The major flavonoid glycoside in Syrian Ficus carica L. leaf extracts (rutin) was identified quantitatively and isolated, then transformed into its aglycone (quercetin) by acidic hydrolysis of ethanolic and aqueous extracts. The influence of the hydrolysis process on isoquercitrin content was investigated, too. The determination of contents of Rutin and Quercetin isolated from Syrian Ficus carica L. leaf extracts was carried out by high performance liquid chromatography, and the isolation was done by using thin layer chromatography plates, then identified by mass spectra. Results showed that rutin content in the ethanolic extract (78.79%) was higher than the aqueous one (61.90%) by using ultrasonic extraction procedure. The quercetin content by hydrolysis process was more satisfactory in the ethanolic extract (81.00%) than the aqueous one (72.53%). Acidic hydrolysis process destroyed some of the isoquercitrin in the extracts. The detection of isoquercitrin was done qualitatively by noticing the mass spectrum and the photo diode array spectrum. Rutin and quercetin were successfully isolated, the relative peak areas for isolated rutin and quercetin were 99.80% and 96.46%, respectively. It was concluded that rutin can be easily converted into quercetin by acidic hydrolysis, allowing the use of Syrian ficus leaf extracts as an optimal cheap natural antioxidant source.

Medicinal plants contain a wide variety of chemicals which have very important roles in numerous applications including medicinal and those related with industry. Essential oils represent valuable sources for natural antioxidants. The aim of our study was to evaluate the chemical composition and antioxidant activity of the essential oils extracted from leaves of Syrian Vitex agnus-castus L. and Rosmarinus officinalis L., where is both essential oils were extracted and analyzed by gas chromatography-mass spectrometry. The antioxidant activities of these essential oils were determined by three different test systems, scavenging effect on 2,2-diphenyl-1-picrylhydrazyl radical, total phenolic and flavonoids contents. The main constituents found in Vitex agnus-castus L. essential oil were 1,8-Cineole (19.34%) and Sabinene (12.50%), while the major constituents in Rosmarinus officinalis L. essential oil were 1,8-Cineole (28.03%) and α-Pinene (14.70%). The results showed that 2,2-diphenyl-1-picrylhydrazyl radical scavenging and total phenolic contents of Vitex agnus-castus L. essential oil were higher than Rosmarinus officinalis L. essential oil. Total flavonoids contents were not detected in both essential oils. The Vitex agnus-castus L. and Rosmarinus officinalis L. essential oils are sources of natural antioxidants. Therefore, further work is needed to identify the compound(s) responsible for the antioxidant activity of Vitex agnus-castus L. and Rosmarinus officinalis L. essential oils.

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Purpose The purpose of this paper is to evaluate the inhibition activity of Tribulus terrestris L. (T. terrestris) fruits extracts with solvents of increasing polarity against α-glucosidase and α-amylase, and to determine the inhibition mode of the most effective extract against both enzymes. Design/methodology/approach Hexane, acetone, ethanol and aqueous extracts of T. terrestris fruits were prepared using ultrasonic sequential extraction and analyzed for their α-amylase and α-glucosidase inhibitory activities by specific assay for each enzyme. The modes of inhibitions were detected using Lineweaver–Burk plots. Findings T. terrestris fruits extracts showed inhibition activity against α-glucosidase and α-amylase which was in the dose-dependent manner. Hexane extract had the highest α-glucosidase inhibition activity (IC50 = 27.28 μg/ml, p = 0.003), followed by acetone and ethanol extracts (IC50 = 60.58 μg/ml and IC50 = 84.21 μg/ml, respectively). The inhibition mode of hexane extract was noncompetitive. While acetone extract showed the highest inhibition activity against α-amylase (IC50 = 6.18 mg/ml, p = 0.002), hexane and ethanol extracts showed no significant difference (IC50 = 13.04 mg/ml and IC50 = 14.20 mg/ml, respectively, p = 0.09). The inhibition mode of acetone extract was competitive. Originality/value T. terrestris fruits extracts had strong inhibition activity against α-glucosidase and α-amylase, and they can be used as a promising anti-diabetic agent.

This study was conducted during the period 2019–2020 to identify Trichoderma spp. isolated from woody soils and assessing their efficacy for biodegradation of tannins through tannase enzyme activity produced. Results obtained confirmed the presence of two species; Trichoderma citrinoviride, which was isolated from Maysalon area near Damascus, and characterized by yellowish green colony with dense growth of spores at the center of the colony, and Trichoderma brevicompactum isolated from the Balluran area near Lattakia characterized by yellow colonies with concentric rings. Trichoderma citrinoviride had higher biodegradation activity, measured by degrading different tannins concentrations (2, 4, 6%) collected from Queircus coccifera from Bmelka area in Tartous in liquid medium and led to 85, 87 and 90% degradation, for the three concentrations, respectively, following 12 days incubation. The activity of the produced tannase was measured to be 37.9 units/mg. Whereas, the decomposition rate of the three tannin concentrations by Trichoderma brevicompactum reached 67, 80 , 89%, respectively, again after 12 days of incubation, with enzyme activity measured to be 35.2 units/mg. Keywords: Trichoderma, tannins, tannase, biodegradation, enzyme activit

Shllalo, A.J. and M. Daghestani. 2018. Comparison of volatile emissions from un-infested and infested almond leaves with Aporia crataegi (L.