Use of non-aqueous capillary electrophoresis for the quality control of commercial saffron samples

Crocins for Ischemic Stroke: A Review of Current Evidence

Crocins (CRs) and the related active constituents derived from Crocus sativus L. (Saffron) have demonstrated protective effects against cerebral ischemia and ischemic stroke, with various bioactivities including neuroprotection, anti-neuroinflammation, antioxidant, and cardiovascular protection. Among CRs, crocin (CR) has been shown to act on multiple mechanisms and signaling pathways involved in ischemic stroke, including mitochondrial apoptosis, nuclear factor kappa light chain enhancer of B cells pathway, S100 calcium-binding protein B, interleukin-6 and vascular endothelial growth factor-A. CR is generally safe and well-tolerated. Pharmacokinetic studies indicate that CR has poor bioavailability and needs to convert to crocetin (CC) in order to cross the blood-brain barrier. Clinical studies have shown the efficacy of saffron and CR in treating various conditions, including metabolic syndrome, depression, Alzheimer’s disease, and coronary artery disease. There is evidence supporting CR as a treatment for ischemic stroke, although further studies are needed to confirm their efficacy and safety in clinical settings.

A Screening Method for P450 BM3 Mutant Libraries Using Multiplexed Capillary Electrophoresis for Detection of Enzymatically Converted Compounds

Capillary electrophoresis (CE) is an analytical method in which charged species are separated by attraction or repulsion performed in submillimeter diameter capillaries or micro- and nanofluidic channels through the application of a high voltage electric field. When capillary electrophoresis is assembled in a multicapillary instrument such as 96-well format (multiplexed), it becomes a powerful high-throughput system with the ability to simultaneously screen several types of samples like genetic mutations, metabolomes, kinase inhibitors, or enzymatic activities to name a few. The usage of a 96-multiplexed capillary electrophoresis system (96-MP-CE) represents a new platform for product-specific high-throughput screening of enzyme mutant libraries from directed evolution campaigns providing a comprehensive view on enzyme activity through the detection of all products formed. We describe the application of 96-MP-CE to screen mutant libraries of P450 BM3. MP-CE was used in directed evolution campaigns toward benzo-1,4-dioxane and α-isophorone.

A 96-multiplex capillary electrophoresis screening platform for product based evolution of P450 BM3

The main challenge that prevents a broader application of directed enzyme evolution is the lack of high-throughput screening systems with universal product analytics. Most directed evolution campaigns employ screening systems based on colorimetric or fluorogenic surrogate substrates or universal quantification methods such as nuclear magnetic resonance spectroscopy or mass spectrometry, which have not been advanced to achieve a high-throughput. Capillary electrophoresis with a universal UV-based product detection is a promising analytical tool to quantify product formation. Usage of a multiplex system allows the simultaneous measurement with 96 capillaries. A 96-multiplexed capillary electrophoresis (MP-CE) enables a throughput that is comparable to traditional direct evolution campaigns employing 96-well microtiter plates. Here, we report for the first time the usage of a MP-CE system for directed P450 BM3 evolution towards increased product formation (oxidation of alpha-isophorone to 4-hydroxy-isophorone; highest reached total turnover number after evolution campaign: 7120 mol_4-OH mol_P450⁻¹). The MP-CE platform was 3.5-fold more efficient in identification of beneficial variants than the standard cofactor (NADPH) screening system.

Identification of phenolic markers for saffron authenticity and origin: An untargeted metabolomics approach

Saffron is a high-quality and expensive spice being widely subjected to adulteration. An UHPLC-ESI/QTOF-MS metabolomic-based approach was therefore used to investigate the discrimination potential between adulterated (added with different percentage of other parts of the flower) and authentic saffron, as well as to trace its geographical origin. Both unsupervised (hierarchical clustering) and supervised OPLS-DA multivariate statistics allowed discriminating authentic saffron from styles added of other floral components, as well as PDO (Protected Designation of Origin) vs non PDO saffron samples according to their chemical fingerprints. The proposed markers were then validated through ROC curves. Anthocyanins and glycosidic flavonols were the best markers of the styles' adulteration. However, other flavonoids (mainly free flavonols and flavones), together with protocatechuic aldehyde and isomeric forms of hydroxybenzoic acid, were also validated as markers for the discrimination of PDO vs non PDO saffron samples. This work outlines the potential of untargeted metabolomics based on UHPLC-ESI/QTOF mass spectrometry for saffron authenticity and traceability.

Molecular species fingerprinting and quantitative analysis of saffron (Crocus sativus L.) for quality control by MALDI mass spectrometry

Herein we describe a rapid, simple, and reliable method for the quantitative analysis and molecular species fingerprinting of saffron (Crocus sativus L.) by direct MS and MS/MS analysis. Experimentally, powdered saffron was subjected to a brief treatment with a 0.3% TFA water/acetonitrile solution, and the resulting mixture was directly placed on the MALDI plate for analysis. This approach allowed the detection of the commonly observed crocins C-1-C-6 and flavonols, together with the identification of the unknown highly glycosylated crocins C-7, C-8 and C-9, and carotenoid-derived metabolites. The strategy endorsed the simultaneous detection and characterization of saffron and adulterant markers using crude extracts of the adulterant itself and synthetic sets of adulterated authentic saffron samples. The implementation of the strategy was to measure the amount of an unknown adulterant from the crude extract using curcumin as a non-isotopic isobaric internal standard. The relationship between the saffron and curcumin molar ratios were established with a correlation coefficient of 0.9942. The ANOVA regression model was significant, F(1, 72) = 13 595.82, p < 0.001, y = (0.0116 ± 0.0001)x + (-0.1214 ± 0.0086). No matrix effects were observed and good results were obtained with respect to instrumental repeatability (*RSD% < 2%) and LOD (1.1%). The analysis of commercial samples of saffron using the proposed approach showed the suitability of the method for routine analysis (minimal sample preparation and very short measuring time per sample).

Anti-tumor effects of crocetin and related molecular targets

Natural products have gained a wide popularity as chemopreventive and anti-cancer agents owing to their multi-mechanistic mode of action, availability and synergism with several conventional chemotherapeutic agents. Crocetin is a carotenoid compound isolated from the stigma of Crocus sativus L. (saffron). Crocetin has shown promising effects as an anti-tumor agent in animal models and cell culture systems. Crocetin retards the growth of cancer cells via inhibiting nucleic acid synthesis, enhancing anti-oxidative system, and inducing apoptosis and differentiation pathways. The present review outlines natural sources of crocetin, and its pharmacokinetic and pharmacological properties relevant to the prevention and treatment of cancer. Also, we discuss molecular targets underlying the putative anti-tumor effects of crocetin.

Analysis of bioactive constituents of saffron using ultrasonic assisted emulsification microextraction combined with high-performance liquid chromatography with diode array detector: a chemometric study

In recent years, there has been an increasing interest in the analysis of the major active components of saffron owing to their significant role in various industries, such as food, medicine and perfume.

Barcoding melting curve analysis for rapid, sensitive, and discriminating authentication of saffron (Crocus sativus L.) from its adulterants

Saffron (Crocus sativus L.) is one of the most important and expensive medicinal spice products in the world. Because of its high market value and premium price, saffron is often adulterated through the incorporation of other materials, such as Carthamus tinctorius L. and Calendula officinalis L. flowers, Hemerocallis L. petals, Daucus carota L. fleshy root, Curcuma longa L. rhizomes, Zea may L., and Nelumbo nucifera Gaertn. stigmas. To develop a straightforward, nonsequencing method for rapid, sensitive, and discriminating detection of these adulterants in traded saffron, we report here the application of a barcoding melting curve analysis method (Bar-MCA) that uses the universal chloroplast plant DNA barcoding region trnH-psbA to identify adulterants. When amplified at DNA concentrations and annealing temperatures optimized for the curve analysis, peaks were formed at specific locations for saffron (81.92°C) and the adulterants: D. carota (81.60°C), C. tinctorius (80.10°C), C. officinalis (79.92°C), Dendranthema morifolium (Ramat.) Tzvel. (79.62°C), N. nucifera (80.58°C), Hemerocallis fulva (L.) L. (84.78°C), and Z. mays (84.33°C). The constructed melting curves for saffron and its adulterants have significantly different peak locations or shapes. In conclusion, Bar-MCA could be a faster and more cost-effective method to authenticate saffron and detect its adulterants.

Saffron Samples of Different Origin: An NMR Study of Microwave-Assisted Extracts

An NMR analytical protocol is proposed to characterize saffron samples of different geographical origin (Greece, Spain, Hungary, Turkey and Italy). A microwave-assisted extraction procedure was developed to obtain a comparable recovery of metabolites with respect to the ISO specifications, reducing the solvent volume and the extraction time needed. Metabolite profiles of geographically different saffron extracts were compared showing significant differences in the content of some metabolites.

Bioactivity assessment and toxicity of crocin: a comprehensive review

Since ancient times, saffron, the dried stigma of the plant Crocus sativus L. has been extensively used as a spice and food colorant; in folk medicine it has been reputed to be efficacious for the alleviation and treatment of ailments. In addition to the three founded major constituents including crocin, picrocrocin and safranal, presence of carotenoids, carbohydrates, proteins, anthocyanins, vitamins and minerals provide valuable insights into the health benefits and nutritional value of saffron. Of the carotenoids present in saffron, highly water-soluble crocin (mono and diglycosyl esters of a polyene dicarboxylic acid, named crocetin) is responsible for the majority of its color, and appears to possess various health-promoting properties, as an antioxidant, antitumor, memory enhancer, antidepressant, anxiolytic and aphrodisiac. It is also worth noting that the crocin principle of saffron exhibited high efficacy along with no major toxicity in experimental models. We would be remiss to not consider the great potential of saffron and crocin, which benefits the cuisine and health of human life throughout the world. The present study provides a comprehensive and updated report of empirical investigations on bioactivities and biological characteristics of crocin.

Determination of volatile components of saffron by optimised ultrasound-assisted extraction in tandem with dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry

In the present research, a combined extraction method of ultrasound-assisted extraction (UAE) in conjunction with dispersive liquid-liquid microextraction (DLLME) was applied to isolation and enrichment of saffron volatiles. The extracted components of the saffron were separated and determined by gas chromatography-mass spectrometry (GC-MS) technique. The mixture of methanol/acetonitrile was chosen for the extraction of the compounds and chloroform was used at the preconcentration stage. The important parameters, such as composition of extraction solvent, volume of preconcentration solvent, ultrasonic applying time, and salt concentration were optimised by using a half-fraction factorial central composite design (CCD). Under the optimal conditions, the linear dynamic ranges (LDRs) were 10-10,000mgL(-)(1). The determination coefficients (R(2)) were from 0.9990 to 0.9997. The limits of detection (LODs) and limits of quantification (LOQs) for the extracted compounds were 6-123mgL(-)(1) and 20-406mgL(-)(1), respectively. The relative standard deviations (RSDs) were 2.48-9.82% (n=3). The enhancement factors (EFs) were 3.6-41.3.

Quality control of saffron (Crocus sativus L.): development of SCAR markers for the detection of plant adulterants used as bulking agents

A method based on sequence-characterized amplified regions (SCARs) was developed from random amplified polymorphic DNA markers (RAPDs) specific for Arnica montana L., Bixa orellana L., Calendula officinalis L., Carthamus tinctorius L., Crocus vernus L. (Hill), Curcuma longa L., and Hemerocallis sp. to detect these common bulking agents in commercial saffron (Crocus sativus). The method enabled the unequivocal detection of low amounts (up to 1%) of each adulterant, allowing the preemptive rejection of suspect samples. Its enforcement limits the number of samples to be subjected to further evaluation with pharmacognostic or phytochemical analyses, especially when multiple batches have to be evaluated in a short time. The dimension of the amplicons is suitable for the analysis of degraded DNA obtained from dried, stored, processed, and finely ground commercial material. Proper SCAR markers may represent a fast, sensitive, reliable, and low-cost screening method for the authentication of dried commercial saffron material.

Application of metabonomic analytical techniques in the modernization and toxicology research of traditional Chinese medicine

In the recent years, a wide range of metabonomic analytical techniques are widely used in the modern research of traditional Chinese medicine (TCM). At the same time, the international community has attached increasing importance to TCM toxicity problems. Thus, many studies have been implemented to investigate the toxicity mechanisms of TCM. Among these studies, many metabonomic-based methods have been implemented to facilitate TCM toxicity investigation. At present, the most prevailing methods for TCM toxicity research are mainly single analysis techniques using only one analytical means. These techniques include nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS), etc.; with these techniques, some favourable outcomes have been gained in the toxic reaction studies of TCM, such as the action target organs assay, the establishment of action pattern, the elucidation of action mechanism and the exploration of action material foundation. However, every analytical technique has its advantages and drawbacks, no existing analytical technique can be versatile. Multi-analysed techniques can partially overcome the shortcomings of single-analysed techniques. Combination of GC-MS and LC-MS metabolic profiling approaches has unravelled the pathological outcomes of aristolochic acid-induced nephrotoxicity, which can not be achieved by single-analysed techniques. It is believed that with the further development of metabonomic analytical techniques, especially multi-analysed techniques, metabonomics will greatly promote TCM toxicity research and be beneficial to the modernization of TCM in terms of extending the application of modern means in the TCM safety assessment, assisting the formulation of TCM safety norms and establishing the international standards indicators.

Characterization of By-products of Saffron (Crocus Sativus L.) Production

The stigma, stamens and sepals of Crocus sativus L,. from two different geographical origins, were analyzed for their crocin and flavonol contents. Identification of crocins, safranal, picrocrocin, and flavonols was carried out by HPLC/DAD and HPLC/MS analysis. Both stigma samples, grown under natural conditions, exhibited high crocin contents (between 342 and 231 mg/g), while the stamens and sepals were rich in flavonols (between 6 and 10 mg/g). The stamens contain mainly kaempferol- 3-O-sophoroside, whereas the sepals contain mainly quercetin and methyl-quercetin glycosides. These data may be useful in order to find a possible exploitation of the by-products of saffron production, in which large quantities of C. sativus flowers are available.

Nonaqueous capillary electrophoresis in pharmaceutical analysis

This review presents different solvents and electrolytes commonly used as BGEs in NACE for the analysis of pharmaceutical compounds. Most NACE applications carried out since 1998 for the analysis of compounds of pharmaceutical interest are presented in four tables: (i) analysis of drugs and related substances, (ii) analysis of chiral substances, (iii) analysis of phytochemical extracts and (iv) analysis of drugs in biological fluids. These selected examples are used to illustrate the interest in NACE versus conventional aqueous CE.

Determination of total safranal by in situ acid hydrolysis in supercritical fluid media: Application to the quality control of commercial saffron

A procedure allowing hydrolysis reactions to be conducted in a dynamic supercritical-CO2 medium was developed for quantifying total safranal (viz. free safranal present in the sample+safranal resulting from picrocrocin hydrolysis), which are the main component of the essential oil and responsible for the characteristic aroma of saffron. The proposed method allows total safranal amounts over the ranges 0.05-1.5 mg mL(-1) to be determined. The standard deviation achieved was 2%. This method was applied to the determination of safranal in natural saffron samples. The results obtained were compared with the "safranal value" total index, which is widely used as a quality measure of saffron products. The comparison revealed that the proposed method provides useful information not contained in the safranal value, based on the fact that, some samples with a high "safranal index" contain low concentrations of safranal. The proposed method is very useful for quality control in commercial saffron samples.