16,17-dihydroxycyclooctatin, a new diterpene from Streptomyces sp. LZ35

Galbonolides from Streptomyces sp. SR107

“…To facilitate the isolation of minor components such as galbonolide derivatives, 4 gene clusters involved in the biosynthesis of hygrocin (hgc), elaiophylin (elp), nigericin (nig), and geldanamycin (gdm) were deleted to afford a clean background mutant strain LZ35ΔhgcAΔelpAΔnigAΔgdmAI (LZ35Δheng, SR107) of Streptomyces sp. LZ35 [13].…”

“…The 13 C NMR spectrum of 4 displayed 21 carbon signals for five methyls, five methylenes (one oxygenated carbon at  C 65.0 and one olefinic carbon at  C 114.8), four methines (two olefinic carbons at  C 141.5 and 127.9), and seven quaternary carbons (including one ester carbonyl at  C 173.3). The 1 H and 13 C NMR spectra of 4 clearly showed a typical galbonolide structure (Table 1). Comparing the 1 H NMR data with those of galbonolide B [11][12], the only difference was that the proton at  Co. Ltd., China).…”

“…According to the HMBC correlations from the methyl protons of H-15, H-2a, H-8a, H-12a and the methylene protons H-10a and H-14 to corresponding carbons (Figure 2), a long-chain from C-1 to C-15 was established. The relatively lowerfield resonance of H-13 (at  H 5.23) and the 1 H- 13 C long-range correlations from H-13 to C-1 suggested that 1 was a 14-membered macrolide. The relative configurations at C-2, C-8 and C-13 of 3 were determined to be the same as those of galbonolide B by the NOE correlations of H-5/H-12a, H-2, H-11, and H-11/H-12a, H-13, and H-2/H-8a, H-5.…”

“…a Recorded in CDCl 3 , 1 H NMR at 600 MHz,13 C NMR at 150 MHz. b Recorded in CD 3 COCD 3 , 1 H NMR at 400 MHz,13 C NMR at 100 MHz.…”

“…The 13 C NMR (DEPT) spectrum of 3 accounted for 20 carbons including four methyls, four methylenes (one olefinic carbons), six methine (three olefinic carbons and one oxygenated), and six quaternary C-atoms (one ester carbonyl at  C 171.2, one ketones at  C 189.6). The direct connectivity between protons and carbons was established from the HSQC spectrum; the tabulated 13 C and 1 H NMR spectral data for 3 are shown in Table 1. The structure was established by careful analysis of HMBC and COSY correlations (Figure 2).…”