, reliable, and high-confidence analytical technique to confirm whether their three incoming raw material batches matched their designated biological origins:

• Lot 1: Declared as Fucoidan Powder derived from Mozuku (Cladosiphon okamurasaki).
• Lot 2: Declared as Fucus vesiculosus extract.
• Lot 3: Declared as Undaria pinnatifida extract.

• CD BioGlyco's Sophisticated Technical Approach

Instead of relying solely on standard composition testing, CD BioGlyco's carbohydrate experts deployed a cutting-edge high-resolution mass spectrometry (HRMS) chemical fingerprinting platform paired with proprietary bioinformatics source-prediction models.

• Experimental Methodology:
  • Instrumentation: Fourier transform mass spectrometry (FTMS) utilizing high-resolution MS1 profiling and data-Dependent acquisition (DDA) MS2 fragmentation. Both positive and negative electrospray ionization modes (ESI+/-) were leveraged to capture an exhaustive molecular profile.
  • Metabolomic Mapping: Seaweeds possess highly distinctive matrix indicators, lipids, fatty acids, and small-molecule metabolites that act as species-specific "barcodes." Our team tracked full retention time (RT), exact calculated molecular weights (Calc. MW), and fragmentation pathways for characteristic components, such as oleic acid, hexadecanoic acid, octadecanoic acid, and (9Z)-octadec-9-enamide.

Fig.4 MS spectrum of (9Z)-octadec-9-enamide from sample sk-1. (CD BioGlyco)

Fig.5 MS spectrum of hexadecanoic acid from sample sk-1. (CD BioGlyco)

Fig.6 MS spectrum of octadecanoic acid from sample sk-1. (CD BioGlyco)

Fig.7 MS spectrum of 3,7,11-trimethyl-2-(methylamino)-1,3-dodecanediol from sample sk-1. (CD BioGlyco)

Fig.8 MS spectrum of 4-dodecylmorpholine from sample sk-1. (CD BioGlyco)

Fig.9 MS spectrum of tetradecanoic acid from sample sk-1. (CD BioGlyco)

Fig.10 MS spectrum of elaidolinolenic acid from sample sk-1. (CD BioGlyco)

• Source Prediction Engine: The detected multi-component molecular signatures, particularly the unique distributions of sulfur-containing matrix compounds, were cross-referenced against our reference database to compute species origin probabilities.

• Analytical Results & Authenticity Verification

The HRMS metabolic profiling yielded flawless, unambiguous source classification data for all three seaweed extract samples, confirming 100% supply chain transparency for the client:

• Technical Highlights from the Data

• Exceptional Source Mapping: The data-driven prediction engine matched all three lots back to their exact biological hosts with an officially designated high confidence level.
• Sulfur-Rich Matrix Profiling: Reflecting the highly sulfated nature of native brown seaweed matrices, 100% of the key target metabolic markers extracted (36, 41, and 42 compounds, respectively) were confirmed to be sulfur-containing chemical entities, providing an incontrovertible chemical baseline for product integrity.
• Precision Spectral Resolution: High-resolution mass spectra (FTMS) successfully resolved exact mass adducts (e.g., [M+H]⁺, [M-H]^-, [M+Na]⁺, and [M+NH₄]⁺), ensuring complete structural differentiation away from any adulterants or cheap filler polymers.

• How This Showcases CD BioGlyco's Superior Capabilities

This project beautifully demonstrates why CD BioGlyco is a premier global partner for marine carbohydrate and fucoidan characterization. By leveraging our fucoidan analysis service, clients gain access to unmatched analytical rigor:

• State-of-the-Art MS Platform: We look beyond simple polymer components, utilizing high-end FTMS and MS/MS multi-dimensional structural elucidation to solve complex authenticity and quality control puzzles.
• Proprietary Marine Bioinformatic Databases: Our established reference libraries of seaweed metabolomes enable us to confidently identify specific species origins where standard commercial testing labs fail.

Publication

Paper Title: Fucoidans from brown alga Fucus evanescens: structure and biological activity.

Technology: ¹H, ¹³C, and 2D (COSY, TOCSY, ROESY, NOESY, HSQC, and HMBC) nuclear magnetic resonance (NMR) spectroscopy

Journal: Frontiers in Marine Science

Published: 2016

Results: The structures of the obtained modified fucoidans were studied by 1D (¹H, ¹³C) and 2D (COSY, TOCSY, ROESY, NOESY, HSQC, and HMBC) nuclear magnetic resonance (NMR) spectroscopy and methylation analysis. As a result, fucoidan was shown to be a regular molecule containing disaccharide repeating units, with a linear main chain of alternating 2-sulfated 1,3-and 1,4-linked α- L-fucose residues. A methylation analysis of desulfated fucoidan showed that 1,3-and 1,4-linked fucose residues had a ratio of 1.2:1. Few sulfate groups were found in position 4 of some 1,3-linked fucose residues. Acetyl groups occupied the free C-3 of 1,4-linked residues and/or the C-4 of 1,3-linked fucose residues (Fig.3).

Fig.3 Structures of fucoidan from F. evanescens. (Menshova, et al., 2016)

Applications

• Fucoidan analysis is used in the development of anticoagulant drugs.
• Fucoidan analysis can be used in the analysis of antiviral and antitumor drugs.
• Fucoidan analysis technology can be used in lipid regulation research.

Advantages

• We have a wide range of methods for polysaccharide analysis and provide custom analysis solutions for our clients.
• Our researchers have extensive experience in polysaccharide analysis and help our clients solve their polysaccharide production and analysis challenges.

As a recognized expert in the field of polysaccharide analysis, CD BioGlyco has developed a complete workflow for fucoidan analysis and has performed many fucoidan analysis projects. Please feel free to contact us for any of your needs in this area.