Depsipeptides from a Guamanian Marine Cyanobacterium, Lyngbya bouillonii, with Selective Inhibition of Serine Proteases.

Bouillomides A (1) and B (2) are two depsipeptide analogues of dolastatin 13. Isolated from a Guamanian sample of Lyngbya bouillonii, the planar structures were elucidated on the basis of HR-ESI-MS and NMR data, while the absolute configurations were determined by employing functional group conversions, modified Marfey’s analysis, and detailed analyses of ROESY correlations. Compounds 1 and 2 selectively inhibited serine proteases elastase (IC50 = 1.9 μM for both) and chymotrypsin (IC50 = 0.17 and 9.3 μM, respectively) while showing no inhibition of trypsin (IC50 > 100 μM).

海兔毒素13的两种缩肽类似物——布伊洛米德A（1）和B（2）。从关岛的布伊隆鞘丝藻样本中分离得到，其平面结构通过高分辨电喷雾质谱（HR - ESI - MS）和核磁共振（NMR）数据得以阐明，而绝对构型则通过官能团转化、改良的马尔菲分析以及旋转坐标系NOESY谱相关的详细分析来确定。化合物1和2选择性地抑制丝氨酸蛋白酶弹性蛋白酶（两者的半数抑制浓度IC₅₀均为1.9 μM）和胰凝乳蛋白酶（IC₅₀分别为0.17 μM和9.3 μM），但对胰蛋白酶无抑制作用（IC₅₀>100 μM）。