Enzymes proceed the reaction with high regio- and stereoselectivity under m
ild conditions, ie. in an aqueous medium at room temperature. However, enzy
matic reactions that catalyze carbon-carbon bond formation have not been ut
ilized in organic synthesis until recently. We had an interest in an aldola
se-catalyzed reaction which proceed carbon-carbon bond formation referred t
o aldol condensation, by which many bioactive compounds have been rationall
y synthesized. On the other hand, recent biological studies on cell recogni
tion (cell adhesion) have disclosed the important roles of oligosaccharides
on cell surfaces, especially which include glucuronic acid, 3-deoxy-D-mann
o-oct-2-ulosonic acid (KDO), and sialic acid in the structures e.g. sialyl
Lewis X and endotoxins, in differentiation, induction, viral and bacterial
infections, and immune response. As well as acidic oligosaccharides, basic
ones have been utilized as practical medicines in the clinical level, like
acarbose that acts as an amylase inhibitor. Based on these background, we e
mbarked the synthesis of carbohydrate related compounds which can control t
he interaction between carbohydrates and carbohydrate recognition protein b
y the use of several aldolases. Azasugars, potent inhibitors toward glycosi
dases, were synthesized using fructose-1,6-diphosphate (FDP)-aldolase and o
ther dihdroxyacetonephosphate (DHAP)-dependent aldolases in the key step. S
ialyl Lewis X mimetic, peptidic mimetic of RNA having anti-Vero toxin activ
ity, mycestericin D, and aza-idulonic acid were prepared by taking advantag
e of L-threonine aldolase catalyzed reaction, which afford beta-hydroxy-alp
ha-L-amino acids. A precursor of KDO, featured acidic sugar of endotoxins w
as provided by the reaction catalyzed with kynureninase, which generates be
ta-anion of L-alanine in its active site during the metabolic reaction from
kynurenine to anthranilic acid.