Neomacrophorin X, a [4.4.3]Propellane-Type Meroterpenoid from Trichoderma sp. 1212-03

Abstract

Neomacrophorin X (1) was isolated from Trichoderma sp. 1212-03. Heteronuclear multiple bond correlation (HMBC) spectral analysis indicated a unique [4.4.3]propellane framework, which was verified by the H andC chemical shift calculations based on density functional theory (DFT) and subsequent comparison with experimental data obtained in CDCl. The DFT-based electronic circular dichroism (ECD) calculations were effective in not only determining the absolute configuration but also confirming the relative structure. The predominant conformation of 1 was found to be solvent-dependent, with different conformations presenting different NMR and ECD profiles. Introduction of J-based analysis with a J-resolved HMBC aided in this investigation. This conformational alternation was reproduced by considering the solvation with the SM5.4 model in the calculation, although it was not sufficiently quantitative. Although the calculations without solvent effects suggested a conformer that satisfies the spectral profiles in CDCl, postcalculations with the SM5.4 solvation protocol stabilized the second major conformer, which reproduces the NMR and ECD profiles in polar solvents. Neomacrophorin X (1) is assumed to be biosynthesized by a coupling between the reduced form of anthraquinone and a neomacrophorin derivative. This hypothesis was supported experimentally by the isolation of pachybasin and chrysophanol, as well as acyclic premacrophorin (2), from the same fungus. Some biological properties of 1 are described.

Isolation of Peribysins O, P, and Q from Periconia macrospinosa KT3863 and Configurational Reinvestigation of Peribysin E Diacetate from Periconia byssoides OUPS-N133

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Unraveling Plant Natural Chemical Diversity for Drug Discovery Purposes

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Identification and Total Synthesis of Two Previously Unreported Odd-Chain Bis-Methylene-Interrupted Fatty Acids with a Terminal Olefin that Activate Protein Phosphatase, Mg2+/Mn2+-Dependent 1A (PPM1A) in Ovaries of the Limpet Cellana toreuma

“…HL60 cells (RCB0041, RIKEN BioResource Center, Tsukuba, Japan) were grown in RPMI 1640 medium supplemented with 10% heat-inactivated FBS (Biowest SAS, Nuaillé, France) and penicillin (50 units/mL)-streptomycin (50 µg/mL) (Gibco Corp., Carlsbad, CA, USA) in a humidified atmosphere at 37 °C under 5% CO 2 . Cytotoxicity of FAs against HL60 cells was assayed by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) (Dojindo Lab., Kumamoto, Japan) method as described previously [28]. Camptothecin was used as a positive control for HL60 cells with an IC 50 value of 23.6 nM.…”