Structure-activity relationship studies of maitotoxin (MTX), a marine natural product produced by an epiphytic dinoflagellate, were conducted using chemically synthesized model compounds corresponding to the partial structures of MTX. Both enantiomers of the LMNO ring system were synthesized via aldol reaction of the LM ring aldehyde and the NO ring ketone. These fragments were derived from a common cis-fused pyranopyran intermediate prepared through a sequence involving Nozaki-Hiyama-Kishi reaction, intramolecular oxa-Michael addition, and Pummerer rearrangement. The NOPQR(S) ring system, in which the original seven-membered S ring was substituted with a six-membered ring, was also synthesized through the coupling of the QR(S) ring alkyne and the NO ring aldehyde and the construction of the P ring via 1,4-reduction, dehydration, and hydroboration. The inhibitory activities of the synthetic specimens against MTX-induced Ca influx were evaluated. The LMNO ring system and its enantiomer induced 36 and 18% inhibition, respectively, at 300 μM, whereas the NOPQR(S) ring system elicited no inhibitory activity.
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http://dx.doi.org/10.1021/acs.joc.7b01658 | DOI Listing |
Bioorg Chem
December 2024
Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address:
In this study, novel 2-styrylquinoline derivatives possessing a planar aromatic system and a flexible side chain with an amino substituent were designed and synthesized as DNA-intercalating antitumor agents. The cytotoxic activity of the synthesized compounds was evaluated against four cancer cell lines including MCF-7 (breast cancer cells), A549 (lung epithelial cancer cells), HCT116 (colon cancer cells) and normal cell line L929 (mouse fibroblast cell line). The results displayed that the anti-cancer activity of the target quinolines is sensitive to the lipophilic nature of the C-6 and C-7 quinoline substituents.
View Article and Find Full Text PDFEur J Med Chem
December 2024
School of Pharmacy and Food Engineering, Wuyi University, 529020, Jiangmen, China; Department of Chemistry, University of Liverpool, L69 7ZD, Liverpool, UK. Electronic address:
Aryl quinolone derivatives can target the cytochrome bc complex of Plasmodium falciparum, exhibiting excellent in vitro and in vivo antimalarial activity. However, their clinical development has been hindered due to their poor aqueous solubility profiles. In this study, a series of bioisosteres containing saturated heterocycles fused to a 4-pyridone ring were designed to replace the inherently poorly soluble quinolone core in antimalarial quinolones with the aim to reduce π-π stacking interactions in the crystal packing solid state, and a synthetic route was developed to prepare these alternative core derivatives.
View Article and Find Full Text PDFChaos
January 2025
Department of Physics, Tohoku University, Sendai 980-8578, Japan.
An Ott-Antonsen reduced M-population of Kuramoto-Sakaguchi oscillators is investigated, focusing on the influence of the phase-lag parameter α on the collective dynamics. For oscillator populations coupled on a ring, we obtained a wide variety of spatiotemporal patterns, including coherent states, traveling waves, partially synchronized states, modulated states, and incoherent states. Back-and-forth transitions between these states are found, which suggest metastability.
View Article and Find Full Text PDFCalcif Tissue Int
January 2025
Jerry L. Pettis Memorial VA Medical Center, VA Loma Linda Healthcare System, Loma Linda, CA, USA.
This study assessed the feasibility of miR17 ~ 92-based antiresorptive strategy by determining the effects of conditional transgenic (cTG) overexpression of miR17 ~ 92 in myeloid cells on bone and osteoclasts. Osteoclasts of male and female cTG mutant mice each showed 3- to fivefold overexpression of miR17 ~ 92 cluster genes compared to those of age- and sex-matched wildtype (WT) littermates. Male but not female cTG mutant mice had more trabecular and cortical bones as well as lower bone resorption reflected by reduction in osteoclast number and resorbing surface.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
State Key Laboratory of Particle Detection and Electronics, Beijing 100049, Hefei 230026, People's Republic of China.
We report the precise measurements of the cross section of e^{+}e^{-}→hadrons at center-of-mass energies from 3.645 to 3.871 GeV.
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