Four new meridamycin congeners from Streptomyces sp. SR107

Abstract

Meridamycin and its naturally occurring analog normeridamycin are non-immunosuppressive macrocyclic polyketides with potent neuroprotective activity in dopaminergic neurons.

Isolation and Identification of Secondary Metabolites From Streptomyces sp. SP301

“…Additionally, the HMBC correlations from H-2 to C-3, C-8, C-9, and C-6a; H-4 to C-3, C-2a, and C-6; H-7 to C-6, C-8, and C-2a; and H-10 to C-4, C-5, and C-6 revealed the connection of each fragment. According to the 1 H NMR, 13 C NMR, 1 H-1 H COSY, HMBC, and NOE-NMR data and molecular weight, the complete structure of 6 is confirmed.…”

“…The high-resolution Mass Spectrometry of aminobenzoate C (3) gave a quasi-molecular ion at m/z 322.1649 [M+H] + which is consistent with the molecular formula C 17 H 23 NO 5 , and unsaturation of 7. Interpretation of the 1 H-, 13 C-, and Heteronuclear Single Quantum Correlation (HSQC)-NMR data (Tables 1 and 2) reveals that 3 contains 17 carbon signals (2 methyls, 3 methylenes, 7 methines, and 5 quaternary carbons). The analysis of 1 H-1 H Correlation Spectroscopy (COSY) signals showed the existence of fragments [a: -CH (5)-CH (6)-; b: -CH 2 (7)-CH (8)-CH (9)-CH 2 (10)-CH (11)-CH (12)-; and c: -CH 2 (8a)-CH 3 (8b)].…”

“…13 C NMR Spectroscopic Data of Compounds 1 to 7 in CD 3 OD. COSY and HMBC further prove the existence of β-glucuronic acid.…”

“…Our research group did a thorough study of strain LZ35, and a series of novel compounds were isolated from it. [8][9][10][11][12][13] However, instead of obtaining new ansamycins from this effort, 7 compounds were isolated from Streptomyces sp. SP301 at the first time.…”

“…The high-resolution Mass Spectrometry of aminobenzoate C (3) gave a quasi-molecular ion at m/z 322.1649 [M+H] + which is consistent with the molecular formula C 17 H 23 NO 5 , and unsaturation of 7. Interpretation of the 1 H-, 13 C-, and Heteronuclear Single Quantum Correlation (HSQC)-NMR data (Tables 1 and 2 Aminobenzoate D (4), with a quasi-molecular ion at m/z of 306.1700 [M+H] + , was determined to have the molecular formula C 17 H 23 NO 4 , and unsaturation of 7. Interpretation of the 1 H NMR data (Tables 1 and 2) reveals that 4 contains 3 aromatic protons (δ H = 6.30 (d, J = 8.5 Hz), 7.57 (d, J = 1.4 Hz), and 7.71 (dd, J = 8.4, 1.6 Hz)).…”