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排序方式: 共有369条查询结果,搜索用时 15 毫秒
41.
Alessandra Russo Venera Cardile Adriana C.E. Graziano Carmen Formisano Marisa Canzoneri 《Natural product research》2015,29(17):1630-1640
The objectives of our research were to study the chemical composition and the in vitro anticancer effect of the essential oil of Salvia verbenaca growing in natural sites in comparison with those of cultivated (Sc) plants. The oil from wild (Sw) S. verbenaca presented hexadecanoic acid (23.1%) as the main constituent, while the oil from Sc plants contained high quantities of hexahydrofarnesyl acetone (9.7%), scarce in the natural oil (0.7%). The growth-inhibitory and proapoptotic effects of the essential oils from Sw and Sc S. verbenaca were evaluated in the human melanoma cell line M14, testing cell vitality, cell membrane integrity, genomic DNA fragmentation and caspase-3 activity. Both the essential oils were able to inhibit the growth of the cancer cells examined inducing also apoptotic cell death, but the essential oil from cultivated samples exhibited the major effects. 相似文献
42.
Marcelo Kobelnik Douglas Lopes Cassimiro Diógenesdos Dos Santos Clóvis Augusto Ribeiro Marisa Spirandeli Crespi 《中国化学》2011,29(11):2271-2277
Solid state compounds of general formula Sr(Diclof)2·5.7H2O and Ba(Diclof)2·4.8H2O were obtained. Thermogravimetry (TG), differential scanning calorimetry (DSC), X‐ray diffraction powder patterns and microscopy analysis were used to characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters have been described here. The kinetic behaviors of these stages were evaluated from several heating rates with samples masses of 2 and 5 mg in open crucibles under a nitrogen atmosphere. The results of the present study improve the knowledge on these compounds including their dehydration and thermal stability. The obtained data depend on the mass of the sample which results in two kinetic behavior patterns. 相似文献
43.
Two methods are presented that were designed to circumvent the persistent problem of benzofuran formation and instead yield a spiroketal of the rubromycin family type. First, using an alternative disconnection, a hemiketal conjugate addition to a naphthaquinone electrophile was investigated. Synthesis of the requisite electrophile provided insight into the selective oxidation and functionalization of the naphthalene portion. Second, the electronic features of the isocoumarin ring system were adjusted, and the corresponding reactivity further supports the hypothesis that electron-rich isocoumarins are capable of spiroketalization. Robust, flexible syntheses from simple precursors were developed that allowed multiple reduced isocoumarins to be generated. Combined, the data presented herein give insight into the sensitivities of this family and illuminate other potential methods of spiroketalization. In addition, the convergent assembly of substrates containing different naphthaquinone and isocoumarin subunits highlights the utility of our 1,3-dipolar cycloaddition approach to generate analogs of these structures for SAR, as well as chemical reactivity studies. 相似文献
44.
Corzana F Busto JH Marcelo F de Luis MG Asensio JL Martín-Santamaría S Sáenz Y Torres C Jiménez-Barbero J Avenoza A Peregrina JM 《Chemical communications (Cambridge, England)》2011,47(18):5319-5321
A novel Tn antigen mimic, in which the natural underlying amino acid has been replaced by the non-natural α-methylserine analogue, is reported. This derivative exhibits a similar affinity for a natural lectin as for the natural Tn and retains the bioactive conformation observed in the Tn-containing glycopeptides with anti-MUC1 antibodies. 相似文献
45.
Monreal MJ Khan SI Kiplinger JL Diaconescu PL 《Chemical communications (Cambridge, England)》2011,47(32):9119-9121
A new inverted sandwich of a μ-η(6),η(6)-toluene diuranium complex reacted with quinoxaline to form a tetranuclear macrocycle with ferrocene diamide uranium(IV) vertices and reduced quinoxaline edges. 相似文献
46.
Marcelo Kobelnik Douglas Lopes Cassimiro Adélia Emilia de Almeida Clóvis Augusto Ribeiro Marisa Spirandeli Crespi 《Journal of Thermal Analysis and Calorimetry》2011,105(2):415-419
The Al and In-diclofenac compounds were prepared. Thermogravimetry (TG) and X-ray diffraction powder patterns were used to
characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters
have been described here. The kinetic studies of these stages were evaluated from several heating rates with mass sample of
2 and 5 mg in open crucibles under nitrogen atmosphere. The results of the present study improve the knowledge on these compounds
including their dehydration and thermal stability. The obtained data leads to a dependence on the sample mass, which results
in two kinetic behavior patterns. 相似文献
47.
Douglas L. Cassimiro Clóvis A. Ribeiro Jorge M. V. Capela Marisa S. Crespi Marisa V. Capela 《Journal of Thermal Analysis and Calorimetry》2011,105(2):405-410
Meglumine, (2R,3R,4R,5S)-6-methylaminohexane-1,2,3,4,5-pentol, is a carbohydrate derived from sorbitol in which the hydroxyl group in position one
is replaced by a methylamine group. It forms binary adducts with substances having carboxyl groups, which have in common the
presence of hydrogen bonding as the main force in the stabilization of these species. During melting, adducts of meglumine
with flunixin (2-[[2-methyl-3-(trifluoromethyl)phenyl]amino]pyridine-3-carboxylic acid) polymerize or self-assemble in amorphous
supramolecular structures with molecular weights around 2.0 × 105 kDa. DSC curves, in a first heating, show isomorphic transitions where the last one at 137 °C for the flunixin-meglumine
adduct originated the supramolecular amorphous polymers with glass transition around 49.5 °C. The kinetic parameters for the
thermal decomposition step of the polymers were determined by the Capela-Ribeiro non-linear isoconversional method. From data
for the TG curves in nitrogen atmosphere and heating rates of 5, 10, 15, and 20 °C min−1, the E
α and B
α terms could be determined and, consequently, the pre-exponential factor, Aα, as well as the kinetic model, g(α). 相似文献
48.
It is well known that any symplectic manifold (M,Ω) has an almost complex structure J which is compatible with Ω. In this paper, we deal with the existence of compatible pairs (J,Ω) on nilpotent Lie algebras
of dimension ≤6, J being an integrable almost complex structure. We prove that if such a pair exists, J must satisfy some extra conditions, namely J must be nilpotent in the sense of [Trans. Am. Math. Soc. 352 (2000) 5405]. Associated to any such a compatible pair, there is a pseudo-Kähler metric g which cannot be positive definite unless
be abelian. All these metrics are Ricci flat, although many of them are nonflat, and we study the behaviour of its curvature tensor under deformation. 相似文献
49.
50.