Chemical characterization of the oligosaccharides in beluga (Delphinapterus leucas) and Minke whale (Balaenoptera acutorostrata) milk.
Carbohydrates were extracted from the milk of a beluga, Delphinopterus leucas (family Odontoceti), and two Minke whales, Balaenoptera acutorostrata (Family Mysticeti), sampled late in their respective lactation periods. Free oligosaccharides were separated by gel filtration and then neutral oligosaccharides were purified by preparative thin layer chromatography and gel filtration, while acidic oligosaccharides were purified by ion-exchange chromatography, gel filtration and high performance liquid chromatography (HPLC). Their structures were determined by 1H-NMR. In one of the Minke whale milk samples, lactose was a dominant saccharide, with Fuc(alpha1-2)Gal(beta1-4)Glc(2'-fucosyllactose), Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc(lacto-N-neotetraose), GalNAc(alpha1-3)[Fuc(alpha1-2)]Gal(beta1-4)Glc(A-tetrasaccharide), Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (para lacto-N-neohexaose), Neu5Ac(alpha2-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (sialyl lacto-N-neotetraose), Neu5Ac(alpha2-6)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (LST c) and Neu5Ac(alpha2-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (sialyl para lacto-N-neohexaose) also being found in the milk. The second Minke whale sample contained similar amounts of lactose, 2'-fucosyllactose and A-tetrasaccharide, but no free sialyl oligosaccharides. Sialyl lacto-N-neotetraose and sialyl para lacto-N-neohexaose are novel oligosaccharides which have not been previously reported from any mammalian milk or colostrum. These and other oligosaccharides of Minke whale milk may have biological significance as anti-infection factors, protecting the suckling young against bacteria and viruses. The lactose of Minke whale milk could be a source of energy for them. The beluga whale milk contained trace amounts of Neu5Ac(alpha2-3)Gal(beta1-4)Glc(3'-N-acetylneuraminyllactose), but the question of whether it contained free lactose could not be clarified. Therefore, lactose may not be a source of energy for suckling beluga whales.
Urashima
Tadasu
T
Department of Bioresource Science, Obihiro University of Agriculture and Veterinary Medicine, Inada cho, Obihiro, Hokkaido, 080-8555, Japan. urashima@obihiro.ac.jp
Sato
Harumi
H
Munakata
Jiro
J
Nakamura
Tadashi
T
Arai
Ikichi
I
Saito
Tadao
T
Tetsuka
Masafumi
M
Fukui
Yutaka
Y
Ishikawa
Hajime
H
Lydersen
Christian
C
Kovacs
Kit M
KM
D000818:Animals; D002850:Chromatography, Gel; D005260:Female; D007774:Lactation; D009682:Magnetic Resonance Spectroscopy; D008892:Milk / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification*; D011247:Pregnancy; D013045:Species Specificity; D014907:Whales
D009844:Oligosaccharides