What is the most efficient method for extracting bioactive compounds, particularly phenolics, from plant materials?

In present work a literature review of application of supercritical fluid extraction (SFE) for isolation of nutraceuticals and some other phytochemicals up to December of 2012 is presented. Manuscript provides knowledge of SFE processes and possible aplications of SFE for extraction of bioactive compounds which serve as nutraceuticals. Compounds are classified into groups based on their chemical nature (carotenoids, flavonoids and other phenolic compounds, essential oils, lipids and fatty acids, and alkaloids and other bioactive phytochemicals) and they are reviewed in tabular form along with plant material, from which they were extracted using supercritical fluids.

Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the presence of total phenolics, while spectrophotometric and chromatographic techniques are utilized to identify and quantify individual phenolic compounds. This review addresses the application of different methodologies utilized in the analysis of phenolic compounds in plant-based products, including recent technical developments in the quantification of phenolics.

Polyphenols are one of the largest and most widespread groups of secondary metabolites in the plants world. These compounds are of particular interest due to their occurrence and the properties they possess. The main sources of phenolic compounds are fruits and vegetables, but lately, more and more studies refer to woody vascular plants, especially to bark, as an important source of phenolic compounds with a potential biological effect. This study aims to bring together information on the phenolic compounds present in the bark of woody vascular plants by discussing extraction methods, the chemical composition of the extracts and potential biological effects. The literature data used in this paper were collected via PubMed (2004–2019). Search terms were: bark, rhytidome, woody vascular plant, polyphenols, phenolic compounds, biologic activity, antioxidant, immunostimulatory, antimutagenic, antibacterial, anti-inflammatory, and antitumoral. This paper intends to highlight the fact that the polyphenolic extracts obtained from the bark of woody vascular plants represent sources of bioactive compounds with antioxidant, immunostimulatory, antimutagenic, antibacterial properties, etc. Future research directions should be directed towards identification and isolation of bioactive compounds. Consequently, biologically active compounds obtained from the bark of woody plants could be exploited on an industrial scale.

In this review, recent advances in greener technology for extracting natural bioactive components from plant origin sources are discussed. Bioactive compounds of plant origin have been defined as natural chemical compounds present in small amounts in plants. Researchers have shown interest in extracting bioactive compounds because of their human health benefits and characteristics of being eco-friendly and generally recognized as safe. Various new extraction methods and conventional extraction methods have been developed, however, until now, no unique approach has been presented as a benchmark for extracting natural bioactive compounds from plants. The selectivity and productivity of traditional and modern extraction techniques generally depend on selecting the critical input parameters, knowing the nature of plant-based samples, the structure of bioactive compounds, and good scientific skills. This work aims to discuss the recent advances in supercritical fluid extraction techniques, especially supercritical carbon dioxide, along with the fundamental principles for extracting bioactive compounds from natural plant materials such as herbs, spices, aromatic and medicinal plants.

Mango (Mangifera indica) has been recognized as a rich source of bioactive compounds with potential pharmaceutical and nutraceutical applications and has attracted increasing interest from research. Phytochemistry studies have demonstrated that phenolic compounds are one of the most important biologically active components of M.indica extracts. Ultrasound- and microwave-assisted extractions and supercritical fluids have been employed to obtain bioactive molecules, such as phenolic acids, terpenoids, carotenoids, and fatty acids. These phytochemicals exhibit antioxidant, antimicrobial, anti-inflammatory, and anticancer activity, and depending on the source (bark, leaves, seeds, flowers, or peel) and extraction method there will be differences in the structure and bioactivity. This review examines the bioactive compounds, extraction techniques, and biological function of different parts of M.indica of great importance as nutraceuticals and functional compounds with potential application as therapeutic agents and functional foods. © 2021 Society of Chemical Industry.

Torbangun (Coleus amboinicus L) leaf is one of the herbs from Indonesia that has been reported to have many bioactive compounds for human health. These phytochemicals are predominantly incorporated into phenolics, such as flavonoids. An extraction process is needed to obtain all the valuable compounds, and conventional solvent extraction, such as heating and maceration, could be easily applied because of its simplicity. However, this method requires high energy, a longer extraction time, and a large amount of solvent. To overcome these limitations, in this study, microwave-assisted extraction (MAE) was utilized to extract phenolic compounds, including flavonoids from torbangun leaves. Three factors (solvent to feed ratio, microwave power, and extraction time) were evaluated to affect the three responses (extract volume, TPC, and TFC). The extraction process optimization was carried out to get a higher response. The Box-Behnken experiment design and Response Surface Methodology (RSM) determined the optimal operating condition. The result shows 30 ml/g of solvent to feed ratio, 300 W of microwave power, and 4.6 minutes of extraction time as the optimum condition. Applying those conditions, the extract is expected to reach 10.13 ml of extract volume, 9.17 mg GAE/ ml extract of total phenolic, and 3.62 mg QE/ ml extract of total flavonoid. In sum, MAE was useful for extracting phenolic compounds from torbangun leaves and could be an alternative method due to its high efficiency.

By-products of plant origin represent an abundant source of bioactive compounds. However, to exploit these resources commercially relevant strategies for their extraction must be developed. This review focuses on the extraction of bioactive compounds from food by-products of plant origin by a number of novel methods, including pressurised liquid extraction and supercritical CO2 extraction. In general supercritical CO2 extraction is most effective for apolar compounds such as carotenoids, while pressurised liquid extraction can be used to extract more polar compounds such as polyphenols. Both techniques are sustainable and green techniques. In addition, pre-treatment of plant by-products by novel non-thermal processing techniques in order to enhance extraction will be highlighted. In general the selection of an appropriate extraction strategy is dependent on the type of compound to be extracted as well as the potential up scaling of the technique.

The bioactive compounds in Vernonia amygdalina leaf were extracted using ethanol through Soxhlet and microwave-assisted extraction (MAE) techniques. The phytochemical analysis was carried out on the ethanolic extracts using the standard techniques. This analysis revealed the presence of flavonoids, alkaloids, steroids, terpenoids, glycosides, tannins, phenols, saponins, and the absence of anthraquinones. Furthermore, gas chromatography-mass spectroscopy (GC-MS) analysis results revealed the presence of more phytochemicals in the extract obtained through MAE compared to Soxhlet extraction technique, whereby phytol was present in a higher percentage. Fourier transform infrared spectroscopy analysis confirmed the presence of phytochemicals in the extracts. Moreover, the IC50 values of the extracts antioxidant activities were evaluated using DPPH and ABTS assays. There exists a clear correlation between total phenolic content, total flavonoid content and antioxidant activity of the extracts. Therefore, this study suggested that higher phenolic compounds responsible for natural antioxidant could be obtained from V. amygdalina leaf using the microwave-assisted extraction technique.

The extraction, isolation, and analysis of bioactive compounds from plants are fundamental in the study of medicinal plants. This review explores various techniques and methods used for the extraction, isolation, and analysis of bioactive compounds from plant materials. Traditional methods such as maceration, percolation, and Soxhlet extraction are commonly used, but novel techniques have emerged to enhance efficiency and selectivity. Microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), supercritical fluid extraction (SFE), and enzyme-assisted extraction are modern approaches that offer improved yields and efficiency. After extraction, bioactive compounds need to be characterized and analyzed. Chromatographic techniques, such as high-performance liquid chromatography (HPLC) and gas chromatography (GC), are commonly employed for separation and quantification. Spectroscopic techniques, including nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), provide valuable structural information. The continuous development of extraction and analytical techniques contributes to the discovery and utilization of bioactive compounds from plants in various applications. Future research can explore metabolomics, high-throughput screening, chemoinformatics, network pharmacology, multivariate data analysis, and computational modeling to enhance phytochemical investigations. The proposed methods and techniques complement traditional approaches, expanding our understanding of plant chemistry and its potential applications.

Background: The extraction of Moringa concanensis (Nimmo leaf) was done in ethanol using Soxhlet and microwave-assisted extraction (MAE) techniques to obtain bioactive compounds. Methods: The standard techniques were used to carry out phytochemical analysis of ethanolic extract. The analysis confirmed the presence of flavonoids, phenols, steroids, alkaloids, terpenoids, glycosides, tannins, and saponins, and also the absence of anthraquinones. Moreover, the extract was evaluated for antioxidant activities using DPPH and ABTS assays. The IC50 value of the extract was also determined. Results: A clear correlation between the total phenolic content, total flavonoid content, and antioxidant activity of the leaf extracts was obtained. Conclusion: This study suggests that a high amount of phenolic compounds could be obtained from Moringa concanensis (Nimmo leaf) by using the microwave-assisted extraction technique, which may be responsible for its antioxidant activity.