RESUMO
A novel beta-N-acetylglucosaminidase (GlcNAcase) inhibitor named TMG-chitotriomycin (1) was isolated from the culture filtrate of Streptomyces anulatus NBRC13369. The strain produced 1 only when colloidal chitin was used as the sole carbon source in the production medium. The structure of 1 was determined by spectral and constitutive sugar analyses of the corresponding alditol derivatives to be an equilibrated mixture of alpha-d-N,N,N-triMeGlcNH2-(1,4)-beta-d-GlcNAc-(1,4)-beta-d-GlcNAc-(1,4)-d-GlcNAc and its C-2 epimer of the reducing end residue. TMG-chitotriomycin (1) showed potent and selective inhibition of insect and fungal GlcNAcases with no inhibition of mammalian and plant GlcNAcases. In contrast, the known GlcNAcase inhibitor nagstatin potently inhibited all GlcNAcases. It should be emphasized that synthesized d-N,N,N-triMeGlcNH2, which is the component sugar of 1, showed no inhibition of the insect Spodoptera litura GlcNAcase. These results suggest that the (GlcNAc)3 unit positioned at the reducing end of 1 is essential for its enzyme inhibitory activity. The unique inhibitory spectrum of 1 will be useful to study chitinolytic systems and to develop selective fungicides or pesticides.
Assuntos
Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Penicillium/enzimologia , Spodoptera/enzimologia , Streptomyces/metabolismo , Álcoois Açúcares/farmacologia , beta-N-Acetil-Galactosaminidase/antagonistas & inibidores , Animais , Bacillus/classificação , Bacillus/enzimologia , Configuração de Carboidratos , Sequência de Carboidratos , Quitinases/antagonistas & inibidores , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/química , Insetos , Dados de Sequência Molecular , Sensibilidade e Especificidade , Especificidade da Espécie , Streptomyces/classificação , Streptomyces griseus/enzimologia , Relação Estrutura-Atividade , Álcoois Açúcares/químicaRESUMO
In the crystal structure of the title compound, [Co(H(2)O)(6)](2)(C(24)H(12)O(16)S(8))·H(2)O, the thia-calix[4]arenetetra-sulfonate (= TCAS(4-)) anions adopt a cone-type conformation with an additional water mol-ecule as a guest mol-ecule in the hydro-phobic cavity. The TCAS(4-) anions are arranged in layers in an up-down fashion. These anionic layers alternate with cationic layers consisting of rather regular octahedral cations (symmetry m). Several medium O-Hâ¯O hydrogen-bond inter-actions exist between the aqua ligands of the [Co(H(2)O)(6)](2+) cations and the O atoms of the sulfonate groups. In addition to the two crystallographically different Co atoms, two S and four O atoms are situated on mirror planes.
