TY - JOUR
T1 - Structural elucidation of anti-metastatic rhamnogalacturonan II from the pectinase digest of citrus peels (Citrus unshiu)
AU - Park, Hye Ryung
AU - Park, Su Beom
AU - Hong, Hee Do
AU - Suh, Hyung Joo
AU - Shin, Kwang Soon
N1 - Funding Information:
This research was financially supported by Korea Food Research Institute (2012).
Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - The aim of this study was to characterize a polysaccharide found in citrus peels with an anti-metastatic property. CPE-II was purified by the pectinase digestion of citrus peels. During in vivo lung metastasis of Colon26-M3.1, administration of 10 μg of CPE-II per mouse showed 81.3% inhibition of metastasis. CPE-II consists of 15 different monosaccharides and 22 different glycosyl linkages, characteristic of rhamnogalacturonan II (RG-II). The primary structure was elucidated based on sugar composition, methylation analysis, oligosaccharide analysis, and sequencing using GC, GC–MS, LC–MS, and ESI–MS/MS analyses. Sequential degradation using partial acid hydrolysis indicated that CPE-II contained Rhap-(1 → 5)-Kdo, Araf-(1 → 5)-Dha, an AceA-containing nonasaccharide, and an uronic acid-rich oligosaccharide in addition to an α-(1 → 4)-galacturono-oligosaccharide main chain. The molecular weight of CPE-II was observed to decrease from 9 to 5 kDa at a pH value of <2.0, as observed by HPSEC. Thus, we propose that the anti-metastatic CPE-II is primarily present as an RG-II dimer.
AB - The aim of this study was to characterize a polysaccharide found in citrus peels with an anti-metastatic property. CPE-II was purified by the pectinase digestion of citrus peels. During in vivo lung metastasis of Colon26-M3.1, administration of 10 μg of CPE-II per mouse showed 81.3% inhibition of metastasis. CPE-II consists of 15 different monosaccharides and 22 different glycosyl linkages, characteristic of rhamnogalacturonan II (RG-II). The primary structure was elucidated based on sugar composition, methylation analysis, oligosaccharide analysis, and sequencing using GC, GC–MS, LC–MS, and ESI–MS/MS analyses. Sequential degradation using partial acid hydrolysis indicated that CPE-II contained Rhap-(1 → 5)-Kdo, Araf-(1 → 5)-Dha, an AceA-containing nonasaccharide, and an uronic acid-rich oligosaccharide in addition to an α-(1 → 4)-galacturono-oligosaccharide main chain. The molecular weight of CPE-II was observed to decrease from 9 to 5 kDa at a pH value of <2.0, as observed by HPSEC. Thus, we propose that the anti-metastatic CPE-II is primarily present as an RG-II dimer.
KW - Anti-metastatic activity
KW - Citrus peels
KW - Pectin
KW - Polysaccharide
KW - Rhamnogalacturonan II
UR - http://www.scopus.com/inward/record.url?scp=84992052704&partnerID=8YFLogxK
U2 - 10.1016/j.ijbiomac.2016.09.100
DO - 10.1016/j.ijbiomac.2016.09.100
M3 - Article
C2 - 27693835
AN - SCOPUS:84992052704
SN - 0141-8130
VL - 94
SP - 161
EP - 169
JO - International Journal of Biological Macromolecules
JF - International Journal of Biological Macromolecules
ER -