Structural characterization of a pectic polysaccharide from Nerium indicum flowers.
A polysaccharide fraction, J6, was isolated from the hot-water extract of flowers of oleander Nerium indicum Mill., using ethanol precipitation, cetyltrimethylammonium bromide (CTAB) complexing, anion-exchange chromatography and gel permeation chromatography. J6 was found to contain L-rhamnose, L-arabinose, D-galactose, and D-galacturonic acid, in the ratio of 10.1:49.8:30.1:10.0. Its structure was investigated by methylation analysis, periodate oxidation, Smith degradation, partial acid hydrolysis, electrospray ionization mass spectrometry and NMR spectroscopic methods. It was found that J6 is an RG-I type polysaccharide, which contains a rhamnogalacturonan backbone, with various branches attached to O-4 of L-rhamnose. The branches probably involve (1-->4)-beta-D-galactan, branched L-arabino-(1-->3)(1-->6)-beta-D-galactan, and (1-->5)-alpha-L-arabinan. J6 stimulated NO production of macrophage RAW264.7 cells in a preliminary test.
Dong
Qun
Q
Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, 201203 Shanghai, China.
Liu
Xuan
X
Yao
Jian
J
Dong
Xiaotang
X
Ma
Chao
C
Xu
Yuxia
Y
Fang
Jinian
J
Ding
Kan
K
D000818:Animals; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D035264:Flowers / Q000737:chemistry; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D030007:Nerium / Q000737:chemistry*; D009569:Nitric Oxide / Q000096:biosynthesis; D019906:Nuclear Magnetic Resonance, Biomolecular; D010368:Pectins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
D004365:Drugs, Chinese Herbal; C552581:pectic polysaccharide J6; D009569:Nitric Oxide; D010368:Pectins