Essential Oil and Bioactive Compounds Variation in Myrtle (Myrtus communis L.) as Affected by Seasonal Variation and Salt Stress

The effect of different NaCl concentrations (control, 2, 4 and 6 dS/m) and three harvesting times in different seasons including spring (9 April), summer (5 July), and fall (23 September) was evaluated on essential oil (EO) yield, composition, phenolic, flavonoid content, and antioxidant activity of myrtle. Essential oil yield ranged from 0.2% in control and fall to 1.6% in moderate salinity (4 dS/m) and spring season. The main constituents obtained from gas chromatography/mass spectrometry analysis were α‐pinene, 1,8‐cineole, limonene, linalool, α‐terpineol, and linalyl acetate in which α‐pinene ranged from 11.70% in moderate and fall to 30.99% in low salinity (2 dS/m) and spring, while 1,8‐cineole varied from 7.42% in high salinity (6 dS/m) and summer to 15.45% in low salinity and spring, respectively. Salt stress also resulted in an increase in total phenolic, flavonoid content, and antioxidant activity. The highest antioxidant activity based on DPPH radical scavenging activity, reducing power (FTC) and β‐carotene/linoleic acid model systems was found in plants harvested in spring and summer in high stress condition. The lowest IC₅₀ values obtained in 6 dS/m in spring (375.23 μg/ml) followed by summer (249.41 μg/ml) and fall (618.38 μg/ml). Eight major phenolic and flavonoid compounds were determined in three harvesting times using high performance liquid chromatography analysis. In overall, late harvesting time of myrtle in fall can lead to reduce the most of major EO components, while it can improve the amount of phenolic acids.     

Investigations on Antioxidant,Antiproliferative and COX‐2 Inhibitory Potential of Alkaloids from Anthocephalus cadamba (Roxb.) Miq. Leaves

In the present study, an ayurvedic medicinal plant, Anthocephalus cadamba (Roxb .) Miq . commonly known as ‘Kadamb’ was explored for its potential against oxidative stress and cancer. The fractions namely AC‐4 and ACALK (alkaloid rich fraction) were isolated from A. cadamba leaves by employing two different isolation methods and evaluated for their in vitro antioxidant and antiproliferative activity. The structure of the isolated AC‐4 was characterized tentatively as dihydrocadambine by using various spectroscopic techniques such as ESI‐QTOF‐MS, ¹H‐ and ¹³C‐NMR, DEPT, COSY, HMQC, and HMBC. Results of various antioxidant assays viz. 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), ABTS cation radical, superoxide anion radical scavenging, and plasmid nicking assay demonstrated that both the fractions viz. AC‐4 and ACALK possess ability to scavenge DPPH, ABTS radicals and effectively protected plasmid pBR322 DNA from damage caused by hydroxyl radicals. Further, when both fractions were evaluated for their potential to suppress growth of HeLa and COLO 205 cells, only ACALK fraction showed antiproliferative effects. ACALK exhibited GI₅₀ of 205.98 and 99.54 μg/ml in HeLa and COLO 205 cell lines, respectively. Results of Hoechst staining in cervical carcinoma (HeLa) cells confirmed that ACALK induced cell death in HeLa cells via apoptotic mode. Both the fractions also inhibited COX‐2 enzyme activity.     

Genetic and Phytochemical Analysis to Evaluate the Diversity and Relationships of Mate (Ilex paraguariensis A.St.‐Hil.) Elite Genetic Resources in a Germplasm Collection

The aim of this study was to evaluate the phytochemical and genetic diversity, relationships and identification of mate (Ilex paraguariensis A.St .‐Hil .) elite genetic resources belonging to the Brazilian germplasm collection and mate breeding program. Mate has been studied due to the presence of phytochemical compounds, especially methylxanthines and phenolic compounds. The samples were collected from the leaves of 76 mate elite genetic resources (16 progenies × 5 localities). Total DNA was extracted from mate leaves and 20 random primers were used for DNA amplification. Methylxanthines (caffeine and theobromine) and phenolic compounds (chlorogenic, neochlorogenic, and criptochlorogenic acids) were quantified by HPLC. The genetic divergence estimated was higher within (92%) than among (8%) the different populations. Analysis of genetic distance between origins provided the formation of two groups by UPGMA cluster analysis, with higher polymorphism (94.9%). The average content of caffeine ranged from 0.01 to 1.38% and theobromine of 0.10 – 0.85% (w/w). The caffeoylquinic acids concentrations (1.43 – 5.38%) showed a gradient 3‐CQA > 5‐CQA > 4‐CQA. The coefficient of genetic variation (CVg) was of low magnitude for all mono‐caffeoylquinics acids. Significant correlations (positive and negative) were observed between the phytochemical compounds. Genetic diversity analysis performed by RAPD markers showed a greater intra‐populational diversity; genetic resources with low caffeine and higher theobromine content were identified and can be used in breeding programs; the correlation between methylxanthines and phenolic compounds can be used as a good predictor in future studies.     

Inhibitory Activities of Butanol Fraction from Butea monosperma (Lam.) Taub. Bark Against Free Radicals,Genotoxins and Cancer Cells

The present study was undertaken to investigate antioxidant, antigenotoxic, and antiproliferative activity of butanol fraction (Bmbu) from bark of medicinal plant Butea monosperma. Antioxidant potency of Bmbu was examined by various in vitro assays. It was also investigated for antigenotoxic activity using Escherichia coli. PQ37 employing SOS chromotest. Further, cytotoxic and apoptosis inducing activity of Bmbu was evaluated in MCF‐7 breast cancer cells. Bmbu showed potent free radical scavenging ability in ABTS assay (IC₅₀ 56.70 μg/ml) and anti‐lipid peroxidation ability (IC₅₀ 40.39 μg/ml). 4NQO and H₂O₂ induced genotoxicity was suppressed by Bmbu in SOS chromotest by 74.26% and 82.02% respectively. It also inhibited the growth of MCF‐7 cells with GI₅₀ value of 158.71 μg/ml. Induction of apoptosis in MCF‐7 cells by Bmbu treatment was deciphered using confocal microscopy, flow cytometry, and neutral comet assay. Bmbu treatment increased cell population in sub‐G₁ phase (69.6%) indicating apoptotic cells. Further, Bmbu treatment resulted in increased reactive oxygen species generation and decreased mitochondrial membrane potential indicating involvement of mitochondrial dependent pathway of apoptosis. HPLC profiling showed the presence of polyphenols such as ellagic acid, catechin, quercetin, and gallic acid as its major constituents. Consequently, it is suggested that the phytoconstituents from this plant may be further exploited for development of novel drug formulation with possible therapeutic implication.     

Antioxidant and Proteinase Inhibitory Activities of Selected Poppy (Papaver somniferum L.) Genotypes

Poppy seeds (Papaver somniferum L.) belong to tasty food ingredients however, they should be considered also as valuable source of biologically active compounds. Content of selected metabolites, antioxidant and proteinase inhibitory activities were analyzed in vitro in extracts from seeds of fifteen poppy genotypes. Considerable variation in all parameters was detected within the set of analyzed poppy genotypes. The genotype Major expressed the highest antioxidant activity determined by all four methodological approaches (DPPH, ABTS, FRAP, RP). The genotype MS 423 exhibited the highest inhibitory activities against trypsin, thrombin and collagenase. Very specific position among all had the genotype Redy . Its grain extract reached significantly high levels in 9 out of 14 measured parameters (TPC, TFC, TTC, TAC, FRAP, RP, inhibitory activities against trypsin, thrombin, collagenase). Edible grains of poppy are valuable source of natural compounds which may be beneficial in pathological states associated with oxidative stress or increased proteinase activities.     

Screening of Polish Fir Honeydew Honey Using GC/MS,HPLC‐DAD,and Physical‐Chemical Parameters: Benzene Derivatives and Terpenes as Chemical Markers

GC/MS of headspace solid phase micro extraction (HS‐SPME) and solvent extractives along with targeted HPLC‐DAD of Polish fir (Abies alba Mill .) honeydew honey (FHH), were used to determine the chemical profiles and potential markers of botanical origin. Additionally, typical physical‐chemical parameters were also assigned. The values determined for FHH were: conductivity (1.2 mS/cm), water content (16.7 g/100 g), pH (4.5), and CIE chromaticity coordinates (L* = 48.4, a* = 20.6, b* = 69.7, C* = 72.9, and h° = 73.5). FHH contained moderate‐high total phenolic content (533.2 mg GAE/kg) and antioxidant activity (1.1 mmol TEAC/kg) and (3.2 mmol Fe²⁺/kg) in DPPH and FRAP assays. The chemical profiles were dominated by source plant‐originated benzene derivatives: 3,4‐dihydroxybenzoic acid (up to 8.7 mg/kg, HPLC/honey solution), methyl syringate (up to 14.5%, GC/solvent extracts) or benzaldehyde (up to 43.7%, GC/headspace). Other markers were terpenes including norisoprenoid (4‐hydroxy‐3,5,6‐trimethyl‐4‐(3‐oxobut‐1‐enyl)cyclohex‐2‐en‐1‐one, up to 20.3%, GC/solvent extracts) and monoterpenes, mainly linalool derivatives (up to 49%, GC/headspace) as well as borneol (up to 5.9%, GC/headspace). The application of various techniques allowed comprehensive characterisation of FHH. 4‐Hydroxy‐3,5,6‐trimethyl‐4‐(3‐oxobut‐1‐enyl)cyclohex‐2‐en‐1‐one, coniferyl alcohol, borneol, and benzaldehyde were first time proposed for FHH screening. Protocatechuic acid may be a potential marker of FFH regardless of the geographical origin.     

Allelopathic Effects,Physiological Responses and Phenolic Compounds in Litter Extracts of Juniperus rigidaSieb. et Zucc.

The allelopathic effects of Juniperus rigida litter aqueous extract (LE) on wheat and Pinus tabuliformis were studied, as well as the physiological responses to the extract. High concentration LE (0.10 g Dw/ml) significantly inhibited the seed germination and seedling growth in receptor plants. The chlorophyll content and root activity in the wheat seedlings were reduced significantly across all treatments; however, those were more prominently reduced at high concentration (0.10 g Dw/ml) but received little stimulation at low concentration (0.025 g Dw/ml) in P. tabuliformis. The content of malonaldehyde (MDA) increased with increasing concentrations of LE, except at 0.025 g Dw/ml. Activities of antioxidant enzymes (POD, CAT and SOD) in receptor plants were all significantly inhibited at high concentrations but stimulated at low concentrations. These results demonstrate that the aqueous extract from J. rigida litter has allelopathic potential. Various phenolic compounds were identified in litter aqueous extract and litter ethanol extract by HPLC. The phenolic compound content in the aqueous extract was significantly lower than that in the ethanol extract. Chlorogenic acid and podophyllotoxin were the predominant phenolic compounds in both types of litter extracts. These findings suggest that the seed germination and seedling growth of P. tabuliformis and wheat would be inhibited when planted near large amounts J. rigida litter.     

Experimental and Theoretical Assessment of Ni‐Based Binary Compounds for the Hydrogen Evolution Reaction

Metallic binary compounds have emerged in recent years as highly active and stable electrocatalysts toward the hydrogen evolution reaction. In this work, the origin of their high activity from a theoretical and experimental point of view is elucidated. Here, different metallic ceramics as Ni₃S₂, Ni₃N, or Ni₅P₄ are grown directly on Ni support in order to avoid any contaminations. The correlation of theoretical calculations with detailed material characterization and electrochemical testing paves the way to a deeper understanding of possible active adsorption sites for each material and the observed catalytic activity. It is shown that heteroatoms as P, S, and N actively take part in the reaction and do not act as simple spectator. Due to the anisotropic nature of the materials, a variety of adsorption sites with highly coverage‐dependent properties exists, leading to a general shift in hydrogen adsorption free energies ΔG _H close to zero. Extending the knowledge gained about the here described materials, a new catalyst is prepared by modifying a high surface Ni foam, for which current densities up to 100 mA cm^?2 at around 0.15 V (for Ni₃N) are obtained.     

Optimization of extraction method for LC–MS based determination of phenolic acid profiles in different Impatiens species

The main aim of presented study was the comparison of various extraction methods for the quantitative and qualitative analysis (LC-ESI–MS/MS) of phenolic acids present in extracts obtained from leaves, flowers, and roots of Impatiens glandulifera. The accelerated solvent extraction (ASE) at three temperature ranges (80° C, 100° C, and 120° C), ultrasound assisted extraction (USAE) at 60° C, and traditional extraction in Soxhlet apparatus were used. Taking into account the extraction yield, and the diversity of the individual compounds, ultrasound assisted extraction proved to be the most efficient method, and it was used to determine the content of phenolic acids in leaves of four other Impatiens species, including I. balsamina, I. noli-tangere, I. parviflora, and I. walleriana. Eleven phenolic acids were identified in all examined species. These were protocatechuic, gentisic, 4- hydroxybenzoic, vanillic, trans-caffeic, syringic, trans-p-coumaric, trans- and cis-ferulic, salicylic, and 3-hydroxycinnamic acids. In the extract from the leaves of I. balsamina and I. walleriana, gallic and cis-p-coumaric acids were found additionally. The most abundant compounds in all examined extracts were protocatechuic and 3-hydroxycinnamic acids. The latest acid was found in the highest yield in I. noli-tangere (266.12 μg/g DW). In the leaves of I. glandulifera a great amount of 4-hydroxybenzoic (41.44 μg/g DW), vanillic (61.50 μg/g DW), and trans-p-coumaric (58.42 μg/g DW) acids was also observed. Our results indicate that protocatechuic, 4-hydroxybenzoic, vanillic, trans-p-coumaric, trans-ferulic, and 3-hydroxycinnamic acids were most characteristic of Impatiens species.Additionally, various phenolic-rich extracts from leaves, flowers, and roots of Impatiens glandulifera were tested for antioxidant activity. The highest antiradical activity was detected for roots using Soxhlet extraction (EC50 = 0.055 mg [DE/ml]).The study demonstrated that members of the genus Impatiens, and in particular Impatiens glandulifera, and Impatiens noli-tangere, contain significant amounts of phenolic acids. In addition, extracts from various parts of I. glandulifera could be interesting as novel sources of natural antioxidants.     

Antioxidant,antibacterial and cytotoxic potential of silver nanoparticles synthesized using terpenes rich extract of Lantana camara L. leaves

Several attempts have been made for green synthesis of silver nanoparticles (AgNPs) using different plant extracts. Present study revealed that, antioxidant, antibacterial and cytotoxic AgNPs were synthesized using terpenes-rich extract (TRE) of environmentally notorious Lantana camara L. leaves. AgNPs were characterized by advanced techniques like UV–Visible and Infra red spectroscopy; XRD, SEM techniques as terpenes coated sphere shaped NPs with average diameter 425 nm. Further, on evaluation, AgNPs were found to exhibit dose – dependent antioxidant potential, good to moderate antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa; and toxicity on Brine shrimp (A. salinanauplii) with LD₅₀ value 514.50 µg/ml.