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The discarded empty aluminium beverage cans can pose a serious environmental contamination issue. Recently, studies are now focusing on reducing and utilising solid wastes which have grown to be a significant environmental concern. Thus, this study focuses on producing γ-Al2O3 from readily available aluminium garbage cans using a Sol-gel technique and analysing its thermal properties using TGA analysis. The effect of the reaction temperatures was further investigated to comprehend the synthesis of alumina at (room temperature, 50 °C, and 70 °C) at a fixed aging duration of 12 h. Experimental findings demonstrated the potential of producing γ-Al2O3 from used aluminium cans, which may then be used as sustainable catalysts and catalytic supports for a variety of applications. The results showed that all the synthesised alumina had a good result with a maximum weight loss less than 5%; this reflected its strong stability. The alumina that was created at 70 °C reaction temperature recorded the lowest weight loss and the highest residue at 2.78% and 97.22%, respectively.

Abstract: Nowadays, free radical chemistry is a field that has gained the wider attention of researchers. Our body generates free radicals’ reactive nitrogen and oxygen species through subjection to several pathological states, endogenous systems, and physicochemical conditions. For the physiological state to occur, it is compulsory to propel a balance between antioxidants and free radicals. Oxidative stress will set in when free radicals can no longer be regulated in the body system. Moreover, free radicals negatively affect DNA, protein, and lipids and cause many diseases in the human body. Thus, natural-sourced antioxidants can be used to manage this oxidative stress. Currently, it has been revealed that some synthetic antioxidants, including butylated hydroxyanisole and butylated hydroxytoluene, are hazardous to human health. Therefore, many efforts have been made in search of natural, non-toxic, and effective compounds that possess anti-oxidative properties. Hence, this review comprehensively presents the roles of plant-based antioxidants in resolving the challenging issues associated with free radical diseases in human beings. It further reviews the characteristics and occurrences of free radicals in the human body, the formation and mechanism of free radicals, some of the physiological impacts of free radicals on human health, sources of free radicals, and plant-sourced antioxidants as a frontier in managing free radicals.

The complicated nature of crude oil emulsions is part of the major setbacks associated with the postulation of methods for phase separation and demulsification in the oil industry. Despite the increasing efforts in generating efficient and dependable demulsification methods, the majority of emulsions cannot be shattered in reduced times. This review examines the trending techniques of crude oil demulsification in the petroleum industry. Several approaches have been examined to discover the best method of demulsification. Hence, this reports reviewed the past studies on the emulsion, formation of oil emulsions, methods of demulsification, characteristics of demulsifier, mechanism of demulsification, kinetics in demulsification, operating parameters influencing the demulsification processes, the structure of demulsifier, and formulations that are involved in the demulsification. The formulations of crude oil demulsification have been investigated to unveil adequate demulsifiers for crude oil. Therefore, demulsification approaches have several applications due to wider varieties of crude oil, separation equipment, brines, chemical demulsifiers, the method in which demulsifiers is been formulated, and product specifications.

Phenolic compounds are essential for growth, pigmentation, resistance to pathogens, reproduction, and among others. This study focused on the optimization of microwave-assisted extraction process variables, i.e., solvent/sample ratio (X1), irradiation time (X2) and microwave power (X3), based on the yields of total phenolic content (TPC) and total flavonoid content (TFC) from Ocimum gratissimum leaf using Box Behnken Design. Furthermore, the chemical compounds in the extract under optimized MAE conditions were identified using LC–ESI–MS/MS analysis; its antioxidant and antibacterial properties were evaluated as well, and optimal MAE conditions, i.e., X1 = 10:1 mL/g, X2 = 3 min and X3 = 553 W, were obtained with TPC and TFC yields of 184.99 ± 3.05 (mg GAE/g extract) and 68.78 ± 2.07 (mg QE/g extract), respectively. The results indicated that the leaf extract of O. gratissimum possesses antioxidant and antibacterial properties. Aside from these, the LC–ESI–MS/MS analysis provided tentative identification of 131 phenolic and other phytochemical compounds in the leaf extract at optimized conditions. The extract showed higher inhibitory activities against all the considered bacteria organisms (at least the concentration of 15 mg/mL). Thus, O. gratissimum leaf can be employed as an industrial crop with potential usage in the nutraceutical and food products.

Carica papaya is a perennial large herbaceous plant known for diverse biological activities. Different parts of this plant such as seeds, leaves, fruits, peels, roots, and stems have been previously reported to possess nutritional and medicinal values. This plant possesses a nutritional value that is rich in vitamins and natural minerals but low in calories. Moreover, every part of this plant had been used in treating different type of diseases which include wound dressing, antibacterial, anthelminthic effects, traditionally used to control birth, and several other activities. These were born out of the in vitro and in vivo studies conducted on the extracts from parts of C. papaya. Furthermore, the occurrences of different kinds of phytochemicals in the extracts might have been responsible for its diverse pharmacological properties. Thus, this article comprehensively outlines and discusses nutritional values, phytochemistry and pharmacological activities of C. papaya.

Since the World Health Organization has suggested the exploration of natural products for cancer management owing to the side effects of chemotherapy and irradiation on humans and breast cancer accounts for the highest number of cancer related deaths globally, this study has examined antiproliferative effects of the aqueous and methanol extracts of Hypsizygus tessellatus (brown and white var.) and Flammulina velutipes caps against two breast cancer cell lines. The antioxidant and antiproliferative activities of these mushroom extracts were evaluated in vitro using chemical-based (for antioxidant activity) and cell (for antiproliferative activity) approaches. Furthermore, the phytochemical composition of the mushroom extracts were identified using mass spectroscopy (UPLC-QTOF/MS). The obtained results showed aqueous extracts of F. velutipes (Enoki) and white H. tessellatus (Bunapi shimeji) caps to possess higher antiodixant activities against DPPH (IC50 = 0.202 and 0.573 mg/mL, respectively), and H2O2 (IC50 = 0.622 and 0.745 mg/mL, respectively) compared tothe methanol extracts. Aqueous extracts of the mushrooms also showed better ferric reducing antioxidant power (FRAP) values against ferric ions compared to the methanol extracts. Finally, the mushroom extracts showed good antiproliferative activities against human breast cancer cell lines. These findings suggest the presence of phytochemicals with antiproliferative and antioxidant acrtivities in the mushroom extracts studied.

Vernonia amygdalina leaves are mostly consumed in Asia and Africa, due to its potential as a good source of antioxidants. In this study, a two-level factorial design was used to evaluate the significant extraction parameters in achieving higher recovery yield of extract, total phenolic content, total flavonoid content, and antioxidants from Vernonia amygdalina leaf. Microwave-assisted extraction technique was employed using aqueous ethanol. The independent parameters were irradiation time (1–5 min), microwave power level (500–700 W), temperature (60–80 °C), feed-to-solvent ratio (1:8–1:12 g/ml), and ethanol concentration (40–80%). Amongst the examined parameters, ethanol concentration, irradiation time, microwave power level, and feed-to-solvent ratio were significant (p

Hibiscus sabdariffa is a multi-cropping system endowed with wide ranges of benefits to humans. Being a plant rich in phenolic compounds, the process intensification of extraction method used for recovering the phenolic compounds from this essential plant is inevitable to easily proffer keen information on the extraction behaviours. Thus, the process intensification and kinetic behaviour of microwave-assisted extraction (MAE) for recuperating total phenolics (TP) content from H. sabdariffa calyces were investigated. The impacts of MAE factors such as solid/sample ratio, microwave power and temperature at varied irradiation time were studied. The effective diffusivity was also estimated. In addition, the extract was characterized to tentatively assign the phenolics using Liquid chromatography tandem mass spectrometry of quadrupole time-of-flight (LC-ESI-MS-MS). The achieved results clearly indicated that the MAE process intensification was acheived with TP content of 70.53 mg GAE/g extract in 3 min at solvent/sample ratio of 14:1 mL/g, microwave power of 500 W and 60 °C of temperature where the highest effective diffusivity coefficient was obtained. Out of the two considered kinetic models (second-order rate and power law), the second-order rate model best describes the MAE process intensification with higher coefficients of determination (R2 > 0.99). Moreover, an aggregate of 77 phenolic compounds was assigned in the extract of H. sabdariffa calyx; signifying the wider potentials of the extract industrially. Thus, this study clearly outlined that H. sabdariffa calyx is an embodiment of diverse phenolic compounds; indicating its potential in pharmaceutical and food industries.

The extracts from Vernonia amygdalina leaves dried using different modes of drying were examined for their antioxidant activities. The component identification was carried out on extract with the highest antioxidant property using GC–MS analysis. Using DPPH, ABTS+ and H2O2 radical scavenging assays, the shade, the sun, oven at 40, 50, and 60 °C dried sample extracts were screened. The obtained scavenging activities were in the order: shade drying > sun drying > oven drying at 40 °C > oven drying at 50 °C > oven drying at 60 °C. The extract from shade-dried sample exhibited the highest activity by scavenging 63.21–92.25% of DPPH, 75.32–93.15% of ABTS+, and 82.53–95.78% of H2O2 radicals, which were higher than those of ascorbic and gallic acid scavenging activities. In addition, the effects of drying methods and extract concentrations on the antioxidant activity of V. amygdalina leaf were significant (p < 0.05). A total number of 11 major compounds were identified from the shade-dried extract viz: phytol (43.69%), (z,z,z)-methyl ester-9,12,15-octadecatrienoic acid (17.60%), 2-methyl-3-hexanol (6.83%), ethyl ester-9,12-octadecadienoic acid (6.07%), ethyl ester linoleic acid (5.19%), ethyl ester hexadecanoic acid (5.06), heneicosane (4.15%), heptacosane (3.25%), and others are less than 3%. Therefore, it can be deduced that an increase in drying temperature may deteriorate the antioxidant activity of Vernonia amygdalina leaf.

The nutraceutical potential of black and white pepper has drawn the attention of many researchers to unravel their pharmaceutical and nutritional properties. These properties could be attributed to the presence of some essential bioactive compounds and mineral elements. This study, therefore, investigated the phenolic and mineral element composition in their oleoresin extracts, using a set of physicochemical and characterization protocols. The result obtained at optimum condition gave a total of 17 and 20 phenolic compounds in black and white pepper extracts, respectively. Moreover, four essential mineral elements (Na, Mg, K, and Ca) were detected. The presence of hazardous elements such as Ar, Se, Pb, and Cr, below the detection limit (BDL) indicated the edibility of the oleoresin extracts. The total phenolic content (TPC) in both extracts was evaluated using Folin-Ciocalteu assay. The result showed that the white pepper extract exhibited higher total phenol content (63.40 ± 0.096 mg GAE/g d.w) than black pepper extract (51.95 ± 0.025 mg GAE/g d.w). The combined action of the mineral elements, total phenolic content and the phytochemical profiles confirmed the potential of oleoresin extracts as natural antioxidants in food and pharmaceutical industries.

Black and white peppers are important oil bearing commodity crop in tropical areas. They are highly beneficial in food industries and herbal medicine, due to their amazing aroma and therapeutic activities. In this study, heat reflux technique was employed to extract medicinal oleoresin from the two peppercorns. For this purpose, various extraction parameters were considered viz: extraction time, particle size and feed-solvent ratio. These extraction parameters were employed to optimize the extraction yield and absorbed energy via Taguchi methodology. The established optimal condition values of the yield and absorbed energy from the parametric study were 13.22 mg/g and 285.60 J/min, respectively in black pepper heat refluxation. Moreover, in white pepper refluxation, the extraction yield and absorbed energy were 14.04 mg/g and 264.82 J/min, respectively. Artificial neural network (ANN) was used for prediction purposes. This was achieved by comparing two algorithms, transfer functions and neurons. A good training and better prediction of the experimental data were observed using the Levenberg Marquardt (LM) feed forward backpropagation algorithm with log sigmoid transfer function as hidden layer and 3-4-5-1 as model topology. Furthermore, a total of 19 and 25 bioactive compounds were identified in black and white pepper extracts, respectively. The results from the Scanning Electron Spectrometry (SEM) showed a remarkable morphological changes during the heat refluxation process.

The integrated bacterial mixed culture consortium with disproportionate oxygen demand was discovered to mutually cooperate with one single biofilm in oxidizing sulfide at different concentration. The present work was carried out to verify the potential of bacterial mixed culture (BMC) in developing a predictive optimum condition for sulfide oxidation in a laboratory batch mode. A face centered central composite design (FCCCD) under response surface methodology (RSM) was employed to predict the synergistic effects of initial hydrogen sulfide concentration (100–500 ppm), temperature (30–40 °C) and aeration rates (50–250 vvm) on BMC sulfide oxidation. A total number of 20 experimental runs with 6 centre points were carried out. The obtained results were analyzed using design expert and statistical validation indices to check the adequacy of the obtained quadratic models. The analysis of variance showed that more than 99% of the variation was explained by the models. There was a good agreement between experimental and predicted data. The optimum sulfide removal of 448.75 ppm was achieved at the temperature of 32.4 °C, initial hydrogen sulfide of 500 ppm and aeration rates of 110.06 vvm in 8 h. Therefore, the finding depicts the adequacy of the obtained model in enhancing BMC sulfide oxidation conditions. The model is further affirmed through SEM-EDXS analysis, revealing oxidized sulfide product aggregate of the micrographs coupled with elemental identification and quantitative composition.

In this study, the oven drying behaviour, as well as changes in the morphological appearance of Vernonia amygdalina leaves before and after drying were investigated. The drying experiments were conducted using a universal oven. Vernonia amygdalina leaves were dried at 40, 50 and 60 °C air temperatures. During the drying processes, the air flow rate was held at 1 m/s2 and the samples spread on the drying trays were placed parallel to the direction of air flow. The obtained data were fitted to eleven different mathematical drying models. Four statistical tools, viz, correlation coefficient, mean bias error, sum of the square error, and reduced chi-square were used to analyse the fittings. Amongst the considered drying models, Midilli-Kucuk drying model showed the best fitting in describing the drying behaviour of Vernonia amygdalina leaves. In addition, the effective diffusivities for the three air temperatures ranged from 4.55 × 10−12 to 5.48 × 10−12 m2/s with the activation energy of 8.048 kJ/mol. Moreover, to evaluate the effect of drying conditions on the morphological changes of Vernonia amygdalina leaves, fresh and dried leaves under different conditions were compared. Thus, drying conditions had effects on microstructure of Vernonia amygdalina leaves. Keywords: Drying, Mathematical models, Morphology, Vernonia amygdalina

Aloe vera is a perennial ethno-medicinal potential plant with a xerophytic characteristic, but not a cactus. It has a famous history owing to its phytopharmaceutical properties and this had made it useful in the pharmaceutical, cosmetic and food industries. Studies had shown the positive effects of its extract against bacteria, organisms. The phytochemical properties of A. vera have fungi, virus and parasitic been exploited for various economic and commercial purposes. This review contributes literature on the bioactive potential composition, processing and the pharmaceutical potential uses, an adverse side-effect that might spring up in case of over dosage and important safety precautions are summarized. More scientific innovations and developments in the aspect of analytical chemistry are on the way to provide more acceptable, purified chemical characterization of A. vera using sophisticated laboratory equipment and machines.

Microwave-assisted extraction (MAE) of phenolic compounds from Chromolaena odorata leaves was investigated using one-factor-at-a-time (OFAT) and two-level factorial design. The MAE parameters studied were irradiation time (A: 1–5 min); microwave power level (B: 400-800 W); extraction temperature (C: 60–80 °C); solvent/feed ratio (D: 8:1–14:1 mL/g); and ethanol concentration (E: 20–60% v/v). The optima yields of TPC and TFC were 56.13 mg GAE/g d.w. and 44.78 mg QE/g d.w., respectively were achieved from MAE of C. odorata leaf at irradiation time of 2 min, microwave power of 600 W, temperature of 60 °C, solvent:feed ratio of 10:1 mL/g, and ethanol concentration of 40% v/v through one-factor-at-time (OFAT) experimental trials. The results obtained from a two-level factorial design experiments reflected that only ethanol concentration (20–60% v/v), irradiation time (1–5 min) and microwave power level (400–800 W) had significant effects on the yields of total phenolic content (TPC) and total flavonoid content (TFC) from C. odorata leaves (p < 0.05). However, temperature and solvent/feed ratio was not significant. In addition, the interactions AB (irradiation time and microwave power) and AE (irradiation time and ethanol concentration) contributed greatly to the recovery yields.

Vernonia cinerea is one of the medicinal plants with several potentials for treating different ailments. In the present study, Microwave-assisted extraction (MAE) was employed in extracting phenolics compounds from this plant. However, different factors that affect this extraction method in the recovery of phenolics compounds abound, these factors need to be screened to determine actual contributing factor in order to minimize cost. Irradiation time (1-5 min), ethanol concentration (20-60% v/v), microwave power (40-80 W), extraction temperature (40-80 oC), and feed/solvent (1:10 - 1:18 g/mL) have been screened using two-factorial design for the recoveries of phenolic compounds from V. cinerea leaves. The results obtained in this study indicated that only microwave power, ethanol concentration, irradiation time and feed/solvent contributed to recoveries of total phenolic content (TPC) and total flavonoid content (TFC) from V. cinerea leaves. Thus, these factors at these ranges can be further optimized to obtain optimal yields of phenolic compounds from V. cinerea leaves.

Carica papaya is a well-known plant with diverse importance to human beings. The efficacy of microwave-assisted extraction (MAE) in the recovery of phenolic compounds from C. papaya leaf was investigated in this study. The MAE process variables were optimized using response surface method; at the optimized conditions, the embedded phenolic compounds in the extract were identified through LC-QTOF-MS analysis. The results showed that the best MAE conditions were: time of irradiation at 3 min; microwave power of 420 W; feed-to-solvent ratio of 1:12 g/mL; and solvent concentration of 56% ethanol/water to achieve 102.59 mg GAE/g d.w. of total phenolic content (TPC). At these conditions, an aggregate of 72 phenolic compounds was tentatively identified. These results infer that MAE as a technique can recover phenolic compounds from C. papaya leaf. Hence, the identified compounds can further be quantified with their respective pharmacological properties in future studies.

The free radicals are reactive molecules that emanate during oxidation; this can then stimulate a chain reaction that can cause cellular damage. A lot of studies had affirmed the implications of free radicals mostly the reactive oxygen species in generating over a hundred degenerative diseases in the human being; these include cancer, acquired immunodeficiency syndrome (AIDS), diabetes, central nervous system injury, arthritis, gastritis, atherosclerosis, reperfusion, and ischemia injury of different tissues. Scientific studies have postulated that the bioactive compounds mainly from natural products can protect the body system from free radicals. Thus, this chapter focuses on the antioxidant potential of Vernonia amygdalina and its toxicology.

The high death rate associated with cancer has fuelled the search for complementary cancer treatment methods in recent times. Among the leading alternative methods is natural products which have attracted much attention due to their high body tolerance. In this study, the caps of Flammulina velutipes (commonly called Enoki), an edible mushroom, were extracted with different solvents and characterized for in vitro antioxidant and anticancer activities. The anticancer activity of the extract was studied against breast cancer cells (MCF-7 and MDA-MD-231) and normal or Vero breast cells (MCF-10a). The radical scavenging, metal reducing power, and anticancer properties of the extracts were investigated via in vitro chemical and cell-based methods. Furthermore, a phytochemical profiling process was performed on the extract fraction with the highest level of biological activities using Liquid chromatography-mass spectrometry coupled with quadrupole time of flight (LC-MS-QTof). The results showed acetone fraction of Enoki caps to exhibit more radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals (IC50 = 0.840 mg/mL) and hydrogen peroxide (H2O2) radicals (IC50 = 0.890 mg/mL) compared to the ethyl acetate fraction (IC50 = 0.97 mg/mL against DPPH and 1.180 mg/mL against H2O2). Additionally, acetone fraction showed a better metal reducing property in a concentration-dependent manner. The in vitro cytotoxicity study showed a preferential level of toxicity of the acetone extract to the studied cancer cell lines compared to the Vero cells. This extract showed more cytotoxicity against MCF-7 (IC50 value ranged from 17.7 µg/mL to 38.36 µg/mL) and MDA-MB-231 (IC50 value ranged from 114.5 µg/mL to 184.2 µg/mL) compared to MCF-10a (>250 µg/mL). These findings present F. velutipes caps as a potential natural source of antioxidant and anticancer agents. Keywords: Anticancer, Antioxidant, Breast cancer, F. velutipes, Phytochemicals

Recently, discovering natural antioxidants have gained more interest due to the fact that most infectious ailment, namely cardiovascular disorder, diabetes and cancer are associated with free radical cells. Thus, the extraction of phenolic compounds from Vernonia cinerea leaves through Soxhlet extraction method was studied. The effects of extraction time (1–4 h), feed-to-solvent (1:10–1:25 g/mL) and ethanol concentration (20–80% v/v) on the yield of extract, total phenolic content (TPC) and total flavonoid content (TFC) were examined. Moreover, the phenolic compounds and functional groups in the extract at maximum conditions were identified using Liquid Chromatography-Mass Spectrometry Quadrupole Time of Flight (LC–Q–TOF–MS) and Fourier Transform Infrared Spectrometry (FTIR), respectively. The antioxidant activity of the extract was as well investigated. The experimental results showed that the highest yield of extract (10.01 ± 0.85% w/w), TPC (53.96 ± 1.45 mg GAE/g d.w.) and TFC (30.09 ± 0.44 mg QE/g d.w.) were achieved using extraction time of 2 h, feed-to-solvent of 1:20 g/mL and ethanol concentration of 60% v/v. However, the extract reflected good antioxidant activity.

Black pepper is a functional plant with nutritional and medicinal benefits. Piperine being the major bioactive compound in black pepper has been applied for the treatment of many free radical-related diseases. This study determined a combination of operating parameters that optimize the microwave extraction of the piperine oil. The effect of irradiation time, microwave power level, feed particle size and feed-solvent ratio on piperine content and absorbed microwave energy were tested using a three-level L9-Taguchi parametric design. The results obtained placed the optimum extraction condition at 90 min of irradiation time, 350 W of microwave power, 0.1 mm of particle size and 1:12 of feed-solvent ratio. Under this optimal condition the optimal piperine oil and absorbed microwave energy of 5.64 w/w and 84.17 J/min were obtained, respectively. The optimal conditions can therefore be employed to design extraction process with higher efficiency and productivity. Keywords: Black pepper, Piperine, Microwave reflux extraction, Taguchi optimization, Signal-to-noise ratio

Emerging evidence has revealed the functional characteristics of black pepper extracts for both nutritional and medicinal purposes. The medicinal properties of this important commodity crop are due to the presence of active piperine which it a viable drug potential in ethnomedicine for the treatment of many degenerative free-radical related diseases. In this study, the microwave-enhanced technique was employed in the extraction of alkaloid oleoresins at optimum condition. The metabolomics-based approach was employed to determine the alkaloid profiles using LC-MS-Quadrupled time of flight mass spectrometer. At optimum microwave condition, a total of 21 bioactive alkaloids were identified with piperine being the most abundant with a mass to charge ratio of 286.1442 m/z. The result from the SEM-monograph and BET-surface characterization showed a remarkable transformation in the micro-cellular matrix as a result of the applied microwave electromagnetic heating.

The tentative identification of bioactive compounds in the extract of Vernonia amygdalina leaf was carried out using positive ionization of Liquid chromatography-mass spectrometry quadrupole time of flight (LC-Q-TOF/MS). The positive ionization is associated with the presence of saponins, flavonoids, alkaloids, terpenoids, and glycosides. Tentative assignments of the secondary metabolites were performed by comparing the MS fragmentation patterns with Waters® UNIFY library which allows positive identification of the compounds based on the spectral match. All the metabolites compounds were estimated and presented in a BPI (Base peak intensity) plot. These data are the unpublished supplementary materials related to “Ethanolic extraction of bioactive compounds from V. amygdalina leaf using response surface methodology as an optimization tool” (Alara et al., 2018).

Cancer management is associated with serious side-effects due to the harmful nature of radiation and chemotherapy on the body cells. These side-effects have necessitated the need for diversifying the alternative or complementary sources of cancer therapy. Natural products have been on the front line as alternative sources of anticancer agents and have attracted much attention in recent times. In this study, the anticancer activity of Hypsizygus tessellatus (white var.) caps (also known as Bunapi shimeji) extracted with acetone and ethyl acetate was evaluated in vitro against MDA-MB-231 and MCF-7 (breast cancer cell lines) and MCF-10a (Vero or normal breast cells). Likewise, the free radical scavenging and metal reducing activities of the extract were evaluated through in vitro chemical-based methods. Furthermore, the phytochemical compositions of the extracts were determined through LC–MS-QTOF-assisted mass spectroscopy. The results of this study indicated that acetone fraction had better radical scavenging activity against DPPH (IC50 = 0.76 mg/mL) and H2O2 (IC50 = 0.84 mg/mL) than ethyl acetate fraction against DPPH (IC50 = 1.10 mg/mL) and H2O2 (IC50 = 1.26 mg/mL) (p

Diabetes mellitus is a metabolic disorder disease emanating from the inability of body’s response to high glucose levels in the blood. However, the side-effects from consuming synthetic drugs have reduced the effectiveness, thus, the potential of purple fleabane (Vernonia cinerea) leaf was investigated using microwave-assisted extraction (MAE) in this study. The influences of extraction factors such as irradiation time, microwave power level, feed/solvent, and ethanol concentration on the recovery yields of polyphenol and flavonoids were as well studied. Thirty experimental runs using a face-centered central composite design (FCCCD) with six centre points were employed and optimal yields were obtained by generating quadratic models based on response surface methodology. The obtained optimal MAE conditions were as follows: irradiation time, 2 min; microwave power level, 444 W; feed/solvent, 1:14 g/mL; and ethanol concentration, 47% v/v. There was an insignificant difference between the predicted and experimental data (p > 0.05), showing good predictive models for the extraction of phenolic compounds from V. cinerea leaves using MAE. Also, the results confirmed that MAE can recover higher phenolic compounds, antioxidant, and anti-diabetic activities from V. cinerea leaves in shorter extraction time. In addition, the phenolic compounds in V. cinerea leaf extract were identified using liquid chromatography-mass spectrometry quadrupole time of flight (LC–MS-Q-TOF) and Fourier transform infrared spectroscopy (FTIR). The extracts showed higher anti-diabetic activity using alpha-amylase and alpha-glycosidase assays which suggested its exploration in pharmaceutical and functional food industries.

The most daunting challenge in microwave extraction is the variability in the output quality due to inherent uncontrollable temperature factors. This study focused on how to optimize the energy absorption and reduce the effects of temperature fluctuations on extracts quality in microwave extraction of white pepper. The Taguchi Orthogonal Optimization array was employed to simultaneously study the effects of four parameter settings on energy absorption. The result obtained from the three-level setting confirmed solvent-to-plant ratio (D) as the most significant factor in the optimization of absorbed microwave energy. This suggests that solvent-to-plant ratio provided a higher contribution to the extraction process with a decreasing significance level of D > A>B > C. The result from the microstructural analysis showed a 40.02% decline in the BET-surface area. The cumulative area decline and morphological changes indicated textural and dispersive transformation from the intermittent microwave electromagnetic heating. Moreover, The LC–MS/QToF analysis shows the presence of 25 and 186 bioactive compounds for negative (–ve) and positive (+ve) electrospray (ESI) ionization modes, respectively. These compounds are responsible for various biological activities of oleoresin oil which has a potential use in many medicinal applications.

The microwave-assisted extraction conditions for the optimal yield of extracts and total phenolic content (TPC) from Vernonia amygdalina leaf were optimized using a face-centered central composite design of response surface methodology. The independent parameters were viz: irradiation time (5–15 min), microwave power (400–600 W), temperature (90–110 °C), and feed-to-solvent ratio (1:8–1:12 g/mL). The optimal conditions for highest yield of extract (22.34% w/w) and TPC (102.24 mg GAE/g d.w.) were obtained at irradiation time of 8 min, microwave power of 416 W, temperature of 100 °C, and feed-to-solvent ratio of 1:8 g/mL. The quadratic model significantly (p

This paper contains data from the elemental and phytochemical profiling of black pepper oleoresin extracts using the LC-MS QToF and ICP-MS analysis. In recent years studies have shown the medicinal properties of extracts from these two cultivars of Piper nigrum. The medicinal properties are attributed to the presence of many secondary metabolites and mineral element in them. The phytochemical profiling was conducted using a Liquid Chromatography equipped with an electrospray time-of-flight mass spectrometer detectors. The mass spectrometer was equipped with an electrospray ionization sources operated in positive ion mode. The alkaloid compounds in the optimized black pepper extract were tentatively characterized in accordance with their ions׳ mass fragmentation.