ABSTRACT
OBJECTIVE: To determine the contents of six oligosaccharides, i. e. glucose, fructose, sucrose, 1-kestose, nystose, 1-fructofuranosylnystose, in the roots of Morinda officinalis in different growing periods by HPAEC-PAD method. METHODS: The separation was performed on Hamilton RCX-10 column(4.1 mm × 250 mm, 7 μm) with gradient elution using mobile phase composed of 100 mmol · L-1 NaOH(A) and mixture of 100 mmol · L-1 NaOH and 500 mmol · L-1 NaOAc (B) at a flow rate of 0.8 mL · min-1 and the temperature was kept at 35℃. The injection volumn was 25 μX. The gradient elution program was as follows: 0-5 min, 1%B; 5-15 min, 1%-9% B; 15-20 min, 9%-12% B; 20-25 min, 12%-16% B; 25-40 min, 16%-50% B; 40-43 min, 50% B; 43-46 min, 50%-1% B. RESULTS: With the increase of growing periods, the content of monosaccharide progressively reduced while that of sucrose gradually increased. The contents of oligosaccharides with polymerization degree of 3 or greater, including 1-kestose, nystose, and 1-fructofuranosylnystose, slowly increased during 1-5 years, then slowed down. CONCLUSION: The contents of six oligosaccharides in the roots of Morinda officinalis vary greatly in different growing periods, indicating that the biosynthesis of oligosacchride in Morinda officinalis is related to growing periods. The result provides a reference for determination of appropriate collection time.