Optimization and comparison of different extraction techniques for sanguinarine and chelerythrine in fruits of Macleaya cordata (Willd) R. Br

Evaluation of the antimicrobial effects of Capsicum, Nigella sativa, Musa paradisiaca L., and Citrus limetta: A review

The extensive use of antibiotics and vaccines against microbial infections can result in long-term negative effects on humans and the environment. However, there are a number of plants that have antimicrobial effects against various disease-causing microbes such as bacteria, viruses, and fungi without negative side effects or harm to the environment. In this regard, four particular plants- Capsicum, Nigella sativa, Musa paradisiaca L., and Citrus limetta have been widely considered due to their excellent antimicrobial effect and ample availability. In this review, we discuss their antimicrobial effects due to the presence of thymoquinone, p-cymene, pinene, alkaloids, limonene, camphene, and melanin. These antimicrobial compounds disrupt the cell membrane of microbes, inhibit cellular division, and form biofilm in bacterial species, eventually reducing the number of microbes. Extraction of these compounds from the respective plants is carried out by different methods such as soxhlet, hydro-distillation, liquid-liquid extraction (LLE), pressurized liquid extraction (PLE), solid-phase extraction (SPE), supercritical fluid extraction (SFE), pulsed electric field (PEF), microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE), ultrasound-assisted extraction (UAE), and high-voltage electrical discharge. Suitable selection of the extraction technique highly depends upon the associated advantages and disadvantages. In order to aid future study in this field, this review paper summarizes the advantages and disadvantages of each of these approaches. Additionally, the discussion covers how antimicrobial agents destroy harmful bacteria. Thus, this review offers in-depth knowledge to researchers on the antibacterial properties of Capsicum, Nigella sativa, Musa paradisiaca L. peels, and Citrus limetta.

Rediscovery of Traditional Plant Medicine: An Underestimated Anticancer Drug of Chelerythrine

In many studies, the extensive and significant anticancer activity of chelerythrine (CHE) was identified, which is the primary natural active compound in four traditional botanical drugs and can be applied as a promising treatment in various solid tumors. So this review aimed to summarize the anticancer capacities and the antitumor mechanism of CHE. The literature searches revolving around CHE have been carried out on PubMed, Web of Science, ScienceDirect, and MEDLINE databases. Increasing evidence indicates that CHE, as a benzophenanthridine alkaloid, exhibits its excellent anticancer activity as CHE can intervene in tumor progression and inhibit tumor growth in multiple ways, such as induction of cancer cell apoptosis, cell cycle arrest, prevention of tumor invasion and metastasis, autophagy-mediated cell death, bind selectively to telomeric G-quadruplex and strongly inhibit the telomerase activity through G-quadruplex stabilization, reactive oxygen species (ROS), mitogen-activated protein kinase (MAPK), and PKC. The role of CHE against diverse types of cancers has been investigated in many studies and has been identified as the main antitumor drug candidate in drug discovery programs. The current complex data suggest the potential value in clinical application and the future direction of CHE as a therapeutic drug in cancer. Furthermore, the limitations and the present problems are also highlighted in this review. Despite the unclearly delineated molecular targets of CHE, extensive research in this area provided continuously fresh data exploitable in the clinic while addressing the present requirement for further studies such as toxicological studies, combination medication, and the development of novel chemical methods or biomaterials to extend the effects of CHE or the development of its derivatives and analogs, contributing to the effective transformation of this underestimated anticancer drug into clinical practice. We believe that this review can provide support for the clinical application of a new anticancer drug in the future.

Bio Discarded from Waste to Resource

The modern linear agricultural production system allows the production of large quantities of food for an ever-growing population. However, it leads to large quantities of agricultural waste either being disposed of or treated for the purpose of reintroduction into the production chain with a new use. Various approaches in food waste management were explored to achieve social benefits and applications. The extraction of natural bioactive molecules (such as fibers and antioxidants) through innovative technologies represents a means of obtaining value-added products and an excellent measure to reduce the environmental impact. Cosmetic, pharmaceutical, and nutraceutical industries can use natural bioactive molecules as supplements and the food industry as feed and food additives. The bioactivities of phytochemicals contained in biowaste, their potential economic impact, and analytical procedures that allow their recovery are summarized in this study. Our results showed that although the recovery of bioactive molecules represents a sustainable means of achieving both waste reduction and resource utilization, further research is needed to optimize the valuable process for industrial-scale recovery.

Anti-apoptotic effect of Buchholzia coriacea Engl. stem back extracts on AsPC-1 and mechanisms of action

Ethnopharmacological relevance

Buchholzia coriacea Engl. is popularly called wonderful cola due to its wide ethnomedicinal use for the treatment of various ailments. We investigated the possible cytotoxic effect of its various fractions on human pancreatic cancer cell (AsPC-1) and also determined its mechanisms of action.

Materials and methods

The AsPC-1 cells were cultivated and separately treated with 5-fluorouracil (5-FU) or Buchholzia coriacea Engl. bark (BC) (ethanol, aqueous, chloroform or ethyl acetate extract) for 72 h. Cell viability, caspase 3 and mitochondrial membrane potential (ΔΨm) were determined in vitro after the treatment. Nitric oxide (NO) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals’ scavenging property, ferric reducing power and lipid peroxidation assays were also done to examine the antioxidant effect of BC in vitro.

Results

Various extracts of BC, especially at 2500 μg/ml and 5000 μg/ml, increased the AsPC-1 viability while 5-FU decreased it. The activity of caspase 3 was increased by 5-FU but reduced by all concentrations of various extracts of BC. Incubation of AsPC-1 with 5-FU showed the majority of cells having the monomeric form of JC-1 dye (bright green fluorescence), which indicated de-energized mitochondria. However, fluorescence photomicrograph of cells incubated with different concentrations (20, 40 and 100 μg/ml) of BC extracts (aqueous, ethanol, chloroform and ethyl acetate) showed strong JC-1 aggregation (yellow), which indicated mitochondria with intact membrane potentials. BC extracts also scavenged NO and DPPH radicals, inhibited lipid peroxidation and increased ferric reduction, though not as much as ascorbic acid.

Conclusion

This study suggests that BC elicits anti-apoptotic activity in AsPC-1 by increasing cell viability, decreasing caspase 3 activity, stabilizing the ∆Ψm, and scavenging free radicals. Even though BC is used ethnomedicinally as anti-cancer agent, our findings in the present study suggest that it has pro-cancer potential in-vitro, especially on pancreatic cells. Its anti-apoptotic activity in AsPC-1 could be of clinical significance, especially to counteract the effect of apoptotic agents on pancreatic cells.

In vitro anti-biofilm efficacy of sanguinarine against carbapenem-resistant Serratia marcescens

Sanguinarine, a plant-derived benzophenanthridine alkaloid, was studied in terms of its anti-biofilm effects against carbapenem-resistant Serratia marcescens (CRSM). Minimum inhibitory concentrations (MICs) and cell membrane integrity were measured to investigate the antimicrobial mechanism of sanguinarine. Additionally, the extent of biofilm formation by CRSM exposed to sanguinarine was measured by crystal violet staining and visualized via field emission scanning electron microscopy and confocal laser scanning microscopy. Sanguinarine displayed moderate activity against CRSM, with a MIC₉₀ of 32 μg ml^-1. Moreover, cell membrane integrity was severely disrupted by sanguinarine at 64 μg ml^-1, and biofilm formation was sharply inhibited at 32 μg ml^-1. The minimum biofilm eradication concentration was 512 μg ml^-1 against mature CRSM biofilms. The overall results suggest that sanguinarine is a potential anti-biofilm agent that can be explored to treat CRSM infections.

Innovative Technologies for Extraction and Microencapsulation of Bioactives from Plant-Based Food Waste and their Applications in Functional Food Development

The by-products generated from the processing of fruits and vegetables (F&V) largely are underutilized and discarded as organic waste. These organic wastes that include seeds, pulp, skin, rinds, etc., are potential sources of bioactive compounds that have health imparting benefits. The recovery of bioactive compounds from agro-waste by recycling them to generate functional food products is of increasing interest. However, the sensitivity of these compounds to external factors restricts their utility and bioavailability. In this regard, the current review analyses various emerging technologies for the extraction of bioactives from organic wastes. The review mainly aims to discuss the basic principle of extraction for extraction techniques viz. supercritical fluid extraction, subcritical water extraction, ultrasonic-assisted extraction, microwave-assisted extraction, and pulsed electric field extraction. It provides insights into the strengths of microencapsulation techniques adopted for protecting sensitive compounds. Additionally, it outlines the possible functional food products that could be developed by utilizing components of agricultural by-products. The valorization of wastes can be an effective driver for accomplishing food security goals.

Isolation and purification of alkaloids from the fruits of Macleaya cordata by ionic-liquid-modified high-speed counter-current chromatography

Macleaya cordata (Willd) R. Br. is a medicinal plant. The most important bioactive compounds of M. cordata are alkaloids that have many biological activities including antifungal, anti-inflammatory, and antitumor. In this study, an ionic-liquid-modified high-speed counter-current chromatography method was established to obtain alkaloids from the fruits of M. cordata. The conditions of ionic-liquid-modified high-speed counter-current chromatography, including solvent systems, the content of ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [C₄ mim][BF₄ ]), and the posttreatment of the ionic liquid, were investigated. Five alkaloids protopine, allocryptopine, sanguinarine, 8-O-demethylchelerythrine, and chelerythrine were separated from the extract of the fruits using a high speed counter-current chromatography with two-phase solvent system composed of dichloromethane/methanol/0.3 mol/L hydrochloric acid aqueous solution/[C₄ mim][BF₄ ] (4:2:2:0.015, v/v). Their purities were 96.33, 95.56, 97.94, 96.22, and 97.90%, respectively. The results indicated that a small amount of ionic liquids as modifier of the two-phase solvent system could shorten the separation time and improve the separation efficiency of the alkaloids from the fruits. The ionic-liquid-modified high-speed counter-current chromatography would provide a feasible way for highly effective separation of alkaloids from natural products.

Online high-pH reversed-phase liquid chromatography × low-pH reversed-phase liquid chromatography tandem electrospray ionization mass spectrometry combined with pulse elution gradient in the first dimension for the analysis of alkaloids in Macleaya cordata (willd.) R. Br

An online high-pH reversed-phase liquid chromatography× low-pH reversed-phase liquid chromatography tandem electrospray ionization mass spectrometry combined with pulse elution gradient in the first dimension was constructed to separate and identify alkaloids from Macleaya cordata (willd.) R. Br. The modulation was performed by using a dual second dimensional columns interface combined with a make-up dilution pump, which is responsible for dilution and neutralization of the first dimensional effluent, and the dual second dimensional columns integrated the trapping and the separation function to reduce the second dimension system dead volume. Taking advantage of the dissociable characteristics of alkaloids, mobile phases with different pH values were applied in the first dimension (pH 9.0) and the second dimension (pH 2.6) to improve the orthogonality of two-dimension separation. Besides, the pulse elution gradient in first dimension and second dimensional gradient were carefully optimized and much better separation was achieved compared to the separation with the traditional two-dimensional liquid chromatography approach. Finally, mass measurement was performed for alkaloids in M. cordata (willd.) R. Br. by coupling proposed two-dimensional liquid chromatography system with triple quadrupole mass spectrometry, and 39 alkaloids were successfully identified by comparing the obtained result with the former reported results.

Cyanobacterial bloom mitigation by sanguinarine and its effects on aquatic microbial community structure

Sanguinarine has strong inhibitory effects against the cyanobacterium Microcystis aeruginosa. However, previous studies were mainly limited to laboratory tests. The efficacy of sanguinarine for mitigation of cyanobacterial blooms under field conditions, and its effects on aquatic microbial community structure remain unknown. To elucidate these issues, we carried out in situ cyanobacterial bloom mitigation tests. Our results showed that sanguinarine decreased population densities of the harmful cyanobacteria Microcystis and Anabaena. The inhibitory effects of sanguinarine on these cyanobacteria lasted 17 days, after which the harmful cyanobacteria recovered and again became the dominant species. Concentrations of microcystins in the sanguinarine treatments were lower than those of the untreated control except during the early stage of the field test. The results of community DNA pyrosequencing showed that sanguinarine decreased the relative abundance of the prokaryotic microorganisms Cyanobacteria, Actinobacteria, Planctomycetes and eukaryotic microorganisms of Cryptophyta, but increased the abundance of the prokaryotic phylum Proteobacteria and eukaryotic microorganisms within Ciliophora and Choanozoa. The shifting of prokaryotic microbial community in water column was directly related to the toxicity of sanguinarine, whereas eukaryotic microbial community structure was influenced by factors other than direct toxicity. Harmful cyanobacteria mitigation efficacy and microbial ecological effects of sanguinarine presented in this study will inform the broad application of sanguinarine in cyanobacteria mitigation.

MLKL mediates apoptosis via a mutual regulation with PERK/eIF2α pathway in response to reactive oxygen species generation

The pseudokinase mixed lineage kinase domain-like protein (MLKL) is a core effector of necroptosis, and its function in necroptosis is widely studied. However, the function of MLKL in apoptosis remains unclear. In the present study, the role of MLKL in chelerythrine (CHE)-promoted apoptosis was studied. A special band of MLKL (i.e., *MLKL) was observed after treatment with CHE. MLKL and *MLKL were accumulated in the nucleus upon treatment with CHE and MLKL silencing reversed the CHE-induced apoptosis. Blockade of CHE-triggered reactive oxygen species (ROS) generation or inhibition of CHE-activated protein kinase-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2 α subunit (eIF2α) pathway reversed the apoptosis. A decreased ROS level inhibited CHE-mediated nuclear translocation of MLKL and *MLKL and the activation of eIF2α, whereas MLKL or eIF2α silencing did not affect the CHE-triggered ROS generation. Furthermore, MLKL silencing prevented the CHE-activated eIF2α signal, and eIF2α silencing blocked the CHE-induced nuclear translocation of MLKL and *MLKL. Our studies suggested that CHE possibly induces apoptosis through the nuclear translocation of MLKL and *MLKL, which is promoted by a mutual regulation between MLKL and PERK-eIF2α pathway in response to ROS formation. The present study clarified the new function of MLKL in apoptosis.

Macleaya cordata extract alleviated oxidative stress and altered innate immune response in mice challenged with enterotoxigenic Escherichia coli

This study examines the effects of dietary Macleaya cordata extract (MCE) on bacterial burden and resistance to enterotoxigenic Escherichia coli (ETEC) in ICR mice. ICR mice were randomly distributed into one of the following groups: (i) basal diet; (ii) basal diet with 200 mg kg^-1 MCE; (iii) basal diet challenged with ETEC; and (iv) basal diet with 200 mg kg^-1 MCE and challenged with ETEC. Following a 7-day period of pre-treatment, CTRL-ETEC and MCE-ETEC mice were subjected to oral infection using 5×10⁸E. coli SEC 470. The results showed dietary 200 mg kg^-1 MCE markedly reduced intestinal ETEC burden (P < 0.05) and the disease-associated mortality was significantly alleviated in the MCE treated group (P < 0.05). In addition, dietary MCE markedly alleviated ETEC-induced oxidative stress, evidenced by the lowered methane dicarboxylic aldehyde (MDA) abundance and enhanced activities of catalase and glutathione peroxidase (P < 0.05). Furthermore, MCE mice exhibited higher immune activity, which might have further mediated ETEC infection. These results indicate MCE plays a preventative role with respect to ETEC infection. Future research should aim to develop MCE as a therapeutic approach to the promotion of intestinal health and a safeguard against ETEC infection.

Endophytic fungi residing in medicinal plants have the ability to produce the same or similar pharmacologically active secondary metabolites as their hosts

Medicinal plants have been used for thousands of years in folk medicines and still are used for their health benefits. In our days medicinal plants are exploited for the isolation of plant-derived drugs as they are very effective and have relatively less or no side effects. However, the natural resources of medicinal plants are gradually exhausted and access to plant bioactive compounds is challenged by the low levels at which these products accumulate in native medicinal plants. For instance, to meet the market demands of 3 Kg per year of vinca alkaloids, powerful plant-derived anticancer drugs, 1.5×106 Kg dry leaves are required. In this regard, this review aims to highlight the fact that endophytic fungi residing in medicinal plants are capable to biosynthesize pharmacologically active secondary metabolites similar or identical to those produced by their host medicinal plant. Furthermore, the evolutionary origin of the genes involved in these metabolic pathways as well as the approaches designed to enhance the production of these metabolites by the isolated endophytic fungi are also discussed.

Microwave assisted direct saponification for the simultaneous determination of cholesterol and cholesterol oxides in shrimp

A novel microwave-assisted direct saponification method for the simultaneous determination of cholesterol and cholesterol oxides in shrimp was developed and validated. Optimal saponification conditions, determined by means of an experimental design, were achieved using 500mg of sample and 20mL of 1mol/L KOH ethanol solution for 16min at 45°C at maximum power at 200W and magnetic stirring at 120rpm. Higher extraction of cholesterol oxides in a reduced saponification time (∼75 times) was achieved in comparison with the direct cold saponification method. The new method showed low detection (≤0.57μg/mL) and quantification (≤1.73μg/mL) limits, good repeatability (≤10.50% intraday and ≤8.56% interday) and low artifact formation (evaluated by using a deuterated cholesterol-D6 standard). Raw, salted and dried-salted shrimps were successfully analyzed by the validated method. The content of cholesterol oxides increased after salting and decreased after drying.

Induction of reactive oxygen species-stimulated distinctive autophagy by chelerythrine in non-small cell lung cancer cells

Chelerythrine (CHE), a natural benzo[c]phenanthridine alkaloid, shows anti-cancer effect through a number of mechanisms. Herein, the effect and mechanism of the CHE-induced autophagy, a type II programmed cell death, in non-small cell lung cancer (NSCLC) cells were studied for the first time. CHE induced cell viability decrease, colony formation inhibition, and apoptosis in a concentration-dependent manner in NSCLC A549 and NCI-H1299 cells. In addition, CHE triggered the expression of phosphatidylethanolamine-modified microtubule-associated protein light-chain 3 (LC3-II). The CHE-induced expression of LC3-II was further increased in the combination treatment with chloroquine (CQ), an autophagy inhibitor, and large amounts of red-puncta were observed in the CHE-treated A549 cells with stable expression of mRFP-EGFP-LC3, indicating that CHE induces autophagy flux. Silence of beclin 1 reversed the CHE-induced expression of LC3-II. Inhibition of autophagy remarkably reversed the CHE-induced cell viability decrease and apoptosis in NCI-H1299 cells but not in A549 cells. Furthermore, CHE triggered reactive oxygen species (ROS) generation in both cell lines. A decreased level of ROS through pretreatment with N-acetyl-L-cysteine reversed the CHE-induced cell viability decrease, apoptosis, and autophagy. Taken together, CHE induced distinctive autophagy in A549 (accompanied autophagy) and NCI-H1299 (pro-death autophagy) cells and a decreased level of ROS reversed the effect of CHE in NSCLC cells in terms of cell viability, apoptosis, and autophagy.

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Chelerythrine induces autophagic flux in non-small cell lung cancer (NSCLC) A549 and NCI-H1299 cells.

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Chelerythrine induces an accompanied autophagy in A549 cells, while a pro-death autophagy in NCI-H1299 cells.

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A decreased level of ROS reverses the chelerythrine-induced apoptosis and autophagy in NSCLC cells.

Optimization of microwave-assisted extraction of bioactive alkaloids from lotus plumule using response surface methodology

In this work, a fast and efficient microwave-assisted extraction (MAE) method was developed to extract main bioactive alkaloids from lotus plumue. To optimize MAE conditions, three main factors were selected using univariate approach experiments, and then central composite design (CCD). The optimal extraction conditions were as follows: methanol concentration of 65%, microwave power of 200 W, and extraction time of 260 s. An high performance liquid chromatography-diode array detector (HPLC-DAD) method was established to quantitatively analyze these phytochemicals in different lotus plumule samples and in different part of lotus. Chromatographic separation was carried out on an Agilent Zorbax Extend-C18 column (4.6 mm×150 mm, 3.5 µm). Gradient elution was applied with the mobile phase constituted with 0.1% triethylamine in water (A) and acetonitrile (B): 40%-70% B at 0-8 min, 70%-100% B at 8-9 min, 100% B for 2 min, and then equilibrated with 40% B for 2 min.

Analysis of the Impact of Isoquinoline Alkaloids, Derived from Macleaya cordata Extract, on the Development and Innate Immune Response in Swine and Poultry

Medicinal extract has been chronicled extensively in traditional Chinese medicine. Isoquinoline alkaloids, extract of Macleaya cordata (Willd.) R. Br., have been used as feed additive in both swine and poultry. Dietary supplementation with isoquinoline alkaloids increases feed intake and weight gain. In addition, recent researches have demonstrated that isoquinoline alkaloids can regulate metabolic processes, innate immune system, and digestive functioning in animals. This review summarizes the latest scientific researches on isoquinoline alkaloids which are extracted from Macleaya cordata (Willd.) R. Br. This review specifically focuses on its role as a feed supplement and its associated impact on growth performance and innate immune system, as well as its capacity to act as a substitute for oral antibiotics.

Soybean-derived glyceollins induce apoptosis through ROS generation

Glyceollins, which are synthesized from daidzein in soybeans infected with fungi, have been shown to have anti-fungal effects and antioxidant properties. However, the anti-proliferative mechanism of glyceollins against tumor cells is unknown. Glyceollin-induced apoptosis was evidenced by a decrease in cell viability and mitochondrial membrane potential, and an increase in early redistribution of plasma membrane phosphatidylserine, the sub G1 phase, and DNA fragmentation in hepa1c1c7 cells. Western blot analysis showed that treatment of the hepa1c1c7 cells with the glyceollins decreased the expression of pro-caspase-3, Bcl-2, and cell cycle-related proteins, but increased the expression of p21 and p27, and cytochrome C release into cytosol. At a concentration of 6 μg mL(-1) or higher, glyceollins significantly stimulated the production of reactive oxygen species (ROS), which appear to be responsible for the apoptotic activity of the compounds. Our present study demonstrated that the high dose of glyceollins possibly caused apoptosis in mouse hepatoma cells through the production of ROS, suggesting the potential to exploit glyceollins as anti-tumorigenic agents.

Antioxidant and antibacterial activity of Rhoeo spathacea (Swartz) Stearn leaves

The decoction and infusion of Rhoeo spathacea (Swartz) Stearn leaves have been recognized as a functional food particularly in South America, but has not yet gained international popularity as a beverage. The primary aim of this study was to establish the viability of R. spathacea aqueous leaf extracts as a beverage, in terms of its antioxidant activity and antibacterial activity. The antioxidant contents of aqueous and methanol leaf extracts were evaluated by the total phenolic content (TPC) and total flavonoid content (TFC) assays. The antioxidant activities measured were DPPH radical scavenging activity (FRS), ferric reducing power (FRP) and ferrous ion chelating (FIC) activity. The aqueous leaf extracts in the forms of decoction and infusion, were found to have comparable TPC and antioxidant activity with other herbal teas previously reported by our research group. Both decoction and infusion also exhibited antibacterial activity against six species of Gram positive and four species of Gram negative bacteria, notably methicillin-resistant Staphylococcus aureus and Neisseria gonorrhoeae. A total of four different known phenolic compounds were identified by HPLC and MS, three of which have not been previously reported to be found in this plant. Both the decoction and infusion of the leaves R. spathacea have potential to be popularized into a common beverage.

Isolation of quaternary benzo[c]phenanthridine alkaloids from Macleaya microcarpa (MAXIM.) FEDDE: comparison of maceration, Soxhlet extraction and pressurised liquid extraction

INTRODUCTION

Macleaya microcarpa (Papaveraceae family) has been of considerable interest in recent years as a prospective source of quaternary benzo[c]phenanthridine alkaloids (QBAs) related to many pharmaceutical beneficial effects. For this purpose, a quantitative, efficient and fast method to isolate the QBAs from the plant material is required.

OBJECTIVE

To optimise and compare pressurised liquid extraction (PLE) with Soxhlet extraction and maceration in order to estimate extraction conditions for fast and efficient isolation of QBAs contained in the roots of Macleaya microcarpa.

METHODOLOGY

The QBAs were extracted by PLE, Soxhlet extraction and maceration at different conditions (solvent, time, etc.). Reversed phase HPLC with diode-array detector was utilised for their determination and quantification. To optimise the PLE procedure, the variable parameters, including temperature (40-150 °C), sample-to-inert material ratio, extraction time (5-30 min) and number of extraction cycles (1-4), were also tested.

RESULTS

Quantitative determination of QBAs resulted in 0.2-2.8 mg/g, 0.3-2.5 mg/g and 0.3-3.1 mg/g for PLE, Soxhlet extraction and maceration. To produce the yields mentioned above, PLE required only up to 30 min compared with 21 h for Soxhlet extraction and 49 days for maceration.

CONCLUSION

PLE provided an effective and fast extraction of QBAs from M. microcarpa roots and can be recommended as an alternative isolation method to conventional techniques for QBAs from the plant sources.

Seasonal variation of bioactive alkaloid contents in Macleaya microcarpa (Maxim.) Fedde

Macleaya microcarpa (Maxim.) Fedde belongs to the genus Macleaya, family Papaveraceae. Together with the better known and more frequently studied species M. cordata (Willd.) R. Br. it is a main source of quaternary benzo[c]phenanthridine alkaloids. Using HPLC we determined the content of eight isoquinoline alkaloids in the aerial and underground parts of 1-, 2-, 12- and 13-year old plants and followed their changes during the vegetative period. The dominant alkaloid of all samples collected in the end of this period was allocryptopine (3.8–13.6 mg/g for aerial parts, 24.2–48.9 mg/g for underground parts). Chelerythrine, sanguinarine and protopine were also present in both parts of the plant. Additionally, measurable concentrations of chelilutine (CL), chelirubine (CR), macarpine (MA) and sanguirubine (SR) were detected in underground parts. The most important finding was that contents of CR, CL, SR and MA in the 12- and 13-year old plant roots were significantly higher (approximately 3-fold for CR, 6-fold for CL, 5-fold for SR, and at least 14-fold for MA) than in 1- or 2-year old plants. The proportion of individual alkaloids in aerial and underground parts thus changed significantly during the vegetative period.

Natural product isolation

Since the 1990s, interest in natural product research has increased considerably. Following several outstanding developments in the areas of separation methods, spectroscopic techniques, and sensitive bioassays, natural product research has gained new attention for providing novel chemical entities. This updated review deals with sample preparation and purification, recent extraction techniques used for natural product separation, liquid-solid and liquid-liquid isolation techniques, as well as multi-step chromatographic operations. It covers examples of papers published since the NPR review 'Modern separation methods' by Marston and Hostettmann,1 with major emphasis on methods developed and the research undertaken since 2000.

Recent developments in sample preparation techniques for chromatography analysis of traditional Chinese medicines

Traditional Chinese medicines (TCMs) have a long history dating back thousands of years. Recently, there has been increasing interest worldwide in the use of TCMs for the prevention and treatment of various illnesses. In China, a large number of analytical tools, especially chromatographic techniques have been used to analyze the constituents of TCMs in order to control their quality and discover new bioactive compounds. In this paper, recent developments in sample preparation techniques for the extraction, clean-up, and concentration of analytes from TCMs are compared. These techniques include headspace solid-phase microextraction (HS-SPME), headspace liquid-phase microextraction (HS-LPME), microwave-assisted extraction (MAE), supercritical-fluid extraction (SFE), pressurized-liquid extraction (PLE), and microwave distillation (MD).

Rapid determination of protopine, allocryptopine, sanguinarine and chelerythrine in fruits of Macleaya cordata by microwave-assisted solvent extraction and HPLC-ESI/MS

An isocratic high-performance liquid chromatographic method coupled with electrospray mass spectrometry was developed to determine protopine, allocryptopine, sanguinarine and chelerythrine in fruits of Macleaya cordata. The sample was extracted with hydrochloric acid aqueous solution using microwave-assisted extraction method. The extracts were separated on a C8 reversed-phase HPLC column with acetonitrile:acetate buffer as mobile phase, and full elution of all analytes was realized isocratically within 10 min. The abundance of pseudomolecule ions was recorded using selected ion recording at m/z 354.4, 370.1, 332.5, 348.5 and 338.5 for protopine, allocryptopine, sanguinarine, chelerythrine and the internal standard, jatrorrhizine, respectively. Internal standard curves were used for the quantification of protopine, allocryptopine, sanguinarine and chelerythrine, which showed a linear range of 0.745-74.5, 0.610-61.0, 0.525-105 and 0.375-75 microg/mL, respectively, with correlation coefficients of 0.9995, 0.9992, 0.9993 and 0.9989, and limits of detection of 3.73, 3.05, 1.60 and 1.11 ng/mL, respectively.

Microwave-assisted extraction of solanesol from tobacco leaves

Solanesol is the starting material for many high-value biochemicals, including co-enzyme Q10 and Vitamin K analogues. In the present study, a microwave-assisted extraction (MAE) technique has been developed for the fast extraction of solanesol from tobacco leaves. Compared to heat-reflux extraction, MAE reduced extraction time and obtained higher percentage extracted of solanesol. The effect of microwave on cell destruction of plant material was observed by scanning electron microscopy (SEM). The microwave-assisted extraction efficiency was further improved by adding NaOH into the extraction solvent, and the maximum percentage extracted of solanesol reached 0.91% (weight solanesol/weight tobacco) in 40 min at an optimum NaOH concentration of 0.05 M. The developed MAE integrated with saponification process provided an efficient method for solanesol recovery from tobacco leaf materials, and it also alleviated emulsification in the following separation and purification procedure as well.

Simultaneous analysis of alkaloids from Zanthoxylum nitidum by high performance liquid chromatography–diode array detector–electrospray tandem mass spectrometry

The chemical profiles of nine alkaloids in Zanthoxylum nitidum, including berberubine, coptisine, sanguinarine, nitidine, chelerythrine, liriodenine, 6,7,8-trimethoxy-2,3-methylendioxybenzophenantridine, oxyavicine and dihydrochelerythrine, were identified by using high performance liquid chromatography-diode array detector-electrospray tandem mass spectrometry (HPLC-DAD-ESI-MS), and a novel and sensitive HPLC-UV method had been developed to simultaneously determine these alkaloids in 70% methanol extract of Zanthoxylum nitidum. The chromatographic separation was performed on an Agilent C(18) analytical column (5 microm, 4.6 mm i.d., 250 mm length) with a gradient solvent system of acetonitrile-0.1% formic buffer (adjusted to pH 4.5 with triethylamine). The methodological validation was carried out and the linearities (r(2)>0.9997) and recoveries (ranged from 98.3% to 101.1%) were acceptable. The limits of detection (LOD) of these alkaloids were ranged from 0.6 ng to 1.5 ng. The results indicated that the contents of alkaloids in Zanthoxylum nitidum varied significantly from habitat to habitat with contents ranged from 0.03 mg/g to 3.34 mg/g. The proposed method is simple, effective and suitable for the quality control of this traditional Chinese medicine (TCM). It suggests that it is necessary to control its quality so as to insure efficacy and safety of TCM.

Rapid determination of solanesol in tobacco by high-performance liquid chromatography with evaporative light scattering detection following microwave-assisted extraction

Solanesol is the starting material for many high-value biochemicals, including coenzyme Q(10) and Vitamin-K analogues. The aim of the current study was to develop a reliable and fast analytical procedure for the determination of solanesol in tobacco using high-performance liquid chromatography (HPLC) with evaporative light scattering detection (ELSD) coupled with microwave-assisted extraction (MAE) as an efficient sample preparation technique. The HPLC conditions were Agilent C18 column using acetonitrile-isopropanol (60:40, v/v) as mobile phase at a flow rate of 1 ml/min. ELSD conditions were optimized at nebulizer-gas flow rate of 1.5 l/min and drift tube temperature of 65 degrees C. The method was validated to achieve the satisfactory precision and recovery, and the calibration range was 0.1-1.5 mg/ml. The developed analytical procedure was successfully applied to determine solanesol content in tobacco samples from different growing regions in China.