Three new dimeric 3-alkyl pyridinium alkaloids, named haliclocyclamines A-C (1-3), were isolated together with five known congeners, cyclostellettamines A (4), B (5), C (6), E (7), and F (8), from the Indonesian marine sponge Haliclona sp. The structures of 1-3 were assigned based on their spectroscopic data (1D and 2D NMR, HRFABMS, ESIMS/MS, UV, and IR). Compounds 1-8 exhibited antimicrobial activities against Mycobacterium smegmatis with inhibition zones of 17, 10, 13, 14, 8, 8, 12, and 12mm, respectively, at 10μg/disc. Compounds 3 and 8 also modestly inhibited the activity of vaccinia H-1-related phosphatase (VHR), a dual-specificity phosphatase, at 17-18μM.
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http://dx.doi.org/10.1016/j.bmcl.2017.05.067 | DOI Listing |
Org Biomol Chem
December 2023
Área de Química Orgánica, Research Centre CIAIMBITAL, Universidad de Almería, Carretera de Sacramento s/n, Almería, 04120, Spain.
The tautomerism of a series of 5-alkyl substituted 3-(2-pyridyl)-1,2,4-triazoles in DMSO--containing water has been investigated by H, C and N NMR spectroscopy. The populations of the three possible regioisomers in the tautomeric equilibrium (A [3-alkyl-5-(2-pyridyl)-1], B [5-alkyl-3-(2-pyridyl)-1] and C [5-alkyl-3-(2-pyridyl)-4]) were determined. Isomers A (17-40%) and B (54-79%) are the major components and their ratio is insensitive to the substitution pattern, except for the unsubstituted and the methoxymethyl substituted derivatives.
View Article and Find Full Text PDFMar Drugs
July 2020
Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, P.O. Box 80260, Jeddah 21589, Saudi Arabia.
The curiosity and attention that researchers have devoted to alkaloids are due to their bioactivities, structural diversity, and intriguing chemistry. Marine-derived macrocyclic alkaloids (MDMAs) are considered to be a potential source of drugs. Trabectedin, a tetrahydroisoquinoline derivative, has been approved for the treatment of metastatic soft tissue sarcoma and ovarian cancers.
View Article and Find Full Text PDFBioorg Med Chem Lett
August 2017
Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, Sendai 981-8558, Japan.
Three new dimeric 3-alkyl pyridinium alkaloids, named haliclocyclamines A-C (1-3), were isolated together with five known congeners, cyclostellettamines A (4), B (5), C (6), E (7), and F (8), from the Indonesian marine sponge Haliclona sp. The structures of 1-3 were assigned based on their spectroscopic data (1D and 2D NMR, HRFABMS, ESIMS/MS, UV, and IR). Compounds 1-8 exhibited antimicrobial activities against Mycobacterium smegmatis with inhibition zones of 17, 10, 13, 14, 8, 8, 12, and 12mm, respectively, at 10μg/disc.
View Article and Find Full Text PDFMar Drugs
February 2017
Center for Biomedicine, European Academy of Bolzano/Bozen, Bolzano 39100, Italy.
Twenty-eight sponge specimens were collected at a shallow water hydrothermal vent site north of Iceland. Extracts were prepared and tested in vitro for cytotoxic activity, and eight of them were shown to be cytotoxic. A mass spectrometry (MS)-based metabolomics approach was used to determine the chemical composition of the extracts.
View Article and Find Full Text PDFJ Photochem Photobiol B
August 2016
Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, Gakuen-Kibanadai, Miyazaki 889-2192, Japan.
As singlet-oxygen ((1)O2) sensitizer, water-soluble P-porphyrins (1) were prepared by the modification of axial ligands of tetraphenylporphyrinatophosphorus by N-alkyl-pyridinium group to give bis[3-(1-alkyl-4-pyridinio)propoxo]tetraphenylporphyrinatophosphorus(V) (alkyl=hexyl (1a) and butyl (1b)) and bis[5-(3-alkyl-1-pyridinio)-3-oxapentyloxo] tetraphenylporphyrinatophosphorus(V) (alkyl=hexyl (1c), butyl (1d), and ethyl (1e)). The quantum yields (ΦΔ) for the formation of (1)O2 were extremely high (e.g.
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