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18 pages, 4876 KiB

Open AccessEditor’s ChoiceArticle

Deep Eutectic Solvent-Based Microwave-Assisted Extraction for the Extraction of Seven Main Flavonoids from Ribes mandshuricum (Maxim.) Kom. Leaves

by Wei Wang, Si-Qiu Xiao, Ling-Yu Li and Qing-Yan Gai

Separations 2023, 10(3), 191; https://0-doi-org.brum.beds.ac.uk/10.3390/separations10030191 - 10 Mar 2023

Cited by 5 | Viewed by 1524

Abstract

Flavonoids exhibit many biological properties, so it is very important to find an efficient and green method to extract them from plant materials. In this paper, DES-MAE (deep eutectic solvent-based microwave-assisted extraction) technique was developed to extract the seven major active flavonoids from [...] Read more.

Flavonoids exhibit many biological properties, so it is very important to find an efficient and green method to extract them from plant materials. In this paper, DES-MAE (deep eutectic solvent-based microwave-assisted extraction) technique was developed to extract the seven major active flavonoids from Ribes mandshuricum leaves, namely, trifolin, isoquercetin, rutin, astragalin, quercetin, hyperoside, and kaempferol. After the completion of the extraction process, macroporous adsorption resin was used for the purification of seven flavonoids. The BBD (Box–Behnken design) method combined with RSM (response surface methodology) was applied to acquire the optimal operating conditions of DES-MAE. The optimal parameters were: temperature: 54 °C, time: 10 min, extraction solvent: choline chloride/lactic acid with a 1:2 mass ratio, water content: 25%, and liquid/solid ratio: 27 mL/g. The yields of the seven target flavonoids were 4.78, 2.57, 1.25, 1.15, 0.34, 0.32, and 0.093 mg/g DW (dry weight), respectively. The direct purification of trifolin, isoquercetin, rutin, astragalin, quercetin, hyperoside, and kaempferol in DES-MAE solution was achieved by using macroporous resin X-5. The recoveries were 87.02%, 81.37%, 79.64%, 87.13%, 97.36%, 88.08%, and 99.39%, respectively. The results showed that DES-MAE followed by MRCC (macroporous resin column chromatography) represents a promising approach to extracting and separating active components from plants. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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14 pages, 3677 KiB

Open AccessArticle

Essential Oils from Six Aromatic Plants of Langtang National Park: Insights on Their Chemical Constituents via GC-MS Analysis

by Samjhana Pradhan, Hem Raj Paudel, Romi Maharjan and Kavita Sharma

Separations 2023, 10(1), 52; https://0-doi-org.brum.beds.ac.uk/10.3390/separations10010052 - 13 Jan 2023

Cited by 1 | Viewed by 1632

Abstract

The present work aims to provide an insight on the chemical constituents of essential oils obtained from six aromatic plants of the Langtang National Park (LNP), Nepal. LNP harbors an enriched biodiversity of medicinal and aromatic plants (MAPs). The composition of essential oils [...] Read more.

The present work aims to provide an insight on the chemical constituents of essential oils obtained from six aromatic plants of the Langtang National Park (LNP), Nepal. LNP harbors an enriched biodiversity of medicinal and aromatic plants (MAPs). The composition of essential oils obtained from Rhododendron anthopogon D. Don, Artemisia dubia Wall. ex Besser, Boenninghausenia albiflora (Hook.) Rchb. ex Meisn., Elsholtzia fruticosa (D. Don) Rehder, Juniperus recurva Buch.-Ham. ex D. Don and Rhododendron setosum D. Don, were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The essential oils were extracted via the hydrodistillation method using the Clevenger apparatus. GC-MS analysis showed that E-caryophyllene, α-pinene, γ-terpinene, β-pinene and δ-cadinene in Rhododendron anthopogon; santolina-triene, β-cubebene and sabinene in Artemisia dubia; β-myrcene, β-cubebene, E-β-ocimene and bicyclogermacrene in Boenninghausenia albiflora; perillene, eucalyptol and β-pinene in Elsholtzia fruticosa; δ-3-carene, cadina-1(6),4-diene and δ-cadinene in Juniperus recurva; trans-sabinyl acetate, sabinene, α-elemol and germacrene D in Rhododendron setosum are the principal components. The major compounds in the essential oil were monoterpenes and sesquiterpenes, representing almost 80% to 90% of the total constituents of the essential oil. In comparison to the previous studies, the results showed a significant difference in the qualitative composition of the essential oil. This is also the first report on the study of chemical constituents from the essential oil of R. setosum. Despite hosting a plethora of MAPs, only a limited number of studies have been carried out to identify their chemical and biological properties. Hence, further investigations on the MAPs of the Langtang region are highly essential to identify the major chemical constituents and explore their biological activities. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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9 pages, 830 KiB

Open AccessArticle

Essential Oils of Taxodium distichum Winter Leaves Obtained by Supercritical Carbon Dioxide Extraction Method and Hydrodistillation

by Nina Djapic

Separations 2022, 9(12), 436; https://0-doi-org.brum.beds.ac.uk/10.3390/separations9120436 - 13 Dec 2022

Cited by 1 | Viewed by 1364

Abstract

The extraction of Taxodium distichum needles was done using supercritical carbon dioxide extraction and hydrodistillation. SC CO₂ extraction of T. distichum winter leaves was conducted at different pressures and temperatures using a central composite rotatable design. The optimal extraction conditions concerning the [...] Read more.

The extraction of Taxodium distichum needles was done using supercritical carbon dioxide extraction and hydrodistillation. SC CO₂ extraction of T. distichum winter leaves was conducted at different pressures and temperatures using a central composite rotatable design. The optimal extraction conditions concerning the yield and α-tocopherol relative amount were determined by response surface methodology. The optimal conditions for the highest extraction yield of 3.97% were at 17.79 MPa and 62.70 °C and the highest α-tocopherol relative amount of 85.99 mg per 100 g of the plant material was at 22.07 MPa and 35.86 °C. The essential oil obtained by hydrodistillation contained 62 compounds and (-)-caryophyllene oxide was dominant (55.55%). The T. distichum essential oil obtained by SC CO₂ extraction and hydrodistillation had a different composition. The desirable compounds influence the choice of the extraction method. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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11 pages, 1703 KiB

Open AccessCommunication

RP-HPLC-DAD Analysis of Mitragynine Content in Mitragyna speciosa Korth. (Ketum) Leaf Extracts Prepared Using Ultrasound Assisted Extraction Technique and Their Cytotoxicity

by Thiruventhan Karunakaran, Yong Sean Goh, Rameshkumar Santhanam, Vikneswaran Murugaiyah, Mohamad Hafizi Abu Bakar and Surash Ramanathan

Separations 2022, 9(11), 345; https://0-doi-org.brum.beds.ac.uk/10.3390/separations9110345 - 03 Nov 2022

Cited by 3 | Viewed by 2626

Abstract

Mitragynine and its congeners are one of the major phytoconstituents present in Mitragyna speciosa Korth. (ketum) leaves and a well-known factor that contributes to ketum’s pharmacological activities. This study describes the usage of a green extraction method to yield botanical leaf extracts of [...] Read more.

Mitragynine and its congeners are one of the major phytoconstituents present in Mitragyna speciosa Korth. (ketum) leaves and a well-known factor that contributes to ketum’s pharmacological activities. This study describes the usage of a green extraction method to yield botanical leaf extracts of ketum. The leaf extracts were assessed for mitragynine content, total phenolic and flavonoid content, and cytotoxicities. The Ultrasound Assisted Extraction (UAE) method showed a varying dry yield of the extracts (0.22–1.92 g) that were obtained with solvents of variable polarities. However, the mitragynine content was consistent among the organic solvent extracts (7.22–9.40%). This method calls for a minimal extraction solvent volume (solid to solvent ratio, 1:30) and a shorter extraction period (20 min). Of the solvents tested, the methanolic extract showed the highest content of total phenolic (419.50 ± 2.50 GAE mg/g) and flavonoids (177.33 ± 3.00 QE mg/g). The extract was nontoxic towards kidney (HEK-293) and Chang liver (HeLa) cell lines. Analysis via UHPLC-ESI-QTOF-MS/MS made it possible to identify mitragynine congeners, such as mitragynine, paynantheine, and speciociliatine, in the leaves extract. In conclusion, the UAE method using methanol as the extraction solvent provides a noncytotoxic ketum botanical extract for future preclinical and clinical studies. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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8 pages, 646 KiB

Open AccessArticle

Chemical Composition of the Fixed Oil of Harconia speciosa and Modulation of the Antibiotic Activity against Non-Resistant and MDR Bacterial Strains

by Erlânio O. de Sousa, Maria do Socorro Costa, Cícera Datiane M. Oliveira-Tintino, Carla de Fátima A. Nonato, Jacqueline C. A. Pinheiro, Henrique Douglas M. Coutinho, Irwin Rose A. de Menezes and José Galberto M. Costa

Separations 2022, 9(9), 249; https://0-doi-org.brum.beds.ac.uk/10.3390/separations9090249 - 07 Sep 2022

Cited by 3 | Viewed by 1572

Abstract

The species Hancornia speciosa (mangabeira) has varied potential. The bark has astringent properties, latex is used for tuberculosis, ulcers, herpes, dermatoses and warts, leaf tea is used for menstrual cramps and the root decoction to treat dislocations and hypertension. The aim of this [...] Read more.

The species Hancornia speciosa (mangabeira) has varied potential. The bark has astringent properties, latex is used for tuberculosis, ulcers, herpes, dermatoses and warts, leaf tea is used for menstrual cramps and the root decoction to treat dislocations and hypertension. The aim of this work was to analyze the chemical composition of the fixed oil and antibacterial activities alone or in association with aminoglycosides against standard and MDR bacteria using broth microdilution assays. In the analysis of the oil by GC/MS, a high content of unsaturated fatty acids (73.46%) was identified in relation to saturated fatty acids (26.15%). Palmitic acid (22.49%) and elaidic acid (69.50%) were the main fatty acids identified. The antibacterial test results showed a more significant oil activity against Staphylococcus aureus SA–ATCC 6538 (MIC = 512 μg/mL). For other strains including standards and multidrug resistant bacteria, the oil presented MIC ≥ 1024 μg/mL. In association with antibiotics, the oil was able to improve antibacterial activity against bacterial strains. A synergic effect was observed for S. aureus SA–10, with MIC reduction of amikacin and gentamicin by 50.00 and 60.00%, respectively. The most significant association was found for Escherichia coli EC–06, with a reduction in MIC of 81.25%. The results indicate that seed oil of H. speciosa has the potential to act on bacterial resistance to aminoglycoside antibiotics. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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18 pages, 17864 KiB

Open AccessArticle

An Efficient Approach for Separating Essential Oil and Polysaccharides Simultaneously from Fresh Leaves of Guajava by Microwave-Mediated Hydrodistillation with Lithium Salts and Antibacterial Activity of Essential Oil

by Xiaonan Zhang, Yan Huang, Lubin Zhang, Hongwei Zhu, Yaqian Niu, Yimin An and Zhiwei Liu

Separations 2022, 9(7), 162; https://0-doi-org.brum.beds.ac.uk/10.3390/separations9070162 - 27 Jun 2022

Cited by 2 | Viewed by 2033

Abstract

The essential oils and polysaccharides from guava leaves have important functions. In the process of microwave extraction of plant essential oils and polysaccharides, pretreatment with lithium salts solution is helpful to increase the extraction rate. The experiment was conducted using a single factor [...] Read more.

The essential oils and polysaccharides from guava leaves have important functions. In the process of microwave extraction of plant essential oils and polysaccharides, pretreatment with lithium salts solution is helpful to increase the extraction rate. The experiment was conducted using a single factor method. Results were optimized by principal component analysis and response surface optimization. The optimal conditions were: LiCl dosage 45 μmol, microwave time 40 min, liquid-solid ratio 10, homogenization time 4.2 min, liquid-material ratio 10, and microwave irradiation power 700 W. The highest yield of essential oil and polysaccharide were 10.27 ± 0.58 mL/kg dry weight (DW) and 50.31 ± 1.88 g/kg·DW, respectively. Three verification experiments showed that the extraction rate of the microwave method was higher than that of the traditional heating method. In addition, the bacteriostatic zones reached the maximum 23.7 ± 0.11 mm when the concentration was 40 μL/mL, and the above results have practical significance. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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12 pages, 1939 KiB

Open AccessArticle

The Preparation of the Essential Oil from Pomelo (Citrus maxima ‘Shatian Yu’) Peel Using Microwave-Assisted Distillation by Pectinase Soaking and Its Anti-Fungal Activity

by Xiaonan Zhang, Yan Huang, Yaqian Niu, Zhiwei Liu, Mengyu Chen, Yimin An and Lubin Zhang

Separations 2022, 9(7), 161; https://0-doi-org.brum.beds.ac.uk/10.3390/separations9070161 - 27 Jun 2022

Cited by 4 | Viewed by 3217

Abstract

To verify the anti-fungus properties of the crop-harmful pseudocercospora, the essential oil (EO) of pomelo peel (PP) was extracted by a single factor combined with response surface optimization. Meanwhile, the composition and activity of EO were studied. The PP was squeezed by [...] Read more.

To verify the anti-fungus properties of the crop-harmful pseudocercospora, the essential oil (EO) of pomelo peel (PP) was extracted by a single factor combined with response surface optimization. Meanwhile, the composition and activity of EO were studied. The PP was squeezed by a screw extruder and pretreatmented by pectinase, then extracted by microwave-assisted steam distillation. The optimal conditions were as follows: pectinase dosage was 69.17 μmol/g, microwave power was 651.42 W and extraction time was 43.84 min. The dry weight (DW) yield of PPEO reached 14.63 mL/kg DW after BBD optimization. There were 23 compounds in the PPEO identified by GC-MS. Limonene, α-phrenbutene, and laurene in PPEO accounted for 79.31%, 4.72%, and 3.46%, respectively. In addition, the antifungal was effective when the concentration of PPEO was 3.5 mg/mL. Therefore, this study has guiding significance for the development of natural resources. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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Review

Jump to: Research

29 pages, 6133 KiB

Open AccessReview

Advances of Imidazolium Ionic Liquids for the Extraction of Phytochemicals from Plants

by Jiahui Gong, Chunyu Liang, Zahid Majeed, Mengfei Tian, Chunjian Zhao, Meng Luo and Chunying Li

Separations 2023, 10(3), 151; https://0-doi-org.brum.beds.ac.uk/10.3390/separations10030151 - 23 Feb 2023

Cited by 4 | Viewed by 2413

Abstract

In this review, we present the research from 2013 to 2022 about the character of ionic liquids, the categories of phytochemicals, and the reasons for selecting imidazolium ionic liquids for phytochemical extraction. Then we introduce the structural formulae of the imidazolium ionic liquids [...] Read more.

In this review, we present the research from 2013 to 2022 about the character of ionic liquids, the categories of phytochemicals, and the reasons for selecting imidazolium ionic liquids for phytochemical extraction. Then we introduce the structural formulae of the imidazolium ionic liquids commonly used in the extraction of phytochemicals, the methods used to prepare imidazolium ionic liquids, and a comprehensive introduction of how imidazolium ionic liquids are applied to extract phytochemicals from plants. Importantly, we discuss the strategies for studying the extraction mechanisms of imidazolium ionic liquids to extract phytochemicals, and the recovery methods regarding imidazolium ionic liquids and their recyclability are analyzed. Then the toxicity in imidazolium ionic liquids is pointed out. Finally, the challenges and prospects of extracting phytochemicals by imidazolium ionic liquids are summarized, and they are expected to provide some references for researchers. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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