Enzymatic resolution of planar chiral ferrocene derivatives

Racemic 3-methyl, 2-ethyl, 2-bromo, and 2-trimethylsilyl derivatives of formylferrocene were kinetically resolved by enantioselective reduction with a fermenting baker's yeast. Moreover, 2-methyl, 3-methyl, 2-ethyl, 2-bromo, and 2-trimethylsilyl derivatives of hydroxymethylferrocene were optically resolved with lipases by transesterification using vinyl esters.     

Investigating amine derivatives of ambruticin VS-5 and VS-4

A structure-activity relationship around the amine group of the ambruticin VS series has been developed for antifungal activity. It was shown that the amine can be alkylated through reductive amination without loss of potency. However, if it is converted into either an amide, carbamate, or urea, a significant loss of potency is observed. Of the alkyl amines, small nonpolar groups are optimal for both potency and oral bioavailability. As a result of this study, one compound (KOS-2079) was taken into an animal efficacy model with success.     

Synthesis, characterization and biological activity of trans-platinum(II) and trans-platinum(IV) complexes with 4-hydroxymethylpyridine

The synthesis and chemical characterization of two new trans platinum complexes, trans-[PtCl(2)NH(3)(4-hydroxymethylpyridine)] (1) and trans-[PtCl(4)NH(3)(4-hydroxymethylpyridine)] (2) are described. Their ability to interact with 5'-GMP by themselves and in the presence of reducing agents in the case of trans-[PtCl(4)NH(3)(4-hydroxymethylpyridine)] were tested. Circular dichroism, electrophoretic mobility in agarose gel, and atomic force microscopy studies showed that the interaction of complex 1 with DNA is stronger than that of complex 2. Cytotoxicity tests against HL-60 tumor cells also showed higher activity for trans-[PtCl(2)NH(3)(4-hydroxymethylpyridine)] than for trans-[PtCl(4)NH(3)(4-hydroxymethylpyridine)]. Complex 1 presents similar behavior to cisplatin, but with a lower IC(50) at 24 h. Complex 1 also showed high apoptosis induction.     

脱氢枞胺及其衍生物的应用研究进展

脱氢枞胺是歧化松香胺的主要成分,具有三环菲骨架结构,是松香重要的改性产品之一。本文综述了脱氢枞胺及其衍生物的应用研究进展,包括脱氢枞胺在手性化合物分离方面的应用和脱氢枞胺衍生物在抑菌、防腐、缓蚀、金属离子浮选、催化、抗癌、抗氧化、抗溃疡、可与雄性激素结合等方面的应用。指出目前脱氢枞胺成盐衍生物及脱氢枞胺N-C衍生物的研究较为广泛,脱氢枞胺B环和C环改性衍生物的研究仍需加强,而且对于B环和C环改性衍生物的深入研究,将进一步促进脱氢枞胺衍生物在生物活性方面的应用。最后对脱氢枞胺衍生物在生物医学工程上的应用前景进行了展望。     

Structures and antitumor activities of planar chiral cyclopalladated ferrocene derivatives

Bis(μ-acetato)-bridged planar chiral cyclopalladated products have been obtained by asymmetric cyclopalladation of the corresponding chiral ferrocenylimines with palladium(II) acetate and sodium acetate in methanol at room temperature. Two diastereomers were isolated in enantiomerically pure form and their absolute configurations have been determined by single-crystal X-ray analysis. It was found that enantiomerically pure cyclopalladated ferrocene displayed the excellent inhibition to two human breast carcinoma cell lines, MDA-MB-231 and MDA-MB-468 and could have good application prospect in pharmaceutical use.     

Preparation and adsorption behavior of macrocyclic tetra‐amine derivatives of chitosan

The new macrocyclic polyamine derivatives of chitosan were synthesized by reacting epoxy‐activated macrocyclic tetra‐amine with the C6 hydroxyl or C2 amino group in chitosan. The obtained copolymers (CTS‐OM, CTS‐NM) contain amino functional groups, the secondary amines, and more polar hydroxyl groups in its skeleton. Elemental analysis, infrared spectra, and solid‐state ¹³C‐NMR analysis confirmed their structures. The adsorption behavior of the macrocyclic polyamine grafted chitosan for Ag⁺, Pb²⁺, Hg²⁺, and Cr³⁺ was investigated. The experimental results showed that the two novel derivatives of chitosan have high adsorption capacity and good selectivity for some metal ions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 407–412, 2005     

Electrostatic dissipation and flexibility of poly(oxyalkylene)amine segmented epoxy derivatives

A family of hydrophilic and flexible epoxy polymers was prepared from the reaction of poly(oxyalkylene)amines and diglycidyl ether of bisphenol‐A (DGEBA) at 1:1 molar ratio of N H to epoxide. The use of a high molecular weight (M_W = 1000–6000) poly(oxyethylene–oxypropylene)amine and a low M_W amine as curing agents provided epoxy materials with good properties in toughness and hydrophilicity. The hydrophilicity, probed by surface resistivity of these cured materials, was found to be affected by the nature and weight content of poly(oxyethylene) segment in the polymer backbone, and also by the degree of crystallinity. Specifically, in the presence of a water‐soluble poly(oxyethylene–oxypropylene)diamine of M_W 2000 the cured epoxies can reach surface resistivity as low as 10^8.6–9.6 Ω/□. In comparison, the water‐insoluble poly(oxypropylene)diamine of M_W 2000 afforded a higher surface resistivity of 10^10.5 Ω/□ because of the difference in hydrophilicity between oxyethylene and oxypropylene functionalities. Poly(oxypropylene)diamine of M_W 230 as the sole curing agent generated an epoxy with even higher surface resistivity of 10¹³ Ω/□ due to a highly crosslinking structure. With proper selection of mixed poly(oxyethylene–oxypropylene)diamine (25 wt%) and 2‐aminoethanol (9 wt%), the DGEBA cured polymer had an appropriate surface resistivity of 10^9.8 Ω/□ for antistatics. Moreover, this material was extremely ductile in appearance and showed over 500 % elongation at break during mechanical tests. The high flexibility is rationalized by the balanced chemical structure of poly(oxyalkylene) segments and bisphenol‐A distributed in a slightly crosslinked system. © 2000 Society of Chemical Industry     

Active species in hydroperoxide decomposition by hindered amine light stabilizers and its reactivity with phenol

Hydroperoxide decomposition by hindered amine light stabilizers (HALSs) is an important process producing active HALS derivatives and has been studied energetically. The decisive active species of the decomposition, however, has not been proposed yet. In this article, HALS nitrosonium that forms in the decomposition of a hydroperoxide by HALSs and a ring‐opening product of the nitrosonium, a nitroso compound, are proposed as active species for hydroperoxide decomposition. Furthermore, the reactivity of the nitrosonium with phenols is discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1310–1317, 2006     

Synthesis and electroluminescence property of new hexaphenylbenzene derivatives including amine group for blue emitters

Three new blue-emitting compounds of 5P-VA, 5P-VTPA, and 5P-DVTPA for organic light-emitting diode (OLED) based on hexaphenylbenzene moiety were demonstrated. Physical properties by the change of the substitution groups of the synthesized materials were systematically examined. Photoluminescence spectrum of the synthesized materials showed maximum emitting wavelengths of about 400 to 447 nm in solution state and 451 to 461 nm in film state, indicating deep blue emission color. OLED devices were fabricated by the synthesized compounds using vacuum deposit process as an emitting layer. The device structure was ITO/2-TNATA 60 nm/ NPB 15 nm/ EML 35 nm/ TPBi 20 nm/ LiF 1 nm/ Al 200 nm. External quantum efficiencies and CIE values of 5P-VA, 5P-VTPA, and 5P-DVTPA were 1.89%, 3.59%, 3.34%, and (0.154, 0.196), (0.150, 0.076), (0.148, 0.120), respectively. 5P-VTPA and 5P-DVTPA exhibited superior highly blue quality and thermal property such as high T_d of 448°C and 449°C.     

Preparation of tertiary amine derivatives from commercially available alcohols and their properties as surfactants

Higher tertiary amines were prepared by transalkylation of triethylamine with commercially available alcohols such as Tergitol 15-S-3 and tridecyl alcohol. This reaction carried out at 250–300 C and 20 kg/cm² initial hydrogen pressure, using Cu−Cr−Mn−O catalyst, gave about 80% yield of higher alkyl tertiary amines. Tertiary amine hydrochlorides, quaternary ammonium bromides and amine oxides were prepared from these tertiary amines. Specific surface tension, wetting power, foaming power and foam stability were measured. The characteristic properties with respect to tertiary amine derivatives containing ether linkages were observed. These products have excellent wetting power, reduced surface tension, low foaming power and unstable foam.     

Chemistry of some fluorescamine–amine derivatives with relevance to the biosynthesis of benzylpenicillin by fermentation

The reaction of fluorescamine with 6‐aminopenicillanic acid (6‐APA) at pH 4 was investigated for its potential use in the biosynthesis of benzylpenicillin. A number of amino acids and penicillin amine derivatives, that reacted with fluorescamine at pH 7–9, were unlikely to do so to a significant extent at pH 4 and hence were unlikely to interfere in results that led to the biosynthesis of benzylpenicillin. Biosynthesis was followed using Penicillium chrysogenum Wis F3‐64, growing in a corn steep liquor medium in a shake flask fed with phenylacetic acid daily. Analysis of benzylpenicillin formation was effected enzymically and fluorimetrically. A sample of the fermentation broth was treated with buffer at pH 7.8 and an active penicillin acylase solution for 1 h at 37 °C. The pH was then lowered to 4 by swamping with acetate buffer and the solution was treated with fluorescamine. The resulting fluorescence was compared with that of a standard 6‐aminopenicillianic acid solution treated in the same manner. In this case the biosynthesis of benzylpenicillin was found to increase over 6 days. The results were compared with those for a control broth where the penicillin acylase was not added. © 2002 Society of Chemical Industry     

The reactivity of 2-furaldehyde and its derivatives in polymerisation reactions involving the carbonyl bond

The homopolymerisation of 2-furaldehyde, 5-methyl-2-furaldehyde and 2-furyl methyl ketone and their cationic copolymerisation (BF₃. Et₂) with olefins were investigated. All attempts to obtain homopolymers failed because of thermodynamic restrictions. 2-Furaldehyde and α-methylstyrene gave an alternating copolymer of low degree of polymerisation, 2-methyl-2-furaldehyde and α-methylstyrene gave copolymers rich in 5-methyl-2-furaldehyde, indicating a penultimate effect in the growth mechanism. The use of less basic comonomers (cyclopentadiene, styrene, isoprene, etc.) resulted in inhibition or strong retardation of the polymerisation. The use of more basic comonomers (acenaphthy-lene, N-vinylcarbazole) resulted in their homopolymerisation. Furyl methyl ketone inhibited the polymerisation of all comonomers tried. A complex between BF₃. Et₂O and 2-furaldehyde was isolated and characterised. A general mechanism is offered to explain the behaviour of these systems.     

Turbidimetric analysis of amine oxides and amine oxide-anionic surfactant mixtures

Automatic turbidimetric analysis has been shown to be a simple and accurate method to determine the actives in anionic surfactants as well as the actives in amine oxides. This technique has been applied to dilute solutions of these surfactants in the μM range. Solutions containing mixtures of anionic surfactants and amine oxides can be positively resolved by turbidimetric titration without interferences. Performing two titrations at different pH values ensures that the amine oxide is completely in its nonionic form or totally protonated and behaving as a cationic surfactant.     

胺类环氧固化剂胺值测定方法的探讨

介绍了伯胺值、仲胺值和叔胺值的测定方法,以及改性胺固化剂理论用量的计算公式。     

Hoechst 33258 as a pH-sensitive probe to study the interaction of amine oxide surfactants with DNA

The use of Hoechst 33258 (HO) as a fluorescent probe to characterize the interactions between DNA and pH-sensitive amphiphiles is discussed. In the case of amine oxide amphiphiles dodecyldimethylamine oxide (DDAO) and p-dodecyloxybenzyldimethylamine oxide (pDoAO), the decrease in fluorescence emission, which signals DNA-amphiphile association, is accompanied by a large hypsochromic shift in the emission maximum of the bound probe; this eventually reaches a value characteristic of HO in a neutral or slightly basic environment. These findings are compared to results obtained by using the more common ethidium bromide (EB) probe, which shows no such shift. Circular dichroism and fluorescence depolarization experiments indicate that fluorescence emission only occurs from the DNA-bound probe, and the observed shift in emission maximum when using HO as a fluorescent probe is due to a variation in the local pH in the vicinity of the probe.     

Synthesis of novel polymeric HALS stabilizers and chain transfer effect of hindered amine norbornene derivatives on ring-opening metathesis polymerization

Cyclooctadiene (COD) was polymerized via ring-opening metathesis polymerization (ROMP) in the presence of 5-norbornene-exo, endo-2-carboxylic acid 2,2,6,6-tetramethyl-4-piperidinyl ester (PN) or 5-norbornene-2-exo-3-endo-dicarboxylic acid bis(2,2,6,6-tetramethyl-4-piperidinyl) ester (2,3-PN) to prepare a new kind of polymeric hindered amine (HALS) stabilizers. Unexpectedly, hindered amine norbornene derivatives PN and 2,3-PN did not act as comonomer but acted as chain transfer agent (CTA). The resulting polymers were characterized by gel permeation chromatography (GPC) and ¹H-NMR. Investigation of polymerization behavior showed that hindered amine groups were introduced into polymer chain by virtue of chain degradation resulted from chain transfer. The molecular weight (M _n) and HALS content of the resulting polymeric HALS stabilizer could be regulated by varying molar ratio of initial monomer to catalyst.     

氧化胺的性能研究

考察了不同碳链的脂肪烷基二甲基氧化胺与脂肪烷基酰胺丙基氧化胺的表面活性、泡沫性能和接触角。实验结果表明:氧化胺具有优异的泡沫稳定性,且随着碳链的增加,泡沫性能降低;脂肪烷基酰胺丙基氧化胺的临界胶束浓度随着碳链的增加而降低,而脂肪烷基二甲基氧化胺的临界胶束浓度随着碳链的增加而增加;氧化胺的接触角随着碳链的增加而变大。     

PEGylated block copolymers containing tertiary amine side-chains cleavable via acid-labile ortho ester linkages for pH-triggered release of DNA

A new type of acid-labile cationic copolymer consisting of a hydrophilic poly(ethylene glycol) (PEG) block and a polymethacrylamide block bearing tertiary amines linked by acid-labile ortho ester rings in side chains (PAOE), with defined chain length, had been synthesized via RAFT polymerization. The copolymers could efficiently bind and condense plasmid DNA at neutral pH into narrowly dispersed nano-scale polyplexes. The hydrolysis of ortho ester group in the side-chains of PAOE followed a distinct exocyclic mechanism and the rate of hydrolysis was much accelerated at mildly acidic pH, resulting in the accelerated disruption of polyplexes and the release of intact plasmid DNA. The three polymers were not toxic to cultured COS-7 cells as measured by MTT assay. As expected, PEG segments of the PEG-b-PAOE copolymers prevented nonspecific transfection of COS-7 cells. Once conjugated to a targeting ligand to enhance cell-specific entry, PEG-b-PAOE with its pH-triggered DNA release properties may achieve efficient intracellular delivery of DNA or other nucleic acid therapeutics.     

Kinetics of isocyanate amine reactions

Development of polyurea-urethane and polyurea reaction injection molding (RIM) systems has created a need for kinetics of polyurea formation. Adiabatic batch reactions in solution were used to determine heats of reaction and relative reactivity of several aromatic amines and n-butanol with phenyl isocyanate (PI). In addition to comparing times required to reach 25, 50 and 75% conversion for both catalyzed and uncatalyzed reactions, n-th order models with Arrhenius rate constants were used to fit some of the exotherms. The reaction of 3,5-diethyl toluene (2,4 and 2,6)-diamine and PI could not be modeled due to unequal reactivity of the two amine groups. This unequal reactivity was studied using high performance liquid chromatography (HPLC) separation of the reaction products. The reactions of primary aliphatic amines and aromatic isocyanates were too rapid to be monitored in the batch apparatus. With a flow apparatus the reaction half time was estimated to be ～ 0.002 s.