BACKGROUND:Ephedra is among Palestinian medicinal plants that are traditionally used in folkloric medicine for treating many diseases. Ephedra is known to have antibacterial and antioxidant effects. The goal of this study is to evaluate the antioxidant activity of different extracts from the Ephedra alata plant growing wild in Palestine, and to analyze their phenolic and flavonoid constituents by HPLC/PDA and HPLC/MS.MATERIALS AND METHODS:Samples of the Ephedra alata plant grown wild in Palestine were extracted with three different solvents namely, 100% water, 80% ethanol, and 100% ethanol. The extracts were analyzed for their total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (AA), as well as phenolic and flavonoids content by HPLC/PDA/MS.RESULTS:The results revealed that the polarity of the extraction solvent affects the TPC, TFC, and AA of extracts. It was found that both TPC and AA are highest for plant extracted with 80% ethanol, followed by 100% ethanol, and finally with 100% water. TFC however was highest in the following order: 100% ethanol > 80% ethanol > water. Pearson correlation indicated that there is a significant correlation between AA and TPC, but there is no correlation between AA and TFC. Simultaneous HPLC-PDA and UHPLC-MS analysis of the ethanolic plant extracts revealed the presence of Luteolin-7-O-glucuronide flavone, Myricetin 3-rhamnoside and some other major polyphenolic compounds that share myricetin skeleton.CONCLUSION:Ephedra alata extract is rich in potent falvonoid glycosidic compounds as revealed by their similar overlaid UV-Vis spectra and UHPLC-MS results. On the basis of these findings, it is concluded that Ephedra alata constitutes a natural source of potent antioxidants that may prevent many diseases and could be potentially used in food, cosmetics, and pharmaceutical products.

An aminopolycarboxylic acid chelating agent; tris(2-aminoethyl)aminehexaacetic acid (TAHA) was prepared and characterized. TAHA formed stable complexes with Cu(II) ions and other metal ions at pH 10. The complexation behavior was studied by spectrophotometry at the complex maximum wavelength. Mixtures of Cu(II) and other metal ions (M2+; Ca2+, Co2+, Ni2+, Cd2+)were titrated with TAHA at pH 10. The stoichiometry of ligand - to - metal was found to be 1:1. The stability constant of Cu(II)–TAHA complex was determined to be 1.86×105 by using the continuous variation method. Beer’s law was obeyed over the concentration range 3.0×10–4 M – 1.2×10–2 M for Cu(II) solution. The results of the quantitative determination of Cu(II) gave LOD and LOQ values of 7.285×10–6 M and 2.428×10–5 M respectively. The percent relative standard deviation (%RSD) for five replicate samples was found to be 1.088% and 4.804% for Cu(II) concentrations of 1.2×10–2 M and 3.0×10–4 M respectively.

A simple, precise, accurate, and selective method was developed and validated for determination of eight phenolic compounds (gallic acid, p-hydroxybenzoic acid, vanilic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and sinapic acid) in date palms. Separation was achieved on an RP C18 column using the mobile phase methanol water with 2% acetic acid (18 + 82, v/v). This method was validated according to the requirements for new methods, which include accuracy, precision, selectivity, robustness, LOD, LOQ, linearity, and range. The method demonstrated good linearity over the range 1-1000 ppm of gallic acid, p-hydroxybenzoic acid, vanilic acid, caffeic acid, and syringic acid with r(2) greater than 0.99, and in the range of 3-1000 ppm for p coumaric acid, ferulic acid, and sinapic acid with r(2) greater than 0.99. The recovery of the eight phenolic compounds ranged from 97.1 to 102.2%. The method is selective because adjacent peaks of phenolic compounds were well separated with good resolution. The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing analytical operators proved that the method is robust and rugged.

A commercially available chelating polymer, polystyrene tris(2-aminoethyl)amine, was used for the removal of chromium from aqueous solution. The influence of pH, contact time, adsorbent dosage and initial Cr (VI) concentration on adsorption was studied. The optimum pH for the removal of Cr (VI) was at pH 5, while optimum contact time and adsorbent dosage were 120 minutes and 10 g/L, respectively. Total chromium and Cr (VI) concentrations were analyzed by ICP-MS and UV-Visible. Adsorption isotherms using Langmuir and Freundlich isotherm models revealed that the data fitted Langmuir isotherm model better than Freundlich with a maximum adsorption capacity of 312.27 mg/g. FTIR spectroscopy, Scanning electron microscopy (SEM) and Energy Dispersive Spectrometry (EDS) analyses were performed on the adsorbent before and after binding Cr (VI). All analyses confirmed the complexation of Cr (VI) to the adsorbent. Desorption experiments using KCl solution indicated 89.3% release of chromium, rendering this method of high potential for adsorbent regeneration.

In this work, a tris(2-aminoethyl)aminodicaboxylate functionality was substituted for the chloride of polyvinyl-benzyl chloride (PVBC) which was lightly cross-linked (2%) with divinyl benzene. The resulting derivatized polymer microspheres were embedded in a hydrogel matrix of poly vinyl alcohol cross-linked with glutaraldehyde to produce a sensing membrane. The latter responded selectively to Cu2+ solutions of different concentration ranges (1 × 10-4 M to 1 × 10-6 M). The response is based on the interaction between the metal cations and the negatively charged deprotonated dicarboxylate functional group, which led to neutralization of the charges. As a result, an increase in the turbidity of the sensing membrane occurred which is attributed to a change in the refractive index of the derivatized polymer microspheres relative to that of the hydrogel. The change in the turbidity of the sensing membrane was measured as absorbance using a conventional spectrophotometer. It was found that Cu2+ ions bind to the aminodicarboxylated-polymer with a formation constant, Kf, of 1 × 105 M-1. SEM, Eds and IR analyses were performed on the aminodicarboxylated microspheres and their Cu2+ complex.

The effect of geographical region and harvesting date (seasonal change) on antioxidant activities (AA), total phenolic content (TPC) and total flavonoid content (TFC) of olive leaves obtained from different geographical regions of Palestine (north, middle, and south) at different maturation stages (June 2013, October 2013, and January 2014) was investigated in this study.Results revealed that both geographical region and maturation stage affect AA, TPC, and TFC of the olive leaves.Highest AA, TPC, and TFC were obtained for samples collected in June.TPC was found to be highest in north and lowest in south, while the highest AA, and TFC contents were alternating between north, middle, and south.During different maturation stages, TPC, TFC, and AA varied between 21.56 -47.52 mg (GAE), 19.3 -32.6 mg catechin equivalents, 318.53 -1106.43µmol FRAP equivalents per gram of dry olive leaves, respectively.

Olive leaves are rich with polyphenolic compounds which exhibit many activities like antimicrobial, antioxidant activities. Natural compounds from olive leaves are safe antioxidants, antibacterials, and preservatives compared to synthetic ones. In this work, olive leaf samples were collected from different geographical regions of Palestine at different maturation stages. The olive leaves samples were dried, grinded, and extracted with water at room temperature for two hours. The crude extracts were then analyzed for their total phenolic content, total flavonoid content, and antioxidant activity. Results revealed that olive leaves are rich with antioxidants (polyphenolic and flavonoid compounds), and the extracts showed antibacterial activities against two gram positive bacteria (staphylococcus aureus, and staphylococcus epiderrmidis) with activity of about 80-90% compared to well known antibiotic (Neomycin). Based on these results, the olive leaf extracts were used in cosmetics, pharmaceutical, and food applications as natural antioxidant and antibacterial agent. In cosmetics, olive leaves extracts were used in moisturizing day cream, anti- aging cream, and shampoo formulations at three concentrations (0.1%, 0.4% and 1.0%, w/w). Results showed that all physical and rheological properties of the formulations with olive leaves extract were the same as commercial product. Furthermore, stability studies showed stable homogenous appearance and effective during one year storage period at room temperature. A questionnaire analysis on 100 volunteers who used these creams and shampoos showed that they are satisfied with these preparations. In pharmaceutical industry, the olive leaf extracts were used as natural antibacterial, and antioxidant in non-sterile pharmaceutical dosage forms instead of conventional chemical preservatives which have toxicity to human beings even at low concentrations especially when used in pediatric/children preparations. Results showed that the extracts work as natural antibacterials and antioxidants for the prepared pediatric syrup and potentially can substitute the chemical preservatives. Regarding food applications of the extracts, they were added into meat fillets as antioxidants and compared to chemical preservatives that are used usually in meats (BHT), and results indicated significant decrease in the amount of secondary oxidation products (represented as malonodialdehyde) of the tested meat samples treated with different concentrations of olive leaves extracts, indicating that this extract can be used as natural antioxidants in meat substituting synthetic ones. Additionally the extracts were tested for the stabilization of edible oils as substituents to synthetic additives (BHT and BHA), and results showed that incorporation of olive leaves extracts in the unsaturated edible oils resulted in significant decrease in primary and secondary oxidation products of the oil, and therefore this extract has protecting effect against induced lipid peroxidation of edible oils.

Three polymers with N-ethanolamino-, N-benzylamino-, and N-t-butylamino-dithiocarbamate groups were synthesized from polyvinylbenzylchloride. Each of the three polymers was incorporated in a hydrogel membrane (PVA) cross-linked with glutaraldehyde to form a sensing element. The latter was, then, evaluated for its optical sensing behavior by subjecting it to varying concentrations (1.0x10 -5 up to 0.1 M) of metal ions (Zn 2+ , Cd 2+ , Pb 2+

In previous work we have developed a dicarboxylate functionalized polymer that demonstrated chemical sensing. It showed good response to pH changes as well as to varying concentrations of copper and calcium ions. Our recent in-vest- tigations showed interesting results upon testing the functionalized sensing polymer on heavy metals. This sensor is composed of microspheres of polyvinyl benzyl malonate lightly-cross-linked with divinyl benzene dispersed in a hydrogel membrane. The response of the optical sensor is based on the interaction between the metal cations with the deprotonated functional group. The polymer, thus, undergoes shrinking as a result of neutralization of adjacent negative charges on the back-bone of the polymer. This causes significant changes in the optical properties of the sensing element. The optical changes were measured as absorbance vs. wavelength as the sensing membrane is exposed to solutions of varying concentrations of heavy metal ions. The sensor showed significant increase in absorbance up to a concentration of 5 × 10-3 M to the following metal ions: Ni2+, Zn2+, and Cd2+. Furthermore, the studied capacity of the derivatized microspheres showed close values to Ni2+, Zn2+, Cd2+ (1.20, 1.09, 1.08 mmol/g respectively). These kinds of properly functionalized polymers appear to be suitable, versatile sensing elements for the detection of low concentrations of heavy metal ions. In addition, all of the tested heavy metals showed a similar value of the equilibrium formation constant, (log Kf1 is 2.63). In contrast, the sensor showed no significant response to varying concentrations of K+ and Mg2+ metal ions.

In this study, a new modified optical chemical sensor based on swellable polymer microspheres is developed using a 5% copolymer of polyvinylpyridine-polyvinyl-benzyl chloride microspheres functionalized as the corresponding dithiocarbamate. This sensor demonstrated significant enhancements in sensitivity, dynamic range and response time. These improvements are related to the presence of pyridine in the polymer backbone, which is believed to increase the space between the groups, thus decreasing steric hindrance, and hence increasing substitution of the dithiocarbamate group. The hydrophilicity of pyridine also allows free movement of the solvent and analyte to and from the inside of the microspheres. These dithiocarbamate-derivatized polymer microspheres were embedded in a hydrogel matrix of polyvinylalcohol cross-linked with glutaraldehyde. This sensor responded selectively to Hg2+ solutions of different concentrations (1 × 10−5 M to 0.1 M). The observed turbidity measured as absorbance varied between 1.05 and 1.75 units at a wavelength of 700 nm. The response is based on the interaction between the metal cations with the negative charges of the deprotonated dithiocarbamate functional group, which led to neutratization of the charges and thus to polymer shrinking. As a result, an increase in the turbidity of the sensing element due to a change in the refractive index between the hydrogel and the polymer microspheres occured. The changes in the turbidity of the sensing element were measured as absorbance using a conventional spectrophotometer.

Chemical variability in the essential oil from leaves of individual plants of Majorana syriaca (common names Syrian marjoram, zaatar, zahtar) plants growing wild at various locations in Palestine were analyzed using a static headspace gas chromatography mass spectrometry (HS-GC/MS). Although Palestine represents a relatively small geographical area, a wide range of variations in oil characteristics were observed, indicating the Palestinian region as an important center of diversity. Essential oil yield was based on steam distillation of air-dried leaves ranged from 10.5 to 54 mg g−1. The major oil constituents, α-phellandrene (1.62–8.13%), α-pinene (1.22%–4.61%), β-myrcene (0.5%–11%), m-cymene (1.86%–8.61%), p-cymene (8.44%–48.6%), γ-terpinene (11.96%–30.8%), thymol (0.26%–11.6%), and carvacrol (0.65%–21.7%), were identified throughout the harvesting period. An analysis of phenolic compounds revealed that wild growing Majorana syriaca could be characterized by the dominant presence of carvacrol. Conversely, water irrigation has showed a prominent effect on the thymol isomer production. Distribution of these isomers can be used as marker to distinguish wild from cultivated Majorana syriaca. KEYWORDS: herbaromatic plantmedicinal plantwild thyme Origanum syriacum Origanum maru

BACKGROUND:A comparative analysis by using static headspace (HS) and steam distillation (SD) GC-MS of the volatile and the semi-volatile secondary metabolites from leaves of cultivated Majorana syriaca.METHODS:The essential oils endogenous to cultivated thyme were isolated and identified by HS-GC-MS technology and compared to those from SD-GC-MS.RESULTS:The HS-GC-MS results showed that the Palestinian cultivated thyme is rich in monoterpene hydrocarbons and phenolic monoterpenes such as alpha-phellandrene, alpha-pinene, beta-myrcene, m-cymene, p-cymene, gamma-terpinene, thymol and carvacrol. In all the samples gamma-terpinene, p-cymene, thymol and carvacrol were the most abundant compounds.CONCLUSIONS:HS and SD-GC-MS have proved that most of the cultivated thyme samples examined has thymol isomer as the major phenolic constituent.

Majorana syriaca (Zaatar in Arabic), belonging to the mint family, Labiates, is cultivated widely and grows wild in the mountains of Palestine between the months April to August. In order to determine the secondary metabolites from wild leaves of Palestinian M. syriaca, comparative analysis by static headspace (HS) and steam distillation (SD) GC-MS was used. Among the samples examined, the major constituents identified varied greatly throughout the different harvesting periods. Headspace revealed major volatiles and semi-volatiles of alpha-pinene, beta-myrecene, o-cymene, p-cymene, gamma-terpinene, thymol, and carvacrol. We found that the most abundant monoterpenes, i.e. gamma-terpinene and p-cymene were decreased in the month of May since they are the biogenetic precursors (via enzymic hydroxylation) of the phenolic terpenes, thymol and carvacrol. The harvesting time, location and the thyme type (i.e., wild) affects the yield of essential oils as reflected by normal steam distillation.

Three different unifloral Palestinian honey samples that originate from Thymus capitatus, Thymelaea hirsuta, and Tolpis virgata were analyzed by using Headspace-Solid Phase Microextraction Gas Chromatography–Mass Spectrometry (HS-SPME-GC–MS). The analysis performed exhibited chromatographic profiles that are characteristics for each type of examined honey. Therefore, the proposed analytical procedure demonstrated a rapid characterization method for the analysis of these types of honeys, by revealing the presence or absence of certain organic volatile constituents. A variety of volatiles, particularly phenols, aldehydes, ketones, acids, and alcohols were detected in these types of honeys. The compounds present in each specific honey offer a marker that can be utilized in relating a given honey to its floral origin. Thymus capitatus honey showed six marker compounds: 1,3-diphenyl-2-propanone, (3-methylbutyl)benzene, 3,4,5-trimethoxy benzaldehyde, 3,4-dimethoxy benzaldehyde, vanilline, and thymol. Thymelaea hirsuta honey is characterized by the presence of a group of alcohols and phenols particularly benzene propanol, benzylalcohol, nonanol, hexanol and 4-methoxyphenol. Tolpis virgata hooney, however, has two marker compounds 3,5-dihydroxytoluene, and tridecane.

An optical chemical sensor based on polymer swelling and shrinking has been studied by way of optical transmission. Polyvinylbenzyl chloride cross-linked with divinylbenzene and derivatized as the dicarboxylate was dispersed as microspheres in a hydrogel membrane. The absorbance was measured vs. the wavelength upon exposing the modified membrane to solutions of varying pH (3.0–9.0). At low pH (3.0), the absorbance had the highest value (1.34), while the absorbance decreased significantly (1.10) when the pH was increased to 9.0, indicating polymer swelling.