Composition and properties of biologically active pectic polysaccharides from leek (Allium porrum).
BACKGROUND
Leek (Allium porrum) is very commonly used vegetable in Bulgaria and is distinctive with high content of bioactive components. Previously we obtained five crude pectic polysaccharides from leek through consecutive extraction. Some of them appeared to be good stimulators of the immune system. Schols and Voragen investigated the composition of modified hairy regions of pectic polysaccharides isolated from leek cell walls. Samuelson et al. identified the polysaccharide structures encountered in hairy regions as bioactive. The aim of this work was to study the isolation, composition and biological activities of pectic polysaccharides from leek.


RESULTS
Two pectic polysaccharides from leek were isolated through consecutive water and acid extraction. The water extractable pectin had higher polyuronic content, higher protein content and lower neutral sugar content. It was found that next to galacturonic acid they also contain glucuronic acid in ratio 9:1 for the water- and 3:1 for the acid-extractable polysaccharide. The main neutral sugar was galactose. The water-extractable pectic polysaccharide had higher molecular weight (10(6) Da) and homogeneity. It was shown that the pectic polysaccharides from leek have considerable immunostimulating activities.


CONCLUSIONS
Leek polysaccharides have relatively high galacturonic and glucuronic acid content and are distinguished with high biological activity.
Kratchanova
Maria
M
Institute of Organic Chemistry with Center of Phytochemistry, Laboratory of Biologically Active Substances, Bulgarian Academy of Sciences, 4000 Plovdiv, Bulgaria. LBAS@plov.omega.bg
Nikolova
Mariana
M
Pavlova
Elena
E
Yanakieva
Irina
I
Kussovski
Veselin
V
D000276:Adjuvants, Immunologic / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D000818:Animals; D001424:Bacterial Infections / Q000517:prevention & control*; D004044:Dietary Proteins / Q000032:analysis; D019422:Dietary Sucrose / Q000032:analysis; D005260:Female; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008970:Molecular Weight; D019697:Onions / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D028321:Plant Preparations / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D010940:Plant Proteins / Q000032:analysis; D014574:Uronic Acids / Q000032:analysis / Q000494:pharmacology
D000276:Adjuvants, Immunologic; D004044:Dietary Proteins; D019422:Dietary Sucrose; D028321:Plant Preparations; D010940:Plant Proteins; D014574:Uronic Acids; D010368:Pectins