Structure of oxazolomycin, a novel β-lactone antibiotic

Total Synthesis of Biologically Active Natural Products Based on Highly Selective Synthetic Methodologies

“…Finally, the synthesis of salinosporamide (73) was achieved from 95 in a six-step sequence involving the removal of the p-methoxybenzyl group, reductive opening of the cyclic acetal, (Me 2 AlTeMe) 2 -promoted dealkylative cleavage 101) of the methyl ester, β-lactonization, and chlorination. 82,84) Oxazolomycin A and neooxazolomycin, originally isolated from a strain of Streptomyces by the group of Uemura in 1985, 102,103) constitute a family of structurally unique oxazole polyene lactam-lactone antibiotics together with seven other congeners identified to date (Chart 21). These oxazolomycins exhibit wide-ranging, potent inhibitory activity against Gram-positive bacteria and antiviral activity against vaccinia, herpes simplex type I, and influenza A (WSN; H1N1) as well as in vivo (74) had long been the only achievement until we have recently reported the syntheses of neooxazolomycin (74) 82) and oxazolomycin A (75).…”

Total synthesis of antibiotics: recent achievements, limitations, and perspectives

“…strain KBFP-2025 (Mori, 1985;Takahashi, 1985) and later rediscovered in the fermentation broth of Streptomyces albus strain JA3453. (Gräfe, 1992) Their molecules characterized by a densely functionalized -lactam/-lactone spirocycle, which is linked through a short polyketide fragment, two polyenic tethers and an amide bond to the unsubstiuted oxazole ring.…”

A new 16-membered tetraene macrolide JBIR-100 from a newly identified Streptomyces species

“…A search in AntiBase [61] using the above spectral data of compound 262 resulted in lajollamycin [394] as the sole known structure (Table 36). The identity with lajolamycin (262) [395] 16-methyloxazolomycin [396] (265), and triedimycin B6 (266) were previously isolated from bacteria. Lajollamycin (262) was isolated from the marine actinomycete Streptomyces nodosus (NPS007994); it is a potent antimicrobial agent against both against drug-sensitive and -resistant Gram-positive bacteria, as well as an in vitro inhibitor of B16-F10 tumor cells [394] .…”