Structural characterization and antifungal activity of Algerian Opuntia ficus-indica polysaccharides: FTIR, GC-MS, colorimetric assays, and bioactivity dataStructural and antifungal data: Sequentially extracted polysaccharides from Algerian Opuntia ficus-indica cladodes (FTIR, GC, colorimetric assays)

This dataset comprises raw and processed Fourier-transform infrared (FTIR) spectra obtained via attenuated total reflectance (ATR) for six polysaccharide fractions extracted from Algerian <em>Opuntia ficus-indica</em> cladodes:

<strong>Mucilage 1 &amp; 2</strong> (water-soluble fractions)
<strong>Pectin 1 &amp; 2</strong> (hot water/EDTA-extracted)
<strong>Hemicellulose</strong> (alkali-extracted)
<strong>Cellulose</strong> (residual fraction)
<strong>Crude extract</strong> (unfractionated control)

<strong>Key Features:</strong>
<strong>- Spectral Range</strong>: 4000–400 cm⁻¹ at 4 cm⁻¹ resolution (32 scans)<br>
- <strong>Identified Functional Groups</strong>:

O–H stretching (3400 cm⁻¹)
Carboxylate C=O (1750 cm⁻¹, pectins)
β-glycosidic linkages (890 cm⁻¹)<br>
- <strong>Correlative Data</strong>: Monosaccharide composition (GC) and antifungal activity against <em>Penicillium sp.</em> are linked to spectral peaks.

<strong>Potential Applications:</strong>

Validation of plant polysaccharide extraction protocols
Structure-activity studies for natural antifungals
Comparative analysis of xerophytic plant adaptations

<strong>Technical Details:</strong>

<strong>Files Included</strong>:<br>

FTIR-DRAOU.xlsx spectra (wavenumber vs absorbance)
<strong>Instrument</strong>: Thermo Scientific FTIR spectrometer (OMNIC™ Software)

<strong>Ethics</strong>: No human/animal subjects involved.

<br> This dataset supports the research article "<em>*Structural characterization and antifungal properties of...*</em>" [DOI/Lien manuscrit si disponible]. It contains:  <br>
<br>
1. <strong>FTIR-ATR Spectra</strong>  <br>
  - Raw spectra (4000-400 cm⁻¹) of mucilage (M1-M3), pectins (P1-P2), hemicelluloses, and cellulose fractions.  <br>
  - Key peaks: 1750 cm⁻¹ (C=O), 890 cm⁻¹ (β-glycosidic linkages).  <br>
<br>
2. <strong>Gas Chromatography (GC)</strong>  <br>
  - Monosaccharide composition (% molar) of all fractions.  <br>
  - Includes arabinose, rhamnose, xylose, galacturonic acid quantifications.  <br>
<br>
3. <strong>Colorimetric Assays</strong>  <br>
  - Neutral sugars (Dubois method) and uronic acids (Blumenkrantz method).  <br>
  - Corrected values using Montreuil-Spik equations.  <br>
<br>
4. <strong>Antifungal Bioassays</strong>  <br>
  - <em>*Penicillium*</em> sp. growth inhibition data (dose-response, IC50).  <br>
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<strong>Methods</strong>:  <br>
- Extraction: Sequential water/EDTA/KOH protocol.  <br>
- GC: Shimadzu GC-2030 (DB-5 column, TMS derivatization).  <br>
- FTIR: Nicolet iS50, 4 cm⁻¹ resolution.  <br>
<br>
<strong>Usage Notes</strong>:  <br>
- Negative uronic acid values in cellulose set to 0.  <br>
- Missing data = "ND" (Not Detected).