Two new phenylpropanoids (1-2), one new nor-monoterpenoid alkaloid (3), one new monoterpene alkaloid (4), together with nine known compounds (5-13) were obtained from the branches of Alstonia scholaris. The structures of the undescribed compounds were determined by extensive spectroscopic analysis. Alkaloid 3 represented the first example of C-4 methylated nor-monoterpenoid alkaloids. A possible biosynthetic pathway for this new type of monoterpene alkaloids was proposed. All the isolates were evaluated for vasorelaxant activity against phenylephrine-induced contraction of rat mesenteric arteries. Compounds 1, 4, 9, 12, and 13 showed significant vasorelaxant activity with relaxation rates above 90% at 200 μM and exhibited moderate vasorelaxant activity with IC values ranging from 41.87 to 93.30 μM by further studies. It was the first report on the potential vasorelaxant activity of monoterpene alkaloids. Monoterpene alkaloids 3 and 4 may be served as the potential lead compounds for the discovery of vasodilators, due to their simple and optimizable structures.
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http://dx.doi.org/10.1016/j.fitote.2022.105143 | DOI Listing |
Magn Reson Chem
January 2025
A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia.
The complete H and C NMR assignments of a trimeric vindoline together with its individual components, dimeric vindolicine and monomeric vindoline, are performed based on a thorough analysis of the ROESY, COSY, HSQC, and HMBC spectra in combination with the state-of-the-art quantum-chemical calculations. A spatial structure of vindoline trimer is determined by means of computational conformational analysis in combination with the probability distribution map of its basic conformers. On the example of monoterpene indole alkaloid, the trimer vindoline, the present study reveals the power of modern computational NMR to perform identification and stereochemical studies of large natural compounds with some limitations, which may arise in the quantum chemical computing workflow.
View Article and Find Full Text PDFPol J Vet Sci
September 2024
Department of Biology and Fish Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 12, 20-033 Lublin, Poland.
The aim of this study was to investigate the activity of thymoquinone (TQ), carvacrol (CAR) and thymol (TYM) against multi-drug resistant nontuberculous mycobacteria (MDR-NTM), alone and in combination with berberine (BER). Antimicrobial activity was first evaluated at concentrations from 8 to 512 μg/mL. Each of the compounds tested exhibited good activity against nontuberculous mycobacteria (NTM) isolated from fish, with MIC values of 32-128 μg/mL.
View Article and Find Full Text PDFMonoterpene indole alkaloids (MIAs) are a large, structurally diverse class of bioactive natural products. These compounds are biosynthetically derived from a stereoselective Pictet-Spengler condensation that generates a tetrahydro-β-carboline scaffold characterized by a 3 stereocenter. However, a subset of MIAs contain a non-canonical 3 stereocenter.
View Article and Find Full Text PDFPlant Physiol Biochem
December 2024
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610213, China. Electronic address:
Cytochrome P450 enzymes (CYPs), the members of the largest superfamily of enzymes in plant kingdom, catalyze a variety of functional group transformations involved in metabolite biosynthesis, end-product derivatization, and exogeneous molecule detoxification. Nevertheless, CYPs' functional characterization and practically industrial application have been largely encumbered by their critical dependency on the reducing equivalent for the catalytic cycling, driven by the tedious electron relay mediated by CYP reductase (CPR). Here, we report a photoinduced electron transfer system that initiates and sustains the CYP-catalyzed reaction cycling.
View Article and Find Full Text PDFArq Bras Cardiol
November 2024
Universidade Federal de São Paulo, São Paulo, SP - Brasil.
Background: D-limonene (D-L) is the major monocyclic monoterpene in citrus plants with anti-inflammatory properties. Pulmonary hypertension (PH) can cause right heart dysfunction and increases the risk of death, partially due to inflammatory response in the heart.
Objective: To evaluate the possible protective effect of D-L on cardiac function in a rat model of monocrotaline-induced PH (MCT-PH).
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