Structure of cyclizidine (antibiotic M146791) : X-ray crystal structure of an indolizidinediol metabolite bearing a unique cyclopropyl side-chain

A new cyclizidine analog—JBIR-102—from Saccharopolyspora sp. RL78 isolated from mangrove soil

“…The structure of 2 was confirmed with NMR spectroscopic data ( Table 1). The results imply that the NMR assignments of 2 by Freer et al 16 are incorrect, and our data are identical to those reported by Leeper et 18 who proposed the absolute configuration of 2 by total synthesis of ent-cyclizidine. Thus, the absolute configuration of 1 was deduced to be the same as that of 2 ( Figure 1a).…”

“…Thus, the absolute configuration of 1 was deduced to be the same as that of 2 ( Figure 1a). Although an acetylcyclizidine has been reported, 16 this is the first report of an isobutyl ester derivative of cyclizidine.…”

Identification of the Polyketide Biosynthetic Machinery for the Indolizidine Alkaloid Cyclizidine

“…3 Surprisingly, only cyclizidine (CLD) and two congeners, JBIR-102 and indolizomycin, are known to be of bacterial origin. 4 In particular, CLD was produced by Streptomyces NCIB 11649, and structural analysis revealed that the indolizidine core of CLD is substituted with two hydroxyl moieties (C9 and C10), a C12/C13 epoxide, and a monosubstituted cyclopropyl trans -dienic subunit at C8 (Figure 1). 4c, 5 CLD showed non-selective immunostimulatory properties and cytotoxic activities against human malignant pleural mesothelioma ACC-MESO-1 cells and cervical carcinoma HeLa cells with IC 50 values of 32 µM and 16 µM, respectively.…”

Biosynthesis of the indolizidine alkaloid cyclizidine: incorporation of singly and doubly labelled precursors

“…Its isolation and structure determination by NMR spectroscopy and X-ray crystallography were first reported in 1982 (1). Intriguingly, a very similar indolizidine alkaloid, indolizomycin 2, was subsequently isolated from a strain created by protoplast fusion of two different Streptomyces species, neither of which produced any similar compounds (2).…”