https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

A systematic analysis of all naturally-occurring glycosylated bacterial secondary metabolites reported in the scientific literature up through early 2013 is presented. This comprehensive analysis of 15 940 bacterial natural products revealed 3426 glycosides containing 344 distinct appended carbohydrates and highlights a range of unique opportunities for future biosynthetic study and glycodiversification efforts.

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A comprehensive review of glycosylated bacterial natural products.

Publisher Summary This chapter reviews recent advances in the chemistry and biochemistry of C-nucleosides, the literature concerning C-arylglycoside (i.e., nonnitrogen heterocyclic C-nucleoside) antibiotics, and recent significant advances in the synthesis of C-nucleosides and C-glycosides. It also discusses biological test data and data that are relevant to structure–activity relationships. Modification of readily available natural C-nucleosides is an attractive route to new C-nucleoside analogs and derivatives, because one starting material often possesses much of the desired functionality and chiral properties. The chapter illustrates this approach with examples. The most frequently used strategy for C-nucleoside synthesis involves the construction of a heterocyclic aglycone from the C-1 substituent of a functionalized sugar intermediate.

The chemistry and biochemistry of C-nucleosides and C-arylglycosides.

The present invention relates to the discovery that certain non-naturally occurring, non-peptide amide compounds and amide derivatives, such as oxalamides, ureas, and acrylamides, are useful flavor or taste modifiers, such as a flavoring or flavoring agents and flavor or taste enhancer, more particularly, savory (the “umami” taste of monosodium glutamate) or sweet taste modifiers, —savory or sweet flavoring agents and savory or sweet flavor enhancers, for food, beverages, and other comestible or orally administered medicinal products or compositions.

Novel flavors, flavor modifiers, tastants, taste enhancers, umami or sweet tastants, and/or enhancers and use thereof

Bleomycin (BLM), an antibiotic obtained from Streptomyces verticillus, is of significance as an antineoplastic agent. The compound is actually the mixture of some 200 related forms which differ from each other in the amine moiety. The drug, at low concentrations, can cause elimination of bases, particularly thymine. This causes strand breakage of DNA and inhibition of cell growth. The influence of BLM on cell growth may be unrelated to the effects on DNA. In general, mitotically dividing cells show more DNA damage than non-dividing cells. G2 seems to be the most sensitive phase indicating that cell death may not be related to a direct effect of BLM on DNA replication. The antibiotic shows specific effects on chromatin and causes chromosomal damage in all sub-phases of interphase. It can affect early prophase chromosomes also. Suggestion has been made that BLM-induced breakage and cell death are similar to those induced by densely ionizing radiations. Whereas the antibiotic affects the frequency of somatic crossing over and produces micronuclei, the data on mutation induction and production of sister-chromatid exchanges do not permit classifying BLM as a potent inducer of these phenomena. The genetic effects of BLM can be modified quantitatively by thiol compounds, caffeine, hyperthermia and H2O2. It is concluded that the available data do not permit assessment of genetic damage in the offsprings of BLM-treated patients. Such studies are urgently needed, as are the studies to find out the effects of BLM on meiotic phenomena.

Genetic toxicology of bleomycin.

Nogalamycin, an anthracycline antibiotic, was active against L1210 leukemia in vitro and in vivo . Several new analogs synthesized recently were more active against P388 leukemia, L1210 leukemia, and/or B16 melanoma than was nogalamycin. This study compares the biological and biochemical effects of these compounds on L1210 leukemic cells. Compounds containing the nogalose moiety inhibited RNA synthesis more than DNA synthesis. Nogalamycin (50% inhibitory dose, 0.4 nmol/ml) and dis -nogamycin (50% inhibitory dose, 0.5 nmol/ml) were much more inhibitory towards RNA synthesis than was dis -nogalamycinic acid (50% inhibitory dose, 3.6 nmol/ml). These results paralleled those of cell growth inhibition as well as drug-DNA interaction as measured by circular dichroism and thermal melting of DNA, suggesting that the inhibition of RNA synthesis by these compounds was the result of a major biochemical lesion, probably mediated through the interaction with DNA. With the 7-alkyl analogs, RNA synthesis again was generally inhibited more than DNA synthesis. The dis isomers, i.e. , 7- dis-O -methylnogalarol, 7- dis-O -methylnogarol, and 7- dis-O -ethylnogarol, inhibited RNA synthesis more than did the corresponding con isomers. This phenomenon correlated well with stronger interaction between the dis isomers and DNA. However, the con isomers were generally more inhibitory towards L1210 cell growth. By and large, the biochemical effects observed with the con isomers, particularly 7- con-O -methylnogarol, could not account for their biological activities which appear to be mediated through some mechanism other than their interaction with DNA. The significance of these findings is discussed in terms of drug development.

https://cancerres.aacrjournals.org/content/canres/39/12/4816.full.pdf

Comparative biological and biochemical effects of nogalamycin and its analogs on L1210 leukemia.

An x-ray study of aerothionin from aplysina fistularis (pallas)

Structure of rubradirin

Sir: Rubradirin'-\" contains a C8H,5NO5* moiety not found in rubradirin B5). We here report that acid hydrolysis of rubradirin afforded this fragment which was found to be a nitrosugar we have named L-rubranitrose. L-Rubranitrose is shown to have structure la. It is stereoisomeric with evernitrose, 26,1), found in the unrelated antibiotics, everninomicins B and C. Anomeric Ia, b was separated from the second component of the hydrolytic mixture, acidic rubradirin aglycone, by distribution of the former into the chloroform layer of a 2-phase system which also contained a 5 % Na2CO3 solution. The two anomers were distinguished by C-1 proton signals at 8 4.75 and 8 5.28. After chromatography, the latter was crystallized, mp 150-153°, [a]„ + 127° -> + 86° (c 1, ethanol). Acetylation of the mixture in acetic anhydride and pyridine afforded anomeric 1-acetyl rubranitrose, from which we were able to crystallize the opposite anomer, 3a, mp 7476°, [x]„ +36° (c 0.4, ethanol). The 1H NMR signal of its C-1 proton showed that this was the anomeric configuration in the rubradirin glycoside (see Table 1). A further analysis of the proton spectra of 1 and 3 accounted for all of the carbons and hydrogens in three segments,

Loraine M. Pschigoda

Papers

Comparative biological and biochemical effects of nogalamycin and its analogs on L1210 leukemia.

An x-ray study of aerothionin from aplysina fistularis (pallas)

Structure of rubradirin

The chemistry of rubradirin. II. Rubranitrose.

Nogalamycin. Stereochemistry and chemical modification