Aggregation and Adsorption Properties of Tetramethylsulfonatoresorcinarenes and their Associates with Nonionogenic Guest Molecules in Aqueous Solutions

Present paper reports on tensiometric studies of tetramethylsulfonatoresorcinarenes 1 and 2 with nonionogenic guests 3 and 4, pyrimidin derivative and O,O-dymethyl-1,1-dimethyl-3-oxobutylphosphonate, respectively. Association of resorcinarenes with these guests leads to dramatic change of adsorption characteristics of their solutions. CCMs₁ of associates (1&3, 1&4, 2&3, and 2&4) are lower and the estimated surface activity, as well as the height of adsorption layers are higher than for individual substances. Aggregation of compounds 1–4 and association of 1 with 3 and 4 in solution were confirmed by ¹H NMR spectra and studied by diffusion NMR with impulse magnetic field gradient.     

Green technologies in organic synthesis: self-condensation of enamines,enaminones and enaminoesters under microwave irradiation in ionic liquid

Abstract

Utilizing green technologies as microwave (MW) irradiation and ionic liquids (ILs), we could produce 1,3,5-trisubstituted benzene 3, 7, 9, and 14 by self-condensation of enamines 1, enaminones 4, 8, and enaminoester 10, respectively, in the presence of pyridinium chloride ([PyH]Cl) for short time. Also, we synthesized pyridine derivatives 17, upon irradiating enaminones 4 in domestic MW oven for short time.     

Rate and Product Studies in the Solvolyses of Two Cyclic Phosphorochloridate Esters

Kinetic and product studies of the solvolyses of acyclic phosphorochloridates are extended to two cyclic diesters, 2-chloro-1,3,2-dioxaphospholane-2-oxide (1) and 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (2). Slightly faster solvolyses are observed for 1 than for the acyclic dimethyl phosphorochloridate (3), and 2 solvolyzes somewhat slower than 3. An extended Grunwald–Winstein equation treatment shows similar sensitivities to changes in solvent nucleophilicity and solvent ionizing power for 1, 2, and 3, and a concerted S_N2 attack is proposed in each case. Product studies for the solvolyses of 2 in aqueous alcohols are presented.

     

Facile Synthesis and in Vitro Cytotoxic Evaluation of Novel Thiadiazole,Pyrazole, and Dithiole-Androstane Derivatives

In the aim of identifying new steroidal cytotoxic agents with potential antiproliferative activity against hepatoma cell lines (Hep-G₂), we synthesized modified steroids containing the thiadiazole, pyrazole, or dithiole moiety. Epiandrosterone 1 reacted with carbon disulfide and sodium hydride to furnish α-oxoketene dithio-disodium salt 2. Treatment of 2 with the hydrazonoyl halides 5a–d produced the thiadiazole anellated androstanone 7a–d, respectively. The reaction of 1 with hydrazine hydrate produced the hydrazide adduct 8, which cyclized upon reflux in acetic acid to form the condensed pyrazoloandrostanone derivative 9. Interaction of 8 with carbon disulfide and sodium hydride formed the disodium salt 10, which reacted with ethylchloroacetate to furnish the final adduct, dithioloandrostane derivative, 13. Compounds 7a, 7d, 9, and 13 were examined for their cytotoxicity against a panel of hepatoma cell lines (Hep-G₂) using MTT assay. The results provide that, at incubation time 72 h, in DMSO, compound 7d (50 μ mol/mL) showed the most significant cytotoxic effect at P < 0.05. The higher dose (100 μ mol/mL) of compound 7d, at 48 h incubation, reversed the effect causing resistance and the growth rate return to the control level.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

An Ab Initio Study of Conformational Energies in Dioxo-, Trioxo-, and Tetroxo-Dithianes

Ab initio Hartree–Fock calculations at the HF/6-31G* level of theory for geometry optimization and the MP2/6-31G*//HF/6-31G* and B3LYP/6-311G(2df,p)//HF/6-31G* levels for a single point total energy calculation are reported for the important energy-minimum conformations of 1,1-dioxo-thiane (2), 1,1-dioxo-1,2-dithiane (3), 1,1-dioxo-1,3-dithiane (4), 1,1-dioxo-1,4-dithiane (5), 1,1,2-trioxo-1,2-dithiane (6), 1,1,3-trioxo-1,3-dithiane (7), 1,1,4-trioxo-1,4-dithiane (8), 1,1,2,2-tetroxo-1,2-dithiane (9), 1,1,3,3-tetroxo-1,3-dithiane (10), and 1,1,4,4-tetroxo-1,4-dithiane (11). According to the MP2/6-31G*//HF/6-31G* calculations, compound 5 is more stable than 3 and 4 by 7.8 and 8.9 kJ mol^?1, respectively. The axial geometries of 6 and 8 are more stable than the equatorial forms by 21.4 and 19.1 kJ mol^?1, respectively, but the equatorial form of 7 is 4.1 kJ mol^?1 more stable than the axial geometry. Compound 11 is more stable than 9 and 10 by 49.3 and 31.0 kJ mol^?1, respectively.     

Test Films for the Determination of Aromatic Amines and Hydrazines in Aqueous Solutions

Conditions of the test determination of toxic aniline (I), N,N-dimethylaniline (II), N,N-diethylaniline (III), 2,2,4-trimethyl-1,2-dihydroquinoline (IV), 1,1-dimethylhydrazine (V), and phenylhydrazine (VI) as their 4,6-dinitrobenzofuroxan (I) and 5,7-dinitrobenzofurazan (II, III, IV, V, VI) derivatives in aqueous solutions were found. Visual and spectrophotometric measurement of the signal was used. The reagents were immobilized in nitrocellulose films. Optimal results of visual determination of color development in test films were obtained with reagents immobilized in nitrocellulose at their concentration of 5 mass % and pH of the test solution in the range 6.0–7.5. The spectrophotometric measurement of the signal of test films was performed at wavelengths of 500–560 nm for I, V, and VI and 610–620 nm for II, III, and IV. The detection limit for spectrophotometric measurement was 0.01, 0.18, 0.13, 0.15, 0.16, and 0.04 mg/L for I, II, III, IV, V, and VI, respectively. The analytical range of the toxicants was 0.05–6.0 mg/L. Test determination is possible in the presence of alkylamines, ammonia, phenols, carboxylic acids, and inorganic salts.     

Secoiridoids and other chemotaxonomically relevant compounds in Pedicularis: phytochemical analysis and comparison of Pedicularis rostratocapitata Crantz and Pedicularis verticillata L. from Dolomites

We compared the respective metabolite patterns of two Pedicularis species from Dolomites. Seven phenylethanoid glycosides, i.e., verbascoside (1), echinacoside (2), angoroside A (3), cistantubuloside B1 (4), wiedemannioside C (5), campneoside II (11) and cistantubuloside C1 (12), together with several iridoid glucosides as aucubin (6), euphroside (7), monomelittoside (8), mussaenosidic acid (9) and 8-epiloganic acid (13) were identified. Pedicularis verticillata showed also the presence of greatly unexpected secoiridoids, ligustroside (14) and excelside B (15), very rare compounds in Lamiales. Both PhGs and iridoids are considered of taxonomical relevance in the Asteridae and their occurrence in Pedicularis was discussed. In particular, the exclusive presence of several compounds such as 8-epiloganic acid (13), campneoside II (11), cistantubuloside C1 (12), ligustroside (14) and excelside B (15) in Pedicularis rostratocapitata, and angoroside A (3), cistantubuloside B1 (4) and wiedemannioside C (5) in P. verticillata could be considered specific markers for the two botanical entities.     

Mercaptopyridine-substituted indium,zinc, and metal-free phthalocyanines: nonlinear optical studies in solution and on polymer matrices

In this article, the nonlinear optical characterizations and optical limiting properties of metal-free (2), zinc (3), and indium (4) tetra 4-(2-mercaptopyridine) phthalocyanines are discussed. Nonlinear optical properties of the samples were evaluated using Z-scan at 532 nm and 10 ns pulse in CHCl₃, and doped on poly(bisphenol A carbonate) (PBC) thin films. Thin films for 2, 3, and 4 are represented as 2-PBC, 3-PBC, and 4-PBC, respectively. We observed two-photon absorption (2PA) and strong reverse saturable absorption as the dominant mechanisms at nanosecond laser excitation in solution and thin films. By virtue of the magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work, sample 4 was found to exhibit strongest nonlinear optical properties followed by 3, while 2 is the weakest nonlinear absorber of the studied samples. Large third-order susceptibility (1.46 × 10^?9 esu and 7.74 × 10^?10 esu) and hyperpolarizability (2.13 × 10^?28 and 8.37 × 10^?29 esu) were estimated for 4-PBC and 3-PBC, respectively. Our studies show that these molecules are suitable candidates for practical passive optical limiters.     

2-Ethanethioamide in Heterocyclic Synthesis: Synthesis and Characterization of Several New Pyridine and Fused Azolo- and Azinopyridine Derivatives

Pyridine-2(1H)-thione derivatives 3a,b were synthesized from the reaction of 1-(phenyl-sulfanyl)acetone (1) and cinnnamonitrile derivatives 2a,b. Compounds 3a,b reacted with different halogenated reagents 7a–f to give 2-S-alkylpyridine derivatives 8a–l, which could be, in turn, cyclized into the corresponding thieno[2,3-b]pyridine derivatives 9a–l. Compounds 9d,j reacted with acetic anhydride, formic acid, carbon disulfide, phenyl isothiocyanate, and nitrous acid to yield the corresponding pyrido[3′,2′:4,5]thieno[2,3-d]pyrimidine 12a,b, 15a,b, 17a,b, 20a,b, and pyrido[3′,2′:4,5]thieno[2,3-d][1,2,3]triazinone derivatives 22a,b, respectively.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and characterization of water-soluble arene-ruthenium complexes and their application in biphasic olefin oxidation

New water-soluble complexes [(η⁶-C₆H₆)RuCl(C₅H₄N-2-CH?=?N-R)]Cl (1) (with R?=?4-hydroxymethylphenyl (a), 2,4-dichlorophenyl (b), 2-fluorophenyl (c), 3-carboxyphenyl (d)) have been synthesized by reacting [(η⁶-C₆H₆)Ru(μ-Cl)Cl]₂ with the N,N′-bidentate ligands in a 1:2 ratio. Full characterization of all complexes was accomplished using ¹H and ¹³C NMR, elemental analyses, UV-Vis spectroscopy, IR spectroscopy and single crystal X-ray crystallography for determination of the structure of 1d, as 1d·4H₂O. The single crystal structure confirmed coordination of the ligand to the ruthenium(II) center leading to a structure commonly described as a pseudo-octahedral, three-legged piano stool. The geometry around the Ru(II) center is such that the arene ring occupies the apex of the stool while the N,N′-bidentate ligand and a chloride occupy the base of the stool. The synthesized Ru(II) complexes were tested as catalysts for oxidation of styrene using NaIO₄ as a co-oxidant in a biphasic system. All complexes were active, giving good yields of benzaldehyde. Catalyst 1c was later investigated for olefin oxidation and gave high yields of the corresponding aldehydes as the major products in all cases.     

Application of organolithium and related reagents in synthesis,Part XII. Synthesis of phenyl- and pyridylpyridopyridazinones and their derivatives

Summary The preparation of the pyridazinones10a,10b,11a,11b, and12a,12b from the ketoamides7,8, and9 and hydrazine hydrate is described. It was found that from ketoamides8b and9b in addition to the expected pyridopyridazinones11b and12b also aminopyridopyridazines14 and15 were formed and that ketoamide7b gave exclusively aminopyridopyridazine13. The pyridopyridazinones10b,11b, and12b were alkylated with alkyl iodides.

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Anwendungen von Organolithium und verwandten Reagenzien in organischen Synthesen, Teil XII. Synthese von Phenyl- und Pyridylpyridopyridazinonen und ihren Derivaten

Zusammenfassung Die Darstellung der Pyridazinone10a,10b,11a,11b und12a,12b aus Ketoamiden7,8 und9 und Hydrazinhydrat wird beschrieben. Es wurde festgestellt, daß aus Ketoamiden8b und9b außer den erwarteten Pyridopyridazinonen11b und12b auch Aminopyridopyridazine14 und15 enstanden und daß das Ketoamid7b ausschließlich ins Aminopyridopyridazin13 überführt wurde. Die Pyridopyridazinone10b,11b und12b wurden mit Alkyljodiden alkyliert.

     

Ultrasound and solvent-induced reversible chromism in a luminescent chalcogenidostannate

Solvothermal treatment of a mixture of Se, SnC1₂, CoC1₂, and dien (dien?=?diethylenetriamine) generated yellow crystals of [Co(dien)₂]₂Sn₂Se₆ (1), which could transform into black 2 with the same formula via rinsing with water. In the presence of water, ultrasound irradiation of black 2 went back to yellow 1. The reversible ultrasound and solvent-induced chromism has never been observed before. Compared with yellow 1, hyperchromism was apparent around 550?nm in the visible absorption spectrum of 2. The fluorescent properties for 1 and 2 were investigated and the mechanisms were validated by density functional theory calculations on the experimental geometries. In addition, electron paramagnetic resonance spectra of yellow 1 are similar to chromic black 2 in the signal at g?=?4.22 and g?=?2.19; the signal at g?=?2.19 of 2 shows a sharp increase.     

LC Method for Analysis of Three Flavonols in Rat Plasma and Urine after Oral Administration of Polygonum aviculare Extract

A high-performance liquid chromatographic method has been developed for the simultaneous analysis of the flavonols myricitrin (1), avicularin (2), and juglanin (3) in rat plasma and urine after oral administration of the total flavonoids from Polygonum aviculare. Samples were prepared by solid-phase extraction then separated on a C₁₈ reversed-phase column by use of a mobile-phase gradient prepared from methanol and aqueous formic acid solution. The flow rate was 1 mL min⁻¹. Detection was performed at 254 nm. The calibration range was 11–1,100 μg mL⁻¹ for both 2 and 3 in plasma; in urine the calibration ranges for 1, 2, and 3 were 32–1,600, 11–1,100, and 22–1,100 μg mL⁻¹, respectively. Intra-day and inter-day RSD were less than 4.33 and 3.62% for 2 and 3, respectively, in plasma, and no more than 4.03 and 2.22% for all the analytes in urine. The analytical sensitivity and selectivity of the assay enabled successful application to pharmacokinetic studies of flavonols 1–3 in rats.

     

Boat form contributions in crowded piperidines: Theoretical and experimental study

The preferred conformations of N-nitroso-t(3)-alkyl-r(2),c(6)-bis(2′-furyl)-piperidin-4-ones 1–3 [alkyl = CH₃, C₂H₅ and CH(CH₃)₂] and N-nitroso-t(3),t(5)-dimethyl-r(2),c(6)-bis(2′-furyl)piperidin-4-one 4 in solutions were assigned by means of ¹H and ¹³C NMR studies. The results derived from NMR spectra indicate the presence of an equilibrium mixture of boat conformation B ₁ and alternate chair conformation CA for the E isomers of 1–3 and Z isomers of 2–3. For the Z isomer of 1 boat form B ₂ is predicted to be the major conformer. The N-nitroso-3,5-dimethyl derivative 4 exists in the boat form B ₁ only. Conformational analysis performed through semiempirical molecular orbital calculations also supports the conformations for 3–4. The presence of one conformer in the equilibrium can be predicted to a reasonable accuracy by theoretical studies in 1–2. The effects due to N-nitrosation on ¹H and ¹³C chemical shifts are also interpreted in terms of these conformations. The conformation of isopropyl group at C(3) was also predicted by spectral and theoretical studies.     

Synthesis,crystal structures,in vitro anticancer,and in vivo acute oral toxicity studies of bis-imidazolium/benzimidazolium salts and respective dinuclear Ag(I)-N-heterocyclic carbene complexes

The synthesis, spectral (FT-IR and NMR), and structural studies of 1,1′-methylene linked 3,3′-2-cyanobenzyl bis-imidazolium salt (L₁) and respective dinuclear Ag(I)-NHC complex (C₁) are reported. The structures of both compounds were established through single-crystal X-ray diffraction. C₁ has a short Ag–Ag separation of 3.16?Å. Both L₁ and C₁ were tested for potential against leukemia (k562) cell line. For comparison, para-xylyl linked bis-benzimidazolium salts (L₂–L₄) and their dinuclear Ag(I)-NHC complexes (C₂–C₄) were synthesized and tested against the same cell line (K562). The IC₅₀ values proved that L₂–L₄ and C₂–C₄ are many fold more active than L₁ and C₁. The mechanism of action and structure activity relationship are discussed. In vivo oral acute toxicity study (sighting study) was carried out which depicts that 2000 mg/kg dose of selected compounds is an appropriate and safe dose for conducting main study on animals.     

C60吡咯烷羧酸衍生物的合成及其在水溶液中的聚集行为

C60与亚氨基二乙酸甲酯[NH(CH₂COOMe)₂]的光化学反应制得2,5-双(甲氧羰基)富勒烯吡咯烷(1), 产率为52% (基于已反应的C60). C60吡咯烷衍生物1与氯乙酸甲酯(ClCH₂COOCH₃)的N-烃基化反应, 在微波辐射、无溶剂及相转移条件下, 得到2,5-双(甲氧羰基)-N-(甲氧羰基)甲基富勒烯吡咯烷(2), 产率47%(基于C60吡咯烷衍生物1). C60吡咯烷衍生物1和2用NaH, CH₃OH水解后, 经盐酸酸化得相应的二羧酸衍生物3和三羧酸衍生物4, 产率分别为65%和53% (基于C60吡咯烷衍生物1和2). C60吡咯烷衍生物1～4的结构由¹H NMR, ¹³C NMR, IR, FAB-MS和元素分析证实. 用电导法测定了C60吡咯烷二羧酸3和三羧酸4钠盐的临界聚集浓度(CAC), 分别为3.58×10^－4 mol/L (3)和3.33×10^－4 mol/L (4). 这一结果被C60吡咯烷衍生物3和4, 在临界聚集浓度(CAC)附近的UV-Vis光谱的特征变化所支持. 透射电子显微镜(TEM)和静态光散射(SLS)等方法也被用于检测C60吡咯烷衍生物3和4在临界聚集浓度(CAC)时的聚集行为, 结果显示, C60吡咯烷衍生物3在缓冲溶液中(0.001 mol/L NaCO₃-NaHCO₃), 其聚集体粒径的大小(R_g≈21 nm)不同于C60吡咯烷衍生物4 (R_g≈23 nm). C60吡咯烷二羧酸3钠盐的临界聚集浓度(CAC)比C60吡咯烷三羧酸4钠盐的临界聚集浓度(CAC)大, 聚集体粒径大小的不同, 表明C60单加成衍生物加成基团中羧基(COOH)数目的多少对其聚集行为的影响. 用化学发光法分别检测了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4在缓冲溶液(0.05 mol/L NaCO₃-NaHCO₃)中对邻苯三酚自氧化产生的超氧阴离子(O₂^－·)的清除活性. C60衍生物3和4对 O₂^－· 的清除呈现有明显的剂量效应, 但当超过一定浓度时(3: ～3.50×10^－4 mol/L, 4: ～3.25×10^－4 mol/L), 清除效率出现转折, 并下降. 这一现象与电导率测定时出现的CAC现象相一致, 进一步证实了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4在较高浓度的水溶液中有聚集的倾向, 也说明了C60吡咯烷二羧酸3和C60吡咯烷三羧酸4的聚集会影响其清除超氧阴离子(O₂^－·)的活性.     

Furylhydroquinones and miscellaneous compounds from the roots of Lithospermum erythrorhizon and their anti-inflammatory effect in HaCaT cells

One new furylhydroquinone derivative (1) and seven known compounds (2–8) were isolated from the roots of Lithospermum erythrorhizon Sieb. et Zucc (Boraginaceae). The structure of 1 was elucidated by extensive spectroscopic methods using NMR and MS. The absolute configuration of shikonofuran J (1) was unambiguously determined by aid of comparison experimental ECD with predicted ECD spectra. All the isolates were tested for their inhibitory activities against IL-6 production in HaCaT cells stimulated by tumor necrosis factor (TNF)-α. It was found that gracicleistanthoside (5) and uridine (7) remarkably down-regulated the TNF-α-induced synthesis of interleukin-6 (IL-6), a pro-inflammatory cytokine associated with cutaneous inflammation, in HaCaT cells.     

具有叶绿素-a碳架的(细菌)卟吩衍生物的合成及其共轭区域变化对光谱性能的影响

以脱镁叶绿酸-a甲酯(MP-a) (1)为起始原料, 通过四氧化锇和高碘酸钠的氧化给出3-位乙烯基和13²-位α-氢的氧化产物2和3, 再用四氧化锇继续氧化卟吩醛2则得到细菌卟吩醛4. 经脱甲酸甲酯和硝酸铊氧化, MP-a (1)转化为焦脱镁叶绿酸衍生物5, 将其进一步用四氧化锇氧化则形成细菌卟吩缩醛6. 卟吩醛2在碱性条件下转化为卟吩e₆三甲酯7, 2与烷基溴化镁的格氏反应给出脱镁叶绿酸醇9, 选择高钌酸四丙基铵(TPAP)和N-甲基吗啉N-氧化物将3-位羟基氧化成羰基, 所生成的卟吩二酮10在酸性条件下脱去甲酸甲酯生成焦脱镁叶绿酸衍生物11, 用四氧化锇对7和11实施氧化, 则分别转化为细菌卟吩衍生物8和12. 同时, 讨论了叶绿素衍生物的共轭区域变化对其光谱性能的影响. 所合成的新卟吩和细菌卟吩衍生物均经UV, IR, ¹H NMR及元素分析证明其结构.     

Chemical and biological studies on Bridelia ferruginea grown in Nigeria

Phytochemical investigation of the methanolic extract of dried leaves of Bridelia ferruginea led to the isolation and identification of fourteen compounds (1–14): compound 1 [mixture of palmitic, stearic and oleic acids], stearyl monoester of 2-O-β-?-glucosylglycerol (2), 6β-hydroxy-(20R)-24-ethylcholest-4-en-3-one (3a), 6β-hydroxy-(20R)-24-ethylcholest-4,22-dien-3-one (3b), lutein (4), vomifoliol (5), corilagin (6), kaempferide-3-O-β-?-glucoside (7), myricetin (8), isomericitrin (9), isoquercetin (10), myricitrin (11), quercitrin (12), rutin (13), and β-sitosterol glucoside (14). The total extract exhibited moderate activity towards CB2 receptor and 90% inhibition against leishmanial pathogen Trypanosoma brucei. Compound 4 exhibited 73% displacement in CB2 receptor with IC₅₀ 56.47 μM, and 93% inhibition towards T. brucei with IC₅₀ 4.16 μM. Compound 11 showed 99% inhibition towards Escherichia coli with IC₅₀ 1.123 μM.     

Isolation and identification of polyphenols from Marsilea quadrifolia with antioxidant properties in vitro and in vivo

Marsilea quadrifolia is an edible aquatic medicinal plant used as a traditional health food in Asia. Four new polyphenols including kaempferol 3-O-(2″-O-E-caffeoyl)-β-d-glucopyranoside (1), kaempferol 3-O-(3″-O-E-caffeoyl)-α-l-arabinopyranoside (3), 4-methy-3′-hydroxypsilotinin (4) and (±)-(E)-4b-methoxy-3b,5b-dihydroxyscirpusin A (18) together with 14 known ones (2, 5–17) were isolated from the ethanol extract of M. quadrifolia. Structures of the new compounds were elucidated by extensive spectroscopic analyses. In DPPH and oxygen radical absorbance capacity antioxidant assays, some compounds showed stronger antioxidant activities and quercetin (9) was the most potent antioxidant in both assays. In a restraint-induced oxidative stress model in mice, quercetin significantly attenuated the increase in plasma ALT and AST levels as well as liver MDA content of restrained mice. Liver SOD activity was also significantly increased by quercetin, indicating a significant in vivo antioxidant activity. As a rich source of polyphenols with strong antioxidant activities, M. quadrifolia may be developed to a product for relieving oxidative stress.