СHROMATOGRAPHIC ANALYSIS OF СYCLOSIVERSIOSIDE F

The plants Astragalus pterocephalus growing in Uzbekistan are a source of triterpene glycosides. The main triterpene glycoside, in terms of content, is a cycloartan glycoside – cyclosiversioside F. To obtain an individual biologically active compound cyclosiversioside F with 95% purity, a proposed method involves extraction with methanol, concentration and dilution with an equal volume of water, then followed by a sequential extraction from the aqueous extract with chloroform, ethyl acetate and butanol. Then a chromatographic separation of the purified amount of extractives on a column with silica gel, isolation of the substance and precipitation from a solvent system must be performed, followed by recrystallization and drying. The optimal conditions for the isolation and separation of the amount of extractive substances have been developed in order to obtain an individual glycoside. Cyclosiversioside F was authenticated by TLC in comparison with an authentic sample. Quantitative analysis of the glycoside was carried out by HPLC. The purity of cyclosiversioside F was confirmed by taking 1H and 13C NMR spectra.

Synthesis and Evaluation of 18F-INER-1577-3 as a Central Nervous System (CNS) Histone Deacetylase Imaging Agent

Background:: Epigenetic dysfunction is implicated in many neurologic, psychiatric and oncologic diseases. Consequently, histone deacetylases (HDACs) inhibitors have been developed as therapeutic and imaging agents for these diseases. However, only a few radiotracers have been developed as HDACs imaging agents for the central nervous system (CNS). We report herein the synthesis and evaluation of [18F]INER-1577-3 ([18F]5) as an HDACs imaging agent for CNS. Methods:: [18F]INER-1577-3 ([18F]5) was synthesized by two methods: one-step (A) and two-step (B) methods. Briefly, radiofluorination of the corresponding precursors (11, 12) with K[18F]/K2.2.2 followed by purifications with HPLC gave ([18F]5). The quality of [18F]INER- 1577-3 synthesized by these methods was verified by HPLC and TLC as compared to an authentic sample. The inhibitions of [18F]INER-1577-3 and related HDACs inhibitors on tumor cells growth were carried out with breast cancer cell line 4T1 and MCF-7. The whole-body and brain uptake of [18F]INER-1577-3 in rats and AD mice were determined using a micro-PET scanner and the data was analyzed using PMOD. Results: : The radiochemical yield of [18F]INER-1577-3 synthesized by these two methods was 1.4 % (Method A) and 8.8% (Method B) (EOB), respectively. The synthesis time was 115 min and 100 min, respectively, from EOB. The inhibition studies showed that INER-1577-3 has a significant inhibitory effect in HDAC6 and HDAC8 but not HDAC2. PET studies in rats and AD mice showed a maximum at about 15 min postinjection for the whole brain of a rat (0.47 ± 0.03 %ID/g), SAMP8 mice (5.63 ± 1.09 %ID/g) and SAMR1 mice (7.23 ± 1.21 %ID/g). Conclusion:: This study showed that INER-1577-3 can inhibit tumor cell growth and is one of a few HDACs inhibitors that can penetrate the blood-brain barrier (BBB) and monitor HDAC activities in AD mice. Thus, [18F]INER-1577-3 may be a potent HDACs imaging agent, especially for CNS.

Chemical Compostions of Essential Oils and Antimicrobial Activity of Hyptis suaveolens (L.) Poit. (Lamiaceae) from Vietnam

Aims: This present study described the chemical constituents and antimicrobial activity of essential oils hydrodistiled from the leaves and flowers of Hyptis suaveolens (L.) Poit. Study Design: This research was designed to accommodate different stages such as collection of authentic sample of Hyptis suaveolens, obtain essential oil by hydrodistillation, chemical analysis of the oil samples by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS) and screening of the essential oils for antimicrobial activity. Place and Duration of Study: School of Natural Science, Vinh University, Vinh City, Nghệ An Province, Vietnam, between August and December 2018. Methodology: The leaves and flowers of H. suaveolens used for this study were gotten from Đồng Văn Commune, Pù Hoạt Nature Reserve, Vietnam. The collection was done in December 2018. Essential oils were distilled off using hydrodistillation method according to established procedure. The determination of antimicrobial efficacy of essential oils of H. suaveolens will be achieved by the method of microdilution broth susceptibility assay. The minimum inhibitory concentration (MIC) and IC50 were evaluated accordingly. Results: The major compounds in the oil were b-caryophyllene (31.1% and 33.7%), caryophyllene oxide (17.6% and 3.9%), phytol (9.9% and 2.7%) and a-humulene (6.7% and 6.6%), respectively. The leaf oil displayed strong antimicrobial activity against Enterococcus faecalis ATCC299212, Bacillus cereus ATCC14579 and Candida albicans ATCC10231 with minimum inhibitory concentrations (MIC) of 16.0, 32.0 and 16.0 µg/mL respectively, while the IC50 values were 5.78, 9.35 and 6.78 µg/mL, respectively. The flower oil showed activity towards the same organisms with MIC values of 64.0, 64.0 and 16.0 µg/mL, respectively; with IC50 values of 20.45, 26.78 and 6.78 µg/mL, respectively. Both essential oils exhibited moderate activity towards Staphylococcus aureus ATCC25923 with MIC of 256.0 µg/mL. Conclusion: The results are indication of the potential of H. suaveolens essential oils as source of antimicrobial agents.

Chemical Composition and Evaluation of the Antimicrobial Activity of the Of Illicium Verum and the Derivations of Protocatechuic Acid

In our present studies we identify the components of essential oil, crude extracts and fraction of Illicium verum, and evaluation of antibacterial activity. We isolated and identified as 3, 4-dihydroxybenzoic acid (protocatechuic acid) through spectroscopic studies and comparison with the data of the authentic sample [1]. The phase MEA itself was emerged as the active fraction comprising antibacterial, antioxidant and nematocidal constituents, including 3, 4-dihydroxybenzoic acid which also possessed antibacterial, Superb antioxidant and nematocidal activities [1].

Pretreatment of Terrestrial Macrofossils

ABSTRACTAcid-alkali-acid (AAA) pretreatment is widely used to clean terrestrial plant macrofossil samples for radiocarbon (14C) dating. There is wide variation amongst laboratories in the AAA method details and less rigorous AAA pretreatment is often used on fragile or small samples. Yet there is little evidence as to the efficacy of the different methods and whether the use of less rigorous methods is justified. We investigated four variations of AAA pretreatment: acid only (no alkali wash); room temperature AAA; “standard” AAA at 85°C; and “aggressive” AAA at 85°C with alkali washes repeated until no discoloration was detected. We tested six different terrestrial macrofossils from four different locations and ranging in age from mid-Holocene to the Last Glacial Maximum. Our results demonstrate that while acid only is not always sufficient to remove young material, there is no difference in 14C age of samples pretreated by any of the AAA variants. We also observed mass loss of 85–90% in the standard and aggressive AAA pretreatments, and much more modest mass loss in the room temperature AAA pretreatment. Therefore, we conclude that room temperature AAA pretreatment is optimal to remove contaminating material from fragile terrestrial macrofossils while retaining the majority of the authentic sample material.

Interpersonal Strategies in E-Complaint Refusals: Textbook Advice Versus Actual Situated Practice

This article reports on the representation and operationalization of interpersonal attention in complaint management by comparing business textbooks, service recovery research, and situated practice. While textbooks commonly recommend the use of interpersonal strategies when writing complaint refusals, service recovery research points toward contextual differences in this regard. We use an authentic sample of complaint refusals from an intercultural business-to-business setting to show that the decontextualized recommendations in textbooks are not always applied in actual practice and that this lack of interpersonal attention need not be problematic.

From Lexis to Discourse

Any exercise of structuring written or spoken discourse starts from Lexis, the most basic unit of communication. We may call it the initiator of discourse. Despite considerable efforts made towards developing the word power of the ESL learners, they face difficulty in using the vocabulary appropriately in a variety of socio-cultural contexts in which they are required to operate. The present chapter attempts to demonstrate how this five-stage pedagogy will enhance learner's ability to make use of the available lexical items in authentic situations so as to produce meaningful discourse. The proposed pedagogy is the result of our experiment with authentic sample of students and language exercises. The five-stage pedagogy comprises the following stages:

Isolation and Characterization of Secondary Metabilites and Evaluation of Antimicrobial, Antioxidant and Thrombolytic Potentials of Erythrina variegata L. Bark

Six compounds, sitosta-4-en-3-one (1), 3β,28-dihydroxyolean-12-en (2), scandenone (3), alpinum isoflavone (4), stigmasterol (5) and lupeol (6) were isolated from the methanol soluble extract of the stem bark of Erythrina variegata. The structure of the compounds was established by extensive NMR studies as well as co-TLC with authentic sample. The petroleum ether, carbon tetrachloride, chloroform and aqueous soluble fractions of the methanolic extract of Erythrina variegata were evaluated for antimicrobial, antioxidant and thrombolytic properties. In the antimicrobial study, most of the fractions of the extract exhibited mild to moderate antimicrobial activity where the zone of inhibition were ranging from 7.69 to 19.51 mm. The chloroform soluble fraction showed significant antioxidant activity with IC50 value 66.28 μg/mL as compared to standard BHT (IC50 value 23.09 μg/mL). The thrombolytic property of different extracts of E. variegata exhibited moderate activity ranging from 31.25 to 57.78 %.

Performance of Fe3O4@SiO2 as the recyclable heterogeneous catalyst in the bisphenol A recovery from polycarbonate wastes

Received polycarbonate wastes from the used optical and digital optical disk (CDs and DVDs) were chemically recycled into bisphenol A (BPA) in 100% recovery yield using diethylene glycol/water as a binary solvent system and Fe3O4@SiO2 as the heterogeneous catalyst at the convenient, green and eco-friendly conditions using conventional heating method. The recovered BPA was analyzed by spectroscopic methods and data compared by an authentic sample.

Grammar and vocabulary testing scores in L2 reading

In language testing bibliography, it has been suggested that L2 grammar and vocabulary scores strongly and positively correlate with L2 reading comprehension. Jeon and Yamashita (2014), conducting a large-scale meta-analysis study, found strong correlations among these two variables: r=.85 for grammar and r=.79 for vocabulary in different tasks. Following this paradigm, the current study examines this relationship (performance on reading skills and language use – grammar and vocabulary) integrated into a single testlet/paper. The hypothesis is tested by examining scores in reading skills and language use (in which grammar an..d vocabulary items are included) extracted from a large authentic sample in Greece with Italian as the target language. Further, any correlation between the acquisition or learning of these sub-skills is assessed. It was found that the two variables do indeed correlate statistically, although the strength of the correlation is not very high. In that respect, this work confirms findings of earlier studies reported in the literature review. This analysis results in several hypotheses which relate to the possible interpretations of the results. This study wishes to contribute to the discussion by adding results from a Greek context using Italian as the target L2.