1 research outputs found
Homogalacturonans from Preinfused Green Tea: Structural Characterization and Anticomplementary Activity of Their Sulfated Derivatives
Two homogeneous water-soluble polysaccharides
(TPSR4-2B and TPSR4-2C)
were obtained from preinfused green tea. Their average molecular weights
were estimated to be 41 kDa and 28 kDa, respectively. A combination
of composition, methylation, and configuration analysis, as well as
NMR spectroscopy, indicated that both TPSR4-2B and TPSR4-2C were poly-(1–4)-α-d-galactopyranosyluronic acid in which 30.5 ± 0.3% and
28.3 ± 0.5%, respectively, of uronic acid existed as methyl ester.
Two sulfated derivatives (Sul-R4-2B and Sul-R4-2C) from TPSR4-2B and
TPSR4-2C were prepared after sulfation with a 2:1 chlorosulfonic acid–pyridine
ratio. The anticomplementary assay showed that Sul-R4-2B and Sul-R4-2C
demonstrated a stronger inhibitory effect on the complement activation
through the classic pathway, compared to that of heparin. Preliminary
mechanism studies by using complement component depleted-sera indicated
that both Sul-R4-2B and Sul-R4-2C selectively interact with C1q, C1r,
C1s, C2, C5, and C9 but not with C3 and C4. The relationship between
DS and the anticomplementary activity of sulfated derivatives of homogalacturonans
showed that low sulfated derivatives of homogalacturonans also exhibited
potent anticomplementary effect, which might greatly reduce the side
effects related to heparin and oversulfated chondroitin sulfate, such
as anticoagulant activity and allergic-type reaction. These results
suggested that sulfated derivatives of homogalacturonans might be
promising drug candidates for therapeutic complement inhibition