9 article(s) from Oku, Naoya
Graphical Abstract
Figure 1: Structures of tenacibactins K–M (1–3).
Figure 2: Key 2D-NMR correlations for 1–3.
Figure 3: (a) Partial 1H NMR spectra of 1 at 25 and 50 °C in DMSO-d6; (b) magnified HMBC spectrum of 1 at 25 ...
Figure 4: MS/MS spectrum of 1 acquired on a quadrupole time-of-flight mass spectrometer in the negative ion m...
Scheme 1: MS/MS fragmentation pathway for compound 1.
Graphical Abstract
Figure 1: Structures of 1–6.
Figure 2: COSY, key HMBC and NOESY correlations of 1–5.
Figure 3: 1H NMR spectra and partial chemical shift assignments for MPA esters 4'a–4'd. Upper: (R)-MPA acylat...
Figure 4: Chiral phase HPLC analysis of methyl ester 4'. Italicized numbers indicate peak areas.
Figure 5: COSY and key HMBC correlations observed for 6.
Figure 6: ΔδH(S-R) values in ppm calculated from PGME amides 6a and 6b.
Figure 7: Selected examples of the related compounds derived from the strains in the genus Streptomyces (a) a...
Graphical Abstract
Figure 1: Structure of the nocarimidazoles 1–4 and the bulbimidazoles 5–7.
Figure 2: COSY and key HMBC correlations for 1 and 2.
Scheme 1: Synthesis of the model compounds 8 and 9.
Figure 3: 1JC,H coupling constant for the imidazole ring of the natural products 1 and 5 and the model compou...
Figure 4: Determination of the absolute configuration of 1 (a), 4 (b), and 5 (c) by the Ohrui–Akasaka method.
Figure 5: Stereochemical diversity of the anteiso-chain chirality in microbial metabolites.
Graphical Abstract
Figure 1: Structures of the compounds 1–5.
Figure 2: COSY (bold lines) and selected HMBC correlations (arrows) for 1–4.
Figure 3: a) Distribution of positive (red) and negative (blue) Δδ(S − R) values (in ppm) calculated from the ...
Graphical Abstract
Figure 1: Structures of compounds 1–5.
Figure 2: COSY-deduced spin-system (bold lines) and key HMBC correlations (arrows) for compound 1, and struct...
Figure 3: Extinction of luminol chemiluminescence by 1.
Graphical Abstract
Figure 1: Structures of pseudosporamide (1) and pseudosporamicins A–C (2–4).
Figure 2: COSY, key HMBC and ROESY correlations of pseudosporamide (1).
Figure 3: 1H NMR ΔδS−R values for PGME amides 5a and 5b obtained from compound 1.
Figure 4: The opposite axial chirality around the biaryl C-6–C-7'' bond influenced by the C-2 configuration i...
Figure 5: The experimental and calculated ECD spectra in MeCN.
Figure 6: COSY, key HMBC and NOESY correlations of compound 2.
Figure 7: NOESY correlations for the spiroacetal moiety of compound 2.
Figure 8: Selected examples of oligomycin-class metabolites from actinomycetes.
Graphical Abstract
Figure 1: Structures of (6E,8Z)- and (6E,8E)-5-oxo-6,8-tetradecadienoic acids (1 and 2).
Figure 2: COSY and key HMBC correlations for 1 and 2.
Figure 3: Spin system simulation for the C8–C9 double bond of 2.
Figure 4: Natural keto fatty acids of various origins.
Figure 5: PPAR activation by 1 and 2.
Graphical Abstract
Figure 1: Structures of compounds 1–8.
Figure 2: Key COSY (bold line) and HMBC (arrow) correlations for 3.
Figure 3: Referential 13C chemical shifts of an allylic carbon in burkholone [14] and haplacutine F [15].
Graphical Abstract
Figure 1: Structure of sacrolide A (1).
Figure 2: Selected COSY (bold lines) and HMBC (arrows) correlations for sacrolide A (1).
Scheme 1: Initial derivatization strategy for the stereochemical analysis of sacrolide A (1).
Scheme 2: Determination of the stereochemistry of sacrolide A (1).
Scheme 3: Plausible biosynthesis of sacrolide A (1).
Figure 3: The effect of sacrolide A (1) on 3Y1 rat fibroblastic cells. (a) Control. (b) 45 min after exposure...
Figure 4: Extracted ion chromatograms for sacrolide A (1) molecular ion at m/z 307 [M – H]− in the LC–MS anal...