Natural products (a.k.a. secondary metabolites) are produced by living organisms that are not essential for their growth, development, or reproduction, but may play a role in their survival or adaptability in nature. Many secondary metabolites isolated from plants and microbes have found use as molecular probes, drug leads, or medicine...
Pseudomonas fluorescens NZI7 was first isolated from a New Zealand mushroom farm in 2001. This Gram-negative bacteria can cause brown blotch disease in the basidiomycete mushroom Agaricus bisporus. P. fluorescens NZI7 can also repel grazing by the nematode Caenorhabditis elegans, a natural predator of P. fluorescens NZI7. Potentially implicated in...
Ribomimetic natural products have long been known for their important biological activities. Structurally, they contain a densely functionalized cyclopentane unit that resembles ribose. Pactamycin, the prominent member of this class of natural products, is a potent protein synthesis inhibitor produced by the soil bacterium Streptomyces pactum. In pactamycin, the aminocyclopentitol...
Among the myriad of natural products are pseudosugar-containing secondary metabolites, e.g., the C7-pseudosugar-containing oligosaccharide acarbose, the C6- pseudosugar-containing aminoglycoside antibiotics, and the five-membered ring pseudosugar-containing antibiotic pactamycin. The C7-pseudosugars are normally derived from sedoheptulose 7-phosphate catalyzed by a family of enzymes called sedoheptulose 7-phosphate cyclases (SH7PCs). This family of enzymes...
Sugar phosphate cyclases (SPCs) are enzymes involved in the biosynthesis of many important natural products. SPCs form a unique cyclitol during the early steps in the biosynthesis of many natural products. These natural products include rifamycin, which is chemically modified to rifampicin and used clinically as an antituberculosis drug, and...
Sunscreen products are used worldwide to protect the skin from ultraviolet radiation. However, some of the ingredients used in sunscreen products are fatal to coral reefs especially in areas where tourism is a large part of the economy. In this study, we explored a synthetic route to produce 4-deoxygadusol, which...
Pactamycin, produced by the soil bacterium Streptomyces pactum, is a cytotoxic antibiotic that belongs to the aminocyclitol family of natural products. This antibiotic has shown various forms of biological activity, including antibacterial, antifungal, antimalarial, and antitumor activities. Despite its outstanding biological activity, the mode of formation of its pharmacophore (the...
Pactamycin, first reported in 1962, is a potent antitumor antibiotic produced by the soil bacterium Streptomyces pactum. Structurally, it contains a cyclopentitol core unit, a 3-aminoacetophenone (3AAP), a 6-methylsalicylic acid (6-MSA), and a N,N-dimethyl urea. The aminocyclopentitol ring is derived from glucose, possibly via N-acetyl glucosamine (GlcNAc), the 3-aminoacetophenone (3AAP)...
Pactamycin, a potent antitumor antibiotic produced by the soil bacterium Streptomycespactum, is a structurally unique aminocyclopentitol-containing natural product. Itconsists of a highly functionalized cyclopentitol core unit, two aromatic rings [3-aminoacetophenone (3AAP) and 6-methylsalicylic acid (6MSA)], and a 1,1-dimethylurea moiety. Despite its potent biological activity, the development of thisantibiotic was hampered...
The discovery of new antibiotics reached its peak during the golden era of antibiotics in the mid 20th century and continued to thrive until the 1980s. However, after more than 50 years of fruitful exploration and exploitation of microbial natural products the discovery rate of new antibiotics has dropped drastically...