Mathematical Modeling of Ocimum basilicum L. Supercritical CO2 Extraction

The effects of pressure and temperature on supercritical extraction of Ocimum basilicum L. in terms of extraction yield and aromatic compounds were investigated. Linalool, eugenol, and δ‐cadinene were indentified as three main compounds of the prepared extracts. The dominant compound in all investigated supercritical basil extracts was linalool. Within the experimental range the extraction parameters had a significant influence on the extraction yield. The obtained results for the sweet basil total extract, cadinene, and linalool best matched with the Gordillo et al. model, therefore, the solubility of total extract, linalool, and cadinene in supercritical CO₂ at investigated temperatures is described as a function of pressure.     

Fractionation of non-polar compounds of basil (Ocimum basilicum L.) by supercritical fluid extraction (SFE)

Fractionation by supercritical fluid extraction (SFE) was used to obtain various extracts from Ocimum basilicum L. (sweet basil). The extractions were done at temperature of 40 °C and 50 °C, and at different pressure, which was increased successively from 100 bar (150 bar, 200 bar) to 300 bar. The identification and quantification of the extract compounds was done using gas chromatography–mass spectrometry (GC–MS) and gas chromatography with flame-ionization detector (GC–FID) analyses. The yield of basil SFE extracts varies from 0.138 to 1.008% (w/w). The major components identified in the extracts were linalool, eugenol, α-bergamotene, germacrene D, γ-cadinene, δ-cadinene, β-selinene and spathulenol. The highest extraction yield, in fractionation process, of linalool (167.03 mg per 100 g of basil) was achieved at pressure of 100 bar and temperature 50 °C (solvent density 0.378 kg/m³).     

The Rice Cation/H+ Exchanger Family Involved in Cd Tolerance and Transport

Cadmium (Cd), a heavy metal toxic to humans, easily accumulates in rice grains. Rice with unacceptable Cd content has become a serious food safety problem in many rice production regions due to contaminations by industrialization and inappropriate waste management. The development of rice varieties with low grain Cd content is seen as an economic and long-term solution of this problem. The cation/H⁺ exchanger (CAX) family has been shown to play important roles in Cd uptake, transport and accumulation in plants. Here, we report the characterization of the rice CAX family. The six rice CAX genes all have homologous genes in Arabidopsis thaliana. Phylogenetic analysis identified two subfamilies with three rice and three Arabidopsis thaliana genes in both of them. All rice CAX genes have trans-member structures. OsCAX1a and OsCAX1c were localized in the vacuolar while OsCAX4 were localized in the plasma membrane in rice cell. The consequences of qRT-PCR analysis showed that all the six genes strongly expressed in the leaves under the different Cd treatments. Their expression in roots increased in a Cd dose-dependent manner. GUS staining assay showed that all the six rice CAX genes strongly expressed in roots, whereas OsCAX1c and OsCAX4 also strongly expressed in rice leaves. The yeast (Saccharomyces cerevisiae) cells expressing OsCAX1a, OsCAX1c and OsCAX4 grew better than those expressing the vector control on SD-Gal medium containing CdCl₂. OsCAX1a and OsCAX1c enhanced while OsCAX4 reduced Cd accumulation in yeast. No auto-inhibition was found for all the rice CAX genes. Therefore, OsCAX1a, OsCAX1c and OsCAX4 are likely to involve in Cd uptake and translocation in rice, which need to be further validated.     

Allelopathic effects of western ragweed on seed germination and seedling growth of selected plants

Western ragweed (Ambrosia psilostachya DC.) top growth and rhizome extracts were inhibitory to germination and growth of seedling shoots and roots of test plants in almost all cases. Germination of all plants tested was reduced an average of 19.5% by the ragweed extracts. Shoot and root growth of plants tested was reduced an average of 56.8% by the ragweed extracts. The combined effects of germination plus growth reductions resulted in the tested plants producing only 34.8% in the extracts compared to production in distilled water.     

Optimized Drying of Kaprow Leaves for Industrial Production of Holy Basil Spice Powder

The present study investigated the changes in color, volatile compounds, total phenolic content, total flavonoid content, and antioxidant activity of two holy basil leaves (kaprow in Thai) Ocimum sanctum L. cultivars, kaprow khao and kaprow daeng, after three drying treatments, namely hot air (HA), low relative humidity air drying (LRH), and far-infrared radiation (FIR). Overall, HA dried showed a greater decrease in L values than did LRH and FIR dried for both kaprow cultivars. A significant decrease in total phenolic content (TPC), total flavonoid content (TFC), and ferric reducing antioxidant power (FRAP) was found in hot-air (HA) dried compared to fresh leaves, while TPC, TFC, and FRAP in LRH and FIR dried kaprow were significantly increased. Kaprow daeng and kaprow khao attributes represented by such compounds as β-caryophyllene, methyl eugenol, and eugenol were found to increase during drying. We found that eugenol was a major volatile compound ranging from 18% in HA dried to 23% in FIR dried samples in kaprow khao, whereas methyl eugenol was the main volatile compound in kaprow daeng ranging from 35% in fresh to 49% in FIR dried samples. Our results have demonstrated that LRH and FIR should be considered as a suitable drying method for kaprow with respect to preserving its color, antioxidant property, phenolic compounds, and volatile compounds. The present study has provided useful information for industrial use of kaprow powder production.     

Starve to Sustain—An Ancient Syrian Landrace of Sorghum as Tool for Phosphorous Bio-Economy?

Phosphorus (P) is an essential macronutrient, playing a role in developmental and metabolic processes in plants. To understand the local and systemic responses of sorghum to inorganic phosphorus (P_i) starvation and the potential of straw and ash for reutilisation in agriculture, we compared two grain (Razinieh) and sweet (Della) sorghum varieties with respect to their morpho-physiological and molecular responses. We found that P_i starvation increased the elongation of primary roots, the formation of lateral roots, and the accumulation of anthocyanin. In Razinieh, lateral roots were promoted to a higher extent, correlated with a higher expression of SbPht1 phosphate transporters. Infrared spectra of straw from mature plants raised to maturity showed two prominent bands at 1371 and 2337 cm⁻¹, which could be assigned to P-H(H₂) stretching vibration in phosphine acid and phosphinothious acid, and their derivates, whose abundance correlated with phosphate uptake of the source plant and genotype (with a higher intensity in Razinieh). The ash generated from these straws stimulated the shoot elongation and root development of the rice seedlings, especially for the material derived from Razinieh raised under P_i starvation. In conclusion, sorghum growing on marginal lands has potential as a bio-economy alternative for mineral phosphorus recycling.     

Gibberellin Oxidase Gene Family in L. chinense: Genome-Wide Identification and Gene Expression Analysis

GAox is a key enzyme for the transformation of gibberellins, and belongs to the 2-ketoglutarate dependent dioxygenase gene family (2ODD). However, a systematic analysis of GAox in the angiosperm L. chinense has not yet been reported. Here, we identified all LcGAox gene family members in L. chinense, which were classified into the three subgroups of GA20ox, C19GA2ox, and C20GA2ox. Comparison of the gene structure, conserve motifs, phylogenetic relationships, and syntenic relationships of gibberellin oxidase gene families in different species indicated that the gene functional differences may be due to the partial deletion of their domains during evolution. Furthermore, evidence for purifying selection was detected between orthologous GAox genes in rice, grape, Arabidopsis, and L. chinense. Analysis of the codon usage patterns showed that mutation pressure and natural selection might have induced codon usage bias in angiosperms; however, the LcGAox genes in mosses, lycophytes, and ambarella plants exhibited no obvious codon usage preference. These results suggested that the gibberellin oxidase genes were more primitive. The gene expression pattern was analyzed in different organs subjected to multiple abiotic stresses, including GA, abscisic acid (ABA), and chlormequat (CCC) treatment, by RNA-seq and qRT-PCR, and the stress- and phytohormone-responsive cis-elements were counted. The results showed that the synthesis and decomposition of GA were regulated by different LcGAox genes in the vegetative and reproductive organs of L. chinense, and only LcGA2ox1,4, and 7 responded to the NaCl, polyethylene glycol, 4 °C, GA, ABA, and CCC treatment in the roots, stems, and leaves of seedlings at different time periods, revealing the potential role of LcGAox in stress resistance.     

Chemical Composition and Ability of Essential Oils from Six Aromatic Plants to Counteract Lipid Oxidation in Emulsions

Essential oils with antioxidant properties are of increasing interest in West Africa where there are many antioxidant rich plants. The objective of this study was to determine the essential oil extracted from six native plants (Lippia multiflora, Lippia rugosa, Monodora tenuifolia, Ocimum gratissimum, Pimenta racemosa, Cymbopogon citratus) extracted by hydrodistillation from local plants in Benin. These samples were also evaluated for their antioxidant capacity using the conjugated autoxidizable triene (CAT) assay performed in stripped tung oil-in-water emulsion. The essential oil of P. racemosa, containing high amounts of chavicol (10.3 %) and eugenol (54.5 %), showed the strongest antioxidant activity, followed by that from O. gratissimum containing large amounts of thymol (50.2 %). The essential oil extracted from M. tenuifolia exhibited a moderate antioxidant activity. This essential oil is primarily composed of sesquiterpene alcohols such as α-cadinol (20.5 %), its isomer, α-muurolol (14.7 %), and germacrene D-4-ol (16.8 %). Essential oils from L. multiflora, L. rugosa and C. citratus oils showed poor ability to protect tung oil from oxidation. Finally, essential oils containing phenolic compounds and, in a lesser extent, sesquiterpene alcohols, exhibited the highest CAT values indicating that these compounds are the key determinants of the antioxidant activity of these essential oils in oil-in-water emulsions.     

Selected chemical and physico-chemical properties of microwave-convective dried herbs

The purpose of the presented study was to describe kinetics of microwave-convection drying of basil (Ocimum basilicum), lovage (Levisticum officinale), mint (Mentha sp.), oregano (Origanum vulgare), parsley (Petroselinum crispum), and rocket (Eruca vesicaria) by means of different mathematical models, as well as to describe changes of polyphenols content, color and sorption properties after drying. The analyzed leaves were dried using microwaves power level of 300 W, in a temperature of 40 °C. Logistic model provided best fit to the experimental data. No significant differences in the drying kinetics could be discerned, while significant influence of herbs species on polyphenols contents, color and sorption properties was noted. The highest retention of phenolic compound, good resistance to color degradation and the highest water vapor adsorption concerned Apiaceae family (lovage, parsley), while worse properties in terms of these parameters were noted in Lamiaceae (basil, oregano, mint) and Brassicaceae (rocket).     

High Activity Solid Base Catalysts for Alkenyl Aromatic Isomerisation

The isomerisation of allylbenzene, dimethoxyallylbenzene (4-allyl-1,2-dimethoxybenzene), eugenol (2-methoxy-4-(2-propenyl)phenol), and estragole (4-allylanisole) into their respective cis/trans internal alkenyl aromatics has been studied over a supported solid base catalysts (K₂CO₃/alumina). The catalyst was active at 305 K with conversions as high as 36%. However all reactants cause deactivation of the catalyst.     

Synthesis,Characterization, and Biological Activity Evaluation of Magnetite-Functionalized Eugenol

This work reports the magnetite-functionalization and biological evaluation of eugenol by the co-precipitation method employed only Fe²⁺ under mild conditions and control from the amount of the incorporated magnetite. Magnetic nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), hydrodynamic size distribution (Zetasizer), and vibrating sample magnetometer (VSM). SEM images showed that EUG·Fe₃O₄ similar in shape to a nanoflower. The FTIR spectrum confirmed the presence of characteristic EUG and Fe₃O₄ bands in the EUG·Fe₃O₄ sample, the XRD analysis showed that the magnetite functionalization with eugenol slightly affected the Fe₃O₄ crystal structure, while the VSM measurements demonstrate that EUG·Fe₃O₄ 1:1 shows a superparamagnetic behavior, suggesting small non-interacting particles. The in vitro safety profile and cytotoxicity of free eugenol, magnetite pristine, EUG·Fe₃O₄ 1:1, EUG·Fe₃O₄ 1:5, and EUG·Fe₃O₄ 1:10 was investigated using human cell lines (keratinocytes and melanoma). The results demonstrate the high biocompatibility of EUG·Fe₃O₄ in HaCat cells and the greater specificity for the A375 cell line. Furthermore, the magnetite-functionalization with eugenol decreased the toxic effects of free eugenol on healthy cells. Antibacterial tests were performed in different bacterial strains. The experimental data showed that among the magnetic compounds, the microorganisms were only sensitive to treatment with EUG·Fe₃O₄ 1:1. Regarding the antibiofilm activity assay, it can be observed that only the EUG·Fe₃O₄ caused a significant decrease in biomass when compared to the positive control. Finally, it can be concluded that EUG·Fe₃O₄ proves to be a potential candidate for future studies for drug delivery of cancer and bacterial infections treatments.

Graphical Abstract

     

Increased formation of phosphatidylinositol-4-phosphate in human platelets stimulated with lysophosphatidic acid

Lysophosphatidic acid (LPA, 1-acyl-sn-glycerol 3-phosphate), at a concentration of 1–40 μM, was found to induce the formation of [³H]inositol-labelled phosphatidylinositol-4-phosphate (PIP) without significantly altering the levels of either phosphatidylinositol (PI) or phosphatidylinositol bisphosphate (PIP₂) in washed human platelets. Preincubation of platelets with the cyclooxygenase/lipoxygenase inhibitor, BW755C at 100 μM, did not alter the LPA-induced formation of PIP. Activation of platelets with the phorbol ester, phorbol 12-myristate 13-acetate (PMA), elicited a similar response (induction of PIP formation). The specific protein kinase C (PKC) inhibitor, GF109203X (10 μM), completely blocked the effect of PMA but not the LPA-induced generation of PIP. The present results indicate that LPA can induce PIP formationvia PI-4-kinase activation, through processes which are independent of the eicosanoid/TxA₂ pathway and are not PKC-dependent.     

Supercritical carbon dioxide essential oil extraction of Lamiaceae family species: Mathematical modelling on the micro-scale and process optimization

In this paper the essential oil supercritical carbon dioxide extraction from leaves of Lamiaceae family species was studied. Recent investigations of Lamiaceae family essential oil storage have shown that most of the oil is found in peltate glandular trichomes on the leaf surface. The effect of supercritical CO₂ on the peltate glands was investigated by Scanning Electron Microscopy. It was observed that exposure to supercritical CO₂ led to disruption of the peltate glands and essential oil release. This phenomenon was used as a basic hypothesis of the mathematical model of the supercritical fluid extraction with CO₂. The model was applied to simulate basil, rosemary, marjoram and pennyroyal supercritical CO₂ extraction on the existing experimental data. An average deviation from the experimental data was less than 0.83%. The model results indicated a possibility of a decrease in the supercritical CO₂ consumption by modified and optimized processing of Lamiaceae family herbaceous material.