Antibacterial Activity of Extracts of Three Croton Species Collected in Mpumalanga Region in South Africa

The antibacterial activities of three Croton species were compared using bioautography and the serial microdilution methods. The methanolic extracts of all the species had low activity against Escherichia coli. The highest activity was observed with Croton megalobotrys against Enterococcus faecalis with a minimal inhibitory concentration (MIC) value of 0.02 mg/ml. Croton steenkapianus extracts were the least active of the species investigated, only managing an MIC value of 0.625 mg/ml against Pseudomonas aeruginosa. Croton megalobotrys leaf powder was serially extracted using solvents of various polarities. The lowest MIC value (0.06 mg/ml) of the serially extracted fractions was observed with acetone against Pseudomonas aeruginosa. The liquid-liquid fractions of the methanol extract of Croton megalobotrys were also tested. The lowest MIC value of 0.02 mg/ml was observed with n-hexane fraction against Enterococcus faecalis. The carbon tetrachloride fraction was further fractionated using column chromatography with silica as the immobile phase. The resulting seven fractions were tested for activity following the bioassay-guided practice, and it emerged that the first three fractions had active compounds against Staphylococcus aureus when the bioautography method was used.     

Antimicrobial and Antioxidant Activities of Two Endemic Plants from Aksaray in Turkey

This study was designed to examine the in vitro antimicrobial and antioxidant activities of the methanol, ethanol, water, n-hexane and dicholoromethane extracts of two Allium species (Allium scabriflorum and Allium tchihatschewii) which are endemic for the flora of Turkey. The antimicrobial efficiency of the plant was evaluated according to disc diffusion and microdilution broth methods. The antimicrobial test results showed that the extracts of A. scabriflorum and A. tchihatschewii showed varying degrees of antimicrobial activity on the tested microorganisms. The extracts were screened for their possible antioxidant activities by three complementary tests; DPPH free radical-scavenging, scavenging of hydrogen peroxide and metal chelating activity assays. All the extracts of A. scabriflorum and A. tchihatschewii exhibited lower DPPH free radical scavenging activity but higher metal chelating activity when compared to standards. The values of scavenging of hydrogen peroxide of the extracts were higher than the standards that of α-tocopherol, BHA, BHT and trolox, but close to that of ascorbic acid. In addition to the antioxidant activity of these plants, the total phenolic compounds and flavonoids were also measured in the extracts. The results presented here may suggest that the extracts of A. scabriflorum and A. tchihatschewii possess antimicrobial and antioxidant properties, and therefore, they can be used as a natural preservative ingredient in food and/or pharmaceutical industry.     

Evaluation of the Antioxidant, Antibacterial, and Antiproliferative Activities of the Acetone Extract of the Roots of Senna Italica (Fabaceae)

Senna italica, a member of the Fabaceae family (subfamily Caesalpinaceae), is widely used traditionally to treat a number of disease conditions, such as sexually transmitted diseases and some forms of intestinal complications. The roots of Senna italica were collected from Zebediela subregion, Limpopo province (S.A), powdered and extracted with acetone by cold/shaking extraction method. The phytochemical composition of the extract was determined by thin layer chromatography (TLC). The chromatograms were visualised with vanillin-sulphuric acid and p-anisaldehyde reagents. The total phenolic content of the extract was determined by Folin-Ciocalteu method and expressed as TAE/g dry weight. The extract was assayed for the in vitro anticancer activity using Jurkat T cells, antioxidant activity using DPPH assay and antibacterial activity by bioautographic method and the microtitre plate method. The acetone extract of the roots of Senna italica inhibited the growth of Jurkat T cells in a dose- and time-dependent manner. The extract also had free radical scavenging activity as well as reasonable antibacterial activity against Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli and Staphylococcus aureus with MICs ranging from 0,08 to 0.16 mg/ml in the same order as ampicillin the positive control. The biological activities observed in the acetone extract validated the ethnomedicinal use of Senna italica.     

Potential of Neuroprotective Antioxidant-Based Therapeutics from Peltophorum Africanum Sond.(Fabaceae)

There is ample scientific and empirical evidence supporting the use of plant-derived antioxidants for the control of neurodegenerative disorders. Antioxidants may have neuroprotective (preventing apoptosis) and neuroregenerative roles, by reducing or reversing cellular damage and by slowing progression of neuronal cell loss. Although demand for phytotherapeutic agents is growing, there is need for their scientific validation before plant-derived extracts gain wider acceptance and use. We have evaluated antioxidant potential of Peltophorum africanum (weeping wattle), a plant widespread in the tropics and traditionally used, inter alia, for the relief of acute and chronic pain, anxiety and depression. The dried leaves, bark and root of P. africanum were extracted with acetone. Thin layer chromatograms were sprayed with 0.2% 2,2-diphenyl-1-picryl hydrazyl (DPPH) in methanol for screening for antioxidants. Quantification of antioxidant activity was assessed against 6-hydroxy-2, 5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) and L-ascorbic acid (both standard antioxidants), using two free radicals, 2,2′-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) and DPPH, respectively. Results of our study show that the bark and root extracts had higher antioxidant activity than L-ascorbic acid and Trolox, a synthetic vitamin-E analogue. The respective TEAC (Trolox Equivalent Antioxidant Capacity) values for the bark and root extracts, and Trolox were 1.08, 1.28 and 1.0. EC₅₀ values for L-ascorbic acid (5.04 µg/mL) was more active than the leaf 6.54 (µg/mL), but much less active than the bark (4.37 µg/mL) and root (3.82 µg/mL) extracts. Continued work on P. africanum, and other plants rich in antioxidants, may avail neuroscientists with potent neuroprotective antioxidant therapeutics.     

The Antimicrobial Activity of Liquidambar Orientalis Mill. Against Food Pathogens and Antioxidant Capacity of Leaf Extracts

Background

Medicinal plants are an important source of substances which are claimed to induce antimicrobial, antimutagenic and antioxidant effects. Many plants have been used due to their antimicrobial treatments. Antimicrobial and antioxidant activities of L. orientalis have not been reported to the present day. The aim of this work was to investigate of the antimicrobial and antioxidant potentials of different extracts from L. orientalis.

Materials and Methods

The extracts were screened for antimicrobial activity against different food pathogens. These bacteria include 4 Gram positive and 3 Gram negative bacteria and one fungi. The leaf extracts of plant were tested by disc diffusion assay. The MIC was evaluated on plant extracts as antimicrobial activity. In addition to, the plant extracts were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydrazylhydrate) free-radical.

Results

The acetone, ethanol and methanol extracts of L. orientalis showed maximum inhibition zone of 12 mm against Yersinia enterocolitica, Listeria monocytogenes and Staphylococcus aureus. In addition to, the methanol extract displayed a strong antioxidant activity (trolox equivalent = 2.23 mM).

Conclusion

L. orientalis extracts have antimicrobial, and antioxidant potential. Our results support the use of this plant in traditional medicine and suggest that some of the plant extracts possess compounds with good antibacterial properties that can be used as antibacterial agents in the search for new drugs.     

Antimycobacterial Evaluation of Fifteen Medicinal Plants in South Africa

Fifteen plant species were collected from the Nelspruit Botanical Garden based on a list of plants provided by Phytomedicine Programme at the University of Pretoria and their ethnopharmacological information. Hexane, dichloromethane (DCM), acetone and methanolic extracts were screened for antimycobacterial activity against Mycobacterium smegmatis. The acetone extract of Milletia stulhimannii was the most active, showing activity against Mycobacterium smegmatis with minimum inhibitory concentration (MIC) value of 0.13 mg/ml. Acetone extracts for all plants had lower MIC values ranging between 0.11–1.25 mg/ml against M. smegmatis. Milletia stulhimannii, Albizia gummifera, Xanthocercis zambesiaca and Barringtonia racemosa have shown great potential as anti-tuberculosis agents. They were active against M. smegmatis with average MIC values of acetone extracts of 0.13 mg/ml.     

A Study on Antimicrobial,Antioxidant and Antimutagenic Activities of Elaeagnus Angustifolia L. Leaves

Backround

The aim of this work was to investigate the antimicrobial, antioxidant, and antimutagenic potentials of methanol extracts from E. angustifolia.

Materials and Methods

Methanol extracts were screened for antimicrobial activity against different species of 4 Gram positive and 3 Gram negative bacteria and one fungus. These bacteria included food pathogens. The leaf extract was tested using disc diffusion assay.

Results

The methanol extract of E. angustifolia showed maximum inhibition zone of 16 mm against Yersinia enterocolitica. Whereas, the inhibition zone was not determined by methanol extract against Escherichia coli ATCC 1122 and Candida albicans RSKK 02029. The MIC was evaluated on plant extracts as antimicrobial activity. All of bacterial strains showed the lowest sensitivity to methanol extract of E. angustifolia (3.5 mg/mL), except Yersinia enterocolitica NCTC 11174. In addition, the plant extracts were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free-radical. Finally, the methanol extract displayed a strong antioxidant activity (Trolox equivalent = 1.49 mM). Also, E. angustifolia methanol extracts were screened for their antimutagenic activity against sodium azide by Ames test in absence of rat microsomal liver enzyme (-S9). The results showed that E. angustifolia methanol extracts can inhibit mutagenic agents of sodium azide. The plant leaf extracts with the inhibition of 36% sodium azide showed moderate potential in decreasing mutagenic agents in Salmonella typhimurium TA100.

Conclusion

E. angustifolia methanol extracts have antimicrobial, antioxidant and antimutagenic potential.     

Evaluation of Antioxidant and Antimicrobial Potential of Two Endangered Plant Species Atropa Belladonna and Matricaria Chamomilla

Background

Plants are the natural source of antioxidants as well as antimicrobial compounds that has great potentials in pharmaceutical industry. In the present study, two medicinal plants Atropa belladonna and Matricaria chamomilla were collected from Northern areas of Pakistan.

Materials and Methods

The extracts of the collected plants were obtained by microwave assisted extraction (MAE) with changing parameters, power level and time; methanol and ethanol were solvents used during extraction. The extracts of plants were tested against different bacterial strains.

Results

It was observed that ethanolic extracts of Atropa belladonna has more significant antimicrobial activity against S.aureus than E.coli. In parallel, methanolic extract of Matricaria chamomilla showed greater significant antibacterial activity against S.aureus when compared with E.coli. In comparison, ethanolic extracts of Matricaria chamomilla has shown more significant results against S. aureus than E.coli (p≤0.05). Both plants had no antibacterial activity against S.typhi. The free radical scavenging activity observed by DPPH assay, indicate that both plants have antioxidant activity at all levels of concentrations in solvent tested during the present work. However, methanolic extracts had greater antioxidant activity when compared with ethanolic extracts.

Conclusion

Present study is thus helpful in highlighting present potentials for antioxidant and antimicrobial properties in the selected plants.     

Anti-Bacterial and Anti-Oxidant Activities of Leaf Extracts of Combretum Vendae (Combretecacea) and the Isolation of an Anti-Bacterial Compound

Background

Combretum vendae A.E. van Wyk (Combretaceae) is used for the treatment of bacterial related infections and oxidative related diseases by indigenous people of South Africa. Dried leaves extracts of C. vendae were investigated for bioactivity against a variety of bacterial strains and their antioxidant potential evaluated.

Materials and methods

Constituents of leaf material were serially extracted using solvents of varying polarities, TLC chromatograms of the fractions were sprayed with 2,2 diphenyl-1-picrylhydrazyl (DPPH) to determine the presence of antioxidant compounds. Bio-autography was used to determine the number of antibacterial compounds active against Staphylococcus aureus, Enterococcus faecalis, Eschericha coli and Pseudomonas aeruginosa. Minimum inhibitory concentration (MIC) values were determined using serial microplate dilution method. The chloroform fraction was subjected to bio-assay guided column chromatography to isolate the active compound.

Results

The mass extracted by different solvents was below 10% dry weight. MIC values for different extracts against different pathogens ranges from 0.08 to 0.64 mg/ml. The compound isolated was identified as acacetin having an R_f value of 0.28 following elution in the Ethanol: Methanol: Water [E: M: W (10: 1.35: 1 v/v). Acacetin had MIC values ranging from 0.16 to 0.35 mg/ml.

Conclusion

We report for the first time the isolation of acacetin as the main antibacterial compound from the leaves of Combretum vendae.     

Evaluation of Phytochemical and Antibacterial Potential of Helicteres Isora L. Fruits Against Enteric Bacterial Pathogens

Antibacterial activities of aqueous, acetone, ethanol and methanol extracts of fruits of Helicteres isora (Mororphali) were studied. The fruit aqueous extracts of H. isora showed prominent antibacterial activities against E.coli, Staphylococcus epidermidis, Salmonella typhimurium and Proteus vulgaris; moderate activity against Enterobacter aerogenes, Staphylococcus aureus, Salmonella typhi and least activity against Pseudomonas aeruginosa. The aqueous extract showed maximal, the ethanol and methanol extract moderate and acetone extracts least antibacterial activities. Phytochemical screening revealed the presence of carbohydrates, anthraquinon glycosides, proteins, tannin and phenolic compounds and steroids These antibacterial properties supports its traditional use of fruits of H. isora in the treatment of enteric or diarrhoeal infections.     

In Vitro Assessment of Antioxidant,Phytochemical and Nutritional Properties of Extracts from the Leaves of Ocimum Gratissimum (Linn)

The antioxidant, phytochemical and nutritional properties of acetone, methanol and aqueous extracts of the leaves of Ocimum gratissimum (Linn) were investigated to evaluate the therapeutic and nutritional potential of the leaves of this plant. The antioxidant of the plant extracts were assessed against 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and ferric reducing agent. Total phenolics, flavonoids, flavonols and proanthocyanidins were determined to assess their corresponding effect on the antioxidant activity of this plant. The extracts exhibited DPPH and ABTS^.+ radical scavenging activities, which was comparable to butylated hydroxytoluene (BHT). The phytochemical screening revealed the presence of alkaloids, tannins, saponin, steroids, cardiacglycoside, flavonoid, terpenoids and phenol. The proximate analysis confirms that the leaves contain appreciable amount of ash, crude protein, lipids, fibre and carbohydrates. The macro and micro elements and constituents revealed that the leaves contain significant amount of sodium, potassium, calcium, magnesium, iron, zinc, phosphorus, copper, nitrogen, and manganese. This study shows that the leaf can be used as a therapeutic agent and justifies its application in folkloric medicine.     

Determination of Antimicrobial Effect,Antioxidant Activity and Phenolic Contents of Desert Truffle in Turkey

Terfezia boudieri Chatin (Scop.) Pers., is a famous macrofungus in the world as well as in Turkey for its pleasant aroma and flavour. People believe that this mushroom has some medicinal properties. Therefore, it is consumed as food and for medicinal purposes. Chloroform, acetone and methanol extracts of T. boudieri were tested to reveal its antimicrobial activity against four Gram-positive and five Gram-negative bacteria, and one yeast using a micro dilution method. In this study, the highest minimum inhibitory concentration (MIC) value was observed with the acetone extract (MIC, 4.8 µg/mL) against Candida albicans. Maximum antimicrobial effect was also determined with the acetone extract (MIC, 39–78 µg/mL). The scavenging effect of T. boudieri on 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals was measured as 0.031 mg/mL at 5 mg/mL concentration, and its reducing power was 0.214 mg/mL at 0.4 mg/mL. In addition, the phenolic contents were determined as follows: the catechin was 20 mg/g, the ferulic acid was 15 mg/g, the p-coumaric acid was 10 mg/g, and the cinnamic acid was 6 mg/g. The results showed that T. boudieri has antimicrobial activity on the gram negative and positive bacteria as well as yeast, and it also has a high antioxidant capacity. Therefore, T. boudieri can be recommended as an important natural food source.     

In vitro antioxidant activity of extracts from the leaves of Abies pindrow Royle

Traditionally, the leaves of Abies pindrow Royle are employed as an ayurvedic remedy for fever, hypoglycaemic, respiratory and inflammatory conditions. In this study, dichloromethane, methanol and acetone extracts of A. pindrow leaves were analysed for their phytochemical content and in vitro antioxidant activities. The methanol extract exhibited highest antioxidant activity while acetone extract showed presence of relatively high total phenol and flavonoids contents. The present study provides evidence that extracts of Abies pindrow leaves are a potential source of natural antioxidants and could serve as a base for future drugs.     

In Vitro Antioxidant Activity of Extracts From the Leaves of Felicia Muricata Thunb. an Underutilized Medicinal Plant in the Eastern Cape Province, South Africa

Felicia muricata is a medicinal plant used for the management of different human and livestock diseases in the Eastern Cape Province of South Africa. The antioxidant potential of the leaves from this herb was investigated using its water, methanol, acetone and ethanol extracts. All the extracts were rich in phenols, proanthocyanidins and flavonols but low in flavonoids. The water extract exhibited low DPPH scavenging activity while the methanol, acetone and ethanol extracts showed higher activities. Again all the extracts showed high ABTS scavenging activity with a correlation between total phenolic content (R²=0.9965), DPPH (R² =0.982) and ABTS (R²=0.927). Traditionally, however, plant extracts are prepared with water as infusions, decoction and poultice. Our results have shown that both the water and ethanol extracts from Felicia muricata displayed strong antioxidant activity. Therefore, it would seem likely that both solvents were able to extract those compounds which are responsible for the antioxidant activity of F. muricata.Key words: Felicia muricata, antioxidant, DPPH, ABTS, radical scavenging activity     

Antibacterial Activity of Tabernaemontana Stapfiana Britten (Apocynaceae) Extracts

Antibacterial and phytochemical screening of methanolic, sequential extracts (hexane, dichloromethane, ethyl acetate and methanol) and alkaloid rich fractions of Tabernaemontana stapfiana Britten was carried out. The phytochemical screening showed the presence of alkaloids, flavonoids, coumarins, tannins and saponins that have been associated with antimicrobial activity. The stem and root bark methanolic extracts showed good activity against the bacterial strains used including the multiple drug resistant Staphylococcus aureus strain with minimum inhibitory concentrations ranging from 15.6 to 500 µg/ml and minimum bactericidal concentrations ranging from 31.25 to 500 µg/ml. The sequential extracts of the root and stem bark had high antimicrobial activity with minimum inhibitory concentrations (MICs) ranging between 3.9 and 250 µg/ml and minimum bactericidal concentrations (MBCs) ranging between 7.8 and 500 µg/ml against the tested microorganisms. The dichloromethane extract of the alkaloid rich fractions however exhibited reduced antibacterial activities as compared to methanol and sequential extracts but the dichloromethane:methanol (4:1) mixture showed high activity with MICs ranging between 15.6 and 250 µg/ml. These antibacterial efficacy studies suggest that Tabernaemontana stapfiana Britten could be a source of antibacterial agents.     

Cytotoxicity,Phytochemical Analysis and Antioxidant Activity of Crude Extracts from Rhizomes of Elephantorrhiza Elephantina and Pentanisia Prunelloides

Background

Elephantorrhiza elephantina (Ee) and Pentanisia prunelloides (Pp) are two medicinal plants which are widely used to remedy various ailments including diarrhoea, dysentery, inflammation, fever, rheumatism, heartburn, tuberculosis, haemorrhoids, skin diseases, perforated peptic ulcers and sore joints in southern Africa (South Africa, Swaziland, Botswana and Zimbabwe). The following study was conducted to explore the in vitro cytotoxicity, antioxidant properties and phytochemical profile of the two medicinal plants.

Materials and Methods

The cytotoxicity of the aqueous and methanol extracts and fractions of both species was studied using the brine shrimp lethality tests (BST) for the first time.

Results

The results demonstrated that the lethality (LC₅₀) for crude extracts for both plants ranged between 1.8 and 5.8 ppm and was relatively greater than that for the methanol, ethyl acetate and chloroform fractions of the extracts which ranged between 2.1 ppm and 27 ppm. This suggested that crude extracts were more potent than their respective fractions, further explaining that the different fractions of phytochemicals in these plant species work jointly (in synergy) to exert their therapeutic efficacy. Both aqueous and methanol extracts of the two medicinal plants demonstrated a high degree of antioxidant capacity against the DPPH radical with the Duh and Yen inhibition percentage ranging between 4.5% and 72%. Phytochemical studies of the rhizome extracts showed that the major compounds present include flavonoids, tannins, anthocyanidins, anthraquinones, triterpenoids (oleanolic acid), the steroidal saponin Diosgenin, the sugars, rhamnose, glucuronic acid, Arabinose and hexoses.

Conclusion

This is the first report of the detection and isolation of diosgenin and oleanolic acid from the rhizome extracts of Ee and Pp. All structures were determined using spectroscopic/spectrometric techniques (1H NMR and 13C and LC-ESI-MS) and by comparison with literature data.     

Antimicrobial Activity of Various Extracts of Ocimum Basilicum L. and Observation of the Inhibition Effect on Bacterial Cells by Use of Scanning Electron Microscopy

The antimicrobial activities of chloroform, acetone and two different concentrations of methanol extracts of Ocimum basilicum L. were studied. These extracts were tested in vitro against 10 bacteria and 4 yeasts strains by the disc diffusion method. The results indicated that the methanol extracts of O. basilucum exhibited the antimicrobial activity against tested microorganisms. While the chloroform and acetone extracts had no effect, the methanol extracts showed inhibition zones against strains of Pseudomonas aeruginosa, Shigella sp., Listeria monocytogenes, Staphylococcus aureus and two different strains of Escherichia coli. The cells of microorganisms, which were treated and untreated with plant extracts, were observed by using the scanning electron microscope. It was observed that the treated cells were damaged.     

Antimicrobial and Anti-Inflammatory Activities of Pleurostylia Capensis Turcz (Loes) (Celastraceae)

Background

Pleurostylia capensis is a large tree that can reach the maximum height of 20 m long, and it have been traditionally used as cosmetic, for steam bath, ritual body wash, and as a purgative to treat symptoms of witchcraft. Using ethanol, chloroform, dichloromethane (DCM), ethyl acetate (EA), and water extracts, leaves, bark and roots of Pleurostylia capensis were investigated scientifically for their effectiveness in antimicrobial, antioxidant and anti-inflammatory activities using standard methods

Materials and Methods

The extracts were evaluated for antimicrobial activity against Gram positive (Staphylococcus aureus, Bacillus cereus, and Mycobacterium smegmatis), Gram negative (Escherichia coli, Klebsiella pneumonia, Klebsiella oxytoca, Streptococcus pyogenes, Pseudomonas aeruginosa and Salmonella typhimurium), and Candida albicans. The antioxidant activity was investigated using 2, 2-diphenlyl-1-picrylhadrazyl (DPPH), free radical scavenging assay. The anti-inflammatory activity of P. capensis extracts was evaluated against both cyclooxygenase enzymes (COX 1 and 2).

Results

The ethyl acetate extracts of P. capensis showed a strong antimicrobial activity against B. cereus, K. pneumonia, S. pyogenes, and M. smegmatis with MIC value of 0.39 and 0.78 mg/ml. While the ethanol bark extract was most active against M. smegmatis with MIC value of 0.78 mg/ml; the least potent activity was observed with dichloromethane, chloroform and water extracts, with an MIC value ranging from 1.56 mg/ml to 50.0 mg/ml. The plant extracts proved to be good antioxidant agent, whereas extracts of ethanol were the most active, with IC50 ranging from 1.00 to 1.74 µg/ml, which is lower, and in close range to Vitamin C (1.40 µg/ml).

Conclusions

Its moderation to potent inhibitory activity was observed in all extracts. Ethanol and dichloromethane extracts were among the most potent when compared to water and petroleum ether extracts. The water extracts showed to be nontoxic on the Hek cell line with an IC50 value of 204.0, and 207.3 µg/ml (roots and bark) respectively. The dichloromethane, ethyl acetate, chloroform and ethanol extracts showed to be toxic on the Hek cell, with IC50 range from 5.94 to 42.91µg/ml. The results obtained indicate the effectiveness of these plants.     

New Antitrypanosomal Tetranotriterpenoids from Azadirachta Indica

Organic extracts of the leaves of Azadirachta indica A. Juss. yielded ten antitrypanosomal terpenoids. Three of these (1 – 3), are novel and are derivatives of nimbolide and nimbin. They were extracted from chloroform fraction of methanol extract. These compounds were found to exhibit strong antitrypanosomal activities against Trypanosoma brucei rhodesiense with MIC values ranging of 6.9, 15.6 and 7.8 µg/ml respectively and were more active than Cymerlarsan ( a standard drug), which had an MIC value of 187.5 µg/ml when tested against T. b. rhodesiense The structures were elucidated by spectroscopic methods including; NMR, MS, UV and IR.     

The Antiplasmodial Agents of the Stem Bark of Entandrophragma Angolense (Meliaceae)

In the search of active principles from the stem bark of Entandrophragma angolense, we submitted the compounds isolated from the dichloromethane - methanol (1:1) extract of the stem bark to antimalarial test against chloroquine resistant strain W2 of Plasmodium falciparum malaria parasite. Only 7α-obacunyl acetate and a cycloartane derivative exhibited a good activity, with IC₅₀s of 2 and 5.4 µg/ml respectively. Other compounds were moderately active.