Olivomycin and related antibiotics XXVIII. Monomeric composition of aureolic acid and proof that the antibiotics LA-7017 and mithramycin are identical to it
Summary1. It has been shown that aureolic acid, antibiotic LA-7017, and mithramycin are identical.2. It has been established that aureolic acid is a glycoside of chromomycinone (I) and contains the monosaccharides D-olivose (II), D-oliose (III), and D-mycarose (IV) in a ratio of 3 : 1 : 1.
Aureolic Acid Group of Anti-tumour Antibiotics
SINCE 1953 several antibiotics of similar biological and physico-chemical properties have been described. These are aureolic acid1, aburamycin2, LA-7017 (ref. 3), M5-18903 (ref. 4), chromomycin5, antibiotic 2410 (ref. 6), NSC A-649 (ref. 7), olivomycin8, mithramycin9 and antibiotics 232, 3014, 7193, 11296 (ref. 10) and SK-229 (ref. 11). Two members of this group, olivomycin and chromomycin, were subjected to extensive chemical research which resulted in the isolation and structural elucidation of their components, olivomycins A, B, C, D (ref. 12) and chromomycins A2, A3, A4 (ref. 13). The other members of the group, however, have been only scantily investigated.
Stretching frequency versus bond distance correlation of OD(H)⋯Y (Y N, O, S, Se, Cl, Br, I) hydrogen bonds in solid hydrates
From a compilation of spectroscopic and structural data of solid hydrates 61 different compounds containing more than 250 OD(H)⋯Y groups have been selected, for which uncoupled OD stretching frequencies, hydrogen bond distances and assignments of sufficient reliability and accuracy are available. ν(OD) versus R(O⋯Y) and R(H⋯Y) diagrams and calculated correlation curves are presented for Y  N, O, S, Se, Cl, Br, I. Depending on the scatter of points and the number of data included in the plots the predictive value and the statistical significance varies from very high for O, S and Cl acceptors down to rather poor for Br and I acceptors. At equal bond distances the frequencies may differ by up to about 150 cm−1 depending on the specific chemical nature of the proton acceptors included in a plot, while the influence of different cation—water contacts is less significant and distinct. Anion effects play, therefore, a dominant role in producing large scatters, while action effects and experimental inaccuracies are of minor importance. Furthermore it is shown, that the relation between ν(OD) and ν(OH) frequencies is almost perfect and the frequency—distance correlations involving ν(OD) are also representative without serious restrictions for corresponding correlations involving ν(OH).