Open Access Original Research Article

Phytochemical Composition and Antibacterial Activity of Fruit Extract of Solanum incanum L. against Ralstonia solanacearum

Lucy N. Karanja, Isaac O. K’Owino, Phanice T. Wangila, Rose C. Ramkat

Asian Journal of Applied Chemistry Research, Page 1-16
DOI: 10.9734/ajacr/2021/v9i430218

Aims: To determine the phytochemical composition and antibacterial activity of Solanum incanum fruits against Ralstonia solanacearum.

Study Design: Experimental design involving completely randomized design

Place and Duration of Study: The study was conducted at department of Chemistry and Biochemistry, School of Sciences and Aerospace studies, Moi University, Kenya, between January and June 2021.  

Methodology: Extraction was done by maceration using ethanol as the extracting solvent. Phytochemical screening was done following standard procedures. Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) were determined using the Folin–Ciocalteu colorimetric method and aluminum chloride colorimetric assay respectively. The extract was further analyzed using Gas Chromatography Mass spectroscopy (GC-MS) and Fourier transformed Infrared (FT-IR). In vitro antibacterial activity was determined using disc diffusion method while in vivo studies was done under greenhouse conditions.

Results: Phytochemical analysis showed presence of alkaloids, glycosides, steroids, tannins, flavonoids, phenols, saponins and terpenoids. The TPC and TFC were found to be 84.997 ± 0.2 mg GAE/g and 20.535 ± 0.2 mg/g QE of dried sample respectively. GC-MS analysis revealed the presence of 15 compounds, (9E)-1-Methoxy-9-Octadecene (26.85%), 9-Octadecenamide (Z) (21.43%), E-15-Heptadecenal (7.28%), E-14-Hexadecenal (6.28%), 2,4-Di-tert-butylphenol (4.96%) among others. FT-IR analysis revealed presence of OH, C-H, N-H, CO functional groups at wavenumbers 3348 cm-1, 2931 cm-1, 1589 cm-1, and 1218 cm-1 respectively. The antibacterial activity for in vitro studies at concentrations 0.01, 0.05, 0.10, and 0.15 g/10 mL, the diameters of zone of inhibition were 20.75 ± 1.3, 25.75 ± 0.5, 27.25 ± 0.5, and 30.75 ± 0.5 mm respectively. This was comparable (P= .02) to that of ampicillin (positive control) which had zones of inhibition of 26.75 ± 0.5, 28.75 ± 0.5, 31.75 ± 0.4, and 35.00 ± 0.0 mm at the  concentrations respectively. For the in vivo studies the plant extract and ampicillin delayed the development of the disease by eight and ten days post-inoculation respectively while symptoms of bacterial wilt for water treatment (negative control) were observed four days post-inoculation.

Conclusion: The plant extract had remarkable antibacterial activity and can be used to make viable formulations to control the devastating bacterial wilt disease.

Open Access Original Research Article

Effect of Manihot esculenta Edible Coating Blended with African Basil (Ocimum gratissimum) Essential Oil on the Shelf-Life of Mango Fruits

Decrah M. Nyangena, Phanice T. Wangila, Jackson K. Cherutoi

Asian Journal of Applied Chemistry Research, Page 17-30
DOI: 10.9734/ajacr/2021/v9i430219

Aims: To establish the shelf -life of mango fruits coated with unmodified and modified M. esculenta edible coating at low (4 ± 2°C) and room temperature (23 ± 2°C) conditions.

Place and Duration of Study: The study was done at Moi University, School of Sciences and Aerospace studies, Department of Chemistry and Biochemistry between January 2021 and June 2021.

Methodology: Ocimum gratissimum leaves essential oils was obtained by hydro-distillation method using Clevenger apparatus. Preparation and modification of the coating were homogenized at 70 ± 2 °C. Physico-chemical parameters including weight loss, titratable acidity (TA), Vitamin C concentration, total soluble solids (TSS), and pH were used to establish the fruits’ shelf-life.

Results: The modified M. esculenta (cassava) starch coating (1.5%) treatment, their interactions and storage duration significantly affected the physico-chemical parameters of mango fruits. The modified coating-maintained TA 0.66%, 0.87%, reduced weight loss by 27.81%,14.62%, delayed the increase of TSS 7.50%, and pH 5.20, 4.93 while retaining the vitamins C 8.13 mg/100g, 15.09mg/100g concentration up to eighteen days and twenty-seven day of storage at 23 ± 2°C and 4 ± 2°C respectively. The distilled water treatment (control) reduced TA to 0.11%, 0.23%, increased weight loss to 47.12%, 24.21%, TSS 20.22%, 17.41%, and pH 8.21, 5.20 while retaining the vitamin C 3.74 mg/100 g, 8.13 mg/100 g concentration at 23 ± 2°C and 4 ± 2°C respectively.

Conclusion: Results of the present study showed that M. esculenta edible coating incorporated with O. gratissimum essential oil extended the shelf life of mangoes up to eighteen and twenty-seven days of storage at room temperature (25 ± 2°C) and low temperature (4 ± 2°C), respectively. This treatment might be an effective farm-based post-harvest treatment in prolonging the shelf life of fresh produce while maintaining their physico-chemical parameters.

Open Access Original Research Article

Assessment of Total Petroleum Hydrocarbons and Polycyclic Aromatic Hydrocarbons in Wastewater from Selected Flow Stations in Agbada II, Rivers State

Akpan Esther Emmanuel, Obi Chidi, Kinigoma Boma

Asian Journal of Applied Chemistry Research, Page 31-40
DOI: 10.9734/ajacr/2021/v9i430221

Aims: This study evaluates total petroleum hydrocarbon (TPH) and polycyclic hydrocarbons (PAHs) concentrations in wastewaters from three locations of the oil-producing flow station in Rivers State.

Study Design: By experiment and the results obtained by analytical means.

Place and Duration of Study: This work was conducted at the Department of Industrial Chemistry/Petrochemical Technology, School of Science and Laboratory Technology, University of Port Harcourt, Choba, Rivers State, Nigeria between February and August, 2021.

Methodology: The evaluation was done using gas chromatography-Flame Ionization Detector (GC-FID), and Gas Chromatography-Mass Spectrometer Detector (GC-MSD).

Results: Results obtained showed low levels of total petroleum hydrocarbons ranging from 0.051, 0.119, and 0.07 mg/l and 0.01, 0.06, and < 0.01 mg/l for polycyclic aromatic hydrocarbons for the three locations, respectively. The results also revealed that the concentrations of the total petroleum hydrocarbons of the samples from the three locations were highest at carbon atom 17 suggesting a biogenic contribution of organic matter. The chromatographs obtained gave evidence that the nature of the contamination was minimally crude oil, because crude oil normally distributes in broad range, as observed in the locations samples as against the narrower carbon range of C8 to C40 characteristics of refined products. The pristane/phytane ratios, which were 0.925, 0.891 and 0.372 for the three samples, depicted an oxygenated environment. The C17/pristane ratios (39.53, 38.93, and 31.48) for all three locations revealed that the wastewaters were slightly weathered. The low concentrations as well as absence of high molecular weight polycyclic aromatic hydrocarbons and higher concentrations of low molecular weight polycyclic aromatic hydrocarbons support the petrogenity of the wastewaters. 

The phenanthrene/anthracene ratios (1.26, 0, and 0) for the three samples confirm the nature of the wastewaters. In addition, the absence of benzo(a)anthracene to chrysene ratio for all three samples point to proper treatment of the wastewaters.

Conclusion: From this study, the level of total petroleum hydrocarbons (TPH) and polycyclic hydrocarbons (PAHs) obtained from all the samples were lower than the maximum recommended levels by the Department of Petroleum Resources (DPR). This study recommends constant monitoring in the total petroleum hydrocarbons and polycyclic hydrocarbons concentrations because even at its low concentrations can be injurious to health of the people residing within the facility and beyond.

Open Access Original Research Article

Cementation of Cd Ions on Zinc Using a Rotating Fixed Bed Impeller Basket Reactor

Yousra Hamdy Farid

Asian Journal of Applied Chemistry Research, Page 41-50
DOI: 10.9734/ajacr/2021/v9i430222

Cementation or metal displacement reaction is one of the most effective techniques for removing toxic metals from industrial waste solutions.

Aims: The main purpose of this work is to study the rate of cementation of cadmium by using a rotating bed of Zn Raschig rings packed in a perforated impeller basket for the investigation of the removal of Cd 2+ from waste solution.

Study Design: The reactor was tested for Cd2+ concentration removed, the diameter of Zinc Raschig rings, and the rotational speed of the basket.

Methodology: The results indicate that there are two rates of cementation for Cd-Zn system, a high rate at the beginning, followed by a lower rate after the initial period. The results also show that percentage removal of Cd2+ ions from solution increases by increasing the speed of basket rotation, and as the diameter of Zn Raschig ring packed in the basket reactor, increases the removal of Cd2+ decreases. The cadmium deposits on zinc as powder.

Results: The removal of Cd2+ is optimum for ring diameter of 0.5 cm, initial concentration of 100 ppm, and basket rotation speed of 500 rpm. The experimental data fit the following equation: Sh=0.041 Sc0.33Re0.40.

This equation can be used for the design scale-up and operation of reactors used to remove Cd2+ from wastewater by cementation.

Conclusion: Rates of cementation were expressed in terms of the rate of mass transfer, the mass transfer coefficient increases as the rotational speed of the basket increases.

Open Access Original Research Article

Chemical Composition and Biological Activities of Eugenia caryophyllata Thunb Essential Oil

Fatiha Abdellah, Badra Boubakeur, Noura Ayad, Laid Boukraa, Si Mohamed Hammoudi, Boumedienne Abdelhak, Rachida Benaraba

Asian Journal of Applied Chemistry Research, Page 51-62
DOI: 10.9734/ajacr/2021/v9i430224

Aims: In this study the antibacterial and antioxidant activities of the essential oil of Eugenia caryophyllata were investigated.

Study design: The study contains determination of the chemical composition of the essential oil of E. caryophyllata and the in vitro evaluation of the antibacterial and antioxidant activity of this oil.

Place and Duration of Study: The study was carried out at the laboratory of research on local animal products of Ibn-Khaldoun University, Tiaret, Algeria during the period from December 2020 to March 2021.

Methodology: The essential oil composition was characterized by gas chromatography/mass spectrophotometrical analyses. The antibacterial activity of this oil was tested against four pathogenic bacteria: Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 33862, Bacillus cereus ATCC 11778 by using disc diffusion method and agar incorporation method to determine the Minimum Inhibitory Concentration (MIC) of the tested oil. The antioxidant activity was evaluated by using DPPH radical scavenging, hydrogen peroxide scavenging assays and ferric reducing antioxidant power (FRAP) assay.

Results: Our results have shown a greater antibacterial effect of E. caryophyllata essential oil against all the bacterial tested strains with inhibition zone diameters varied from 17.5 to 20.5 mm and minimal inhibition concentration (MIC) ranged between 0.8 μl / ml and 4.4 μl / ml, B. cereus and S. aureus are the most sensitive species with a MIC value of 0.8 μl / ml, however P. aeruginosa is the most resistant species with a MIC value of 4.4 μl / ml. The result of the antioxidant effect showed that the essential oil of E. caryophyllata is a powerful antioxidant that expresses a higher antioxidant activity than the standard antioxidants: gallic acid, vitamin C and BHT.

Conclusion: The obtained results suggest that the essential oil of E. caryophyllata has a strong antibacterial and antioxidant effect and it may be an alternative natural source medicine to prevent and treat many diseases caused by pathogenic bacteria and oxidative stress.