In an analytical study of microbial broths,the actinomycete strain Kitasatospora sp.P07101 was found to produce three new congeners,which were designated hazimycins B(1),C(2),and D(3),together with the previously repo...In an analytical study of microbial broths,the actinomycete strain Kitasatospora sp.P07101 was found to produce three new congeners,which were designated hazimycins B(1),C(2),and D(3),together with the previously reported hazimycin(renamed hazimycin A(4)).The structures of these hazimycins were examined using various spectroscopic methods including nuclear magnetic resonance(NMR),and the results revealed that 1–3 were analogues of hazimycin with the replacement of one of the two isonitrile groups in 4 by an NH-formyl group in 1,the two isonitrile groups and an amide group by two NH-formyl groups and a nitrile group in 2,and the two isonitrile groups and two amide groups by two NH-formyl groups and two nitrile groups in 3.Only hazimycin A exhibited moderate antimicrobial activities against Gram-positive bacteria and Candida albicans.These results indicated that the presence of two isonitrile groups in the hazimycin structure is essential for antimicrobial activity.展开更多
A novel one-pot protocol for the synthesis of substituted 2-aminooxazoline from isonitriles and 2-aminoethanol was developed and the reactions involved imidoyl diiodide intermediates,which were generated by mixing iso...A novel one-pot protocol for the synthesis of substituted 2-aminooxazoline from isonitriles and 2-aminoethanol was developed and the reactions involved imidoyl diiodide intermediates,which were generated by mixing isonitriles and iodine in CH_2C1_2 at room temperature.展开更多
The reactions of [CptRhCl(m-Cl)]2 (1) (Cpt = tBu2C5H3) with Li2E2C2B10H10 (E = S, Se) lead to the green 16-electron dichalcogenolate complexes CptRh(E2C2B10H10) [E = S(2a), Se(2b)]. The 16-electron complexes 2a and 2b...The reactions of [CptRhCl(m-Cl)]2 (1) (Cpt = tBu2C5H3) with Li2E2C2B10H10 (E = S, Se) lead to the green 16-electron dichalcogenolate complexes CptRh(E2C2B10H10) [E = S(2a), Se(2b)]. The 16-electron complexes 2a and 2b can take up two-electron donor ligands such as tert-butyl isoni-trile and carbon monoxide to give the 18-electron dichalco-genolate derivatives Cpt(L)(E2C2B10H10) [L = tBuNC, E = S(3a), Se(3b); L = CO, E = S(4a), Se(4b)]. The molecular structures of complexes 2a and 3a were determined by X-ray crystal structure analysis. The molecular structure of 16- electron complex 2a shows the pseudoaromatic system in IrSe2C2 five numbered ring.展开更多
基金supported in part by a Kakenhi Grant 23790020(to Nobuhiro Koyama)a Kitasato University Research Grant for Young Researchers(to Nobuhiro Koyama)
文摘In an analytical study of microbial broths,the actinomycete strain Kitasatospora sp.P07101 was found to produce three new congeners,which were designated hazimycins B(1),C(2),and D(3),together with the previously reported hazimycin(renamed hazimycin A(4)).The structures of these hazimycins were examined using various spectroscopic methods including nuclear magnetic resonance(NMR),and the results revealed that 1–3 were analogues of hazimycin with the replacement of one of the two isonitrile groups in 4 by an NH-formyl group in 1,the two isonitrile groups and an amide group by two NH-formyl groups and a nitrile group in 2,and the two isonitrile groups and two amide groups by two NH-formyl groups and two nitrile groups in 3.Only hazimycin A exhibited moderate antimicrobial activities against Gram-positive bacteria and Candida albicans.These results indicated that the presence of two isonitrile groups in the hazimycin structure is essential for antimicrobial activity.
文摘A novel one-pot protocol for the synthesis of substituted 2-aminooxazoline from isonitriles and 2-aminoethanol was developed and the reactions involved imidoyl diiodide intermediates,which were generated by mixing isonitriles and iodine in CH_2C1_2 at room temperature.
基金supported by the National Natural Science Foundation of China(Grant No.29925101)the Special Founds for the Major State Basic Research Projects(Grant No.G19990-64800).
文摘The reactions of [CptRhCl(m-Cl)]2 (1) (Cpt = tBu2C5H3) with Li2E2C2B10H10 (E = S, Se) lead to the green 16-electron dichalcogenolate complexes CptRh(E2C2B10H10) [E = S(2a), Se(2b)]. The 16-electron complexes 2a and 2b can take up two-electron donor ligands such as tert-butyl isoni-trile and carbon monoxide to give the 18-electron dichalco-genolate derivatives Cpt(L)(E2C2B10H10) [L = tBuNC, E = S(3a), Se(3b); L = CO, E = S(4a), Se(4b)]. The molecular structures of complexes 2a and 3a were determined by X-ray crystal structure analysis. The molecular structure of 16- electron complex 2a shows the pseudoaromatic system in IrSe2C2 five numbered ring.
