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1.
Nat Prod Res ; : 1-11, 2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36148610

RESUMO

Two new glycosylflavones, 6''-O-acetyl-8-C-ß-D-galactopyranosylchrysoeriol (1) and 8-C-ß-D-galactopyranosylchrysoeriol (2) were isolated from the methanol extract of the leaves of Ochna afzelii Oliv., along with four known compounds namely 8-C-ß-D-galactopyranosylapigenin (3), ochnaflavone (4), sitosterol-3-O-ß-D-glucopyranoside (5) and D-mannitol (6). Isolation was performed chromatographically and the structures of the purified compounds were elucidated by analyzing their spectroscopic and mass spectrometric data. The antibacterial activity of extract, fractions, and compounds 1 - 4 was evaluated using broth microdilution method against Gram-positive and Gram-negative bacteria while the antioxidant capacity was performed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) methods. The new flavones (1 and 2) displayed moderate antibacterial activities (MIC = 32 - 64 µg/mL) and weak antioxidant properties.

2.
Nat Prod Res ; 36(2): 515-522, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32627596

RESUMO

A new ceramide is being reported herein together with six known compounds from the methanol extract of the leaves of Lannea schimperi (Hochst. ex A.Rich.) Engl. The metabolites were obtained through repeated open column chromatography and were characterized by spectroscopic and spectrometric techniques. The radical-scavenging activity of the crude extract and isolated compounds was evaluated using the DPPH radical. The obtained results suggest the studied species as prominent candidate to fight reactive oxygen species (ROS).


Assuntos
Anacardiaceae , Ceramidas , Antioxidantes , Metanol , Extratos Vegetais , Folhas de Planta
3.
Z Naturforsch C J Biosci ; 77(3-4): 125-131, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-34787980

RESUMO

The antiplasmodium assay-guided investigation of the roots, stem bark, and leaves of Persea americana Mill. led to the isolation of a new fatty alcohol, perseatriol (1), along with six known compounds (2-7). Their structures were elucidated based on the analysis of their NMR and MS data. All crude extracts and fractions exhibited good antiplasmodial activity on Plasmoduim falciparum 3D7 with IC50 values ranging from 0.76 to 10.5 µg/mL; they also displayed cytotoxicity against HeLa cells with low selectivity indexes (SIs). A preliminary Plasmodium lactate dehydrogenase (pLDH) assay was also performed on the isolated compounds. 9,9'-Di-O-feruloyl-5,5'-dimethoxysecoisolariciresinol (4) turned out to be non-toxic and displayed the best activities on P. falciparum with an IC50 value of 0.05 µM, comparable to the reference drug chloroquine with an IC50 value of 0.03 µM. Furthermore, besides compound 4, this work reports the first isolation of lutein (2) and scopoletin (3) from P. americana. The crude extracts of roots, stem bark, and leaves of P. americana, their fractions and compounds completely suppressed the growth of P. falciparum. The observed activity supports the use of P. americana in folk medicine for the treatment of malaria.


Assuntos
Antimaláricos , Lauraceae , Persea , Antimaláricos/química , Antimaláricos/farmacologia , Células HeLa , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plasmodium falciparum
4.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443305

RESUMO

The local botanical Imperata cylindrica in Cameroon was investigated for its antibacterial potency. The methanol extract afforded a total of seven compounds, including five hitherto unreported compounds comprising three flavonoids (1-3) and two C-15 isoprenoid analogues (4 and 5) together with known derivatives (6 and 7). The novelty of the flavonoids was related to the presence of both methyl and prenyl groups. The potential origin of the methyl in the flavonoids is discussed, as well as the chemophenetic significance of our findings. Isolation was performed over repeated silica gel and Sephadex LH-20 column chromatography and the structures were elucidated by (NMR and MS). The crude methanol extract and isolated compounds showed considerable antibacterial potency against a panel of multi-drug resistant (MDR) bacterial strains. The best MIC values were obtained with compound (2) against S. aureus ATCC 25923 (32 µg/mL) and MRSA1 (16 µg/mL).


Assuntos
Antibacterianos/farmacologia , Flavonoides/farmacologia , Poaceae/química , Prenilação , Terpenos/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Flavonoides/química , Flavonoides/isolamento & purificação , Testes de Sensibilidade Microbiana , Espectroscopia de Prótons por Ressonância Magnética , Terpenos/química , Terpenos/isolamento & purificação
5.
Molecules ; 26(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34443397

RESUMO

A total of nine sesquiterpenoid lactones together with phenolic compounds and other terpenes were identified from the crude methanol extract of Elephantopus mollis Kunth. Compounds were isolated using different chromatographic techniques and their structures were determined by NMR and IR spectroscopy as well as mass spectrometry. The structures of some detected compounds were assigned based on LC-ToF-ESI-MS screening of main fractions/subfractions from flash chromatography and comparison with isolated analogues as standards. The findings revealed not only the in-source loss of water as the base peak in hirsutinolides but also the in-source loss of corresponding alcohol when the oxygen at position 1 is alkylated. The present study also draws up a complement of data with respect to hirsutinolide-like sesquiterpene lactones whose LC-MS characteristics are not available in the literature. The chemophenetic significance is also discussed. Some of the isolated compounds were reported for the first time to be found in the species, the genus as well as the plant family. The medium-polar fractions of the crude extract, also containing the larger amount of sesquiterpenoid lactones, exhibited activity both against a cancer cell line and bacterial strains. Isolated lactones were also active against the cancer cell line, while the chlorogenic derivatives also valuable in Elephantopus genus showed potent radical scavenging activity. This is the first report of cytotoxic and antibacterial activities of our samples against the tested strains and cell line. The present study follows the ongoing research project dealing with the characterization of taxa with antibacterial and antiparasitic activities from Cameroonian pharmacopeia.


Assuntos
Asteraceae/química , Proliferação de Células/efeitos dos fármacos , Extratos Vegetais/química , Sesquiterpenos/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Cromatografia Líquida , Humanos , Espectrometria de Massas , Neoplasias/tratamento farmacológico , Extratos Vegetais/farmacologia , Sesquiterpenos/isolamento & purificação
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