According to Brandao and Andrade (1999), pectins with high degree of methoxylation
gelify in acid medium in the presence of high sugar concentrations.
or the hydroxylation of polychlorinated biphenyls (PCBs) in hydroxylated polychlorinated biphenyls (OH-PCBs) or methoxylated polychlorinated biphenyls (MeO-PCBs) increase their persistence and bioaccumulation .
The aim of German scientists and colleagues was to investigate both water-binding and gelling properties of two orange fiber preparations from pulp and peel with a galacturonan polysaccharide content of greater than 27% and a degree of methoxylation
greater than 65%.
Degree of Methoxylation
. The DM of pectin, a key functional parameter, was estimated as the ratio of the molar amount of methanol groups to the molar amount of GalA.
For the preparation of the jellies 65% of the clarified peach juice, 35% sugar, 1% high methoxylation
pectin (Danisco, Sao Paulo, Brazil) and 0.5% citric acid were used.
Second, the mixture was stirred in a cold room for 6 days for methoxylation
, followed by washing several times with methanol and rinsing several times with 80% acetone to remove the free methanol.In a previous study (Monsoor et al.
The structure activity relationship of polyphenols isolated from other plant sources has shown that [alpha]-amylase inhibitory activity is influenced by a number of hydroxyl groups and their positions, methylation, methoxylation
, glycosylation, and so on.
The most striking feature of these heterocyclic chemical compounds was aryl units directly or indirectly substituted at carbon C-2 or C-3 in the furan ring, while fused benzene rings were characterized by typical signals of an ABX spin system or typical signals of singlet protons H-4 and H-7 and methoxylation
and/or hydroxylation for carbons C-5 and C-6 (Table 1 and Figure 7).
Variations in the hydroxylation and methoxylation
cause differences in activity among the tricyclic hydroxylmethoxy-xanthones.
[alpha],[omega]-bis(3-1-methoxy-2-hydroxypropoxy)propyl)polydimethylsiloxane was synthesized by hydrosilylatlon, methoxylation
and equilibrium reactions; [alpha]-N,N-dihydroxyethylaminopropyl-[omega]-butylpolydimethylsiloxane was synthesized via hydroxyl protection, alkylation, anionic ring-opening polymerization, hydrosilylatlon.
Foroumadi, "Antiproliferative activity of flavonoids: influence of the sequential methoxylation
state of the flavonoid structure," Phytotherapy Research, vol.
Brandsma, "Efficient procedures for the Cu(I)-catalyzed methoxylation
of 2-and 3bromothiophene," Synthetic Communications, vol.