Profiling of seized Cannabis sativa L. flowering tops by means of microwave-assisted hydro distillation and gas chromatography analyses

This research aimed to support police forces in their battle against illicit drug trafficking by means of a multi-technique approach, based on gas chromatography. In detail, this study was focused on the profiling of volatile substances in narcotic Cannabis sativa L. flowering tops. For this purpose, the Scientific Investigation Department, RIS Carabinieri of Messina, provided 25 seized samples of Cannabis sativa L. The content of Δ9-tetrahydrocannabinol (THC), useful to classify cannabis plant as hemp (≤ 0.2 %) or as marijuana (> 0.2 %), was investigated. Essential oils of illicit drug samples were extracted using a microwave-assisted hydro-distillation (MAHD) system; GC-MS and GC-FID analytical techniques were used for the characterization of the terpenes and terpenoids fingerprint. Furthermore, the enantiomeric and carbon isotopic ratios of selected chiral compounds were investigated using a heart-cutting multidimensional GC (MDGC) approach. The latter exploited a combination of an apolar column in the first dimension, and a chiral cyclodextrin-based column in the second one, prior to parallel isotope-ratio mass spectrometry (C-IRMS) and MS detection. Finally, all the data were gathered into a statistical model, to demonstrate the existence of useful parameters to be used for the classification of seized samples.

Measurement of short-chain fatty acids in human plasma by means of fast gas chromatography-mass spectrometry

A rapid and practicable analytical method for the measurement of short-chain fatty acids (SCFAs) in human plasma was developed. The extraction procedure involved the use of acidified water and methyl tert-butyl ether (MTBE), while the separation and detection of SCFAs, including acetic, propionic, and butyric acids was carried out by using gas chromatography-mass spectrometry (GC-MS) technique. The novelty of the research involves reducing the analysis time (less than 7 min) by using the novel fast GC-MS method. A narrow-bore GC capillary column of dimensions 30 m × 0.25 mm ID × 0.25 μm df with acid-modified poly(ethylene glycol) stationary phase was employed for the chromatographic separation. The signals of target compounds were acquired in selected ion monitoring (SIM) mode monitoring a quantifier ion (Q) and two qualifier ions (q1 and q2). Linearity of the method, limits of detection (LoD) and quantification (LoQ) were evaluated. In detail, regression coefficients of the calibration curves were between 0.9960 and 0.9933; LoDs ranged from 0.02 μM to 0.03 μM, while LoQs from 0.06 μM to 0.10 μM.

Human blood lipid profiles after dietary supplementation of different omega 3 ethyl esters formulations

The validity of omega 3 fatty acids (ω3 FAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as dietary supplements has been widely proved. It's well known in fact, that they protect against cardiovascular diseases, reduce the levels of triacylglycerides (TAGs) and cholesteryl esters (CEs) in blood, and have anti-inflammatory activity. For these reasons, in the last few years the production of dietary supplement containing ω3 has increased significantly. In this context, the possibility to obtain ω3 and other high value molecules from alternative sources as fish waste, in accordance with the principles of circular economy, becomes an enormous attractive. In addition, the opportunity of creating new products, with greater health benefits, represents an interesting challenge. The current study was focused on the extraction of ω3 fatty acids and peptides from tuna waste industry, to realize a new dietary supplement. To this purpose, a supercritical fluid extraction (SFE) method was developed to separate, isolate, and enrich the different fractions subsequently used to produce an innovative formulate. The obtained supplement was characterized in terms of fatty acids esterified ester (FAEE) composition by gas chromatography (GC) coupled to both flame ionization detection (FID) and mass spectrometry (MS), and content of heavy metals by inductively coupled plasma-mass spectrometry (ICP-MS). The effects of ω3 supplementation on metabolism and circulating lipid profiles was tested on 12 volunteers and assessed by GC-FID analysis of whole blood collected on paper support (Dried Blood Spot, DBS) at the beginning of the study and after thirty days. The results of plasma fatty acids levels after 30 days showed a significant decrease in the ω6/ω3 ratio, as well as the saturated/polyunsaturated fatty acids (SFA/PUFA) ratio, compared to subjects who took the ω3 ethyl esters unformulated. The novel formulated supplements proved to be extremely interesting and promising products, due to a significant increase in bioavailability, that makes it highly competitive in the current panorama of the nutraceutical industry.

Fast gas chromatography-tandem mass spectrometry under milder electron ionization conditions for the assay of vitamin D metabolites in human serum

The proposed research was focused on the development of a gas chromatography-tandem mass spectrometry (GC-QqQ-MS) method under milder electron ionization (EI) conditions for the assay of vitamin D metabolites in human serum. Efficiency of three different silylation agents was evaluated for the conversion of vitamin D species into trimethylsilyl (TMS) derivatives, among which N-methyl-N-(trimethylsilyl)-trifluoroacetamide (MSTFA) proved to be the most effective. Indeed, the MSTFA reagent was able to convert in TMS ether even the 25-hydroxyl vitamin D derivative that, as known, possesses steric hindrance problems. The separation of vitamin D compounds was obtained in about 11.5 min using a narrow-bore column of dimensions 30 m × 0.25 mm ID × 0.10 μm df with a poly(5% diphenyl/95% dimethyl siloxane) stationary phase. The mass spectrometry ionization of the silylated derivatives was performed under milder EI conditions (20-eV energy) that, respect to common 70-eV energy, generated scan mass spectra with higher relative and absolute intensities of high-mass diagnostic ions, along with a reduced abundance of the low-mass. The signals of the ionized compounds were acquired in multi-reaction-monitoring (MRM) mode, thus enabling the obtainment of highly-sensitive and selective quantitative data. The developed method was validated in term of linearity, accuracy, limits of detection (LoD) and quantification (LoQ). In detail, regression coefficients of the calibration curves were between 0.9959 and 0.9999; LoDs ranged from 0.06 ng mL-1 to 0.73 ng mL-1 and LoQs from 0.16 ng mL-1 to 2.45 ng mL-1. With respect to accuracy, the serum SRM 972a certified reference material (Vitamin D metabolites in frozen human serum) (Levels 1-4) was analyzed.

Flowering phenophases influence the antibacterial and anti-biofilm effects of Thymus vulgaris L. essential oil

BACKGROUND

Essential oils are becoming increasingly popular in medicinal applications because of their antimicrobial effect. Thymus vulgaris L. (Lamiaceae) is a well-known and widely cultivated medicinal plant, which is used as a remedy for cold, cough and gastrointestinal symptoms. Essential oil content of thyme is responsible for its antimicrobial activity, however, it has been reported that the chemical composition of essential oils influences its biological activity. In order to explore flowering phenophases influence on the chemical composition of thyme essential oil and its antibacterial and anti-biofilm activity, plant materials were collected at the beginning of flowering, in full bloom and at the end of flowering periods in 2019.

METHODS

Essential oils from fresh and dried plant materials were distilled and analyzed with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). The antibacterial activity was performed by broth microdilution and thin layer chromatography-direct bioautography (TLC-DB) assays and the anti-biofilm effect by crystal violet assay, respectively. Scanning electron microscopy was applied to illustrate the cellular changes of bacterial cells after essential oil treatment.

RESULTS

Thymol (52.33-62.46%) was the main component in the thyme essential oils. Thyme oil distilled from fresh plant material and collected at the beginning of flowering period exerted the highest antibacterial and anti-biofilm activity against Haemophilus influenzae, H. parainfluenzae and Pseudomonas aeruginosa.

CONCLUSION

The different flowering periods of Thymus vulgaris influence the antibacterial and anti-biofilm activity of its essential oils, therefore, the collection time has to be taken into consideration and not only the full bloom, but the beginning of flowering period may provide biological active thyme essential oil.

Supercritical Fluid Extraction of Oils from Cactus Opuntia ficus-indica L. and Opuntia dillenii Seeds

This study aimed to assess the capability of supercritical fluid extraction (SFE) as an alternative and green technique compared to Soxhlet extraction for the production of oils from Opuntia ficus-indica (OFI) seeds originating from Yemen and Italy and Opuntia dillenii (OD) seeds from Yemen. The following parameters were used for SFE extraction: a pressure of 300 bar, a CO₂ flow rate of 1 L/h, and temperatures of 40 and 60 °C. The chemical composition, including the fatty acids and tocopherols (vitamin E) of the oils, was determined using chromatographic methods. The highest yield was achieved with Soxhlet extraction. The oils obtained with the different extraction procedures were all characterized by a high level of unsaturated fatty acids. Linoleic acid (≤62% in all samples) was the most abundant one, followed by oleic and vaccenic acid. Thirty triacylglycerols (TAGs) were identified in both OFI and OD seed oils, with trilinolein being the most abundant (29-35%). Vanillin, 4-hydroxybenzaldehyde, vanillic acid, and hydroxytyrosol were phenols detected in both OFI and OD oils. The highest γ-tocopherol content (177 ± 0.23 mg/100 g) was obtained through the SFE of OFI seeds from Yemen. Overall, the results highlighted the potential of SFE as green technology to obtain oils suitable for functional food and nutraceutical products.

Melissa officinalis L. as a Sprout Suppressor in Solanum tuberosum L. and an Alternative to Synthetic Pesticides

The goal of this research was to screen plant essential oils (EOs) as sprout inhibitors or suppressors in potato (Solanum tuberosum L.). Three controlled environment experiments were conducted to screen 18 EOs and several pure compounds as sprout inhibitors. The EOs were applied using the wicked method on potato cv. Gala in 19 L plastic containers. The results indicated that Melissa officinalis L. EO inhibited sprouting, while Coriandrum sativum L. seed oil and the EO blend of Lavandula angustifolia Mill. and Salvia sclarea L. suppressed sprouting. The EOs of interest were analyzed using gas chromatography coupled to mass spectrometry (GC-MS) and/or a flame ionization detector (GC-FID); the detailed chemical profiles are provided. The M. officinalis EO was fractionated into seven fractions, and these were tested on minitubers. We identified two fractions (F and A) that suppressed potato sprouting better than the whole oil. The GC-MS-FID analyses of M. officinalis EO fraction A identified myrcene, Z-ocimene, E-ocimene, trans-caryophyllene, and α-humulene as the main constituents, while the main constituents of fraction F were α-terpineol, β-citronellol, and geraniol. The pure isolated compounds, together with the major compound in M. officinalis EO (citral), were tested for sprout suppression on three potato cultivars (Ranger Russet, Terra Rosa, and Dakota TrailBlazer), which revealed that β-citronellol reduced the sprout length and the number of sprouts in all three cultivars, while citral and (+)-α-terpineol reduced the sprout length and the number of sprouts in Ranger Russet relative to the two controls in all three cultivars. Myrcene had a stimulating effect on the number of sprouts in Cv. Terra Rosa. However, none of the pure compounds suppressed sprouting completely or were comparable to the EO of M. officinalis.

Lipids in Archaeological Pottery: A Review on Their Sampling and Extraction Techniques

Several studies have been performed so far for the effective recovery, detection and quantification of specific compounds and their degradation products in archaeological materials. According to the literature, lipid molecules are the most durable and widespread biomarkers in ancient pottery. Artificial ageing studies to simulate lipid alterations over time have been reported. In this review, specific lipid archaeological biomarkers and well-established sampling and extraction methodologies are discussed. Although suitable analytical techniques have unraveled archaeological questions, some issues remain open such as the need to introduce innovative and miniaturized protocols to avoid extractions with organic solvents, which are often laborious and non-environmentally friendly.

Anti-inflammatory effects of lavender and eucalyptus essential oils on the in vitro cell culture model of bladder pain syndrome using T24 cells

BACKGROUND

Interstitial cystitis (IC) has a chronic chemical irritation and inflammation of non-bacterial origin in the bladder wall leading to various severe symptoms. There is evidence that chronic inflammation is significantly associated with abnormal urothelial barrier function, epithelial dysfunction. This is the underlying cause of urothelial apoptosis and sterile inflammation.

METHOD

The anti-inflammatory effects of lavender and eucalyptus essential oils (EOs) and their main components (linalool and eucalyptol) were investigated in the T24 human bladder epithelial cell line on TNFα stimulated inflammation, at 3 types of treatment schedule. The mRNA of pro-inflammatory cytokines (IL-1β, IL-6, IL-8) were measured by Real Time PCR. Human IL-8 ELISA measurement was performed as well at 3 types of treatment schedule. The effects of lavender and eucalyptus EOs and their main components were compared to the response to NFκB inhibitor ACHP (2-amino-6-[2-(cyclopropylmethoxy)-6-hydroxyphenyl]-4-(4-piperidinyl)-3-pyridinecarbonitrile).

RESULT

There is no significant difference statistically, but measurements show that lavender EOs are more effective than eucalyptus EO. Long time treatment (24 h) of both lavender EO and linalool showed higher effect in decreasing pro-inflammatory cytokine mRNA expression than ACHP inhibitor following TNFα pre-treatment. Moreover, both lavender EOs were found to be significantly more effective in decreasing IL-8 secretion of T24 cells after TNFα pre-treatment compared to the ACHP NFκB-inhibitor.

CONCLUSION

The lavender EOs may be suitable for use as an adjunct to intravesical therapy of IC. Their anti-inflammatory effect could well complement glycosaminoglycan-regenerative therapy in the urinary bladder after appropriate pharmaceutical formulation.

Listeria monocytogenes exposed to antimicrobial peptides displays differential regulation of lipids and proteins associated to stress response

With the onset of Listeria monocytogenes resistance to the bacteriocin nisin, the search for alternative antimicrobial treatments is of fundamental importance. In this work, we set out to investigate proteins and lipids involved in the resistance mechanisms of L. monocytogenes against the antimicrobial peptides (AMPs) nisin and fengycin. The effect of sub-lethal concentrations of nisin and lipopeptide fengycin secreted by Bacillus velezensis P34 on L. monocytogenes was investigated by mass spectrometry-based lipidomics and proteomics. Both AMPs caused a differential regulation of biofilm formation, confirming the promotion of cell attachment and biofilm assembling after treatment with nisin, whereas growth inhibition was observed after fengycin treatment. Anteiso branched-chain fatty acids were detected in higher amounts in fengycin-treated samples (46.6%) as compared to nisin-treated and control samples (39.4% and 43.4%, respectively). In addition, a higher relative abundance of 30:0, 31:0 and 32:0 phosphatidylglycerol species was detected in fengycin-treated samples. The lipidomics data suggest the inhibition of biofilm formation by the fengycin treatment, while the proteomics data revealed downregulation of important cell wall proteins involved in the building of biofilms, such as the lipoteichoic acid backbone synthesis (Lmo0927) and the flagella-related (Lmo0718) proteins among others. Together, these results provide new insights into the modification of lipid and protein profiles and biofilm formation in L. monocytogenes upon exposure to antimicrobial peptides.

Simultaneous evaluation of the enantiomeric and carbon isotopic ratios of Cannabis sativa L. essential oils by multidimensional gas chromatography

Recent times have witnessed an upsurge of interest in hemp and hemp-derived products, as driven by the scientific findings specific to the pharmacological properties of Cannabis sativa L. and its constituents. There has been evidence that the terpene profile, along with the cannabinoid content, produces in humans the effects associated with different strains, beyond fragrance perception. A great deal of effort has been put into developing analytical approaches to strengthen the scientific knowledge on cannabis essential oil composition and provide effective tools for ascertaining the authenticity of commercial cannabis samples. For this concern, enantio-selective-GC-C-IRMS has proven to be effective for assessing the ranges characteristic of the genuine samples and detecting any fraudulent additions. This research aimed at providing for the first time the enantiomeric and isotopic ratios of target terpenes in cannabis essential oils, obtained from microwave-assisted hydro-distillation from the fresh and dried inflorescences of different cannabis varieties. Implementing multidimensional gas chromatography separation was mandatory prior to detection, in order to obtain accurate δ¹³C values and enantiomeric data from completely separated peaks. For this purpose, a heart-cut method was developed, based on the coupling of an apolar first dimension column to a secondary chiral cyclodextrin-based stationary phase. Afterwards, the data gathered from enantio-selective-MDGC-C-IRMS/qMS analysis of a set of genuine samples were used to evaluate the quality of nineteen commercial cannabis essential oils purchased from local stores. Remarkably, the data in some cases evidenced enantiomeric ratios and δ¹³C values outside the typical ranges of genuine oils. Such findings suggest the usefulness of the method developed to ascertain the genuineness and quality of cannabis essential oils.

Anti-inflammatory effect of lavender (Lavandula angustifolia Mill.) essential oil prepared during different plant phenophases on THP-1 macrophages

BACKGROUND

Pseudomonas aeruginosa is the most common Gram-negative bacterium associated with nosocomial respiratory infections. Lavender essential oil is mainly used in aromatherapy, but it has several pharmacological and therapeutic properties. Furthermore, it possesses antifungal and antibacterial activities. The anti-inflammatory activity of essential oils may depend on the composition and the ratio of the compounds. The constitution of the essential oils extracted from the different stages of flowering period varies, which makes it plausible that the collection time of the flowers influences the anti-inflammatory effects. Different types of essential oils reduce inflammation acting similarly by modulating the activity and action of the NFκB signalling pathway, which is the major regulator of the transcription of pro-inflammatory cytokines.

METHODS

Lavender essential oils were distilled from lavender plant cultivated in Hungary and the flowers were harvested at the beginning and at the end of flowering period. The experiments were carried out on THP-1 human monocyte/macrophage cell line as in vitro cell culture model for monitoring the effects of lavender essential oils and the main compound linalool on P. aeruginosa LPS stimulated inflammation. The mRNA and protein levels of four pro-inflammatory cytokines, IL-6, IL-1β, IL-8 and TNFα were determined by Real Time PCR and ELISA measurements. The effects of essential oils were compared to the response to two NFκB inhibitors, luteolin and ACHP.

RESULTS

Linalool and lavender essential oil extracted from plants at the beginning of flowering period were successful in decreasing pro-inflammatory cytokine production following LPS pretreatment. In case of IL-8 and IL-1β lavender oil showed stronger effect compared to linalool and both of them acted similarly to NFκB inhibitors. Pretreatments with linalool and lavender essential oil/beginning of flowering period prevented pro-inflammatory cytokine production compared to LPS treatment alone. Although lavender essential oil/end of flowering period decreased IL-6, IL-1β and IL-8 mRNA expression in case of LPS pretreatment, it was not capable to reduce cytokine secretion.

CONCLUSION

Based on our results it has been proven that lavender essential oil extracted at the beginning of flowering period is a potent inhibitor of the synthesis of four pro-inflammatory cytokines IL-6, IL-8, IL-β and TNFα of THP-1 cells. This supports the relevance of the collection of the lavender flowers from early blooming period for essential oil production and for the utilization as an anti-inflammatory treatment.

Identification of high-value generating molecules from the wastes of tuna fishery industry by liquid chromatography and gas chromatography hyphenated techniques with automated sample preparation

The present work aims to a promising re-utilization of the massive waste derived from the tuna fishing industry, for which by-products can represent more than 50% of the original material. Due to the considerable content in polyunsaturated fatty acids and noble proteins, such wastes can be used as primary source of functional ingredients in the production of nutraceuticals. The composition of the lipid and protein tuna fractions was investigated by means of gas chromatography-mass spectrometry and high-performance liquid chromatography-tandem mass spectrometry methods (in wastes and edible parts), and a preliminary characterization of potential bioactive peptides was achieved. Automated sample preparation allowed speeding up the analytical workflow, while allowing for highly sensitive and selective lipid characterization. The ω3 fatty acid content was found higher in waste products compared to the muscle, in terms of fatty acids as well as complex lipids. As for peptides, extraction by isoelectric solubilization/precipitation was performed, followed by enzymatic digestion and high-performance liquid chromatography-tandem mass spectrometry analysis. Furthermore, the use of bioinformatics tools highlighted the presence of potential antimicrobial peptides in the samples investigated.

Reliable identification and quantification of anabolic androgenic steroids in dietary supplements by using gas chromatography coupled to triple quadrupole mass spectrometry

The aim of the present research was the identification and quantification of specific anabolic androgenic steroids (AASs) and other sterane structured compounds in dietary supplements (DSs). The adulteration of DSs by these compounds is of a particular concern in athletes, because it might lead to a positive doping result. The research was focused on the optimization of a highly sensitive and selective GC-based analytical strategy using triple quadrupole MS as detector. Chromatographic method and multiple reaction monitoring (MRM) transitions of 28 target compounds were optimized. Sample clean-up was carried out by using a solid phase extraction (SPE) procedure, while the derivatization of AASs was performed by using N-methyl-N-(trimethylsilyl)-trifluoroacetamide (MSTFA). The method was validated, and the following parameters were investigated: linearity range, limit of detection, accuracy, and precision expressed in terms of intra-day precision. The calibration curves were evaluated by using regression model and resulting in a good determination coefficients (R² ≥ 0.9912). The residuals were scattered randomly around zero. The limits of detection (LODs) were lower than 7.0 ng g^-1 or ng ml^-1 . The accuracy assessment was evaluated in different forms of DSs characterized by high sample-to-sample variability (liquid, powder, tablet, capsule, protein, and herbal-based). Intra-day assay precision was in all cases lower than 20%. The developed analytical method was successfully applied to the analysis of 67 commercially available dietary supplements. In five cases, one or more steroid-type compounds were found in the concentration of 5 ng g^-1 -100 μg g^-1 , which might result adverse analytical findings in athletes.

The opposite nitric oxide modulators do not lead to the opposite changes of metabolites under cadmium excess

Responses of common medicinal herb Matricaria chamomilla to short-term cadmium (Cd) exposure (48 h) alone or in combination with nitric oxide (NO) scavenger (PTIO) or donor (SNP) were studied. Modulators revealed expected impact on NO formation (depletion under PTIO but elevation under SNP) and confirmed anomalous impact on Cd accumulation (stimulation by both modulators). Changes of proline and free amino acids in the roots and fatty acids (mainly α-linolenic acid) in the shoots indicate rather relation to elevated Cd uptake than to altered NO formation. On the contrary, root profile of fatty acids revealed the most prominent changes in response to PTIO (elevation of monounsaturated and polyunsaturated fatty acids) which confirm that NO depletion stimulates their biosynthesis. Soluble phenols were elevated by SNP co-application in the roots while accumulation of chlorogenic acid and umbelliferone revealed clear regulation by NO (i.e. enhancement in response to SNP and depletion in response to PTIO). Data indicate that quantities of some metabolites are affected by accumulated Cd or NO formation and that the opposite NO modulators do not automatically lead to the opposite changes of plant metabolites.

Antimicrobial Activity of Different Artemisia Essential Oil Formulations

The extreme lipophilicity of essential oils (EOs) impedes the measurement of their biological actions in an aqueous environment. We formulated oil in water type Pickering Artemisiaannua EO nanoemulsions (AEP) with surface-modified Stöber silica nanoparticles (20 nm) as the stabilizing agent. The antimicrobial activity of AEP and its effects on mature Candida biofilms were compared with those of Tween 80 stabilized emulsion (AET) and ethanolic solution (AEE) of the Artemisia EO. The antimicrobial activity was evaluated by using the minimum inhibitory concentrations (MIC₉₀) and minimum effective concentrations (MEC₁₀) of the compounds. On planktonic bacterial and fungal cells beside growth inhibition, colony formation (CFU/mL), metabolic activity, viability, intracellular ATP/total protein (ATP/TP), along with reactive oxygen species (ROS) were also studied. Artemisiaannua EO nanoemulsion (AEP) showed significantly higher antimicrobial activity than AET and AEE. Artemisiaannua EO nanoemulsions (AEP) generated superoxide anion and peroxides-related oxidative stress, which might be the underlying mode of action of the Artemisia EO. Unilamellar liposomes, as a cellular model, were used to examine the delivery efficacy of the EO of our tested formulations. We could demonstrate higher effectiveness of AEP in the EO components’ donation compared to AET and AEE. Our data suggest the superiority of the AEP formulation against microbial infections.

Nitric oxide affects cadmium-induced changes in the lichen Ramalina farinacea

Metabolic responses of epiphytic lichen Ramalina farinacea to cadmium (Cd) and/or nitric oxide (NO) scavenger (cPTIO) were studied. Accumulation of Cd and other metallic nutrients was not affected by cPTIO while total and absorbed amounts differed. Cd-induced NO formation was suppressed by cPTIO but ROS signal was synergistically enhanced, confirming that NO is essential to keep ROS under control. This excessive ROS generation could be a reason for depleted amount of all fatty acids, including SFAs, MUFAs and PUFAs. Total content of fatty acids reached 3.89 mg/g DW in control with linoleic (40%), palmitic (24%), oleic (12.8%) and stearic (8%) acids as major compounds: interestingly, shift in relative ratio of saturated (from 40 to 35% of total FAs) versus polyunsaturated fatty acids (from 42 to 48% of total FAs) was observed. Glutathione was suppressed by all treatments but Krebs acids were almost unaffected by cPTIO, indicating no regulatory role of NO in their accumulation. On the contrary, Cd-induced elevation in NO signal was related to increase in ascorbate and proline content while cPTIO suppressed it, indicating a tight relation between NO and these metabolites. Data are compared also with algae and vascular plants to show similarities between various life lineages.

Metabolic responses of Ulva compressa to single and combined heavy metals

Accumulation of metals and metabolic responses were studied for two Cd and Cu concentrations (1 and 10 μM) either alone or as a combination in marine macroalga after 7 days of exposure. Cd accumulated more at a low dose (115 μg of Cd/g DW) but Cu at a high dose (378 μg of Cu/g DW); Cu suppressed Cd accumulation (by 57%). Na and Zn levels were unaffected, but higher metal doses depleted K and Ca levels. Higher metal concentrations strongly stimulated reactive oxygen species and depleted nitric oxide (NO) formation, but differences between the action of Cd and Cu were not extensive. Higher metal doses increased cell wall thickness with a potential relation to NO signal that is visible mainly in the apoplast in those treatments. A higher Cu dose depleted proline, ascorbic acid, and phenol levels more than Cd, whereas Cd elevated nonprotein thiols and ascorbic acid in combined treatments. An eventual role of malic or citric acid in metal chelation was not evident: malic acid level decreased in all treatments. The total content of fatty acids reached 16.7 mg/g DW in control with the quantitative order of PUFAs > SFAs > MUFAs; palmitic, vaccenic, linoleic, and α-linolenic acids were the major compounds. Cu was more toxic for fatty acids than Cd (even at 1 μM); mainly, PUFA levels strongly decreased (from 43% of total acids in control to 28.9% and 5.4% at 1 and 10 μM Cu treatment, respectively). Results are precisely and critically discussed in relation to limited literature focused on macroalgae, and a comparison with microalgae is also provided.

Accumulation and toxicity of organochlorines in green microalgae

Toxicity of mine dump effluent containing five hexachlorocyclohexane (α, β, γ, δ and ε-HCH, sum 159.4 μg/L) and two trichlorobenzene (TCB, sum 65.2 μg/L) isomers to two microalgae (Scenedesmus quadricauda and Coccomyxa subellipsoidea) was studied over 24 h exposure and also with 2- and 10-fold diluted stock solution (i.e. 1×, 0.5× and 0.1× strength). Individual isomers revealed rather dose-dependent accumulation typically higher in Scenedesmus than in Coccomyxa (max. sum of HCH 14.99 μg/g DW with bioaccumulation factor 94) and δ-HCH was dominant isomer. TCB isomers showed low accumulation in algae. 0.1× dose elevated chlorophylls and carotenoids in Coccomyxa while enzymatic activities (SOD, CAT, and APX), thiols (glutathione and phytochelatin 2) and ascorbic acid were rather elevated by 1× dose in both species. Malic acid, rather than citric acid, increased in response to 0.5× and 1× concentration. Sum of fatty acids was higher in Coccomyxa than in Scenedesmus with palmitic, oleic, linoleic and α-linolenic acids being dominant compounds in both species. Detailed profiling revealed that saturated and monounsaturated fatty acids increased in Coccomyxa while polyunsaturated fatty acids in Scenedesmus in response to increasing dose of organochlorines. Accumulation of organochlorines and metabolic responses in algae are reported here for the first time.

Quali-quantitative characterization of the volatile constituents in Cordia verbenacea D.C. essential oil exploiting advanced chromatographic approaches and nuclear magnetic resonance analysis

Cordia verbenacea D.C. (Boraginaceae, Varronia curassavica Jacq. synonym) is a medicinal plant, native from Brazil, especially the leaves are used in folk medicine. The aim of this study was to extend the characterization of the volatile fraction of the essential oil obtained from this plant, by using GC-FID, GC-MS, and chiral GC. Moreover, to further clarify the composition of the volatile fraction, preparative multidimensional-GC (prep-MDGC) was used to collect unknown compounds, followed by NMR characterization. Specifically, the chemical characterization, both qualitative and quantitative, of the volatile fraction of the essential oil obtained from Cordia verbenacea cultivated in the Minas Gerais area (central area of Brazil) was investigated for the first time. The principal components from a quantitative point of view were α-pinene (25.32%; 24.48g/100g) and α-santalene (17.90%; 17.30g/100g), belonging to the terpenes family. Chiral-GC data are reported for the enantiomeric distribution of 7 different components. Last, to obtain the complete characterization of the essential oil constituents, prep-MDGC analysis was used to attain the isolation of two compounds, not present in the principal MS databases, which were unambiguously identified by NMR investigation as (E)-α-santalal and (E)-α-bergamotenal, reported for the first time in Cordia verbenacea essential oil.

Ionic liquids as stationary phases for fatty acid analysis by gas chromatography

The present paper provides an overview of the application of ionic liquid (IL) columns for GC analysis of fatty acid methyl esters (FAMEs).