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1.
Nat Prod Res ; : 1-11, 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36815546

ABSTRACT

A new 3-arylcoumarin, 7-hydroxy-6-(1,1-dimethylallyl)-2',5'-dihydroxy-4'-(3,3dimethylprenyl)-3-arylcoumarin (desmoarylcoumarin) 1, a previously unreported oleanane-type triterpenoid, 3ß,22ß,23-trihydroxyolean-12-en (episoyasapogenol B) 2, together with five known flavonoids including darbergioidin (3), isoferreirin (4), quercetin (5), vitexin (6), swertizin (7), and one carbohydrate, sucrose (8) were isolated from the methanolic extract of the roots of Desmodium salicifolium. Their structures were elucidated mainly by extensive spectroscopic analysis (1D and 2D) and mass spectrometric (HRFAB-MS) data. The methanolic extract, EtOAc and n-BuOH fractions as well as some isolated compounds were assessed for their antibacterial and antioxidant activities. The EtOAc fraction exhibited moderate activity against Enterococcus faecalis with MIC value of 128 µg/mL. The methanolic extract and the EtOAc fraction displayed DPPH scavenging activity with EC50 values of 5.99 and 2.06 µg/mL, respectively. Compound 1 showed a moderate antibacterial activity against Enterococcus faecalis with a MIC of 16 µg/mL. It also showed moderate DPPH scavenging activity.

2.
Nat Prod Res ; 37(8): 1356-1364, 2023 Apr.
Article in English | MEDLINE | ID: mdl-34844474

ABSTRACT

A new triterpenoid saponin (Mimonoside D: 3-O-α-L-arabinopyranosyl-3ß-hydroxyolean-12-en-28-oic acid 28-O-ß-D-xylopyranosyl-(1→2)-ß-D- glucopyranoside ester (1)) was isolated from the aerial parts of Mimosa diplotricha Sauvalle together with nine known compounds: 7,4'-dihydroxyflavone (2), kaempferol (3), lupeol (4), betulinic acid (5), ß-sitosterol (6), ß-sitosterol-3-O-ß-D-glucopyranoside (7), lutein (8), 5,2'-dihydroxy-7,4',5'-trimethoxyflavone (9) and vitexin (10). Their structures were elucidated on the basis of spectroscopic (1 D and 2 D nuclear magnetic resonance) and high-resolution mass spectrometric data as well as by comparison of their spectral data with those of related compounds. Compounds 2, 7 and 8 had already been isolated from M. diplotricha, while compounds 3, 4, 5 and 6 have been isolated from other Mimosa species. Compound 2 moderately inhibited Proteus mirabilis (MIC = 32 µg/mL), weakly inhibited Pseudomonas aeruginosa (MIC = 64 µg/mL) and very weakly inhibited Staphylococcus aureus (MIC = 128 µg/mL) and Enterococus faecalis (MIC = 128 µg/mL).


Subject(s)
Fabaceae , Mimosa , Saponins , Triterpenes , Saponins/pharmacology , Saponins/chemistry , Triterpenes/pharmacology , Triterpenes/chemistry , Plant Extracts/chemistry , Molecular Structure
3.
Nat Prod Res ; 37(20): 3461-3469, 2023.
Article in English | MEDLINE | ID: mdl-35687822

ABSTRACT

Phytochemical investigation of the methanol extracts from the leaves and bark of Senna siamea resulted in the isolation of one new flavone C-glycoside: apigenin-8-C-[6''-(E)-feruloyl]-ß-D-glucopyranoside] (1), together with sixteen known compounds including quercetin-3-O-α-L-rhamnoside (2), vitexin (3), isovitexin (4), quercetin-3-O-ß-D-glucopyranoside (5), quercetin-3-O-ß-D-arabinopyranoside (6), quercetin (7), kaempferol (8), methyl inositol (9), sucrose (10), betulinic acid (11), vanillic acid (12), stigmastane-3ß,6α-diol (13), aurantiamide acetate (14), robinetinidol (15), catechin (16) and epicatechin (17). The structures of these compounds were established on the basis of their spectroscopic (1 D and 2 D NMR) and mass spectrometric (ESI-TOF-MS) data. The methanol extracts, fractions and some of the isolated compounds were screened for their antimicrobial properties against five microbial strains. The methanol extract and the ethyl acetate fraction from the bark showed very weak antifungal activity against C. glabrata with the same MIC value of 128 µg/mL. Compound 7 was weakly active against C. albicans with MIC of 32 µg/mL.

4.
Nat Prod Res ; 37(10): 1641-1650, 2023 May.
Article in English | MEDLINE | ID: mdl-35921518

ABSTRACT

A previously unreported gallocatechin glycoside, (2 R,3S) 4'-O-methyl-gallocatechin-3-O-α-ʟ-rhamnopyranoside (1) and an unseparable mixture of two previously undescribed dihydromyricetin glycosides, (2 R,3R) 4'-O-methyl-dihydromyricetin-3-O-α-ʟ-rhamnopyranoside (2a) and (2 R,3S) 4'-O-methyl-dihydromyricetin-3-O-α-ʟ-rhamnopyranoside (2 b) along with three known compounds were isolated from the n-butanol soluble fraction of the stem bark of Olax subscorpioidea Oliv. Their structures were elucidated by detailed spectroscopic analyses, including 1H NMR, 13C NMR, 1H-1H COSY, HSQC, HMBC, NOESY, HR-ESI-MS and chemical methods. The crude ethanol extract, the fractions, and some of the isolated compounds were screened for their antioxidant and antibacterial activities. They showed significant antioxidant activities with EC50 ranging from 6.29 to 18.19 µg/mL in 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and EC50 ranging from 85.77 to 86.39 mmol FeSO4/g in ferric reducing antioxidant power (FRAP) methods compared with 2.29 µg/mL and 3.52 mmol FeSO4/g for the positive control (ʟ-ascorbic acid). Nevertheless, no inhibition was observed against the tested bacterial strains at a MIC less than 256 µg/mL.


Subject(s)
Antioxidants , Flavonoids , Flavonoids/chemistry , Antioxidants/chemistry , Plant Bark/chemistry , Plant Extracts/chemistry , Glycosides/chemistry
5.
Artif Cells Nanomed Biotechnol ; 50(1): 188-197, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35766301

ABSTRACT

This study aimed to synthesize the silver nanoparticles (SNPs) and loaded chitosan nanoparticles (LCNPs) using Euphorbia prostata based on their anticandidal activity. Antioxidant capacity and the total phenolic and total flavonoid content of plant samples and synthesized nanoparticles (NPs) were also evaluated. SNPs and LCNPs were prepared, respectively using chemical reduction of silver salt solution and ionotropic gelation method. The anticandidal activity was assessed by broth micro-dilution method and the antioxidant activity was determined using free-radical scavenging assays. The synthesized NPs after the optimization process were found to be spherical with sizes ranging from 12 to 100 nm. Spectroscopic analysis of NPs showed the appearance of peaks in prescribed wavelength ranging between 402 and 493 nm. The synthesized NPs showed potent anticandidal activity compared to the free extract. The SNPs formulations NpEPM 7.5 and NpEPMR 7.5, showed significantly low MIC values ranging between 2 and 128 µg/mL. In the case of LCNPs, NpEPM (4:1) and NpEPME (4:1) also showed lower MIC values ranging from 32 to 256 µg/mL. The plant samples as well as NPs showed antioxidant potential. In addition, plant extracts and NPs possess the potent biological potential and can be further investigated through in vivo experiments.


Subject(s)
Chitosan , Euphorbia , Metal Nanoparticles , Antioxidants/pharmacology , Chitosan/pharmacology , Silver/pharmacology
6.
Adv Pharmacol Pharm Sci ; 2022: 6626834, 2022.
Article in English | MEDLINE | ID: mdl-35464619

ABSTRACT

Eriobotrya japonica (loquat) has been used in African traditional medicine with numerous beneficial health effects. The extracts from loquat contain several bioactive compounds with a plethora of pharmacological properties. However, a scientific study on the activity against the aetiological agent of cryptococcosis has not yet been reported. Therefore, this study aimed to investigate the antifungal potential of various extracts from Eriobotrya japonica against clinical isolates of Cryptococcus neoformans. Quantitative and qualitative phytochemical analyses of extracts were made by following standard procedures. The broth microdilution method and the checkerboard methods were used to determine the antifungal activity and the combination of extracts with antifungals drugs. The methanol extract of seeds and the hexane extract of leaves exhibited the best significant antifungal activity with MIC values of 32 µg/mL. Furthermore, the combination of both extracts with nystatin and clotrimazole showed synergistic interactions with a 32-fold reduction in the MIC values of nystatin. Our findings indicate that Eriobotrya japonica extracts are a potential source of new antifungals that could be developed for use in the treatment of cryptococcosis. The anticryptococcal and antifungal activities potentiating activity of the studied extracts indicate their potential in the management of cryptococcosis. Further study should be considered to identify the bioactive principles against Cryptococcus neoformans.

7.
Nat Prod Res ; 36(23): 5991-5998, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35369818

ABSTRACT

Chemical investigation of the MeOH extract of the leaves of Scyphocephalium mannii (Benth. & Hook.f.) Warb. (Myristicaceae) led to the isolation and characterization of one new metabolite (+)-(7'S, 8S, 8'S)-4,4'-dihydroxy-3,3',5,5'-tetramethoxy-2,7'-cyclolignan (1) along with five known compounds. Their structures were elucidated by spectroscopic means, including 1 D and 2 D NMR, HRESI-MS and by comparison with published data. The absolute configuration of compound 1 was determined by single-crystal X-RAY diffraction. Compound 1 showed moderate antifungal activity against Cryptococcus neoformans with respective MIC and MMC values of 64 and 256 µg/mL.


Subject(s)
Anti-Infective Agents , Myristicaceae , Molecular Structure , Magnetic Resonance Spectroscopy , Plant Leaves , Anti-Infective Agents/pharmacology
8.
Nat Prod Res ; 36(24): 6369-6374, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35073788

ABSTRACT

An aliphatic alkene namely pentapentacontene (4) was isolated for the first time from a natural source, Gardenia aqualla, along with fourteen other compounds including nonacosanol (1), tetratriacontanol (2), octatriacontanol (3), ß-sitosterol (5) and stigmasterol (6), daucosanol (7), ursolic acid (8), uvaol (9), 3ß,19α,23ß,24α-tetrahydroxyurs-12-en-28-oic acid (10), lupenone (11), oleanolic acid (12), vanillin (13), vanillic acid (14) and D-mannitol (15). α-glucosidase inhibitory assay revealed that MeOH and EtOAc extracts of leaves had the best activity with IC50 of 9.65 and 20.03 µg/ml respectively. All the tested compounds showed dose dependent inhibition of α-glucosidase and some of them were found to be comparable to acarbose. Compound 10 was the most potent with IC50 = 1.72 µM. It also showed the most interesting antibacterial activity, against the isolate strain of S. typhi and P. aeruginosa and also exhibited the most significant antifungal activities against all the tested yeasts.


Subject(s)
Gardenia , Rubiaceae , Triterpenes , Rubiaceae/chemistry , alpha-Glucosidases/chemistry , Glycoside Hydrolase Inhibitors/chemistry , Plant Extracts/chemistry , Triterpenes/pharmacology , Anti-Bacterial Agents/pharmacology
9.
Nat Prod Res ; 36(2): 515-522, 2022 Jan.
Article in English | MEDLINE | ID: mdl-32627596

ABSTRACT

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).


Subject(s)
Anacardiaceae , Ceramides , Antioxidants , Methanol , Plant Extracts , Plant Leaves
10.
Nat Prod Res ; 35(15): 2507-2514, 2021 Aug.
Article in English | MEDLINE | ID: mdl-31674835

ABSTRACT

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).


Subject(s)
Caffeic Acids/pharmacology , Cassia , Free Radical Scavengers/pharmacology , Piperidines/pharmacology , Caffeic Acids/isolation & purification , Cassia/chemistry , Free Radical Scavengers/isolation & purification , Microbial Sensitivity Tests , Phytochemicals/isolation & purification , Phytochemicals/pharmacology , Piperidines/isolation & purification , Plant Bark/chemistry , Plant Extracts
11.
Z Naturforsch C J Biosci ; 74(11-12): 289-293, 2019 Nov 26.
Article in English | MEDLINE | ID: mdl-31525160

ABSTRACT

A new saponin, 3-O-ß-d-3-oxo-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (1), was isolated from the methanol extract of stem bark of Crossopteryx febrifuga together with the known 3ß-d-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (2), shanzhiside methyl ester (3), shanzhiside (4), ß-sitosterol (5), ß-sitosterol-3-O-ß-d-glucopyranoside (6), ursa-12,20(30)-diene-27,28-dioic acid (7), hederagenin (8), and oleanolic acid (9). The structures were established by comprehensive interpretation of their spectral data 1D- (1H and 13C), 2D-NMR (1H-1H COSY, HMQC, HMBC), spectroscopic, and electrospray ionisation time-of-flight mass spectrometry analysis. The isolated compounds and extracts were screened for their antibacterial properties. Although the EtOAc and n-BuOH extracts exhibited considerable antibacterial activity against Pseudomonas aeruginosa with minimum inhibitory concentration (MIC) value of 32 µg/mL, compounds 2 and 8 showed moderate activity against Enterococcus faecalis with MIC values of 256 and 128 µg/mL, respectively. The new compound (1) exhibited a moderate antibacterial activity against Staphylococcus aureus with an MIC value of 512 µg/mL.


Subject(s)
Glucosides/isolation & purification , Rubiaceae/chemistry , Triterpenes/isolation & purification , Bacteria/drug effects , Carbohydrate Conformation , Carbon-13 Magnetic Resonance Spectroscopy , Glucosides/chemistry , Glucosides/pharmacology , Microbial Sensitivity Tests , Proton Magnetic Resonance Spectroscopy , Triterpenes/chemistry , Triterpenes/pharmacology
12.
Pharm Biol ; 55(1): 929-936, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28164737

ABSTRACT

CONTEXT: Peptic ulcer is one of the most common diseases affecting mankind. Although there are many products used for its treatment, most of these products produce severe adverse reactions requiring the search for novel compounds. Some Afromomum species are used traditionally to cure acute gastritis. OBJECTIVE: To evaluate the antiulcer activity of the methanol extract of Aframomum pruinosum Gagnepain (Zingiberaceae) seeds against two major etiologic agents of peptic ulcer disease; Helicobacter pylori and non-steroidal anti-inflammatory drugs. MATERIALS AND METHODS: The anti-Helicobacter activity of A. pruinosum was evaluated using the broth microdilution method. After oral administration of indomethacin (5 mg/kg) for 5 consecutive days, gastric ulcerated animals were divided into control group and five other groups: three groups that recieved respectively 125, 250 and 500 mg/kg of plant extract, the fourth group received Maalox (50 mg/kg) and the fifth group, Misoprostol (100 µg/kg), respectively, for 5 days. Ulcer areas, gastric mucus content and nitric oxide gastric levels of animals were assessed 24 h after this treatment. RESULTS: A. pruinosum extract shows a moderate anti-Helicobacter activity with an MIC value of 128 µg/mL. A. pruinosum extract, like Misoprostol and Maalox, markedly reduces the % of ulcerated area from 8.15 ± 0.33 to 1.71 ± 0.44% (500 mg/kg). It also increased significantly mucus and NO gastric production with respective values of 4.44 ± 1.35 and 965.81 ± 106.74 µmol/g (500 mg/kg). DISCUSSION AND CONCLUSION: These findings suggest that A. pruinosum methanol extract possesses antiulcer properties as ascertained by the comparative decreases in ulcer areas, increase of mucus and NO gastric production.


Subject(s)
Anti-Bacterial Agents/pharmacology , Anti-Ulcer Agents/pharmacology , Gastric Mucosa/drug effects , Helicobacter pylori/drug effects , Indomethacin , Seeds/chemistry , Stomach Ulcer/prevention & control , Zingiberaceae/chemistry , Aluminum Hydroxide/pharmacology , Animals , Anti-Bacterial Agents/isolation & purification , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Combinations , Gastric Mucosa/metabolism , Gastric Mucosa/pathology , Helicobacter pylori/growth & development , Magnesium Hydroxide/pharmacology , Male , Methanol/chemistry , Microbial Sensitivity Tests , Misoprostol/pharmacology , Mucus/metabolism , Nitric Oxide/metabolism , Phytotherapy , Plants, Medicinal , Rats, Sprague-Dawley , Solvents/chemistry , Stomach Ulcer/chemically induced , Stomach Ulcer/metabolism , Stomach Ulcer/pathology , Time Factors
13.
Nat Prod Commun ; 12(3): 367-368, 2017 Mar.
Article in English | MEDLINE | ID: mdl-30549887

ABSTRACT

Three alkaloids including a new one, N-formyldihydrochelerythrine (1), together with four other known compounds were isolated from the stem bark of Caloncoba glauca. The structure of the new compound was elucidated from spectroscopic and mass spectrometric evidence. This is the first report of alkaloids from the genus Caloncoba. Sesamin (4) [MIC = 256 µg/mL (Candida albicans) and dihydrochelerythrine (2) [MIC = 32 (C. albicans and C. parapsilosis), and 128 µg/mL (C. krusei)] had moderate to weak antifungal activity.


Subject(s)
Benzophenanthridines/chemistry , Salicaceae/chemistry , Molecular Structure
14.
Ethiop J Health Sci ; 26(6): 555-560, 2016 Nov.
Article in English | MEDLINE | ID: mdl-28450771

ABSTRACT

BACKGROUND: Cryptococcus neoformans is responsible of cryptococcosis, a life-threatening infection that affects healthy and immunocompromised individuals. It is the first cause of adult acute meningitis in some sub-Saharan African countries with a mortality rate of about 100% in cases of inappropriate therapy. This study aimed at examining the occurrence and the antifungal patterns of Cryptococcus isolates from pigeon droppings and bat guanos in the west region of Cameroon. METHODS: A total of 350 samples were randomly collected from three selected localities of west region of Cameroon. The identification was performed based on capsule production assessed by Indian ink preparation. Additional tests performed were urea broth, glycine and tryptophan assimilation tests. The antifungal susceptibility test was performed by the broth microdilution method. RESULTS: Mycological analysis led to the identification of 98 isolates, of which 57 isolates of C. neoformans var. gattii and 41 isolates of C. neoformans var. neoformans. All the isolates showed resistance to antifungals tested except nystatin which showed MIC mean values ranging between 0.5 µg/mL and 0.65 µg/mL. CONCLUSION: The prevalence of C. neoformans in pigeons and bats excreta in the west region of Cameroon is 28.57 %. C. neoformans var. gattii and C. neoformans var. neoformans are the main serotypes. Isolates found to be resistant to fluconazole and ketoconazole. Our results emphasize the need for further study on the molecular epidemiology in comparison with clinical isolates.


Subject(s)
Antifungal Agents/pharmacology , Cryptococcus neoformans/drug effects , Cryptococcus neoformans/isolation & purification , Feces/microbiology , Animals , Cameroon , Chiroptera , Columbidae , Microbial Sensitivity Tests
15.
BMC Complement Altern Med ; 14: 58, 2014 Feb 17.
Article in English | MEDLINE | ID: mdl-24533718

ABSTRACT

BACKGROUND: Spices and herbs have been used in food since ancient times to give taste and flavor and also as food preservatives and disease remedies. In Cameroon, the use of spices and other aromatic plants as food flavoring is an integral part of dietary behavior, but relatively little is known about their antifungal potential.The present work was designed to assess the antifungal properties of extracts from spices used in Cameroonian dietary. METHODS: The in vitro antifungal activities of twenty three extracts from twenty one spices were assessed by the broth micro-dilution method against eight fungi. Also, the in vivo activity of Olax subscorpioidea extract (the most active extract) was evaluated in rat model of disseminated candidiasis due to Candida albicans by estimating the fungal burden in blood and kidney. RESULTS: Seven extracts (30%) exhibited moderate to significant antifungal activities, inhibiting the growth of the microorganisms at concentrations ranging from 0.048 to 0.39 mg/mL. Olax subscorpioidea extract exhibited the highest antifungal activity particularly against Candida albicans and Candida tropicalis (MIC of 0.097 mg/mL and 0.048 mg/mL respectively). Sixteen extracts (70%) were weakly active (MICs > 6.25 mg/mL). Oral administration of O. subscorpioidea extract at the dose 2 g/kg of body weight (bw) to artificially infected rats revealed a drop in the number of colony forming units per milliliter (cfu/mL) of Candida albicans cells in the blood below the detection limit (100 cfu/mL) while a modest decrease was observed in the kidney. CONCLUSION: The present work shows that some of the spices studied possess interesting antifungal properties and could be used to treat candidiasis. Among the plant species tested, Olax subscorpioidea displayed the most promising result.


Subject(s)
Antifungal Agents/therapeutic use , Candida albicans/drug effects , Candidiasis/drug therapy , Magnoliopsida , Phytotherapy , Plant Extracts/therapeutic use , Spices , Animals , Antifungal Agents/pharmacology , Cameroon , Candidiasis/microbiology , Diet , Female , In Vitro Techniques , Kidney/drug effects , Kidney/microbiology , Microbial Sensitivity Tests , Olacaceae , Plant Extracts/pharmacology , Rats, Wistar
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