The oxazolomycin family: a review of current knowledge

Abstract

Oxazolomycin A and neooxazolomycin were firstly isolated in 1985 by the group of Uemura et al. from the Streptomyces sp. bacteria.

Oxazolomycins produced by Streptomyces glaucus and their cytotoxic activity

“…10 The stereochemistry of characteristic oxazolomycins had been determined through X-ray crystallography and total synthesis experiments. 2,[21][22][23][24][25][26][27] The stereochemistry of the spiro b-lactone-g-lactam unit in natural oxazolomycins possessed 2R,3S,15S-conguration. [21][22][23][24][25][26][27] The congurations of the chirality carbons on the aliphatic chain of compound 1 were deduced as 4S,6R,7R,3 0 R based on the almost same 13 C NMR data of 1 with those of oxazolomycin A, lajollamycin, and synthesized oxazolomycins with the same side chain fragment.…”

“…1,2 The common structural characteristics of this class of compounds contain a unique spiro fused b-lactone-g-lactam core and a terminal oxazole ring, and these two structural moieties are linked by a triene and an (E,E)-diene aliphatic chain. 1,2 Natural sources of oxazolomycins are extremely rare, and only een members, including neooxazolomycin, 3 oxazolomycins A, B, C, 4,5 curromycins A, B (also known as triedimycins A, B), 6,7 16-methyl oxazolomycin, 8,9 KSM-2690 B, KSM-2690 C, 10 lajollamycins, 11,12 bisoxazolomycin A, and oxazolomycin A2 (ref. 13) have been found up to this point, and all of them were isolated from Streptomyces spp.…”

Asymmetric Total Synthesis of Oxazolomycins B and C

“…[5] While neooxazolomycin (2) has a bicyclic γ-lactone-γ-lactam core, the other members of the oxazolomycin family commonly have a spiro-β-lactone pyroglutamate core and exhibit wide-ranging antibacterial and antiviral activities as well as in vivo antitumor activity. [5,6] Their interesting bioactivities have been proposed to arise from their protonophoric properties [7] and structural similarity with the pharmacophore of salinosporamide A and omuralide. [8] Because of their structural complexity and potent biological activities, considerable efforts have been made toward synthesis.…”

“…[8] Because of their structural complexity and potent biological activities, considerable efforts have been made toward synthesis. [5,9,10] However, only oxazolomycin A (1), neooxazolomycin (2), and lajollamycin B (8) have been successfully synthesized thus far. [10] Kende et al achieved the first total synthesis of neooxazolomycin in 1990.…”

“…bacteria in 1985, [1] 15 members of this family, including oxazolomycins B ( 3 ) and C ( 4 ), [2] curromycins A ( 5 ) and B ( 6 ), [3] and lajollamycins ( 7 – 10 ), [4] have been identified to date [5] . While neooxazolomycin ( 2 ) has a bicyclic γ‐lactone‐γ‐lactam core, the other members of the oxazolomycin family commonly have a spiro‐β‐lactone pyroglutamate core and exhibit wide‐ranging antibacterial and antiviral activities as well as in vivo antitumor activity [5,6] . Their interesting bioactivities have been proposed to arise from their protonophoric properties [7] and structural similarity with the pharmacophore of salinosporamide A and omuralide [8] …”