Metabolites of microorganisms. 229. Absolute configuration of naphthomycin A determined by X-ray analysis and chemical degradation.

A new ansamycin antibiotic, naphthomycin H from a Streptomyces species Y-83,40369.

“…Since the chemical shifts and coupling constants of olefinic protons at C(13) and C(21) are nearly identical with those of naphthomycin A the double bonds C(12)= C(13) and C(21)=C(22) have been tentatively assigned E-configuration2,3). The coupling constants of the triene system in naphthomycin H (J2,3=11.5, J4,5=11, J6,7=15 Hz) prove that C(2)=C(3) and C(4)=C(5) have Z-geometry, whereas the other double bond C(6)=C(7) has E-geometry as shown in the structure (2). The comparative biospectrum of the naphthomycins H, A and B are presented in Table 4.…”

1H and 13C NMR chemical shifts of 2-n-alkylamino-naphthalene-1,4-diones

“…The X-ray crystal structures of these compounds reveal intra and intermolecular N-H⋅⋅⋅O interactions. Besides, the C(3) substitution may affect the 1 aromatic proton H(5) takes part intermolecular C-H⋅⋅⋅O interaction (Table 2) in most of the crystal structures of known derivatives; if such interactions exist in the solution, the chemical shift variation is expected. The 1 H chemical shift was observed at~δ ¼ 7.8-7.9 ppm in all compounds; this implies that the intermolecular C-H⋅⋅⋅O interaction does not directly affect its chemical shift [45].…”

“…Energy-minimal optimized geometrical configurations of alkylamino derivatives with methyl, chlorine, and bromine substituted at C(3) positions within the M06-2X/6-311þþG (d,p) density functional framework are depicted in Figures 4,5,6 and 7 [36,44]. 1 H NMR chemical shifts (δH) were simulated through the SCRF-PCM theory and are reported in Tables 3, 4, and 5. As can be noticed from the table, the alkyl protons emerge with up-field δ H signals.…”

“…Annamycin antibiotics with aminonaphthoquione in its core include naphthomycin K, divergolides C and divergolide D, naphthomycin A [ 1 , 2 , 3 , 4 ]. Annamycin antibiotic finds applications in treating tuberculosis, leprosy, and AIDS-related mycobacterial infections.…”

3-Amino-5-hydroxybenzoic Acid in Antibiotic Biosynthesis. XII. Origin of the Oxygen Functionality of the Ansamycin Antibiotic Actamycin.

“…E/784 exemplifies hydroxy, chloro and alkylthio substitution at C-30, and comprises actamycin (1), 5,13,14) naphthomycins H (3)15) and J (5),1) and their higher 2-methyl homologues naphthomycins D (2),16) A (4) 17,18) and I (6)1) (Fig. 1).…”