Phenolics antibiotic properties

The addition of smoke to meat also imparts antioxidant properties (42). This has also been shown on application of smoke to fatty fishes (43). Porter ( 6) has reviewed the antioxidant properties of smoke and concluded that a number of phenolic compounds are responsible. Several of these phenolic components, including phenol, guaiacol and catechol, are not only potent antioxidants but also have antibiotic activity. 

The humulones 23a-d have been known for many years, but they can still be considered as a topical family of natural products (Figure 8). Found in hop resins and brewing hops, these natural ortho-quinols aroused early interest because of their antibiotic and tuberculostatic properties. Oxidative dearomatizing hydroxylation of their phenolic parents 24a-d was used in their synthesis [1]. 

As in the case of antibiotics, this group of substrates may be readily functionalized by aminomethylation due to the presence of phenolic rings, which permit preparation of pnxlucts with basic properties. Flavonoids such as rutin " and silymarin pos.sess two hydroxylated aromatic nuclei, both of which may undergo aminomethylation, thus preventing the clear detection of the site of attack however, the products obtained usually maintain the pharmacological activity of the initial material. In the case of arctigenin, aminomethylation can lake place only in the ortho position with respect to the hydroxy group, and chrysin (487, Fig. 180) reacts at position 8. 

Resorcinol has antiseptic properties similar to those of phenol, and was used to dress minor wounds before the era of antibiotics. It has antifungal properties, and was also applied on chancroids and syphilitic ulcers. Its bactericidal effect is 30% of that of phenol. 

Polyphenolic compounds occur widely distributed in nature and may possess a variety of interesting biological properties, e. g. antibiotic, antiviral and antitumor activity. The synthesis and further elaboration of these compounds often requires the selective protection or deprotection of specific phenolic hydroxy groups. To achieve this goal, the methods highlighted above for the various aliphatic polyols can also be applied successfully. 

Physical Properties. Oligosaccharide antibiotics are colorless solids, which are often crystalline and have defined melting points and optical rotations, [a]D (see Tables 1 and 2). They have a characteristic uv spectrum resulting from the phenolic ester residue, Amax 285 nm (s ca 22), which shifts... 

In contrast to the biocatalytic potential of the MTs, which already have been applied in enzyme cascades, that of a number of enzymes with exceptional substrate specificity or catalytic properties has not been fiiUy exploited. This is especially tme for C-methyltransferases, which catalyze the challenging Friedel-Crafts methylation of phenols [102], tyrosine, or coumarine derivatives (M. Tengg et al, unpublished results), or antibiotics such as actinomycin [103]. 

---