UHPLC Analysis of Saffron (Crocus sativus L.): Optimization of Separation Using Chemometrics and Detection of Minor Crocetin Esters

Fingerprint of Characteristic Saffron Compounds as Novel Standardization of Commercial Crocus sativus Extracts

Food supplements based on saffron (Crocus sativus L.) dried stigma extracts are widely consumed due to their multiple bioactive properties. Saffron extract (SE) standardization is of crucial importance, as it determines the reproducibility of the product quality and is essential for the evaluation of its bioactive effect and safety. Although SEs are commonly standardized considering their safranal content, the lack of specificity of the official methods may give inaccurate measurements. In addition to the development of more precise methodologies, the evaluation of alternative saffron components, such as crocins and picrocrocin, for standardization purposes would also be of interest. Thus, in this study, qualitative and quantitative information regarding picrocrocin and crocin isomers of different commercial saffron extracts was first obtained by a validated methodology using liquid chromatography (HPLC) coupled to diode array (DAD) and mass spectrometer (MS) detectors. Principal component analysis (PCA) was applied to gain insight into the compositional variability and natural grouping of SE. These studies suggested the potential use of the relative content of crocin isomers and trans-/cis-crocins and trans-4 GG/picrocrocin ratios as novel criteria for SE standardization. Their reproducibility and stability under controlled storage conditions for 36 months was demonstrated in a commercial standardized SE (affron^®).

Efficacy of Hydroponically Cultivated Saffron in the Preservation of Retinal Pigment Epithelium

Saffron treatment is a broad-spectrum therapy used for several retinal diseases, and its effectiveness depends on a particular molecular composition (REPRON^® saffron). Its production requires specific crops and procedures that, together with low yields, make this spice expensive. To reduce costs, the use of hydroponic crops is gradually increasing. In this study, we tested the protective properties of a hydroponic saffron (sH) batch in models of retinal pigmented epithelium (RPE) degeneration. ARPE-19 cells were pretreated with 40 µg/mL saffron and exposed to different types of damage: excess light and retinol (LE + RET) or oxidative stress (H₂O₂). After analyzing the composition of all saffron types with spectroscopy, we performed cell viability and immunofluorescence analysis for both protocols. We compared the sH results with those of a validated batch of saffron REPRON^® (sR) and those of a saffron non-REPRON^® (sNR) batch. sH and sR, which we found had the same chemical composition, were more effective than sNR in increasing cell survival and attenuating the morphological changes related to apoptosis. In conclusion, hydroponic culturing is a suitable strategy to produce high-quality saffron to reduce costs and increase the accessibility of this promising treatment for retinal degeneration.

Saffron Characterization by a Multidisciplinary Approach

Saffron is a spice obtained from the drying process of the stigmas of the flower Crocus sativus Linnaeus. It is well known that the organoleptic characteristics of this spice are closely linked to the production area and harvesting year. The present work aims to evaluate whether saffron samples produced in different years and origins present sensibly different crocin profiles. To achieve this goal, 120 saffron samples were harvested between 2016 and 2020 in four different Italian areas. The crocins were analysed, identified, and quantified by high-performance liquid chromatography-electrospray-tandem mass spectrometry (HPLC-ESI-MS/MS) in multiple reaction monitoring mode (MRM). Subsequently, ANOVA-simultaneous component analysis (ASCA) was used to evaluate whether the origin and annuity significantly affected the composition of the crocins. ASCA confirmed the relevance of these effects. Eventually, soft independent modelling by class analogy (SIMCA) models were created for each of the four different origins. Mixtures of saffron from different areas were also prepared to test the robustness of the models. SIMCA provided satisfying results; in fact, models provided 100% sensitivity for three origins (Cascia, Sardinia, and Città della Pieve) on the external test set (48 samples) and 88% (sensitivity on the external test set) for the Spoleto class.

Effective Isolation of Picrocrocin and Crocins from Saffron: From HPTLC to Working Standard Obtaining

Saffron is widely cultivated and used as a spice. Recently published data on the chemical composition and pharmacological potential of saffron determine its use in pharmacy and medicine. The proposed high-performance thin-layer chromatography (HPTLC) method allows good separation of 11 analytes. The saffron quality (Iran, Ukraine, Spain, Morocco samples) assessment was based on the European Pharmacopoeia monograph and ISO 3632. The HPTLC method for the safranal, crocin, and picrocrocin quantification was proposed and validated. The crocins content in Ukrainian saffron was from 17.80% to 33.25%. Based on qualitative and quantitative assessment results, the saffron sample from Zaporizhzhia (Ukraine) had the highest compounds content and was chosen to obtain the working standards of picrocrocin and crocins (trans-4GG, trans-2G, trans-3Gg) by preparative chromatography. The compounds were isolated from lyophilized extract of saffron using a Symmetry Prep C₁₈ column (300 × 19 mm × 7 µm), and identified by spectroscopic techniques (HPLC-DAD, UPLC-ESI-MS/MS). The purity of crocins and picrocrocin was more than 97%. A novel method proposed to obtain working standards is simple and reproducible for the routine analysis of saffron quality control.

Engineering high levels of saffron apocarotenoids in tomato

Crocins and picrocrocin are high-value hydrophilic pigments produced in saffron and used commercially in the food and pharmaceutical industries. These apocarotenoids are derived from the oxidative cleavage of zeaxanthin by specific carotenoid cleavage dioxygenases. The pathway for crocins and picrocrocin biosynthesis was introduced into tomato using fruit specific and constitutive promoters and resulted in 14.48 mg/g of crocins and 2.92 mg/g of picrocrocin in the tomato DW, without compromising plant growth. The strategy involved expression of CsCCD2L to produce crocetin dialdehyde and 2,6,6-trimethyl-4-hydroxy-1-carboxaldehyde-1-cyclohexene, and of glycosyltransferases UGT709G1 and CsUGT2 for picrocrocin and crocins production, respectively. Metabolic analyses of the engineered fruits revealed picrocrocin and crocetin-(β-D-gentiobiosyl)-(β-D-glucosyl)-ester, as the predominant crocin molecule, as well as safranal, at the expense of the usual tomato carotenoids. The results showed the highest crocins content ever obtained by metabolic engineering in heterologous systems. In addition, the engineered tomatoes showed higher antioxidant capacity and were able to protect against neurological disorders in a Caenorhabditis elegans model of Alzheimer's disease. Therefore, these new developed tomatoes could be exploited as a new platform to produce economically competitive saffron apocarotenoids with health-promoting properties.

1H-NMR Metabolic Profiling and Antioxidant Activity of Saffron (Crocus sativus) Cultivated in Lebanon

Despite the beneficial health properties shown by Lebanese saffron, its qualitative and quantitative composition has never been investigated before. In the present study, NMR spectroscopy, together with antioxidant activity assays, were applied to evaluate the chemical composition of saffron samples of different geographical origins (Lebanon, Italy, Iran, and India) and to categorize the Lebanese saffron for the first time. The distinction between Lebanese saffron and that produced in other countries was attributed to its higher linolenic and linoleic fatty acids, glucose and picrocrocin contents. Moreover, spices produced in three different regions of the Lebanese territory have been clearly differentiated. Saffron cultivated in the Qaa region displayed a high glucose, fatty acids and polyphenols content, whereas Hermel saffron exhibited the largest rate of picrocrocin and glycosylated carotenoids. Finally, samples from Baalbeck showed lower rates for the majority of metabolites. Moreover, Lebanese saffron showed a high antioxidant activity in ABTS and DPPH assays. A low dose of saffron extract (10 µg/mL) inhibited the growth of human lung adenocarcinoma cells, probably due to the high polyphenolic content. This study highlights the quality and peculiarity of Lebanese saffron cultivated in Northern Beqaa district and allows for a good discrimination between spices produced in relatively close territory.

Identification and characterization of apocarotenoid modifiers and carotenogenic enzymes for biosynthesis of crocins in Buddleja davidii flowers

Crocetin biosynthesis in Buddleja davidii flowers proceeds through a zeaxanthin cleavage pathway catalyzed by two carotenoid cleavage dioxygenases (BdCCD4.1 and BdCCD4.3), followed by oxidation and glucosylation reactions that lead to the production of crocins. We isolated and analyzed the expression of 12 genes from the carotenoid pathway in B. davidii flowers and identified four candidate genes involved in the biosynthesis of crocins (BdALDH, BdUGT74BC1, BdUGT74BC2, and BdUGT94AA3). In addition, we characterized the profile of crocins and their carotenoid precursors, following their accumulation during flower development. Overall, seven different crocins, crocetin, and picrocrocin were identified in this study. The accumulation of these apocarotenoids parallels tissue development, reaching the highest concentration when the flower is fully open. Notably, the pathway was regulated mainly at the transcript level, with expression patterns of a large group of carotenoid precursor and apocarotenoid genes (BdPSY2, BdPDS2, BdZDS, BdLCY2, BdBCH, BdALDH, and BdUGT Genes) mimicking the accumulation of crocins. Finally, we used comparative correlation network analysis to study how the synthesis of these valuable apocarotenoids diverges among B. davidii, Gardenia jasminoides, and Crocus sativus, highlighting distinctive differences which could be the basis of the differential accumulation of crocins in the three species.

Bioanalytical Method Development and Validation Study of Neuroprotective Extract of Kashmiri Saffron Using Ultra-Fast Liquid Chromatography-Tandem Mass Spectrometry (UFLC-MS/MS): In Vivo Pharmacokinetics of Apocarotenoids and Carotenoids

Kashmir saffron (Crocus sativus L.), also known as Indian saffron, is an important Asian medicinal plant with protective therapeutic applications in brain health. The main bioactive in Kashmir or Indian Saffron (KCS) and its extract (CSE) are apocarotenoids picrocrocin (PIC) and safranal (SAF) with carotenoids, crocetin esters (crocins), and crocetins. The ultra-fast liquid chromatography(UFLC)- photodiode array standardization confirmed the presence of biomarkers PIC, trans-4-GG-crocin (T4C), trans-3-Gg-crocin (T3C), cis-4-GG-crocin (C4C), trans-2-gg-crocin (T2C), trans-crocetin (TCT), and SAF in CSE. This study’s objectives were to develop and validate a sensitive and rapid UFLC-tandem mass spectrometry method for PIC and SAF along T4C and TCT in rat plasma with internal standards (IS). The calibration curves were linear (R² > 0.990), with the lower limit of quantification (LLOQ) as 10 ng/mL. The UFLC-MS/MS assay-based precision (RSD, <15%) and accuracy (RE, −11.03–9.96) on analytical quality control (QC) levels were well within the acceptance criteria with excellent recoveries (91.18–106.86%) in plasma samples. The method was applied to investigate the in vivo pharmacokinetic parameters after oral administration of 40 mg/kg CSE in the rats (n = 6). The active metabolite TCT and T4C, PIC, SAF were quantified for the first time with T3C, C4C, T2C by this validated bioanalytical method, which will be useful for preclinical/clinical trials of CSE as a potential neuroprotective dietary supplement.

Saffron: Chemical Composition and Neuroprotective Activity

Crocus sativus L. belongs to the Iridaceae family and it is commonly known as saffron. The different cultures together with the geoclimatic characteristics of the territory determine a different chemical composition that characterizes the final product. This is why a complete knowledge of this product is fundamental, from which more than 150 chemical compounds have been extracted from, but only about one third of them have been identified. The chemical composition of saffron has been studied in relation to its efficacy in coping with neurodegenerative retinal diseases. Accordingly, experimental results provide evidence of a strict correlation between chemical composition and neuroprotective capacity. We found that saffron's ability to cope with retinal neurodegeneration is related to: (1) the presence of specific crocins and (2) the contribution of other saffron components. We summarize previous evidence and provide original data showing that results obtained both "in vivo" and "in vitro" lead to the same conclusion.

Schisandra chinensis bee pollen's chemical profiles and protective effect against H2O2-induced apoptosis in H9c2 cardiomyocytes

Background

Schisandra chinensis (Turcz.) Baill bee pollen extract (SCBPE) is often used as a functional food in China due to its good antioxidant property. However, its chemical compositions and effects on H9c2 cardiomyocytes against H₂O₂-induced cell injury still lacks of reports thus far. This study aimed to characterize the main components of SCBPE and investigate its protective effects against H₂O₂-induced H9c2 cardiomyocyte injury.

Methods

The main components of SCBPE were analyzed via ultraperformance liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (UPLC–QTOF MS/MS). The three main nucleosides in SCBPE were quantitatively analyzed via ultraperformance liquid chromatography–diode array detection. Furthermore, the potential mechanism by which SCBPE exerts protective effects against H₂O₂-induced H9c2 cardiomyocyte injury was explored for the first time via cell survival rate measurements; cell morphological observation; myocardial superoxide dismutase (SOD) activity and malondialdehyde (MDA) and glutathione (GSH) level determination; flow cytometry; and quantitative polymerase chain reaction.

Results

Two carbohydrates, three nucleosides, and nine quinic acid nitrogen-containing derivatives in SCBPE were identified or tentatively characterized via UPLC–QTOF MS/MS. The nine quinic acid nitrogen-containing derivatives were first reported in bee pollen. The contents of uridine, guanosine, and adenosine were 2.4945 ± 0.0185, 0.1896 ± 0.0049, and 1.8418 ± 0.0157 μg/mg, respectively. Results of in vitro experiments showed that cell survival rate, myocardial SOD activity, and GSH level significantly increased and myocardial MDA level significantly decreased in SCBPE groups compared with those in H₂O₂ group. Cell morphology in SCBPE groups also markedly improved compared with that in H₂O₂ group. Results indicated that SCBPE protected H9c2 cardiomyocytes from H₂O₂-induced apoptosis by downregulating the mRNA expressions of Bax, cytochrome C, and caspase-3 and upregulating the Bcl-2 mRNA expression.

Conclusions

This study is the first to report that SCBPE could protect against oxidative stress injury and apoptosis in H₂O₂-injured H9c2 cells. Results indicated that the nucleosides and quinic acid nitrogen-containing derivatives could be the main substances that exert protective effects against H₂O₂-induced H9c2 cardiomyocyte injury.

Geographical Classification of Italian Saffron (Crocus sativus L.) by Multi-Block Treatments of UV-Vis and IR Spectroscopic Data

One-hundred and fourteen samples of saffron harvested in four different Italian areas (three in Central Italy and one in the South) were investigated by IR and UV-Vis spectroscopies. Two different multi-block strategies, Sequential and Orthogonalized Partial Least Squares Linear Discriminant Analysis (SO-PLS-LDA) and Sequential and Orthogonalized Covariance Selection Linear Discriminant Analysis (SO-CovSel-LDA), were used to simultaneously handle the two data blocks and classify samples according to their geographical origin. Both multi-block approaches provided very satisfying results. Each model was investigated in order to understand which spectral variables contribute the most to the discrimination of samples, i.e., to the characterization of saffron harvested in the four different areas. The most accurate solution was provided by SO-PLS-LDA, which only misclassified three test samples over 31 (in external validation).

Retention Modelling of Phenoxy Acid Herbicides in Reversed-Phase HPLC under Gradient Elution

Phenoxy acid herbicides are used worldwide and are potential contaminants of drinking water. Reversed phase high-performance liquid chromatography (RP-HPLC) is commonly used to monitor phenoxy acid herbicides in water samples. RP-HPLC retention of phenoxy acids is affected by both mobile phase composition and pH, but the synergic effect of these two factors, which is also dependent on the structure and pKa of solutes, cannot be easily predicted. In this paper, to support the setup of RP-HPLC analysis of phenoxy acids under application of linear mobile phase gradients we modelled the simultaneous effect of the molecular structure and the elution conditions (pH, initial acetonitrile content in the eluent and gradient slope) on the retention of the solutes. In particular, the chromatographic conditions and the molecular descriptors collected on the analyzed compounds were used to estimate the retention factor k by Partial Least Squares (PLS) regression. Eventually, a variable selection approach, Genetic Algorithms, was used to reduce the model complexity and allow an easier interpretation. The PLS model calibrated on the retention data of 15 solutes and successively tested on three external analytes provided satisfying and reliable results.

Investigating the effect of Crocus sativus L. petal hydroalcoholic extract on inflammatory and enzymatic indices resulting from alcohol use in kidney and liver of male rats

Background

Studies have shown that consumption of high levels of alcohol causes many negative effects on the liver and kidneys where antioxidant ingredients can be a proper solution to reducing the resulting damages. So, the present study investigated the effect of hydroalcoholic extract of Crocus sativus L. (saffron) petal with antioxidant properties on the changes in inflammatory and enzymatic indices resulting from alcohol use in the male rats’ kidney and liver.

Materials and methods

After preparing the extract, LD₅₀ was determined and high-performance liquid chromatography (HPLC) was employed to specify the type and the rate of the active ingredients of the extract. Then, 36 male Wistar rats were randomly assigned into six groups (n=6). The first group was only administered with normal saline and the second group only received ethyl alcohol 6 mL/kg/day·BW. The third and the fourth groups received ethyl alcohol 6 mL/kg/day·BW plus 167.5 and 335 mg/kg/day·BW saffron petal extract for 8 weeks. The fifth and the sixth groups received ethyl alcohol 6 mL/kg/day·BW for the first 8 weeks and were subsequently gavage fed on saffron extract for 167.5 and 335 mg/kg/day·BW, respectively, during the next 8 weeks. In the beginning and after the termination of the treatment, blood samples were collected from all rats.

Results

The LD₅₀ of the extract was about 670 mg/kg. The HPLC results indicated that the extract contains important antioxidant ingredients. At the end of the study, the serum concentration of the inflammatory indices, renal enzymes, and hepatic enzymes experienced a significant reduction in all of the intervened groups compared to the negative control group (minimum significant difference: P<0.05) except for the treatment group 1.

Conclusion

Based on the current results, the extract has a protective effect in a dosage-dependent way and greater protective roles were documented for higher dosages.

UGT709G1: a novel uridine diphosphate glycosyltransferase involved in the biosynthesis of picrocrocin, the precursor of safranal in saffron (Crocus sativus)

Saffron, a spice derived from the dried red stigmas of Crocus sativus, is one of the oldest natural food additives. The flowers have long red stigmas, which store significant quantities of the glycosylated apocarotenoids crocins and picrocrocin. The apocarotenoid biosynthetic pathway in saffron starts with the oxidative cleavage of zeaxanthin, from which crocins and picrocrocin are derived. In the processed stigmas, picrocrocin is converted to safranal, giving saffron its typical aroma. By a targeted search for differentially expressed uridine diphosphate glycosyltransferases (UGTs) in Crocus transcriptomes, a novel apocarotenoid glucosyltransferase (UGT709G1) from saffron was identified. Biochemical analyses revealed that UGT709G1 showed a high catalytic efficiency toward 2,6,6-trimethyl-4-hydroxy-1-carboxaldehyde-1-cyclohexene (HTCC), making it suited for the biosynthesis of picrocrocin, the precursor of safranal. The role of UGT709G1 in picrocrocin/safranal biosynthesis was supported by the absence or presence of gene expression in a screening for HTCC and picrocrocin production in different Crocus species and by a combined transient expression assay with CsCCD2L in Nicotiana benthamiana leaves. The identification of UGT709G1 completes one of the most highly valued specialized metabolic biosynthetic pathways in plants and provides novel perspectives on the industrial production of picrocrocin to be used as a flavor additive or as a pharmacological constituent.

Biologically active compounds and pharmacological activities of species of the genus Crocus: A review

The present article is the first comprehensive review on the chemical composition and pharmacological activities of the raw materials of Crocus species. In the present review, data on chemical constituents and pharmacological profile of Crocus sativus stigmas, as well as of other plant parts (perianth, stamens, leaves, corms) of different Crocus spp. are given. This review discusses all the classes of compounds (carotenoids, flavonoids, anthocyanins, terpenoids, phenol carboxylic acids, etc.) detected in raw materials of Crocus plants providing information on the current state of knowledge on phytochemicals of Crocus species. Almost all structural formulas of the compounds identified and isolated from Crocus species are given; all compounds are presented in accordance with the types of the studied raw materials. The latest hypotheses relating to the biosynthesis pathways of the main biologically active compounds of saffron (crocin, picrocrocin, safranal), as well as chemotaxonomy of Crocus genus are briefly summarized. The present review discusses the most thoroughly studied pharmacological activities (namely, antioxidant, antiparasitic, hypolipidemic, antihypertensive, immunomodulatory, antimicrobial, antitumor, cytotoxic, antidepressant) of saffron stigmas extracts, of its individual phytochemicals (safranal, crocin, crocetin), as well as pharmacological activities of raw materials of other Crocus species. This comprehensive review will be informative for scientists searching for new properties of saffron stigmas, as well as for saffron producers, since the present review highlights the prospects for the use of waste products in the production of the expensive spice. In addition, the present review provides information on pharmacological properties and composition of other Crocus species as promising medicinal and food plants. In the present review the emphasis will be put on the chemical constituents of Crocus species and the intraspecies variation in phytochemicals and pharmacological activities.

Qualitative and Quantitative Analysis of the Major Ingredients of a Herbal Preparation, Ciwujia Injection by Combination of HPLC-Q-TOF-MS, HPLC-TQ-MS/MS and UPLC-PDA

Background:

Ciwujia injection, prepared from water extraction of Acanthopanax senticosus, is widely used for the treatment of cardiovascular diseases in the clinic in China. The ingredients of the preparation are still not efficiently clear and its quality control method requires further improvement. </P><P> Objective: In this paper, the qualitative and quantitative methods for quality control of Ciwujia injection were originally developed by a combination of HPLC-Q-TOF-MS, HPLC-TQ-MS/MS and UPLCPDA.

Methods:

With HPLC-Q-TOF-MS and HPLC-TQ-MS/MS, compounds were identified firstly by comparison of their MS spectra and retention times with those of standards or recorded information in the literature. Further, a new UPLC-PDA method was originally established to simultaneously determine the multiple ingredients in the preparations.

Results:

For qualitative analysis, 22 compounds were identified by the presented method. For quantitative analysis, the validated method exhibited good linearity (R2 > 0.998), repeatability (RSD < 1.50%), intra- and inter-day precisions (RSD < 8.33%) and recoveries (95.93-108.58%) for the simultaneous determination of the active ingredients, including protocatechuic acid-3-glucoside, l-phenylalanine, protocatechuic acid, neochlorogenic acid, chlorogenic acid, gentiopicroside, eleutheroside B, and cryptochlorogenic acid, and was successfully utilized to analyze the eight compounds in 4 batches of Ciwujia injection.

Conclusion:

The presented method is simple and rapid for quality control of Ciwujia injection, and could provide a useful reference for the quality control and routine analysis of others Ciwujia preparations.