Chemistry of Natural Compounds最新文献

A new phenylpropanoid glycoside, named β-(3,4-dihydroxyphenyl)ethyl-O-α-L-rhamnopyranosyl-(1→3)-β-D-(4-O-caffeoyl)-(6-O-benzoyl)glucopyranoside (1), and three known phenylpropanoid glycosides 2–4 were isolated from the endophytic fungus Pestalotiopsis uvicola GMH31 for the first time. Their structures were determined by their comprehensive spectral data and reported references.

Novel dihydrofuran cembrane-type diterpene, 8-epi-8-hydroxyisosarcophytoxid-6-ene (1), along with eight known compounds – 8-hydroxyisosarcophytoxid-6-ene (2), sarcophytonin A (3), isosarcophytoxide (4), (+)-17-hydroxyisosarcophytoxide (5), (2S*,7S*,8S*,11R*,1Z,3E)-7,8:2,16-diepoxycembra-1(15),3,12(20)-trien-11-ol (6), crassmol A (7), (2S,3R,4E,8E)-N-hexadecanoyl-2-amino-4,8-octadecadiene-1,3-diol (8), and sarcomilasterol (9) – were isolated from the soft coral, Sarcophyton sp., collected from the coast of Irijima, Urasoe City, Okinawa Prefecture, Japan. The chemical structures of the isolated compounds were elucidated by the FTIR, NMR, and HR-ESI-MS analyses. The relative stereochemistry of 1 was determined using NOESY. Compounds 1–9 were evaluated for their inhibitory effects on HCT116 cell proliferation. All compounds demonstrated antiproliferative activity at 25 μM, with compound 9 showing the most pronounced effect (IC₅₀ = 10.55 ± 0.68 μM).

In this study, two new benzoazepines (1 and 2), together with five known analogs (3–7) were isolated from the cigar-tobacco-derived endophytic Aspergillus fumigatus. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. All compounds were evaluated for their antibacterial activities against five nitrosobacteria strains Nitrosomonas communis, Nitrosomonas nitrosa, Nitrosospira multiformis, Nitrobacter winogradskyi, and Nitrospira inopinata. Interestingly, compounds 1–7 exhibited notable antibacterial activity with bacteriostatic diameters within the range 13.8 ± 1.9–26.3 ± 2.5 mm against five nitrosobacteria strains, and most of the bacteriostatic diameters are higher than that of positive controls. Owing to the nitrosobacteria having the ability to convert nitrogen components into nitrite in tobacco, and then converting to tobacco-specific nitrosamines (TSNAs), the above compounds have the potential to reduce TSNAs in tobacco by inhibiting nitrosobacteria during the fermentation process of tobacco leaves.

Chemoselective approaches to the synthesis of ester and cyclic acetal derivatives of ecdysteroids with 5-bromovaleric and lipoic acids and aromatic heterocyclic aldehydes were proposed. Chemoselective formation of 2-monoester derivatives (compounds 4–7) or dioxolane adducts (compounds 8–10) occurred during condensation of an ecdysteroid with an acid or aldehyde. Compound 8, which was prepared by acid-catalyzed condensation of 20-hydroxyecdysone with furfuraldehyde, was an analog of the phytoecdysteroid serfurosterone A, which was isolated from the plant Achyranthes bidentata.

The new chromone derivative 1-[(2-methylpropanoyl)chromone]-β-D-glucopyranoside (1) together with eight known compounds (2–9) were isolated from Humulus lupulus (common hops). The structures of the isolated compounds were confirmed by detailed analyses of NMR and HR-ESI-MS data. The glucose fragment in 1 was determined as the D-glucoside based on GC analysis. Compounds 2, 4, and 5 exhibited significant inhibitory activity against diacylglycerol kinase ζ (DGKζ). Compound 5 demonstrated strong inhibition of DGKζ with an IC₅₀ value of 1.60 μM. Molecular docking studies gave important information about the role of the galloyl group in DGKζ inhibition.