Guadinomines A, B, C1, C2 and D consist of a
carbamoylated cyclic guanidinyl moiety, an alkyl chain
moiety having several hydroxyl and amino groups and a
dipeptide moiety. The relative stereochemistry of six
stereogenic centers in the side chain was not elucidated.
Guadinomic acid is the simplest molecule having a
carbamoylated cyclic guanidinyl moiety and a hydroxyl
hexanoate moiety. This compound was synthesized
asymmetrically by Tsuchiya et al. as K01-0509B and they
confirmed the connected position of carbamoyl group and
its stereochemistry as shown in Fig. 1 [6]. The common
substructure of the cyclic guanidinyl moiety is very unique
and only a few natural products have been reported to
share the substructure, namely microbial NA22598A1