Sequential determination of fat- and water-soluble vitamins in Rhodiola imbricata root from trans-Himalaya with rapid resolution liquid chromatography/tandem mass spectrometry

Fast, sustainable, and simultaneous analysis of water- and fat-soluble vitamins by the two-dimensional microcarbon fiber fractionation system hyphenated with MS detection

BACKGROUND

Vitamins are micronutrients that are required for normal growth and development of living organisms. However, due to their various chemical properties (e.g., acid-base behavior, the presence of numerous forms) and fluctuating concentration levels within complex matrices, simultaneous analysis of multi-class vitamins, including their active forms, is a challenging task. The growing nutrient shortage in foods is concerning for food consumers, manufacturers, and quality control organizations. Hence, a simple, fast, and greener approach that can simultaneously analyze multi-class vitamins is required to aid food testing and clinical laboratories in evaluating vitamin content more rapidly and accurately.

RESULTS

A green and rapid analytical method based on online two-dimensional microscale carbon fiber/activated carbon fiber fractionation-mass spectrometry (2DμCFs-MS) was developed and validated for simultaneous determination of vitamins (water- and fat-soluble vitamins and some analogs) in food supplements and fortified energy drinks. Vitamins have been successfully separated into three different fractions using the minimum toxic solvent (only 0.7 mL of organic solvent) in a single run within 6 min. The limit of detection (LOD) ranges from 0.1 to 10.4 ng/mL, and the limit of quantification (LOQ) ranges from 0.39 to 34.5 ng/mL. The method also showed adequate repeatability and intermediate precision, with RSD<10 % and R2 > 0.99 for most vitamins. The analytical method was evaluated in terms of greenness, with an analytical greenness (AGREE) score of 0.68.

SIGNIFICANCE

The 2DμCFs-MS system was developed to separate and detect multi-class vitamins simultaneously, which can be used as a beneficial tool to investigate vitamin content for food labeling and determining the vitamins in biological fluids and other complex samples. The developed method can tackle the challenge of simultaneous and fast routine analysis of multi-class vitamins.

Green synthesis of silver nanoparticles using Rhodiola imbricata and Withania somnifera root extract and their potential catalytic, antioxidant, cytotoxic and growth-promoting activities

This study presents the development of a sustainable production process of environmentally benign silver nanoparticles (AgNPs) from aqueous root extract of Rhodiola imbricata (RI) and Withania somnifera (WS) for mitigating environmental pollution and investigating their potential applications in agriculture and biomedical industry. RIWS-AgNPs were characterized using several analytical techniques (UV-Vis, DLS, HR-TEM, SAED, EDX and FTIR). The antioxidant and anticancer activity of RIWS-AgNPs were estimated by DPPH and MTT assay, respectively. UV-Vis and DLS analysis indicated that equal ratio of RIWS-extract and silver nitrate (1:1) is optimum for green synthesis of well-dispersed AgNPs (λ_max: 430 nm, polydispersity index: 0.179, zeta potential: - 17.9 ± 4.14). HR-TEM and SAED analysis confirmed the formation of spherical and crystalline RIWS-AgNPs (37-42 nm). FTIR analysis demonstrated that the phenolic compounds are probably involved in stabilization of RIWS-AgNPs. RIWS-AgNPs showed effective catalytic degradation of hazardous environmental pollutant (4-nitrophenol). RIWS-AgNPs treatment significantly increased the growth and photosynthetic pigments of Hordeum vulgare in a size- and dose-dependent manner (germination (77%), chlorophyll a (12.62 ± 0.07 μg/ml) and total carotenoids (7.05 ± 0.04 μg/ml)). The DPPH assay demonstrated that RIWS-AgNPs exert concentration-dependent potent antioxidant activity (IC₅₀: 12.30 μg/ml, EC₅₀: 0.104 mg/ml, ARP: 959.45). Moreover, RIWS-AgNPs also confer strong cytotoxic activity against HepG2 cancer cell line in dose-dependent manner (cell viability: 9.51 ± 1.55%). Overall, the present study for the first time demonstrated a green technology for the synthesis of stable RIWS-AgNPs and their potential applications in biomedical and agriculture industry as phytostimulatory, antioxidant and anticancer agent. Moreover, RIWS-AgNPs could potentially be used as a green alternative for environmental remediation.

Simultaneous determination of 49 amino acids, B vitamins, flavonoids, and phenolic acids in commonly consumed vegetables by ultra-performance liquid chromatography-tandem mass spectrometry

A sensitive and reliable method was developed and validated for the simultaneous determination of 49 amino acids, B vitamins, flavonoids, and phenolic acids based on a rapid metabolomic extraction procedure combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in a single chromatographic run and applied in analysis of 26 commonly consumed vegetables. The chromatographic and sample preparation conditions were optimized, given the high diversity of the target analytes. Eight isotope-labeled standards were applied to validate the method in terms of recovery, linearity, matrix effects, precision, and sensitivity. Most recoveries in four vegetable matrices ranged from 65.0% to 105.3% with associated RSDs < 20%. Low LOQs ranged from 0.06 to 17 µg/kg. Linear calibration curves with different ranges were established with R² > 0.993. Among the 26 vegetables, purple cabbage, broccoli, and red lettuce were found to contain the highest concentrations of free amino acids, B vitamins, and phenolic compounds.

Microwave Assisted Cloud Point Extraction for the Determination of Vitamin K Homologues in Vegetables by Liquid Chromatography with Tandem Mass Spectrometry

Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) with a triple quadrupole (QqQ) is proposed for determining the vitamin K homologues, phylloquinone (PK), menaquinone-4 (MK) and menadione (MD), in vegetables. The analytes were isolated from the samples (1-1.5 g) by ultrasound assisted extraction using acetonitrile (2 mL), and the liquids were submitted to microwave assisted cloud point extraction with Triton X-45. The enrichment factors were between 20 and 50, depending on the vitamin homologue in question. The analytes were determined by LC-ESI-QqQ-MS/MS in the multiple reaction monitoring (MRM) mode, providing unequivocal identification and quantification, with limits of detection of 0.8, 1.0, and 16 ng/g for MK, PK, and MD, respectively. Recovery assays for samples spiked at two concentration levels, between 40 and 600 ng/g depending on the compound, provided recoveries in the 90-114% range. Only PK was detected in the samples analyzed, at concentrations in the 90-2350 ng/g range.

Rapid and visual readout of vitamin B1 based on the electrostatic interaction induced aggregation of gold nanoparticles

In this work, a simple and rapid colorimetric assay for the quantitative detection of vitamin B1 (VB1) has been fabricated based on citrate-stabilized gold nanoparticles (AuNPs). The UV-Vis spectra of AuNPs varied and the relative color changed from red to purple with the sequential addition of VB1. The characterization results of AuNPs with and without the addition of VB1 confirmed that the observed phenomena were attributed to the aggregation of AuNPs induced by VB1 through electrostatic interaction. The assay was rapid and sensitive to VB1 with a detection limit of 10.9 nM ranging from 30 nM to 650 nM in 15 min. Meanwhile, the developed assay displayed excellent selectivity to VB1 since AuNPs showed negligible response to common metal ions and biological molecules. Moreover, the feasibility for the quantitative detection of VB1 in tablets and human urine samples has also been demonstrated.

Schematic illustration for colorimetric detection of VB1 with AuNPs based on the electrostatic interaction.

Enhanced Production of Phenolic Compounds in Compact Callus Aggregate Suspension Cultures of Rhodiola imbricata Edgew

Rhodiola imbricata is a rare medicinal plant of the trans-Himalayan region of Ladakh. It is used for the treatment of numerous health ailments. Compact callus aggregate (CCA) suspension cultures of Rhodiola imbricata were established to counter extinction threats and for production of therapeutically valuable phenolic compounds to meet their increasing industrial demands. The present study also investigated the effect of jasmonic acid (JA) on production of phenolic compounds and bioactivities in CCA suspension cultures. CCA suspension cultures established in an optimized Murashige and Skoog medium supplemented with 30 g/l sucrose, 3 mg/l NAA, and 3 mg/l BAP showed maximum biomass accumulation (8.43 g/l DW) and highest salidroside production (3.37 mg/g DW). Upon 100 μM JA treatment, salidroside production (5.25 mg/g DW), total phenolic content (14.69 mg CHA/g DW), total flavonoid content (4.95 mg RE/g DW), and ascorbic acid content (17.93 mg/g DW) were significantly increased in cultures. In addition, DPPH-scavenging activity (56.32%) and total antioxidant capacity (60.45 mg QE/g DW) were significantly enhanced upon JA treatment, and this was positively correlated with increased accumulation of phenolic compounds. JA-elicited cultures exhibited highest antimicrobial activity against Escherichia coli. This is the first report describing the enhanced production of phenolic compounds and bioactivities from JA-elicited CCA suspension cultures of Rhodiola imbricata.

Trans-Himalayan Rhodiola imbricata Edgew. root: a novel source of dietary amino acids, fatty acids and minerals

Roots of Rhodiola imbricata Edgew from Indian trans-Himalayan cold desert known for their nutritional and medicinal attributes were evaluated for the dietary amino acids, fatty acids and mineral composition. Nine essential and twelve non-essential amino acids were quantified. The contents ranged between 91.33 and 1640.67 µg/g. Histidine (1434.33 µg/g), lysine (1329.33 µg/g) and threonine (1015.67 μg/g) were dominant essential amino acids, while glycine (1640.67 µg/g), proline (1263.67 µg/g), alanine (1142.33 µg/g), cystine HCL (1136.33 μg/g) and nor leucine (1038.67 μg/g) were major non essential amino acids. The total lipid was found to be rich source of saturated fatty acids such as capric acid (19.91%), caproic acid (10.87%), palmitic acid (9.42%), lignoceric acid (6.16%) and behenic acid (5.71%), which together constituted 52% of the lipid content. Linoleic acid (15.06%), oleic acid (12.38%), arachidonic acid (8.38%), linolelaidic acid (6.11%) and docosadienoic acid (5.99%) were prominent unsaturated fatty acids (UFAs). Mono unsaturated fatty acids (MUFAs) and poly unsaturated fatty acids (PUFAs) were 35.64% and 12.33% of the lipid content respectively. Calcium (11034.17 mg/kg), potassium (2143.25 mg/kg), iron (1441.17 mg/kg), magnesium (581.99 mg/kg), phosphorous (376.72 mg/kg) and sodium (109.75 mg/kg) were detected as the major dietary minerals.

Ultrasound assisted combined molecularly imprinted polymer for selective extraction of nicotinamide in human urine and milk samples: Spectrophotometric determination and optimization study

Ultrasound-assisted dispersive solid phase microextraction followed by UV-vis spectrophotometer (UA-DSPME-UV-vis) was designed for extraction and preconcentration of nicotinamide (vitamin B₃) by HKUST-1 metal organic framework (MOF) based molecularly imprinted polymer (MIP). This new material was characterized by FTIR and FE-SEM techniques. The preliminary Plackett-Burman design was used for screening and subsequently the central composite design justifies significant terms and possible construction of mathematical equation which give the individual and cooperative contribution of variables like HKUST-1-MOF-NA-MIP mass, sonication time, temperature, eluent volume, pH and vortex time. Accordingly the optimum condition was set as: 2.0mg HKUST-1-MOF-NA-MIP, 200μL eluent and 5.0min sonication time in center points other variables were determined as the best conditions to reach the maximum recovery of the analyte. The UA-DSPME-UV-vis method performances like excellent linearity (LR), limits of detection (LOD), limits of quantification of 10-5000μgL^-1 with R² of 0.99, LOD (1.96ngmL^-1), LOQ (6.53μgL^-1), respectively show successful and accurate applicability of the present method for monitoring analytes with within- and between-day precision of 0.96-3.38%. The average absolute recoveries of the nicotinamide extracted from the urine, milk and water samples were 95.85-101.27%.

A novel method for the determination of chemical purity and assay of menaquinone-7. Comparison with the methods from the official USP monograph

An HPLC method with UV detection and separation with the use of a C30 reversed phase analytical column for the determination of chemical purity and assay of menaquinone-7 (MK7) in one chromatographic run was developed. The method is superior to the methods published in the USP Monograph in terms of selectivity, sensitivity and accuracy, as well as time, solvent and sample consumption. The developed methodology was applied to MK7 samples of active pharmaceutical ingredient (API) purity, MK7 samples of lower quality and crude MK7 samples before purification. The comparison of the results revealed that the use of USP methodology could lead to serious overestimation (up to a few percent) of both purity and MK7 assay in menaquinone-7 samples.

Rapid and sensitive screening of some acidic micronutrients in infant foods by HPLC with fluorescent detector

BACKGROUND

Currently, commercially prepared complementary foods have become an important part of the diet of many infants and toddlers. But the method for simultaneous analysis of different types of micronutrient remains poorly investigated, which hinders the rapid and comprehensive quality control of infant foods. In the presented study, we first tried to employ the fluorescence labeling strategy combined with high-performance liquid chromatography-fluorescence detection for simultaneous determination of some acidic micronutrients including biotin, nicotinic acid, linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, arachidonic acid and linoleic acid in infant foods.

RESULTS

2-(5-Benzoacridine) ethyl-p-toluenesulfonate was used as the fluorescence labeling reagent for simultaneous labeling of the seven components. The labeling conditions were optimized systematically by response surface methodology. The correlation coefficients for the calibration curves of the tested compounds ranged from 0.9991 to 0.9998. Limits of detection were in the range of 1.99-3.05 nmol L(-1) . Relative standard deviation values of retention time and peak area of seven compounds were less than 0.05% and 0.75%, respectively. The intra- and inter-day precision was in the range of 1.81-3.80% and 3.21-4.30%, respectively. When applied to analysis of several infant foods it showed good applicability.

CONCLUSION

The developed method has been proven to be simple, inexpensive, selective, sensitive, accurate and reliable for analysis of some acidic micronutrients in infant foodstuffs. Furthermore, this developed method also has powerful potential in the analysis of many other complementary foodstuffs. © 2015 Society of Chemical Industry.

Quantitative ethnobotanical survey of medicinal flora thriving in Malakand Pass Hills, Khyber Pakhtunkhwa, Pakistan

STUDY OBJECTIVE

Ethnobotanical knowledge is proving to be invaluable for drug discovery in the wake of effective prospecting from biodiversity. On the other hand, the escalating human pressure is threatening the endogenous flora. Situated at the foothill of the Himalayas, Pakistan boasts of rich floristic distribution. However, many lush yet imperiled regions of this country has never been explored. It inspired us to evaluate and document the taxonomic composition, significance of medicinal plants and associated traditional knowledge in the District of Malakand, Khyber Pakhtunkhwa Province.

MATERIALS AND METHODS

Vegetation growing in Malakand pass hills, Pakistan was studied and data were collected using an open-ended questionnaire, in addition to interviewing the local elderly, knowledgeable persons, and herbal practitioners. Relative Frequency Citation (RFC) and Use Value (UV) of the medicinal plants were calculated and their correlation was determined by Pearson correlation coefficient.

RESULTS

This study encompasses 92 plant species belonging to 56 families thriving in the study area. The information gathered includes ethnobotanical inventory and their pharmacological uses. Quantitative analysis throws light on the consistence of RFC and UV. Asteraceae and Lamiaceae were the most abundant families represented by 6 species each. Shoots were the most used parts (23.6%) and wound healing (7.91%) was the most common therapeutic use.

CONCLUSION

The result obtained from the study implies that local inhabitants rely on these plants for their medicinal requirements. Also, the statistics reveal that, the vegetation can be assessed for potential drug leads. However, urban expansion is threatening the existence of indigenous flora and old generation with ancient herbal wisdom is perishing. So, it appears imperative to preserve the traditional knowledge. This survey is expected to contribute to the discovery of novel bioactive constituents, stimulate conservation efforts of the perturbed flora and promote sustainable exploitation of the medicinal bounty.

Multicomponent analysis of fat- and water-soluble vitamins and auxiliary substances in multivitamin preparations by qNMR

A nuclear magnetic resonance (NMR) spectroscopic method was tested to control 12 vitamins and accompanying substances in multivitamin preparations. The limits of detection (LODs) and limits of quantification (LOQs) varied in the 9.0-77.0 mg/kg and in the 34.5-93.5 mg/kg range, respectively. The coefficients of variation (CVs) ranged between 0.9% and 12%. The (1)H NMR spectra showed linearity for the 140-260 mg sample weight (R(2) > 0.918). The NMR spectra of multivitamin preparations showed the presence of different degradation products of ascorbic acid. The NMR method was applied to 13 different multivitamin preparations including tablets, capsules, and effervescent tablets with average recovery rates between 85% and 132%. A number of accompanying substances (citric acid, mannitol, saccharin, cyclamate, sum of steviol glycosides, and butylhydroxytoluene) were additionally identified and quantified. NMR was found to be suitable for the simultaneous qualitative measurement of water- and fat-soluble vitamins and accompanying substances and shows some promise for quantitative determination of at least 5 vitamins (B1, B3, B5, B6, and E) in multivitamin preparations.

Liquid chromatography with isotope-dilution mass spectrometry for determination of water-soluble vitamins in foods

Vitamins are essential for improving and maintaining human health, and the main source of vitamins is the diet. Measurement of the quantities of water-soluble vitamins in common food materials is important to understand the impact of vitamin intake on human health, and also to provide necessary information for regulators to determine adequate intakes. Liquid chromatography (LC) and mass spectrometry (MS) based methods for water-soluble vitamin analysis are abundant in the literature, but most focus on only fortified foods or dietary supplements or allow determination of only a single vitamin. In this work, a method based on LC/MS and LC/MS/MS has been developed to allow simultaneous quantitation of eight water-soluble vitamins, including multiple forms of vitamins B3 and B6, in a variety of fortified and unfortified food-matrix Standard Reference Materials (SRMs). Optimization of extraction of unbound vitamin forms and confirmation using data from external laboratories ensured accuracy in the assigned values, and addition of stable isotope labeled internal standards for each of the vitamins allowed for increased precision.

Nutritional profile of phytococktail from trans-Himalayan plants

We estimated the nutritive value, vitamin content, amino acid composition, fatty acid content, and mineral profile of a phytococktail comprising sea buckthorn (Hippophae rhamnoides), apricot (Prunus armeniaca), and roseroot (Rhodiola imbricata) from trans-Himalaya. The free vitamin forms in the phytococktail were determined by rapid resolution liquid chromatography/tandem mass spectrometry (RRLC-MS/MS). Vitamin E and B-complex vitamins were detected as the principle vitamins. Reversed-phase high performance liquid chromatography (RP-HPLC) with pre-column derivatization was used for identification and quantification of amino acids. Eight essential and eleven non-essential amino acids were quantified, and the content ranged between 76.33 and 9485.67 µg/g. Among the essential amino acids, L-methionine, L-phenylalanine, L-lysine, L-leucine, and L-histidine were found to be the dominant contributors. We also quantified the fatty acids in the phytococktail by using gas chromatography coupled with a flame ionization detector (GC-FID) with fatty acid methyl esters (FAMEs) derivatization. The analysis revealed the presence of 4 major fatty acids contributing to the total lipid content. Palmitic acid was found to be the rich source of saturated fatty acid (SFA) and constituted ∼31% of the total lipid content. Among the unsaturated fatty acids (UFAs), palmitoleic acid (43.47%), oleic acid (20.89%), and linoleic acid (4.31%) were prominent. The mineral profiling was carried out by inductively coupled plasma optical emission spectrometer (ICP-OES), and it was found to contain a number of important dietary mineral elements. The harsh climatic conditions, difficult terrain, and logistic constraints at high altitude regions of Indian trans-Himalayan cold desert lead to the scarcity of fresh fruits and vegetables. Therefore, the source of multiple vitamins, essential amino acids, fatty acids, and dietary minerals from the phytococktail would provide great health benefit in the stressful environment and could be used as a high value nutritional supplement.

Chemical composition and antioxidant capacities of phytococktail extracts from trans-Himalayan cold desert

BACKGROUND

Himalayan plants are widely used in traditional system of medicine both as prophylactics and therapeutics for high altitude maladies. Our aim was to evaluate the antioxidant capacities and bioactive compounds of methanol and n-hexane extracts of the phytococktail comprising of sea buckthorn (Hippophae rhamnoides), apricot (Prunus armeniaca) and roseroot (Rhodiola imbricata) from trans-Himalaya.

METHODS

The 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and nitric oxide (NO) radical scavenging capacities and lipid peroxidation inhibition (LPI) property of the extracts were determined. Total antioxidant power was determined by ferric reducing/antioxidant power (FRAP) assay. Total polyphenol, flavonoid, flavonol, proanthocyanidin and carotenoid were also estimated for both extracts. We have identified and quantified the phyto-chemotypes present in the methanol and n-hexane extracts by hyphenated gas chromatography/mass spectrometry (GC/MS) technique.

RESULTS

Antioxidant capacity assays using DPPH, ABTS, NO, LPI and FRAP exhibited analogous results where the phytococktail showed high antioxidant action. The phytococktail was also found to possess high quantity of total polyphenol, flavonoid, flavonol and carotenoid. A significant and linear correlation was found between the antioxidant capacities and bioactive principles. A total of 32 phyto-chemotypes were identified from these extracts by GC/MS chemometric fingerprinting. Major phyto-chemotypes identified by GC/MS were glycosides, phenylpropanoids and derivatives, terpenoids, alkaloids, phytosterols, fatty acids and esters, alkaloids and derivatives, organic acid esters and aromatic ethers with positive biological and pharmacological actions.

CONCLUSION

The phytococktail extracts were found to contain considerable amount of diverse bioactive compounds with high antioxidant capacities. The presence of hydrophilic and lipophilic antioxidants in the phytococktail could have contributed to the higher antioxidant values. Hence, the phytococktail could be used as natural source of antioxidants to ameliorate disorders associated with oxidative stress.