Comparative study of the antifungal activity of sequential extracts of Fuchsia lycioides against Candida sp.

The genus Fuchsia is generally used in herbal preparations to treat conditions caused by microorganisms. Based on the popular use of this type of plants, the objective of this study was to obtain sequential extracts of increasing polarity from the branches of Fuchsia lycioides by maceration at room temperature and by the Soxhlet method at 60ºC, to later evaluate the antifungal capacity of the extracts against different clinical isolates of the Candida genus. The ethyl acetate extract exhibited strong anti-fungal activity, selectively inhibiting C. albicans strains with MIC and CMF values of 10 and 15 µg/mL, respectively; comparable with the drug itraconazole®. The analysis of the extract by GC-MS showed a high concentration of terpenoids (mainly phytol) and phenylpropanoids (mainly cinnamic acid), possibly responsible for the antifungal activity of the ethyl acetate extract of F. lycioides.

Bioassay Guided Fractionation of Senna singueana and Its Potential for Development of Poultry Phytogenic Feed Additives

There has been burgeoning interest in plant-based feed additives following restrictions placed on the use of antibiotic feed additives in many countries. Phytogenic feed additives are recommended to have a range of useful properties to support the growth and development of poultry to a similar level as that obtained by supplementing feed with antibiotics. The aim of this study was to evaluate the antibacterial, anti-lipoxygenase and antioxidant activity, and in vitro safety of fractions and isolated compounds from leaves of Senna singueana. Antibacterial activities of the fractions and isolated compounds were determined against a panel of bacteria using a two-fold serial microdilution assay and qualitative bioautography assays. Anti-lipoxygenase activity was evaluated using the ferrous oxidation-xylenol orange (FOX) method. Antioxidant activity was assessed qualitatively and quantitatively using radical scavenging assays. Dichloromethane and ethyl acetate fractions from solvent-solvent partitioning had the best antibacterial activity with MIC values ranging from 156 to 313 μg/ml. Fractions obtained from column chromatography had significant to weak antibacterial activity with MIC values ranging from 50 to 1,250 μg/ml. Bioautography showed clear bands of bacterial inhibition, indicating the presence of a number of active compounds in several fractions. The ethyl acetate fraction and all the tested column fractions had potent anti-lipoxygenase activity with IC50 values of ≤2.5 μg/ml which were lower than that of quercetin (positive control), indicating anti-inflammatory potential. The ethyl acetate fraction and several column fractions had powerful antioxidant activity with IC50 values of ≤5 μg/ml in the ABTS assay. Cytotoxicity values against Vero kidney cells ranged from LC50 = 40.0–989.3 μg/ml. Bioassay-guided fractionation led to the isolation and identification of a known bioactive compound, luteolin. S. singueana is a promising candidate for the development of poultry phytogenic feed additives.

In Vitro Antibacterial Activity, Preliminary Phytochemical Screening Profile, and In Vivo Toxicity of Seven Traditional Medicinal Plants in Ethiopia

The threat of antibiotic-resistance calls for novel antibacterial agents. This study was aimed at screening medicinal plants for their antibacterial properties, phytochemical content and safety. Leaves of Allophylus abyssinicus (Hochst.) Radlk., Dicliptera laxata C.B.Clarke, Ligustrum vulgare L., Solanecio gigas (Vatke) c. Jeffrey and Gymnanthemum myrianthum (Hook.f.) H.Rob.; leaf and stem-bark of Olinia rochetiana A. Juss. and the seed of Cucurbita pepo L. were used. Chloroform and ethanol were used to extract G. myrianthum, D. laxata and O. rochetiana; ethyl acetate and methanol for the rest, and water for all. The extracts were tested against clinical/standard strains of Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus by the agar-diffusion method. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined. Acute toxicity to mice was checked and preliminary phytochemical screening was done. Thirteen extracts, out of 24, were active (inhibition zone >7 mm) at differing levels (9.67±0.33-25.66±0.57 mm) against at least one bacterial strain. The MICs and MBCs were 1.95-15.6 mg/mL and 7.8-125 mg/mL respectively. The aqueous extract of S. gigas, methanol extracts of L. vulgare and A. abyssinicus, and ethanol extract of O. rochetiana leaf were the most active (MIC 1.95mg/ml) against S. aureus. Ethyl acetate extracts of A. abyssinicus, L. vulgare and S. gigas; aqueous of C. pepo, O. rochetiana and G. myrianthum; and all D. laxata had no antibacterial activity. P. aeruginosa was the least susceptible to any extract, although the methanol and aqueous extracts of S. gigas performed better against it. Preliminary phytochemical screening of selected extracts for phenols, flavonoids, tannins, steroids, terpenoids, steroidal glycosides, alkaloids, saponins, resins and glycosides showed positivity at least for four of these phytochemicals with glycoside and terpenoids in nearly all extracts and resin in none. The plants were not toxic to mice at 2000 mg/kg. Further consideration of S. gigas, L. vulgare, A. abyssinicus and O. rochetiana is recommended in light of their promising potential and safety.

Phytochemical compositions and antimicrobial activity of leaf extracts of Calotropis procera against food spoilage microorganisms

Background: The purpose of this study was to determine the phytochemical composition and antimicrobial potential of crude n-hexane, ethyl-acetate, methanol and aqueous extracts of Calotropis procera leaves against food spoilage microorganisms. Methods: Standard protocols were employed for the analysis of qualitative phytochemical compositions of the extracts, and antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Pseudomonas aerugenosa and Aspergillus niger. Results: Phytochemical analysis revealed the presence of tannin, saponin, alkaloids, flavonoids, reducing sugar and phenolics. Terpenoids were absent in ethyl acetate and n-hexane extracts while cardiac glycoside was absent in all extracts. All extracts produced antimicrobial activity at a varying zone of inhibition. The widest inhibition zone was produced by methanol extract (21.35±0.43 mm) on staphylococcus aureus while the lowest inhibition zone (12.05±0.45 mm) was observed in the n-hexane fraction. Similarly, the widest inhibition zone (17.24±0.95 mm) was produced by methanol on A. niger while the lowest inhibition zone (5.45±0.42 mm) was produced on n-hexane on A. niger. However, the ethyl acetate extract showed no visible inhibitory zone on all the tested microorganisms. The minimum inhibitory concentration ranged from 32 mg/ml (S. aureus and B. cereus) for ethanol extracts to 128 mg/ml (B. cereus, P. aerugenosa and A. niger) for n-hexane extract. Conclusion: The result shows that the plant is a good source of bioactive compounds that can be used as a natural alternative to a chemical agent in preserving and controlling food poisoning organisms.

Solvent Screening, Optimization and Kinetic Parameters of The Biocatalytic Epoxidation Reaction of Beta-Pinene Mediated by Novozym®435

Monoterpenes are secondary metabolites widely used in the flavors and fragrance industries and can have their structure altered to enhance their applicability, such as producing epoxides, which are used as synthetic blocks for pharmaceuticals. Epoxides are commonly synthesized by the use of inorganic acids as catalysts, although the acid medium induces epoxide degradation. To overcome these limitations biocatalysis is shown as an alternative, in view that lipases can perform the reaction in a non-acidic medium. Related to, this work aimed to perform the synthesis of beta-Pinene epoxide using Pseudozyma antarctica lipase B (Novozym®435) as biocatalyst and to determine the independent variables that influence the reaction using experimental design tools. Different solvent systems were evaluated for until 72 h, in reactions with molar ratio of 2:2:1 (beta-Pinene, octanoic acid, and urea-hydrogen peroxide - UHP) at 40°C, 250 rpm, and 10%(w/v) of the biocatalyst. Ethyl acetate showed higher conversion (40% in 24 h) into the product without the formation of by-products. The atom economy (AE) was determined using metrics of green chemistry and ethyl acetate proved to have a higher atom economy (67.8%), while the other solvents that used octanoic acid as an acyl donor had 41.3%. In the following reactions, ethyl acetate was maintained as the solvent, while the temperature, molar ratio, and the percentage of the biocatalyst were varied. The increase in the molar ratio (beta-Pinene:UHP, 1:1) and percentage of biocatalyst (20%w/v) resulted in 80% of the product after 3 hof reaction at 40°C. To evaluate the impact of each independent variable, an FFD was performed by varying temperature, molar ratio, stirring, and percentage of enzyme, in one level. All variables were statistically significant, with different rates of impact. Due to this, the same variables were maintained on the CCRD, varying in two levels. The conversion ranged from good to excellent (32 - 93%). The independent variables that influenced the direction were temperature > stirring > molar ratio. In conclusion, the combination of two different tools of experimental design provided the development of an optimized model for beta-Pinene epoxidation, achieving high yields within 3 h.

Microscopic Identification and Determination of Total Flavonoid Content of Moringa Leaves Extract and Ethyl Acetate Fraction (Moringa oleifera L.)

This research was conducted to identify simplicia microscopically, phytochemical screening and determination of total flavonoid content of extract and ethyl acetate fraction from Moringa (Moringa oleifera L.) leaves using UV-Visible Spectrophotometry method. The experimental design used in this study was to perform microscopic identification of Moringa leaf powder simplicia, make 96% and 70% ethanol extract and ethyl acetate fraction of Moringa leaves from 70% ethanol extract, then carry out phytochemical screening and determination of total flavonoid content with quercetin standards. Phytochemical screening on the ethyl acetate fraction of Moringa leaves included tests for the content of flavonoids, saponins, tannins and alkaloids. The results of microscopic identification of Moringa leaf simplicia showed the presence of calcium oxalate crystals in the form of rosettes, mesophyll and stomata. The result of determination of total flavonoid content in 96% ethanol extract was 16.69 ± 0.74% (w/w), 70% ethanol extract was 10.84 ± 0.49% (w/w), Moringa leaf ethyl acetate fraction 14 .45 ± 0.90% (w/w). The highest total flavonoid content was found in the 96% ethanol extract of Moringa leaves in accordance with the 2017 Indonesian Herbal Pharmacopoeia, that the thick extract of Moringa leaves containing no less than 6.30% (w/w) total flavonoids was calculated as quercetin.