Ethanol Reagent Research Articles

Employing acetoacetamide as a key synthon for synthesizing novel thiophene derivatives and assessing their potential as antioxidants and antimicrobial agents

AbstractThe objective of this study is to synthesize novel heterocyclic scaffolds containing a thiophene moiety using easily accessible acetoacetamide as a key synthon. The reaction of acetoacetamide with diazonium salts resulted in the formation of the corresponding thiophene derivatives 4a–c. Additionally, the reaction of acetoacetamide derivative 3 with malononitrile, ethyl cyanoacetate, or 2‐cyanoacetamide, along with elemental sulfur, under refluxing in dioxane containing triethylamine afforded thiophene‐containing derivatives 5a–c. Furthermore, compound 3 reacted with phenyl isothiocyanate in dry dimethylformamide and K2CO3 to yield compound 7. In situ alkylation of the non‐isolable salt 6 was achieved by the addition of methyl iodide, resulting in the formation of methylthio‐thiophene‐2‐carboxamide 8. Compound 7 was employed with numerous alpha‐halogenated reagents in ethanol, affording thiazole derivative 9 and thiophene derivatives 10a and 10b, respectively. Moreover, compound 8 was reacted with hydrazine to produce the 1H‐pyrazole‐4‐carboxamide derivative 11. Additionally, refluxing acetoacetamide derivative 3 with malononitrile and/or ethyl cyanoacetate in dioxane, in the presence of catalytic amount of triethylamine afforded 4‐imino‐3,7‐dimethyl‐4H‐pyrido[1,2‐a]thieno[3,2‐e]pyrimidin‐9(5H)‐one derivatives 12a and 12b. Furthermore, the reactivity of acetoacetamide derivative 3 with 2‐cyanoacetohydrazide was investigated through refluxing the reactants in dioxane, which subsequently yielded the corresponding cyanoacetamide derivative 13. The chemical identity of the newly synthesized compounds was determined by employing infrared spectroscopy (IR), 1H NMR, and 13C NMR techniques. Newly synthesized heterocycles incorporating thiophenes were evaluated for their antioxidant and antimicrobial potentials. Notably, thiophene scaffolds 5a, 10b, 11, and 13 displayed notable antioxidant and antimicrobial activities.

Synthesis of 4-(pyrazol-1-yl)pyrimidines from 4-hydrazinopyrimidines and investigation of their structure and some chemical properties

By reacting 2-benzyl-4-hydrazinopyrimidines with ethoxymethylidene derivatives of β-dicarbonyl compounds, the corresponding substituted 4-(1H-pyrazol-1-yl)pyrimidines were synthesized. In a number of examples, intermediates - products of condensation of the reagents in ethanol, were isolated, indicating that the initial attack on the nitrogen atom of the hydrazine fragment involves the ethoxymethylidene group. It was noted that subsequent cyclization of the intermediates in acetic acid leads to 4-(1H-pyrazol-1-yl)pyrimidines. Alkylation of the synthesized non-fused bicyclic systems was carried out and it was proved that the nitrogen atom N-1 of the pyrimidine ring undergoes alkylation. A complex of 2-benzyl-4-(5′-methyl-4′-ethoxycarbonylpyrazol-1′-yl)-6-methylpyrimidine with copper (II) chloride was synthesized. X-ray diffraction analysis proved that, in contrast to the metal complexes of similar pyrazolylpyrimidines, in this case, a single-dentate complex with a linear structure of the composition ligand:metal, 2/1, is formed, and the nitrogen atom N-1 of the pyrimidine ring participates in the formation of a bond with the metal atom, as well as during alkylation. It was found that H/D exchange occurs in pyrazolylpyrimidine molecules in a solution of CD3ONa in CD3OD. Using the methods of 1H NMR spectroscopy and high-resolution mass spectrometry, it was proved that the hydrogen atoms of the alkyl groups of the studied systems undergo isotope exchange. The kinetics of H/D exchange was studied using some examples. It has been shown that the presence of an allyl group in the pyrimidine ring significantly affects the direction and rate of the H/D exchange. The structure of all synthesized substances was confirmed by NMR methods (1H, 13C, NOESY), high-resolution mass spectrometry and in some examples X-ray diffraction analysis was also performed.

Catalyst- and metal-free C(sp2)–H bond selenylation of (N-hetero)-arenes using diselenides and trichloroisocyanuric acid at room temperature

In this paper, we report an eco-friendly approach for the C(sp2)–H bond selenylation of imidazopyridines and other N-heteroarenes as well as simple arenes at ambient temperature. This new protocol consists of the reaction between (N-hetero)-arenes and the diorganyl-diselenides and trichloroisocyanuric acid (TCCA)-ethanol reagent system. In a short reaction time, the desired selenylated products were obtained regioselectively in good yields, with tolerance for a wide range of functional groups.

Interaction of 5-arylfurfurals with malononitrile dimer

The interaction of 5-arylfurfurals with dimer malononitrile was studied. A number of previously unknown 3-amino-2,4-dicyano-5-(5-arylfuran-2-yl) -penta-2,4-dienenitriles were obtained, which were investigated in the cyclocondensation reaction with dimedone. The reaction was performed by heating the reagents in ethanol in the presence of piperidine. The reaction was monitored by TLC (eluentbenzene–acetone, 4:1 by volume). It was found that the cyclocondensation reaction proceeds with the formation of pyran and pyridine cycles – fragments of 9-oxa-1-aza-anthracene. The structure of the obtained compounds was confirmed by 1 H NMR spectra. 1 H NMR spectra were recorded on a Bruker instrument with an operating frequency of 400 MHz, solvent – DMSO- d 6 . Chemical shifts are given relative to the solvent signal (DMSO, 2.50 ppm). General procedure of obtaining 3-amino-2,4-dicyano-5-(5-aryl-furan-2-yl)-penta-2,4-dienenitriles ( 1 ). A mixture of 0.003 mol of 5-arylfurfural, 0.003 mol of malonodinitrile dimer and 4 drops of piperidine in 20 ml of ethanol was heated on a boiling water bath until the precipitate dissolved. After cooling, formed precipitate was filtered off and recrystallized from ethanol–DMF (10:1). Synthesis of 2,4-diamino-7,7-dimethyl-5-oxo-10-(5-aryl-furan-2-yl)-6,7,8,10-tetrahydro-5 H -9-oxa-1-aza-anthracene-3-carbonitriles ( 2 ). A mixture of equimolar amounts of substances ( 1 ) and dimedone (0.0014 mol), 0.03 mol of piperidine in 15 ml of ethanol was boiled until complete dissolution of the precipitate. The reaction mixture was cooled, neutralized with concentrated hydrochloric acid. The formed precipitate was filtered off, washed with water and recrystallized from ethanol. Keywords: 5-arylfurfurals, malonodinitrile dimer, dimedone, cyclocondensation reactions, 9-oxa-1-aza-anthracene derivatives.

Preferential removal of benzene, toluene, ethylbenzene, and xylene (BTEX) by persulfate in ethanol-containing aquifer materials.

The effective approaches to eliminate impacts of ethanol on the biodegradation of benzene, toluene, ethylbenzene, and xylene (BTEX) are concerned in the bioremediation of groundwater contaminated with ethanol-blended gasoline. In situ chemical oxidation (ISCO) is a common technique widely used for the remediation of contaminated groundwater. However, the selectivity of ISCO for BTEX and ethanol removal is poorly understood. Therefore, a batch experiment was performed with different aquifer materials, including calcareous soil, basalt soil, granite soil, dolomite, and sand. Gasoline was used to provide dissolved BTEX and ethanol reagent was used as additive to improve the quality of gasoline and to reduce the possibility of air pollution caused by gasoline. Persulfate (PS) was used as a chemical oxidant to oxidize organic contaminants. The target concentrations of BTEX and ethanol were 20mg/L and 1000mg/L, respectively. The results showed that ethanol could be preferentially degraded in the absence of PS and inhibit BTEX biodegradation. However, BTEX could be preferentially removed prior to ethanol in all aquifer materials used at ambient temperature, when PS was added at a PS/BTEX molar ratio of 150. Over 94% BTEX in sand, dolomite, and granite soil was preferentially removed with the first-order decay rate constants of 0.890-2.703day-1 within the first ~ 10days, followed by calcareous and basalt soil at the constants of 0.123-0.371day-1. Ethanol could compete with BTEX for sulfate radical at the first-order decay rate constants of 0.005-0.060day-1 for the first 25days, which was slower than that of BTEX. The pH quickly decreased to < 2.5 in dolomite, sand, and granite soil, but maintained > 6.2 in calcareous soil. Rich organic matter in calcareous and basalt soil had an inhibition effect on BTEX oxidation by PS. The pH buffer in calcareous soil may imply the potential of PS oxidation combined with bioremediation in carbonate rock regions.

Kavain Interference with Amphetamine Immunoassay.

We encountered unexpected false positive urine results in three patients for amphetamine-type substances by immunoassay, measured as part of community drug prevention programmes. Kavain was identified in all three urine samples by gas chromatography mass spectrometry (GC-MS). No other potential cross-reactants were found.Kavain is a kava-lactone present in kava, a ceremonial and recreational drink derived from roots and stem of the plant Piper Methysticum. It is consumed regularly by many indigenous Pacific and Australian Aboriginal communities. Urine immunoassay was performed on a Beckman Coulter AU480 Analyser using CEDIA amphetamine-type substances reagent and DRI ethanol reagent. Three different kava powders were purchased from local kava clubs and dissolved in ethanol, then evaporated and reconstituted in blank urine and analysed by immunoassay, GC-MS for amphetamine-type substances. Additionally authentic kavain standard was also tested for cross reactivity by immunoassay and analysed by GC-MS to compare the mass fragmentation pattern and retention time with the kava powder and patient specimens. The patient urine samples tested positive by CEDIA immunoassay for amphetamines. However, when analysed by GCMS they were negative for amphetamine-type but contained kavain.The kava powders and kavain standard all cross reacted with the amphetamine immunoassay to give falsely detected results. GCMS did not identify any amphetamine-type compounds in any of the Kava powders nor in the kavain standard. To our knowledge, this is the first report of false positive amphetamine measurements due to kavain, a component of the kava drink, widely consumed in Oceania and Australasia.

Potential of palm fatty acid distillate as a feedstock in the synthesis of ethyl esters using solid SO4 2-/TiO2-SiO2 catalysts

Utilization of by-products from the cooking oil industry, such as palm oil fatty acid distillates (PFAD) can reduce the cost of producing ethyl ester/biodiesel. This PFAD is processed into biodiesel using SO4 2 −/TiO2-SiO2 solid catalyst and ethanol reagent. The central composite design in Response Surface Methodology is applied in optimizing the effect of process variables such as the amount of catalyst, ethanol to PFAD molar ratio and reaction time. The results of the study show that the best-operating conditions with 98.89% ethyl ester conversion were achieved with the catalyst amount of 5% w, a molar ratio of 13 in reaction time of 2.25 hours. The presence of SO4 2 −/TiO2-SiO2 catalyst components can be characterized using SEM-EDX. A functional group showing the presence of ethyl ester in biodiesel products has been identified using FTIR. Ethyl ester properties related to biodiesel properties can be shown as saponification value: 583.8446 mg/g, iodine value: 8.8714 mg/g and cetane value: 49-54.

Fourier transform infrared and gas cromatography-mass extracts from Euscaphis japonica bark

Due to the lack of studies on the chemical constituents of Euscaphis japonica bark, infrared spectroscopy and gas chromatography-mass spectrometer (GC-MS) techniques were used to analyze the ethanol, phenyl alcohol and methanol extracts from Euscaphis japonica bark, laying a foundation for the efficient utilization of Euscaphis japonica bark. Through experimental verification, different extracts of Euscaphis japonica bark can yield different chemical substances: Stigmast-4-en- 3-one, (1R,8a alpha)-1,4a beta-dimethyl -7 beta -(1-hydroxy-1-methylethyl)decalin-1 alpha-ol, lactose, Vitamin E, 9,12-octadecadienoic acid, n-hexadecanoic acid, Arsenous acid Tris(trimethylsilyl)ester 4-hydroxy-3-methoxycianamylic alcohol, etc. It was determined that most of the chemicals in Euscaphis japonica bark are soluble in ethanol reagents. According to the relevant mass spectrometry data, Euscaphis japonica bark contains useful pharmaceutical ingredients and chemical raw materials and has broad development prospects.

Evaluation of OMNIgene Sputum and Ethanol Reagent for Preservation of Sputum Prior to Xpert and Culture Testing in Uganda.

Xpert MTB/RIF (Xpert) and culture are the most reliable methods for tuberculosis diagnosis but are still poorly accessible in many low-resource countries. We aimed to assess the effects of OMNIgene Sputum (OM-S) and ethanol in preserving sputum for Xpert and OM-S for mycobacterial growth indicator tube (MGIT) testing over periods of 15 and 8 days, respectively. Sputum samples were collected from newly diagnosed smear-positive patients. For Xpert, pooled samples were split into 5 aliquots: 3 for Xpert on days 0, 7, and 15 without additive and 2 with either OM-S or ethanol at day 15. For MGIT, 2 aliquots were tested without preservative and 2 with OM-S at 0 and 8 days. Totals of 48 and 47 samples were included in the analysis for Xpert and culture. With Xpert, using day 0 as a reference, untreated samples stored for 7 and 15 days showed concordances of 45/46 (97.8%) and 46/48 (95.8%). For samples preserved with OM-S or ethanol for 15 days compared with untreated samples processed at day 0 or after 15 days, OM-S concordances were 46/48 (95.8%) and 47/48 (97.9%), while those of ethanol were 44/48 (91.7%) and 45/48 (93.8%). With MGIT, concordances between untreated and OM-S-treated samples were 21/41 (51.2%) at day 0 and 21/44 (47.7%) at day 8. In conclusion, Xpert equally detected tuberculosis in OM-S-treated and untreated samples up to 15 days but showed slightly lower detection in ethanol-treated samples. Among OM-S-treated samples, MGIT positivity was significantly lower than in untreated samples at both time points.

Ultimate analysis and acid value of biodiesel from waste oil and ethanol

Waste cooking oil is a renewable energy source that is easily obtainable in a domestic environment. This energy source can be used as a substitute for diesel fuel known as biodiesel. Biodiesel can be produced from the process of esterification and transesterification reagent used cooking oil with ethanol. The content of fossil fuels as an energy source in general can be seen from the content of the main elements of which are carbon and hydrogen. The purpose of this study to determine the content of carbon, hydrogen, and acid in biodiesel produced from waste cooking oil and ethanol reagent using phosphoric acid catalyst in the process of esterification and sodium hydroxide in the transesterification process. Ultimate analysis was conducted by using ASTM method D7582 Biomass and acid number is determined by titration. The results Showed that the content of biodiesel from waste cooking oil with ethanol reagent pro analysis or ethanol from wine and distillate results are carbon and hydrogen as the main element contained as fuel in general. Percentage of Free Fatty Acids (FFA) and Acid Value in biodiesel highest in ethanol reagent pro analysis.

Template-Free Solvothermal Synthesis of Flower-Like BiOBr Microspheres in Ethanol Medium for Photocatalytic Applications

Three-dimensionally (3D) BiOBr microflowers were prepared by a simple solvothermal method, employing Bi(NO3)3 · 5H2O and NaBr as starting reagents in ethanol. The structural, light absorption and morphological properties of as-prepared BiOBr microspheres were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–Vis diffuse reflectance spectroscopy (DRS), etc. The results showed that ethanol acted not only as a solvent but also as a template in 3D BiOBr preparation. The BiOBr microspheres exhibited superior photocatalytic activity compared with 2D BiOBr nanosheets, far exceeding that of TiO2 (Degussa, P25). It was found that both superoxide radical (O2•-) and holes (h+) played a key role in the degradation of RhB by BiOBr microflowers.

Synthesis, physical, chemical and biological properties of 8-amino-7-[2-hydroxy-3- (3,4-dimethylphenoxy)propyl]-3-methylxantines

The problem of searching for biologically active compounds amidst xanthine derivatives is a crucial one and an issue for long-term investigation. Aiming to enlarge the chemical library of prospective bioactive com- pounds, we obtained a range of previously undescribed 8-amino derivatives of 7-[2-hydroxy-3-(3,4-dimeth- ylphenoxy)propyl-1-]3-methylxanthine. 8-bromo-7-[2-hydroxy-3-(3,4-dimethylphenoxy)propyl-1-]3-methylxanthine and its chemical modification were the object of the study. PTP-M device, Elementar Vario L cube, Bruker SF-400 were used to confirm the structure of synthesized compounds. The biological effects of synthesized compounds were predicted by the Prediction of Activity Spectra for Substances (PASS) program. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. In order to search for new biologically active compounds among xanthine derivatives, an 8-amino-7-[2- hydroxy-3-(3,4-dimethylphenoxy)propyl]-3-methylxantines, never described before, was synthesized. The study of the reactions of 8-bromo-7-[2-hydroxy-3-(3,4-dimethylphenoxy)propyl-1-]3-methylxanthine with primary, secondary and heterocyclic amines has shown that the substitution of the bromine atom in a posi- tion 8 by the amine residue occurs by heating the reagents in aqueous dioxane or ethanol. The structure of the synthesized compounds has been proved with certainty by elemental analysis and nuclear magnetic res- onance (NMR) spectroscopy. The antioxidant activity of the obtained compounds has been explored. The priorities for further search of biologically active compounds in a range of xanthine derivatives have been set out.

Detection of atmospheric gaseous amines and amides by a high-resolution time-of-flight chemical ionization mass spectrometer with protonated ethanol reagent ions

Abstract. Amines and amides are important atmospheric organic-nitrogen compounds but high time resolution, highly sensitive, and simultaneous ambient measurements of these species are rather sparse. Here, we present the development of a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) method, utilizing protonated ethanol as reagent ions to simultaneously detect atmospheric gaseous amines (C1 to C6) and amides (C1 to C6). This method possesses sensitivities of 5.6–19.4 Hz pptv−1 for amines and 3.8–38.0 Hz pptv−1 for amides under total reagent ion signals of ∼ 0.32 MHz. Meanwhile, the detection limits were 0.10–0.50 pptv for amines and 0.29–1.95 pptv for amides at 3σ of the background signal for a 1 min integration time. Controlled characterization in the laboratory indicates that relative humidity has significant influences on the detection of amines and amides, whereas the presence of organics has no obvious effects. Ambient measurements of amines and amides utilizing this method were conducted from 25 July to 25 August 2015 in urban Shanghai, China. While the concentrations of amines ranged from a few parts per trillion by volume to hundreds of parts per trillion by volume, concentrations of amides varied from tens of parts per trillion by volume to a few parts per billion by volume. Among the C1- to C6-amines, the C2-amines were the dominant species with concentrations up to 130 pptv. For amides, the C3-amides (up to 8.7 ppb) were the most abundant species. The diurnal and backward trajectory analysis profiles of amides suggest that in addition to the secondary formation of amides in the atmosphere, industrial emissions could be important sources of amides in urban Shanghai. During the campaign, photo-oxidation of amines and amides might be a main loss pathway for them in daytime, and wet deposition was also an important sink.

QuickTox™ Kit for QuickScan Aflatoxin FREE.

The QuickTox Kit for QuickScan Aflatoxin FREE uses competitive lateral flow technology and a reader based system for quantitative determination of total aflatoxins in varied matrixes. Aqueous based extraction protocols are used for corn and wheat, reducing use of solvents. Fifty percent ethanol (Reagent Alcohol) extraction is used for oats, sorghum, and barley. Eighty percent ethanol (Reagent Alcohol) extraction is used for whole peanut, peanut seed, and peanut hull samples. Matrix specific assay procedures and calibration curves are used to enable analyses across multiple sample types. The performance of this assay was examined using naturally contaminated aflatoxin corn samples and spiked samples of barley, oats, sorghum, wheat, whole peanut, peanut seed, and peanut hull samples. All data were judged against previously established acceptance criteria. Performance was evaluated in linearity, selectivity, matrix, lot consistency, and robustness experiments in the sponsor's laboratory. Results produced in all studies except robustness were within acceptable ranges. Out of range robustness study results reflected simultaneous deviation in sample volume and assay development time compared to the standard assay procedures. Aflatoxin B1, B2, and G1 were detected with approximately equal sensitivity; sensitivity for G2 was 64% that of B1. The presence of other common mycotoxins did not interfere with the assay. Matrix studies in an independent laboratory examined corn and barley to challenge both aqueous and ethanol based extraction procedures. All data points in these studies fell within the ranges defined in the acceptance criteria. The assay exhibited a linear dose response over the range tested, 0-100 ppb, with R(2) values exceeding 0.93 and RSDr values for results ranging from 2.27 to 23.84%.

Estimation of Rhein from Cassia fistula Linn. using validated HPTLC method

Background: Rhein is the major anthraquinone found in Cassia fistula Linn, which is traditionally used as an important component of plant based medicine. Aims and Objective: To develop and validate a High Performance Thin Layer Chromatographic method for the estimation of Rhein from C. fistula Linn. Materials and Methods: Chromatographic separation was achieved on silica gel 60 F254 plates with n‑hexane: Ethyl acetate: Formic acid (5:5:0.2, v/v/v) as a mobile phase. Detection of Rhein was carried out by derivatizing the plate with 10% ethanolic KOH reagent followed by heating at 110°C for 10 min. CAMAG TLC scanner 4 equipped with winCATS software was used for densitometric scanning at 550 nm. The accuracy of the method was checked by conducting various validation parameters according to ICH (International Conference on Harmonization) guidelines. Results: The method was found applicable to evaluate the content of Rhein in different plant parts of C. fistula and the impact of different geographical regions on the Rhein content in fruit pulp of C. fistula was also studied. Estimation of Rhein from a herbal formulation containing C. fistula fruit pulp was also carried out using the validated HPTLC method. The developed method was found sensitive and accurate for the estimation of Rhein from various plant matrices. Conclusion: The developed method was found useful for the quantitation of bioactive marker Rhein and can be used as a routine quality control tool for the assessment of botanicals. Key words: Cassia fistula, fruit pulp, geographical variation, HPTLC, Rhein

Fine tuning of the metal–organic framework Cu3(BTC)2 HKUST-1 crystal size in the 100 nm to 5 micron range

Cu3(BTC)2 (BTC = 1,3,5-benzene tricarboxylate) was synthesized from cooled reagents in ethanol–water solvent mixtures and in ethanol solvent at room temperature involving quenching at −196 °C and freeze drying in order to limit crystal growth. These approaches are handy to synthesize this MOF with narrow particle size distribution in the range of 100 nm to 5 microns and to achieve excellent crystallinity and unprecedented porosity. The nano-version of Cu3(BTC)2 outperforms micron size crystals in catalyzing methanolysis of styrene oxide.

Solvothermal Synthesis and Characterization of Zinc Indium Sulfide Microspheres

Znln 2 S 4 microspheres have been solvothermally prepared at 160°C for 12 h with ZnCl 2 ·2H 2 O, lnCl 3 , and thiourea as the starting reagents in ethanol. The morphology, structure, and phase composition of the as-prepared product were characterized by means of X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED). Results revealed that the prepared Znln 2 S 4 microspheres were composed of sheetlike nanocrystals. The average diameter of the microspheres and the thickness of the nanosheets are about 1-6 μm and 10-50 nm, respectively. A possible growth mechanism of the Znln 2 S 4 nanosheet-built microspheres was proposed and briefly discussed.

TLC separation of catechins and theaflavins on polyamide plates

Summary The potential of polyamide as adsorbent for separation of nine compounds – (±)-catechin (DL-C), (–)-epicatechin (EC), (–)-epigallocatechin (EGC), (–)-epicatechin gallate (ECg), (–)-epigallocatechin gallate (EGCg), theaflavin (TF1), theaflavin 3-gallate (TF2A), theaflavin 3’-gallate (TF2B), and theaflavin 3,3’-digallate (TF3) – was studied. Polyamide TLC plates dried with a hair dryer, application as bands, and development in a horizontal chamber gave the best results. Detection was performed using iron(III) chloride– ethanol reagent. Twofold development with chloroform–methanol 2:3 (v/v) as mobile phase resulted in the separation of TF1, TF2A, TF2B, and TF3 from all the other compounds. EGCg, ECg, and EGC were separated but EC and DL-C were not separated from each other. The best mobile phase for each of the compounds is reported. The best separation of the five main catechins (EC, DL-C, EGC, ECg, and EGCg) was achieved by use of n-butanol–acetone–acetic acid 5:5:3 (v/v). In addition, separation of the flavonols myricetin, quercetin, kaempferol, and rutin and the phenolic acids gallic acid, chlorogenic acid, and caffeic acid was achieved by twofold development with chloroform–methanol 2:3 (v/v). The applicability of the method was checked by screening of extracts of green, black, oolong, and pu-erh tea.

Bactericidal and Sporicidal Activities of an Improved Iodide Formulation and Its Derivative

Bactericidal and sporicidal activities of an improved iodide formulation (tentatively designated as the distilled KMT reagent: pH around 3) and its derivative (tentatively designated as the distilled ethanol reagent: pH around 2.5) were examined in several dilutions against vegetative bacteria and Bacillus subtilis spores, and they were compared with two kinds of intermediate-level disinfectants, i.e., 7% povidone-iodine (ISODINE) and ethanol for disinfection (76.9-81.4 vol %). Each solution of distilled KMT reagent up to a dilution of 1:100 showed potent bactericidal activity against most tested bacteria when used for 30 seconds at 20 degrees C. Bactericidal activities at these dilutions were almost comparable with those of the same dilution of ISODINE. Although the 1:10 dilution of ISODINE did not show comparable sporicidal activity, the same dilution of distilled KMT reagent showed potent sporicidal activity. On the other hand, the 1:2 dilution of distilled ethanol reagent showed potent sporicidal activity when used for 5 minutes at 60 degrees C. Ethanol for disinfection did not show any sporicidal activity even with treatment for 60 minutes at 60 degrees C. With treatment for 30 sec at 37 degrees C, the 1:2 dilution of distilled ethanol reagent was found to have effective bactericidal activity almost comparable with that of ethanol for disinfection. Appropriate dilutions of both the distilled KMT reagent and distilled ethanol reagent may be applicable as antiseptics which are able to achieve high-level disinfection.

Validated high-performance thin-layer chromatography method for steviol glycosides in Stevia rebaudiana

A high-performance thin-layer chromatographic (HPTLC) method was developed and validated as per ICH (International Conferences on Harmonization) guidelines for simultaneous quantification of three steviol glycosides, i.e. steviolbioside, stevioside and rebaudioside-A in Stevia rebaudiana leaves. For achieving good separation, mobile phase of ethyl acetate–ethanol–water (80:20:12, v/v/v) on pre-coated silica gel 60 F 254 HPTLC plates were used. The densitometric quantification of steviol glycosides was carried out at λ = 510 nm in reflection–absorption mode after spraying with acetic anhydride:sulphuric acid:ethanol reagent. The calibration curves were linear in the range of 160–960 ng/spot for steviolbioside, 1–6 μg/spot for stevioside and 0.5–3 μg/spot for rebaudioside-A with good correlation coefficients (0.998–0.999). The method was found to be reproducible for quantitative analysis of steviol glycosides in S. rebaudiana leaves collected from ten different locations and will serve as a quality control indicator to monitor the commercial production of stevioside and its allied molecules during different stages of its processing.