RESUMO
The genus Vernonia is an extremely rich source of biologically active sesquiterpene lactones. The present report describes the spectroscopic structure elucidation and the cytotoxic and antimicrobial properties of five hitherto unknown germacranolide-like sesquiterpenoids and several known compounds. These new derivatives include a compound (1) with an unprecedented 10/5/5/6 tetracyclic framework featuring a hexahydro-1H,3H,7H-furo[3',4':3,4]furo[3,2-c]pyridin-1-one core resulting from an intramolecular cyclization cascade involving a methacrylate substituent and a low molecular weight amine. Furthermore, an elemane-germacranolide hybrid (2) and three amino acid-derived lactones (3-5) were characterized. A plausible biosynthetic pathway to the key alkaloid is presented, while shielding tensor calculations using DFT in combination with the DP4+ method were applied to elucidate its stereostructure. The newly characterized compounds along with ten known sesquiterpene lactones and phenolic compounds have been isolated from Vernonia tufnelliae, a medicinal plant from the western region of Cameroon. Their structures were consistent with spectroscopic and spectrometric data recorded. The present report is the first investigation of the chemistry and biology of V. tufnelliae.
Assuntos
Antineoplásicos , Sesquiterpenos , Vernonia , Lactonas/química , Estrutura Molecular , Compostos Fitoquímicos , Sesquiterpenos/química , Vernonia/químicaRESUMO
Two new fatty acid esters of triterpenoids (1-2) together with eleven known compounds (3-13) were obtained after investigation of the CH2Cl2-MeOH (1:1) crude extract from the leaves of Schefflera barteri Harms. All these compounds (1-13) were isolated for the first time from this plant among which compounds 3, 4, 6 and 9-13 were also isolated from the genus Schefflera for the first time. The structures of the isolated compounds were elucidated by analyses of their spectroscopic data (1D and 2D NMR, and MS). The antibacterial and cytotoxic activities of crude extracts, fractions and compounds (1, 2, 5, 6, 8 and 9) were investigated against both Gram-negative and Gram-positive bacteria strains as well as on human cervix carcinoma and colon adenocarcinoma cancer cell lines, respectively. They showed weak to significant activity towards the strains and malignant cells used.
Assuntos
Araliaceae , Triterpenos , Araliaceae/química , Ésteres/análise , Ácidos Graxos/análise , Feminino , Humanos , Extratos Vegetais/química , Folhas de Planta/química , Triterpenos/químicaRESUMO
A phytochemical study of the methanol extract of the fruit of Maesa lanceolata resulted in the isolation of a new alkenylbenzoquinone (1), alongside the known compounds (Z)-2,5-dihydroxy-6-methyl-3-(pentadec-10'-enyl)-1,4-benzoquinone (2), 2,5-dihydroxy-6-methyl-3-(nonadec-14'-enyl)-1,4-benzoquinone (3), 2,5-dihydroxy-6-methyl-3-(tridecyl)-1,4-benzoquinone (4), (2S,3S,4R,2'R,9E)-[2'-hydroxytetraeicosanoyl]-2-aminooctadec-9-ene-1,3,4-triol (5), monopalmitin (glyceryl palmitate) (6), lupeol (7), and 3-O-(ß-D-glucopyranoside)-ß-sitosterol (8). The structures of the compounds were established by the means of spectroscopic (1 D- and 2 D-NMR) and spectrometric techniques (MS). The isolated compounds were assessed for their antibacterial, cytotoxic, and antiradical activities. Compound 2 showed moderate activity against Staphylococcus warneri (DSMZ 20036), while the other compounds were inactive. The two quinones 1 and 2 were significantly cytotoxic, with IC50 values of 0.005 µM and 12.5 µM respectively, and were weakly active towards DPPH radical (IC50 >250 µg/mL).
Assuntos
Frutas , Maesa , Antibacterianos/análise , Antibacterianos/farmacologia , Benzoquinonas/química , Frutas/química , Estrutura Molecular , Extratos Vegetais/químicaRESUMO
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 PlantaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Infections due to multidrug-resistant (MDR) bacteria constitute a real problem in the public health worldwide. Hypericum roeperianum Schimp. ex A. Rich (Hypericaceae) is used traditionally for treatment of various ailments such as abdominal pains, constipation, diarrhea, indigestion, nausea, and bacterial diseases. AIM OF THE STUDY: This study was aimed at investigating the antibacterial and antibiotic-modifying activity of the crude methanol extracts (HRB), ethyl-acetate soluble fraction (HRBa), residual material (HRBb), and 11 compounds from the bark of Hypericum roeperianum against multi-drug resistant (MDR) bacteria expressing active efflux pumps. MATERIALS AND METHODS: The antibacterial activity, the efflux pump effect using the efflux pump inhibitor (EPI), phenylalanine-arginine-ß-naphthylamide (PAßN), as well as the antibiotic-modifying activity of samples were determined using the broth micro-dilution method. Spectrophotometric methods were used to evaluate the effects of HRB and 8,8-bis(dihydroconiferyl) diferulate (11) on bacterial growth, and bacterial membrane damage, whereas follow-up of the acidification of the bacterial culture was used to study their effects on bacteria proton-ATPase pumps. RESULTS: The crude extract (HRB), HRBa, and HRBb had selective antibacterial activity with MICs ranging from 16 to 512 µg/mL. Phytochemical 11 displayed the best antibacterial activity (0.5 ≤ MIC ≤ 2 µg/mL). The activity of HRB and 11 in the presence of EPI significantly increased on the tested bacteria strains (up to 32-fold). The activity of cloxacillin (CLO), doxycycline (DOX), and tetracycline (TET), was considerably improved (up to 64-fold) towards the multidrug-resistant Enterobacter aerogenes EA-CM64 strain. The crude extract (HRB) and 11 induced the leakage of bacterial intracellular components and inhibited the proton-ATPase pumps. CONCLUSIONS: The crude extract (HRB) and 8,8-bis(dihydroconiferyl)diferulate from the bark of Hypericum roeperianum are good antibacterial candidates that deserve further investigations to achieve antibacterial drugs to fight infections involving MDR bacteria.
Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Hypericum/química , Extratos Vegetais/farmacologia , Antibacterianos/administração & dosagem , Antibacterianos/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Sinergismo Farmacológico , Proteínas de Membrana Transportadoras/metabolismo , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/administração & dosagem , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Casca de Planta , Extratos Vegetais/administração & dosagemRESUMO
Two hitherto unknown neo-clerodane-type diterpenoids along with twelve known compounds have been isolated from Conyza pyrrhopappa Sch.Bip. ex A.Rich, a medicinal plant traditionally used across tropical Africa to relieve fever. The structures of isolates have been elucidated by a combination of spectroscopic techniques. The crude extract and the isolated compounds were evaluated in the Hela-S3 cell line and in a panel of microorganisms (bacteria and fungi) at concentrations up to 50 µg/mL. The new compounds were inactive while the pentamethylated flavonoids showed low to significant activity against the cancer cell line used. However, none of the samples showed any activity against the tested microorganisms at this concentration. The present manuscript is the first investigation of the cytotoxicity of phytochemicals and extract from C. pyrrhopappa.
Assuntos
Conyza , Diterpenos Clerodânicos , Extratos Vegetais/farmacologia , Plantas Medicinais , Conyza/química , Diterpenos Clerodânicos/isolamento & purificação , Diterpenos Clerodânicos/farmacologia , Células HeLa , Humanos , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Plantas Medicinais/químicaRESUMO
An unprecedented saponin is being reported herein together with five known compounds from the methanol extract of the roots of Albizia adianthifolia. The metabolites were obtained over repeated open column chromatography methods and spectroscopic followed by spectrometric techniques. The isolated compounds were tested against eleven Gram-negative bacteria including multidrug resistant strains. The results revealed considerable inhibition of the new saponin against the studied bacteria with MIC values ranging from 16 to 128 µg/mL.
Assuntos
Albizzia , Antibacterianos/farmacologia , Saponinas , Albizzia/química , Antibacterianos/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Saponinas/isolamento & purificação , Saponinas/farmacologiaRESUMO
The isolation and spectroscopic data of a hitherto undescribed polyketide (1) from Hypericum roeperianum Schimp. (Hypericaceae) together with six known compounds (2-7) is herein reported. The structure elucidation is based on extensive 1D- and 2D-NMR, infrared, UV and MS experiments. The structures of the known compounds were confirmed by comparison of their spectroscopic data with those of similar reported compounds in the literature. Some of the isolated compounds had a significant activity against a panel of multidrug-resistant bacterial strains.Supplemental data for this article can be accessed at https://doi.org/10.1080/14786419.2019.1677655.
Assuntos
Hypericum/química , Casca de Planta/química , Policetídeos/isolamento & purificação , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Policetídeos/químicaRESUMO
A new caffeate derivative from the ethanol extract of the stem bark of Cassia sieberiana DC. is described herein along with the known secondary metabolites spectaline (2), iso-6-cassine (3), 3-O-methyl-chiro-inositol (4), monobehenin (5), octyl nonadecyloate (6), ß-sitosterol (7), stigmasterol (8) and sitosterol 3-O-ß-D-glucopyranoside (9). The chemical structures were elucidated by means of various spectroscopic and spectrometric techniques. Extract and isolated compounds were devoid of inhibitory action against the herein selected bacterial strains (MICs > 256 µg/mL) but showed capacities to reduce 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (EC50 < 3 µg/mL) considerably better than the "gold standard" trolox (EC50 6.47 ± 0.48 µg/mL).
Assuntos
Ácidos Cafeicos/farmacologia , Cassia , Sequestradores de Radicais Livres/farmacologia , Piperidinas/farmacologia , Ácidos Cafeicos/isolamento & purificação , Cassia/química , Sequestradores de Radicais Livres/isolamento & purificação , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Piperidinas/isolamento & purificação , Casca de Planta/química , Extratos VegetaisRESUMO
A phytochemical study of the methanol extract of the leaves of Embelia schimperi resulted in the isolation of three new alkenylresorcinols, 1: â-â3: , together with the known analogs 4: â-â7: . Their structures were established by a combination of spectroscopic techniques. Compounds 1: â-â7: exhibited moderate cytotoxic activity against human cervical cancer cells HeLa-S3 and more pronounced antimicrobial properties towards bacteria and filamentous fungi. The present study falls into an ongoing research project on the characterization of bioactive phenolic lipids from plants of the family Primulaceae.
Assuntos
Anti-Infecciosos , Embelia , Anti-Infecciosos/farmacologia , Humanos , Compostos Fitoquímicos , Extratos Vegetais/farmacologia , Folhas de PlantaRESUMO
BACKGROUND: The proliferation and resistance of microorganisms area serious threat against humankind and the search for new therapeutics is needed. The present report describes the antiplasmodial and anticancer activities of samples isolated from the methanol extract of Albizia zygia (Mimosaseae). MATERIAL: The plant extract was prepared by maceration in methanol. Standard chromatographic, HPLC and spectroscopic methods were used to isolate and identify six compounds (1-6). The acetylated derivatives (7-10) were prepared by modifying 2-O-ß-D-glucopyranosyl-4-hydroxyphenylacetic acid and quercetin 3-O-α-L-rhamnopyranoside, previously isolated from A. zygia (Mimosaceae). A two-fold serial micro-dilution method was used to determine the IC50s against five tumor cell lines and Plasmodium falciparum. RESULTS: In general, compounds showed moderate activity against the human pancreatic carcinoma cell line MiaPaca-2 (10 < IC50 < 20 µM) and weak activity against other tumor cell lines such as lung (A-549), hepatocarcinoma (HepG2) and human breast adenocarcinoma (MCF-7and A2058) (IC50 > 20 µM). Additionally, the two semi-synthetic derivatives of quercetin 3-O-α-L-rhamnopyranoside exhibited significant activity against P. falciparum with IC50 of 7.47 ± 0.25 µM for compound 9 and 6.77 ± 0.25 µM for compound 10, higher than that of their natural precursor (IC50 25.1 ± 0.25 µM). CONCLUSION: The results of this study clearly suggest that, the appropriate introduction of acetyl groups into some flavonoids could lead to more useful derivatives for the development of an antiplasmodial agent.
Assuntos
Albizzia/química , Antimaláricos/farmacologia , Citotoxinas/farmacologia , Extratos Vegetais/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Camarões , Linhagem Celular Tumoral , Cromatografia Líquida , Humanos , Espectrometria de Massas , Estrutura Molecular , Folhas de Planta/química , Plasmodium falciparum/efeitos dos fármacosRESUMO
The effectiveness of anticancer chemotherapy is greatly impeded by the resistance of malignant cells to cytotoxic drugs. In this study, the cytotoxicity of the crude extract (DCB) and compounds isolated from the bark of Dichrostachys cinerea, namely, betulinic acid (1), glyceryl-1-hexacosanoate (2), 7-hydroxy-2-(4-hydroxyphenyl)-4H-chromen-4-one (3), and 6-hydroxy-2-(4-hydroxyphenyl)-4H-chromen-4-one (4), was investigated. The study was extended to the assessment of the mode of induction of apoptosis by DCB and compound 1. The resazurin reduction assay was used for cytotoxicity studies. Assessments of cell cycle distribution, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were performed by flow cytometry. Constituents of DCB were isolated by column chromatography. Triterpenoid 1 and flavone 4 had cytotoxic effects towards the 9 tested cancer cell lines with IC50 values below 50 µM. The recorded IC50 values varied from 7.65 µM (towards multidrug-resistant CEM-ADR5000 leukemia cells) to 44.17 µM (against HepG2 hepatocarcinoma cells) for 1, 18.90 µM (CCRF-CEM leukemia cells) to 88.86 µM (against HCT116p53+/+ colon adenocarcinoma cells) for 4, and 0.02 µM (against CCRF-CEM cells) to 122.96 µM (against CEM/ADR5000 cells) for doxorubicin. DCB induced apoptosis in CCRF-CEM cells mostly mediated by MMP alteration and enhanced ROS production; compound 1 induced apoptosis through caspases activation and MMP alteration and increased ROS production. Dichrostachys cinerea is an interesting cytotoxic plant and deserves more studies leading to new antineoplastic agents to fight cancer and mostly leukemia.
RESUMO
BACKGROUND: Albizia adianthifolia (Schum.) is medicinally used in Cameroon to manage bronchitis and skin diseases. Our previous study documented the antibacterial potential of its roots' methanol extract. In this study, methanol roots extract was subjected to chromatography techniques and fractions (AARa and AARb), sub-fractions (AARa1-4, AARb1-2 and AARb11-14) together with isolated phytochemicals were assessed for their antimicrobial as well as their antibiotic-potentiating effects towards Gram-negative multidrug resistant (MDR) bacteria. METHODS: The antibacterial activities of the samples (determination of Minimal Inhibitory « MIC ¼ and Minimal Bactericidal Concentration « MBC ¼) were determined by the modified rapid p-iodonitrotetrazolium chloride (INT) colorimetric assay, as well as those of antibiotics in association with the compounds. Column chromatography was applied to isolate phytochemicals from roots extract and their chemical structures were determined using spectroscopic techniques. RESULTS: The phytochemicals isolated were stearic acid (1), a mixture (1:1) of stigmasterol and ß-sitosterol (2 + 3), ß-sitosterol 3-O-ß-D-glucopyranoside (4), palmatin (5), homomangiferin (6) and mangiferin (7). Fraction AARa exhibited selective inhibitory effects whilst all tested bacteria were inhibited by AARb in MIC ranges of 8 to 1024 µg/mL. Sub-fractions AARb1-2 had MIC values between 8 µg/mL and 1024 µg/mL on all tested bacteria. Phytochemicals 4, 2 + 3 and 7 inhibited the growth of 54.54% (6/11), 45.45% (5/11) and 27.27% (3/11) tested bacterial strains, respectively. When tested with an efflux pumps inhibitor (Phenylalanine-Arginine-ß-Naphthylamide or PAßN), the inhibitory effects of compounds 2 + 3 and 4 increased towards all the tested bacteria. In association with erythromycin (ERY), streptomycin (STR) and tetracycline (TET), compounds 2 + 3 and 4 had the most significant synergistic activity on the seven selected bacteria. CONCLUSION: The present study provides information on the possible use of Albizia adianthifolia and its constituents in the control of Gram-negative infections including MDR phenotypes.
Assuntos
Albizzia/química , Antibacterianos/isolamento & purificação , Sinergismo Farmacológico , Compostos Fitoquímicos/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/farmacologiaRESUMO
BACKGROUND: Successful cancer chemotherapy is hampered by resistance of cancer cells to established anticancer drugs. Numerous natural products reveal cytotoxicity towards tumor cells. PURPOSE: The present study was aimed to determine the cytotoxicity of a betaine-type alkaloid, ungeremine, towards 9 cancer cell lines including various sensitive and drug-resistant phenotypes. The mode of action of this compound was further investigated. METHODS: The cytotoxicity, ferroptotic and necroptotic cell death were determined by the resazurin reduction assay. Caspase activation was evaluated using the caspase-Glo assay. Flow cytometry was applied for the analysis of cell cycle analysis (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP) (JC-1) and reactive oxygen species (ROS) (H2DCFH-DA). Apoptotic, necroptotic and autophagic markers were determined by Western blotting. CCRF-CEM leukemia cells were used for all mechanistic studies. RESULTS: Ungeremine displayed cytotoxic activity towards the 9 cancer cell lines tested, including drug-sensitive and MDR phenotypes. The IC50values obtained varied from 3.67⯵M (in MDA-MB-231-BCRP breast carcinoma cells) to 75.24⯵M (against in CEM/ADR5000 leukemia cells) for ungeremine and from 0.02⯵M (against CCRF-CEM cells) to 122.96⯵M (against CEM/ADR5000 cells) for doxorubicin (control drug). Ungeremine induced ferroptosis, necroptosis, autophagy as well as apoptosis mediated by caspase activation, MMP alteration and increase ROS production. CONCLUSION: The present investigation showed that ungeremine is a promising cytotoxic compoundthat could be further explored in the future to develop new anticancer drugs to fight sensitive and resistant phenotypes.
Assuntos
Alcaloides/toxicidade , Alcaloides de Amaryllidaceae/toxicidade , Antineoplásicos Fitogênicos/toxicidade , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Indolizinas/toxicidade , Extratos Vegetais/toxicidade , Alcaloides de Amaryllidaceae/química , Antineoplásicos Fitogênicos/química , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Indolizinas/química , Extratos Vegetais/química , Espécies Reativas de Oxigênio/metabolismoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Fagara tessmannii Engl. is an African medicinal plant used in Cameroonian traditional medicine to treat various types of cancers. AIM OF THE STUDY: This work was designed to determine the cytotoxicity of the crude extract (FTB), fractions (FTBa-d) and compounds isolated from the bark of Fagara tessmannii, namely lupeol (1), fagaramide (2), zanthoxyline (3), hesperidin (4), nitidine chloride (5), fagaridine chloride (6), and ß-sitosterol-3-O-ß-D-glucopyranoside (7). The study was extended to the mode of induction of apoptosis by FTB, compounds 5 and 6. MATERIALS AND METHODS: The resazurin reduction assay was used to evaluate the cytotoxicity of samples. The cell cycle, apoptosis, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were measured by flow cytometry. Column chromatography was used for the purification of FTB. Meanwhile, nuclear magnetic resonance (NMR) spectroscopic analysis was applied for structural elucidation. RESULTS: The crude extract, fractions FTBa, FTBc, FTBd as well as compounds 5 and 6 revealed cytotoxicity towards the 9 tested cancer cell lines. The IC50 values ranged from 17.34⯵g/mL (towards U87MG.ΔEGFR glioblastoma cells) to 40.68⯵g/mL (against CCRF-CEM leukemia cells) for FTB, from 16.78⯵g/mL (towards U87. MGΔEGFR cells) to 37.42⯵g/mL (against CEM/ADR5000 leukemia cells) for FTBa, from 19.47⯵g/mL (towards U87. MG glioblastoma cells) to 41.62⯵g/mL (against CCRF-CEM cells) for FTBc, from 14.17⯵g/mL (against HCT116p53-/- colon adenocarcinoma cells) to 22.28⯵g/mL (towards CEM-ADR5000 cells) for FTBd, from 1.75⯵M (against CCRF-CEM cells) to 23.52⯵M (against U87. MGΔEGFR cells) for compound 5, from 1.69⯵M (against CCRF-CEM cells) to 22.06⯵M (against HepG2 hepatocarcinoma cells) for compound 6 and from 0.02⯵M (against CCRF-CEM cells) to 122.96⯵M (against CEM/ADR5000 cells) for doxorubicin. FTB induced apoptosis in CCRF-CEM cells mediated by enhanced ROS production. Compound 5 induced apoptosis through caspases activation and increase ROS production. Meanwhile, 6 induced apoptosis mediated by caspases activation, MMP alteration and enhanced ROS production. CONCLUSION: Fagara tessmannii as well as its constituents 5 and 6 revealed considerable cytotoxicity and may be suitable candidates deserving to be further explored to develop new anticancer drugs to combat sensitive and resistant phenotypes.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias/tratamento farmacológico , Extratos Vegetais/farmacologia , Zanthoxylum/química , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Humanos , Concentração Inibidora 50 , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Neoplasias/patologia , Casca de Planta , Extratos Vegetais/administração & dosagem , Espécies Reativas de Oxigênio/metabolismoRESUMO
Two new furoquinoline alkaloids, maculine B (1) and kokusaginine B (2) and one new dihydrooxazole alkaloid, veprisazole (3), along with four known compounds namely, N13-methyl-3-methoxyrutaecarpine (4), flindersiamine (5), skimmianine (6) and tilianin (7) were isolated from the methanol extract of the stem bark of Araliopsis soyauxii Engl. by various chromatographic methods. Their structures were determined using spectrometry and spectroscopic techniques including NMR and MS. The cytotoxicity of the new compounds compared to that of doxorubicin, the reference anticancer compound, was determined on a panel of nine cancer cell lines including sensitive and drug resistant phenotypes. The three previously undescribed alkaloids displayed selective activities. Maculine B (1), the most active one among the newly described compounds, exhibited IC50 below 30⯵M against CCRF-CEM leukemia and U87MG glioblastoma cells.
Assuntos
Alcaloides/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Casca de Planta/química , Rutaceae/química , Alcaloides/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Camarões , Linhagem Celular Tumoral , Dioxóis , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Flavonoides , Furanos , Glicosídeos , Humanos , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , QuinolinasRESUMO
Allanblackia genus, an endless source of bioactive compounds, was investigated for its antibacterial properties. The chemical study of the methanol extract from the fruits of Allanblackia gabonensis resulted in the isolation of the undescribed guttiferone BL (1) along with the known kaempferol (2), morelloflavone (3), morelloflavone 7â³-O-ß-D-glucopyranoside (4), ß-sitosterol 3-O-ß-D-glucopyranoside and ß-sitosterol. Their structures were determined using spectrometry and spectroscopic techniques. The antibacterial activity was evaluated against five Gram-negative and two Gram-positive strains using a broth micro-dilution method. Compounds displayed low to significant activity against the tested bacterial strains with MICs ranging from 8 to 512 µg/mL. Morelloflavone (3) presented significant activity against E. coli ATCC8739 (MIC = 8 µg/mL) while guttiferone BL (1) exhibited low activity (MICs = 256-512 µg/mL) against all the tested strains. The crude extract also had moderate to significant activity against the tested bacterial strains.
Assuntos
Antibacterianos/farmacologia , Benzofenonas/farmacologia , Clusiaceae/química , Antibacterianos/química , Benzofenonas/isolamento & purificação , Biflavonoides/isolamento & purificação , Biflavonoides/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Escherichia coli/efeitos dos fármacos , Frutas/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Quempferóis/isolamento & purificação , Quempferóis/farmacologia , Metanol/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Extratos Vegetais/químicaRESUMO
A new alkylbenzoquinone named embeliquinone (1) together with five known compounds, lupeol (2), 3-O-[6'-O-palmitoyl-ß-d-glucosyl]-spinasta-7,22(23)-diene (3), quercetin (4), (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxy-heneicosanoylamino]-heneicosane-1,3,4-triol-8-ene (5), and ß-sitosterol-3-O-ß-d-glucopyranoside (6) were isolated from the MeOH leaf extract of Embelia rowlandii by using repeated open column chromatography techniques. The structure of the new compound was characterized by analyses of 1D- and 2D-NMR, and MS data. Embeliquinone (1) had moderate anti-cell proliferation activity against A549 cell line with the IC50 value of 21.8 µM. In addition, 1 exhibited weak antibacterial activities against Klebsiella pneumoniae and Staphylococcus aureus with an MIC value of 206.0 µM in both cases.
Assuntos
Antibacterianos/farmacologia , Benzoquinonas/farmacologia , Embelia/química , Células A549 , Antibacterianos/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Benzoquinonas/química , Proliferação de Células/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Células MCF-7 , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Extratos Vegetais/química , Folhas de Planta/química , Staphylococcus aureus/efeitos dos fármacosRESUMO
Phytochemical studies of the seeds of the Cameroonian medicinal plant, Salacia staudtiana, resulted in the isolation and identification of five new cardenolides (1-5) as well as a new dihydro-ß-agarofuran (9), along with eight known compounds. The structures of all compounds were elucidated by 1D/2D NMR, ESI-HRMS data and comparison with literature data. The relative configurations of the new compounds were defined by X-ray crystallography analysis, NOESY correlations and coupling constants. We evaluated their antibacterial efficacy against two commonly dispersed environmental strains of Escherichia coli and Bacillus subtilis, and two pathogenic strains of Staphylococcus aureus and Pseudomonas aeruginosa, compared to the standard antibiotics, streptomycin and gentamicin. Moreover, we assessed the antibacterial activity of the crude extract of the seeds in parallel to evaluate the plausible synergistic effects of the compounds in chemical defense of the seeds during germination and plant reproduction. The isolated compounds showed moderate antibacterial activities against the tested organisms. Compounds 1 and 3 and the crude extract exhibited distinct antibacterial activities against B. subtilis and S. aureus. The isolated compounds showed weak DPPH radical scavenging properties compared to the reference standard (Trolox). Our study lends evidence to the antibacterial chemical defense of S. staudtiana seeds by seed-borne compounds.