Extraction Of Total Phenolics Research Articles

Microencapsulation of Hibiscus sabdariffa extract in taro starch: Determination of optimal conditions of bioactive compound retention using response surface methodology.

Hibiscus sabdariffa (HS) extract contains a large amount of bioactive compounds with antioxidant, anticarcinogenic, and antihypertensive effects. The extraction of total phenols, flavonoids, and anthocyanins is more efficient at boiling temperature (~91 °C) than that performed at room temperature (~27 °C). In this study, a central composite rotatable design (CCRD) was used to optimize the inlet temperature conditions of a spray dryer and the concentration of taro starch solids to obtain microcapsules with the highest retention of bioactive compounds in hibiscus extracts. Optimized microcapsules (OM) were obtained at an inlet temperature of 118 °C and solid concentration of 26.5 %. Low moisture content (4.54 %) and water activity (0.2) and high content of total phenols (3374.91 mg GAE/100 g), flavonoids (372.81 mg QE/100 g), monomeric anthocyanins (36.74 mg C-3-GE/100 g), and angiotensin-converting enzyme inhibitory activity (80.01 %), were determined in OM using response surface methodology. OM showed a range of spherical agglomerate sizes (10--32 μm). These results indicate that CCRD is a good tool for establishing the optimal conditions for solid concentration and drying temperature to maximize the protection of bioactive compounds using taro starch as the wall material.

Antibacterial and Antioxidant Activities of Hydroalcoholic and Phenolic Extracts from Ternstroemia dentisepala and T. lineata Leaves.

Traditional Mexican medicine commonly uses infusions of Ternstroemia spp. to treat insomnia, injuries, and infections. The antibacterial activities of Ternstroemia dentisepala and Ternstroemia lineata were evaluated for the first time against a panel of Gram-positive and Gram-negative bacteria that have implications for human health, including Enterococcus faecalis, Streptococcus agalactiae, Streptococcus pyogenes, Salmonella typhi, Pseudomonas aeruginosa, and Vibrio parahaemolyticus. Furthermore, the scavenging potential of the hydroalcoholic (HAEs) and total phenolic extracts (TPEs) from the leaves of both plants by a 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay (ABTS•+) was determined. Also, the total phenolic contents of the HAEs using the Folin-Ciocalteu reagent were assayed. T. dentisepala HAE and TPE were active against all bacterial strains tested, with a minimum inhibitory concentration between 1.0 and 6.0 mg/mL, with the last one being the most active. However, the T. lineata extracts only demonstrated effectiveness against S. typhi and P. aeruginosa. The TPEs from T. dentisepala and T. lineata improved the activity by approximately 30% in all bacteria tested in comparison with the HAEs. The T. dentisepala HAE had a higher total phenolic content than the T. lineata extract, which was consistent with its ABTS•+-scavenging activity. The two HAEs had different chemical profiles, mostly because of the types and amounts of phenolic compounds they contained. These profiles were obtained using thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and proton nuclear magnetic resonance (1H NMR) experiments.

Synergistic antimicrobial activities of aqueous extract derived from olive byproduct and their modes of action

BackgroundPlant-derived antimicrobials (PDAs) are considered a viable alternative to synthetic antimicrobial agents. Diverse antimicrobial mechanisms of PDAs significantly reduce the risk of developing antimicrobial resistance. Utilization of PDAs also offers economic and environmental advantages, as they can be derived from agricultural byproducts, such as olive pomace.ResultsIn this study, a green, water-based, ultrasound-assisted extraction (UAE) was deployed to obtain aqueous olive pomace extract (OPE) from dry olive pomace. Total phenolic content, extraction yield, chemical compositions, and antimicrobial activities of OPE were evaluated. In addition, the potential synergistic interaction between the phenolic components in OPE and the antimicrobial mechanisms underlying the synergistic interaction were characterized. The results show that ca. 25 mg GAE/g of extraction yields were achieved by the UAE of dry olive pomace. Based on the high-performance liquid chromatography (HPLC) analysis, diverse phenolic compounds such as gallic acid (GA), hydroxytyrosol (HT), and 4-hydroxyphenylacetic acid (4-HPA) were identified in OPE. OPE exhibited strong antimicrobial activities, and 0.2 mg GAE/mL of OPE achieved > 5 log reductions of Escherichia coli O157:H7 and Listeria innocua cells within 30 min of treatment. A 3D isobologram analysis demonstrated that OPE exhibited strong synergistic antimicrobial activities, compared to those of individual phenolic components (GA, HT, or 4-HPA), showing interaction index (γ) of 0.092 and 0.014 against E. coli O157:H7 and L. innocua, respectively (γ < 1: synergistic activity). Antimicrobial mechanism analyses revealed that phenolic components in OPE exerted strong synergistic activities through diverse modes of action, and increased levels of oxidative stress, membrane damage, and decreased levels of metabolic activities were observed in the OPE-treated bacterial cells.ConclusionsThese findings demonstrate an approach for valorizing agricultural byproducts to develop plant byproduct-based antimicrobials with strong synergistic activities. Multiple modes of action of this byproduct extract may enable the control of diverse microbes in food and agriculture systems.Graphical abstract

The Influence of Micronization on the Properties of Black Cumin Pressing Waste Material.

The purpose of this study was to investigate the effect of micronization on the characteristics of black cumin pressing waste material. The basic composition, amino acid, and fatty acid content of the raw material-specifically, black cumin pressing waste material-were determined. The samples were micronized in a planetary ball mill for periods ranging from 0 to 20 min. The particle sizes of micronized samples of black cumin pressing waste material were then examined using a laser analyzer, the Mastersizer 3000. The structures of the produced micronized powders was examined by X-ray diffraction. Additionally, the FTIR (Fourier-transform infrared) spectra of the micronized samples were recorded. The measurement of phenolic and antiradical properties was conducted both before and after in vitro digestion, and the evaluation of protein digestibility and trypsin inhibition was also conducted. The test results, including material properties, suggest that micronization for 10 min dramatically reduced particle diameters (d50) from 374.7 to 88.7 µm, whereas after 20 min, d50 decreased to only 64.5 µm. The results obtained using FTIR spectroscopy revealed alterations, especially in terms of intensity and, to a lesser extent, the shapes of the bands, indicating a significant impact on the molecular properties of the tested samples. X-ray diffraction profiles revealed that the internal structures of all powders are amorphous, and micronization methods have no effect on the internal structures of powders derived from black cumin pressing waste. Biochemical analyses revealed the viability of utilizing micronized powders from black cumin pressing waste materials as beneficial food additives, since micronization increased total phenolic extraction and antiradical activity.

Ultrasound assisted intensified enzymatic extraction of total phenolic compounds from pomegranate peels

Pomegranate peels contain a considerable amount of bioactive chemicals, such as phenolic compounds including gallic acid and ellagic acid. The current study aims to optimize the extraction of total phenolic content (TPC) and its antioxidant capacity from a Pomegranate peel using various approaches involving enzyme and ultrasound, also focusing on process intensification using combination. The optimal parameters for ultrasound treatment were established as treatment time of 25 min, 130 W power, 50 % duty cycle, and a liquid–solid ratio of 50:1 at a fixed 22 kHz frequency, resulting in maximum TPC (21.521 mg GAE/ml) and antioxidant capacity (17.962 mg GAE/ml). Similarly, enzymatic treatment was optimized resulting in best conditions of a time of 55 min, 50 °C as temperature, pH of 5, and a 2 % enzyme concentration. Ultrasound-assisted enzymatic extraction (UAEE) experiments revealed that combining 25 min of ultrasonic treatment with 25 min of enzymatic treatment yielded the highest TPC (30.608 mg GAE/ml) and antioxidant capacity (27.703 mg GAE/ml). It was clearly demonstrated that UAEE outperformed EAE and UAE in terms of Total Phenolic Compound extraction and antioxidant capacity, with the order of efficiency being UAEE > EAE > UAE.

Assessment of Antioxidant Activity, Total Phenolic and Flavonoid Contents of Albizia saponaria L. Bark Extract

Langir (Albizia saponaria L.), belonging to the family of the Fabaceae, is a medicinal endemic plant of South Sulawesi, Indonesia. The Albizia genus shows antioxidant, antibacterial, anthelmintic, antidandruff, and anti-inflammatory properties. In this study, total phenolic (TP) and total flavonoid (TF) extracts from the bark of A. saponaria were screened for robust antioxidant activity in order to identify potential sources of new compounds for use in pharmaceutical formulations in the future. TP and TF of the 96% ethanol extract and fractions (hexane, ethyl acetate, butanol, and water) were calculated by the Folin–Ciocalteu and aluminum chloride procedures, respectively. Furthermore, the antioxidant activity was determined by DPPH free radical scavenging method and ABTS assay. Generally, both extract and fractions showed significant radical scavenging activities. Ethyl acetate fraction exhibited more potent radical scavenging activity in the DPPH method (IC50 35.27 ± 2.85 µg/mL) and ABTS assay (IC50 60.04 ± 0.98 µg/mL), followed by 96% ethanol extract, and hexane, butanol, and water fractions. Furthermore, the highest TP (4.50 ± 0.01 mg/g GAE) and TF (3.55 ± 0.04 mg/g QE) were obtained from ethyl acetate fraction. There was a strong correlation between antioxidant activity with TP (DPPH, R2 = 0.6436; ABTS, R2 = 0.7676) and TF content (DPPH, R2 = 0.5533; ABTS, R2 = 0.5961). The extract’s antioxidant properties may be attributable to its higher phenolic and flavonoid content. In summary, the phenolic and flavonoid content of the ethyl acetate fraction indicates its potential utility as a source of antioxidants.

Optimization of Ultrasonic-Assisted Extraction of Antioxidants in Apple Pomace (var. Belorusskoje malinovoje) Using Response Surface Methodology: Scope and Opportunity to Develop as a Potential Feed Supplement or Feed Ingredient

Apple pomace represents an underexploited source of bioactive compounds. This study examines the optimization of total phenolic content (TPC) and antioxidant extraction yield of apple pomace (variety: Belorusskoje malinovoje) using response surface methodology. The green extraction technique used was ultrasound-assisted extraction, and it was compared with conventional solvent extraction. The impact of extraction time and amplitude of ultrasound-assisted extraction on the yield of polyphenols and antioxidants has been evaluated. Total phenolic content was determined using an established TPC assay. The antioxidant activity of the apple pomace was determined using established assays 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+). Furthermore, the potential of apple pomace as a feed material was explored by assessing its nutritional composition, vitamins, minerals, fatty acids, and amino acid content. The extraction of antioxidants and phenolic compounds was efficiently optimized using RSM. The optimal conditions for TPC and DPPH• analyses were achieved with an extraction time of 17.5 min and an ultrasound-assisted extraction amplitude of 20%. Optimal conditions for ABTS•+ were 5 min extraction time and 20% amplitude. Conventional and ultrasound-assisted extraction methods yielded comparable results. Moreover, apple pomace exhibits potential as a feed ingredient despite its modest protein content. This study contributes to the utilization of apple pomace by providing additional information on its antioxidant content and nutritional composition, thus contributing to its sustainable utilization in various industries, especially the livestock feed sector.

Microwave-assisted extraction of total phenolics from pumpkin (Cucurbita pepo L.) pulp and peel: optimization process, antioxidant and antimicrobial properties

Microwave-assisted extraction of total phenolics from pumpkin (Cucurbita pepo L.) pulp and peel: optimization process, antioxidant and antimicrobial properties

Choline chloride-urea-based natural deep eutectic solvent for highly efficient extraction of polyphenolic antioxidants from Pluchea indica (L.) Less leaves

Pluchea indica leaves (PIL) is a polyphenolic-rich plant. Polyphenols, such as phenolics and flavonoids, are natural antioxidants. This study aims to evaluate the ability of natural deep eutectic solvent (NADES) based on ultrasonic-assisted extraction (UAE) for highly efficient extraction of the polyphenolic antioxidant compounds from PIL. Choline chloride-urea (ChCl-U) was selected based on screening of 17 types of NADES. This study uses Response Surface Methodology (RSM) to help determine optimal extraction conditions. The selected variables include molar ratio, temperature, and the water addition in the NADES. The responses used for the RSM study were total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing power (RP) methods with microtiter analysis. The best condition for polyphenolic antioxidants extraction using ChCl-U NADES was a 1:3 molar ratio, temperature of 52 °C, and 26% of water addition in NADES. Under these conditions, the extraction of total phenolics and flavonoids from PIL with antioxidant activity increased up to 1.2 folds and 3.1 folds compared with 50%-ethanol and methanol, respectively. The morphology of the leaves before and after extraction was also evaluated with a scanning electron microscope (SEM) to observe the effects of ultrasonic vibrations with different solvents. Furthermore, the compound di-caffeoylquinic acid (DCQA) in PIL was selectively found in ChCl-U extract through quadrupole time-of-flight mass spectrometry (UPLC-QToF-MS/MS) analysis. Thus, ChCl-U combined with UAE can be developed for polyphenolic extraction from PIL for extract production as an antioxidant.

In Vitro Antioxidant Activity, Flavonoid and Phenolic Contents of 70% Methanol Extract from Purple and Yellow Passion Fruit Peel

Peel of purple and yellow passion fruit has the potential to be an antioxidant. The flavonoid and total phenol compound groups are two examples of natural antioxidant compounds that can potentially be antioxidants. Many studies have used 70% methanol solvent to extract flavonoids and total phenolics from plants. The aim of this study is to analyze the potential of 70% methanol extract from the peel of purple and yellow passion fruit as an in vitro antioxidant using the DPPH method, total flavonoid, and phenolic levels. The passion fruit peel powder was macerated with 70% methanol for four days. The total flavonoid contents were determined using quercetin, and total phenols were determined using gallic acid. The 2.2-diphenyl-1-picrylhydrazyl (DPPH) was used for in vitro antioxidant activity by determining the percent inhibition of DPPH radicals. The flavonoid content in the 70% methanol extract of purple and yellow passion fruit peel is 1.2824 and 1.9775 mg QE/g extract, respectively. In contrast, the total phenolic content in 70% methanol extract of purple and yellow passion fruit peel is 15.8 and 3.6 mg GAE/g extract, respectively. The 70% methanol extract of purple passion fruit peel at a concentration of 80 mg/L resulted in a more significant percent inhibition of DPPH free radicals (72.80 %) than yellow passion fruit (64.91 %). In conclusion, the results suggest that 70 % methanol extract from purple and yellow passion fruit peel can decrease free radicals and be a natural antioxidant.Keyword: Antioxidant activity, Flavonoid, Methanol extract, Passion fruit peel, Total phenol

Optimization of ultrasound-assisted extraction of sorghum phenolics and effect on the stability of 3-deoxyanthocyanins.

Sorghum 3-deoxyanthocyanins (3-DXAs) have greater stability when compared to other anthocyanins. However, the efficiency in extracting these phenolic compounds from cereals, using conventional methods, is low, because most of them are bound to the cell wall. Thus, the aim of this study was to optimize the ultrasound-assisted extraction (UAE) of anthocyanins and total phenolics from sorghum flour, and evaluate the stability of the 3-DXAs. Two frequencies (25 and 45kHz) were applied in a Central Composite Rotational design to investigate the effect of the variables time (5-75min) and temperature (30-65°C) using the UAE, with amplitude of the ultrasonic power set at 400W. In addition, the stability of the 3-DXAs present in the extracts was evaluated. It was possible to successfully optimize the extraction of total anthocyanins (both frequencies) and phenolics (at 45kHz), and then to obtain equations, to predict their concentrations, with high R2 . The efficiency of UAE was observed, increasing the yield of total anthocyanins, phenolics, and antioxidant capacity at the frequencies of 25 and 45kHz by 30% and 27%, 10% and 5%, and 30% and 15%, respectively. The apigeninidin was the major 3-DXA found in the extracts, and the luteolinidin was the most stable over storage time. Overall, there was no difference in the 3-DXAs stability obtained by the UAE compared to the conventional method. Thus, ultrasound is an alternative to obtaining sorghum extracts rich in 3-DXAs and other phenolic compounds. PRACTICAL APPLICATION: The health benefits of sorghum 3-deoxyanthocyanins coupled with the growing interest of the food industry in producing healthier food products have motivated this study, because it is important to find ways to optimize 3-deoxyanthocyanins extraction. We have demonstrated that ultrasound-assisted extraction was efficient in extracting high amounts of 3-deoxyanthocyanins and other phenolics from sorghum flour. Moreover, some 3-deoxyanthocyanins have shown to be more stable than others after extraction. Thus, the ultrasound has great potential to produce sorghum phenolic extracts rich in 3-deoxyanthocyanins, which can be used as natural colorants and functional ingredients in foods.

A Comparison between Total Phenols and Total Alkaloids Antibacterial Activity Extracted from Bulbs of Narcissus tazetta L

Narcissus tazetta plant from Amaryllidaceae family is known to be rich in bioactive metabolites such as Alkaloids, phenolics and flavonoid which detected in almost species of this family. N. tazetta cultivated in Iraq, had not yet been studied for its active components as antimicrobial; thus the current study employed the antibacterial activity for total phenolic compounds and total alkaloids extracted from this plant. The plant bulb pieces were defatted with n-hexane before extraction of total phenols(TP) and total alkaloids(TA) from the plant. Results showed that the plant contains about 0.95g/140g bulb as total phenols residue and 0.7g/150g bulb as total alkaloids residue. The major Tp compounds observed in HPLC assay were Salycilic acid, Sinapic acid, vanillic acid, Caffeic acid, Chlorogenic acid, and p-coumaric acid in desending quantity. Four layer had been collected that might contain different kinds of alkloids. The methanolic layer (1) and layer (3) which represented the chloroform layer after acidification represented the richest layers in 'Glanthamine' alkloid represented by HPLC assay. The antibacterial as inhibitory effects of TP and TA on E.coli, P.auroginosa, S.aureus and Bacillus subtillus, showed moderate antibacterial activity for both plant extracts in coparisin to some trade antibiotics.

Efficiency of Microwave and Ultrasound-Assisted Extraction as a Green Tool for Polyphenolic Isolation from Monofloral Honeys

Monofloral honey is obtained from the nectar of single-source plants and has a higher market value due to its polyphenol content associated with its biological properties, especially its antioxidant capacity. In this work, advanced extraction techniques using microwave- (MAE) and ultrasound-assisted (UAE) extraction of phenolic compounds in monofloral honey were optimized and compared. Optimal parameters for MAE were an irradiation time of 15 min, a temperature of 60 °C, and a microwave power of 300 W, and for UAE, a sonication time of 10 min, a temperature of 35 °C, and an ultrasound amplitude of 60%. The extraction solvent used was 70% ethanol. In the extracts of different monofloral honey samples (mint, fennel, raspberry, lavender, sage, buckwheat, maroon, heaven) obtained at optimal MAE and UAE conditions, polyphenolic compounds were determined using UPLC-ESI/MS2 analysis and antioxidant capacity using ORAC, ABTS, and DPPH assays. The results showed that UAE was the more efficient technique for the extraction of total flavanones, flavones, hydroxycinnamic acids, and total phenols, and MAE for total flavonols and hydroxybenzoic acids. The antioxidant ORAC and DPPH capacity was higher for the extracts obtained with MAE, while the ABTS capacity was higher for those obtained with UAE.

From waste to wonder: Unleashing the antimicrobial and antioxidant potential of acerola residue using a central composite rotatable design

This study aimed to optimize the extraction conditions of the antioxidant and antimicrobial compounds from acerola residue and evaluate the optimized extract's bioactivity. A central composite rotatable design (CCRD) was used to evaluate the effect of three independent variables (time, temperature, and ethanol concentration) on the total phenolic content, antioxidant activity, and extraction yield. The optimized extract was evaluated for phenolic profile, yellow flavonoid, total anthocyanins, total and condensed tannins, and antimicrobial activity. Optimum conditions were achieved at 110 min, 20 °C, and 34% ethanol. The optimized extract showed high content of total phenolic compounds (903.64 mg GAE .100 g−1 d.m) and the phenolic profile revealed the presence of 16 substances, especially gentisic acid (60.46 ± 4.94 mg .100 g−1). The optimized extract showed high antioxidant activity (3510.64 mgTE .100 g−1), and antimicrobial action against Salmonella Typhimurium and Listeria monocytogenes strains, making it a promising alternative in the food, chemical, and pharmaceutical industries.

INFLUENCE OF PROCESS PARAMETERS ON HAWTHORN(CRATAEGUS MONOGYNA JACK.)EXTRACTION

Given that many synthetic medications can induce a variety of negative reactions in patients, a search for natural substances with minimal side effects in patients has been conducted. Nowadays,researchers are focusing on plant medicines, which have been used to heal illnesses since ancient times. The plant Crataegus monogynaJack. (hawthorn) is the most abuntant plant in the Rosaceae family that is also used in traditional medicine. C. monogyna's pharmaceutical, phytochemical, functional, and therapeutic qualities are based on a wide range of useful secondary metabolites, which include phenolic compound (flavonoids, anthocyanins, tannins), vitamin C and antioxidants.Total (poly)phenols, flavonoids and anthocyanins contents in C. monogynaJacq.extracts were measured using the Folin-Ciocalteu reagent, aluminium chloride and the pH differential methods, respectively. The extraction lasted 15to 120 min, with a solid-to-solvent ratio of 1:15 w/v and 1:30 w/v and solvents of 30% and 60% ethanol.According to the results, the extraction process has the highest velocity within the first 15 min, when the majority of (poly)phenols and flavonoids are extracted, but it becomes slower as time passes. Higher yields are obtained by utilizing a solid-to-solvent ratio of 1:30 w/v rather than a solid-to-solvent ratio of 1:15 w/v, which indicates that when the amount of drug increases over a certain optimal value, the resistance to mass transferfrom a solid material to liquid increases. Finally, the results about the impact of the ethanol contentin the solvent demonstrate that a larger ethanol content greatly favors the extraction of flavonoids, but this is not as evident for the extraction of total (poly)phenols and anthocyanins.KEYWORDS:anthocyanins, extraction, flavonoids, (poly)phenols

Investigating the Microwave-Assisted Extraction Conditions and Antioxidative and Anti-Inflammatory Capacities of Symphytum officinale WL Leaves

Symphytum officinale (comfrey) is a perennial herb native to West Asia and Europe. Its root extracts are commonly used as a natural remedy to treat muscle, joint, skin, and bone disorders, especially in Europe. However, more information is needed on the biomedical functions of comfrey leaves. This study’s sequencing results of internal transcribed spacer and trnL–trnF genes showed that plants purchased from the local market were comfrey and named S. officinale WL (WL). The suitable extraction conditions of the WL leaves with the highest extract yield and total phenols and flavonoid contents by microwave-assisted extraction were identified. The antioxidative and anti-inflammatory activities and possible molecular mechanism(s) of the WL leaf extract (WLE) were evaluated. Furthermore, the major component of WLE was identified as rosmarinic acid by HPLC. Results showed that the optimal extract condition was obtained with 750 W microwave power, 50 °C, 75% methanol, the solid-to-solvent ratio of 1:10, and 15 min. Results of all DPPH, ABTS, and superoxide radical scavenging activities, reducing power, ferrous ion chelating activity, and ferric reducing antioxidant power showed high antioxidative capacities of WLE. Furthermore, WLE showed prominent DNA-protecting activity. WLE attenuated lipopolysaccharide-stimulated inflammation by suppressing iNOS, COX-2, IL-1β, IL-6, and TNF-α expressions in the RAW264.7 macrophages. These attenuations are involved in the inactivation of lipopolysaccharide-stimulated NF-κB and MAPK signaling pathways. Therefore, the comfrey leaf extract obtained via a time- and energy-saving microwave-assisted extraction may be a potential antioxidative and anti-inflammatory biomedicinal agent.

Chlorhexidine-Silver Nanoparticle Conjugation Leading to Antimicrobial Synergism but Enhanced Cytotoxicity.

This study explored the potential synergism within chlorhexidine-silver nanoparticle conjugates against Influenza type A, Staphylococcus aureus, Escherichia coli, and Candida albicans. Silver nanoparticles (SN) were obtained by the reduction of silver ions with green tea total phenolic extract and conjugated with chlorhexidine (Cx). The particles were characterized by UV-Vis and FTIR spectroscopies, dynamic light scattering, X-ray diffraction, and transmission electron microscopy. A stable negatively charged nano-silver colloid (ζ = -50.01) was obtained with an average hydrodynamic diameter of 92.34 nm. In the presence of chlorhexidine, the spectral data and the shift of the zeta potential to positive values (ζ = +44.59) revealed the successful sorption of the drug onto the silver surface. The conjugates (SN-Cx) demonstrated potentiation in their effects against S. aureus and C. albicans and synergism against E. coli with minimal inhibitory concentrations of SN at 5.5 µg/mL + Cx 8.8 µg/mL. The SN showed excellent virucidal properties, increasing with time, and demonstrated low toxicity. However, the coupling of the cationic chlorhexidine with nano-silver did not reduce its intrinsic cytotoxicity on various cell lines (MDCK, BJ, and A549). The newly synthesized antimicrobial agent exhibited an extended and promising therapeutic spectrum and needs to be further evaluated regarding the designated route of administration in three-dimensional cell models (e.g., nasal, bronchial, dermal, ocular, etc.).

Optimization of the Extraction System of Total Phenolic from Garcia mangostana using Response Surface Methodology

Mangosteen (Garcia mangostana) consist of 40% flesh and 60% pericarp. Mangosteen pericarp has unpleasant taste of bitterness and usually disposed as waste. However, mangosteen pericarp contains xanthones which are polyphenolic compound that proven has high antioxidant activity were found abundantly in mangosteen pericarp. This study aims to investigate water extraction optimum operating conditions to be applied in industry by using RAM (response surface methodology) for the recovery of total phenolic extract from the pericarp of mangosteen. Box-Behnken experimental design used 3 factors. Solid-to-liquid ratio (g/ml), temperature (°C) and extraction time (hour) were analysed to compare the response of total phenolic content (TPC). Under the operating conditions, the highest TPC is 0.906 (g/l) at the factors of 1:10 (g/ml), 65 °C, and 3-hour. The optimum parameters determined by using RSM are at 1:10 (g/ml), 59.74 °C, and 2.87-hour with TPC 0.835 (g/l).

Microwave-assisted extraction of shikimic acid from different morphological parts of water hyacinth (Eichhornia crassipes)

Water hyacinth is a proliferative aquatic weed which destructs biodiversity. Though water hyacinth is a notorious weed, it is a useful resource if used judiciously. One of the important compounds in water hyacinth is shikimic acid, a precursor to produce antiviral drug oseltamivir phosphate. A greener extraction of shikimic acid, phenolic compounds and estimation of antioxidant activity of extract were performed using microwave-assisted extraction from the different morphological parts of water hyacinth. Impact of parameters such as extraction time, solvent volume, temperature and power has been studied. Among various parts of the plant, stem contained higher shikimic acid (2.70%, w/w), leaves had higher total phenolic content (12.15 mg GAE/ g biomass) and extract from stem exhibited the maximum antioxidant activity (75.13%). Further, the optimization of process parameters using central composite design was employed to maximize the yield of shikimic acid (2.61%, w/w) which was achieved at 1.08 min, 45 °C, and 30 mL. Although Ultrasound-assisted extraction has provided a higher yield (3.2%, w/w) of shikimic acid compared to microwave-assisted extraction, the extraction time was reduced by 96% in case of microwave-assisted extraction, thereby reducing energy consumption, utility requirement and carbon emission.

A Systematic Ex-Vivo Study of the Anti-Proliferative/Cytotoxic Bioactivity of Major Olive Secoiridoids' Double Combinations and of Total Olive Oil Phenolic Extracts on Multiple Cell-Culture Based Cancer Models Highlights Synergistic Effects.

Several individual olive oil phenols (OOPs) and their secoiridoid derivatives have been shown to exert anti-proliferative and pro-apoptotic activity in treatments of human cancer cell lines originating from several tissues. This study evaluated the synergistic anti-proliferative/cytotoxic effects of five olive secoiridoid derivatives (oleocanthal, oleacein, oleuropein aglycone, ligstroside aglycone and oleomissional) in all possible double combinations and of total phenolic extracts (TPEs) on eleven human cancer cell lines representing eight cell-culture-based cancer models. Individual OOPs were used to treat cells for 72 h in half of their EC50 values for each cell line and their synergistic, additive or antagonistic interactions were evaluated by calculating the coefficient for drug interactions (CDI) for each double combination of OOPs. Olive oil TPEs of determined OOPs' content, originating from three different harvests of autochthonous olive cultivars in Greece, were evaluated as an attempt to investigate the efficacy of OOPs to reduce cancer cell numbers as part of olive oil consumption. Most combinations of OOPs showed strong synergistic effect (CDIs < 0.9) in their efficacy, whereas TPEs strongly impaired cancer cell viability, better than most individual OOPs tested herein, including the most resistant cancer cell lines evaluated.