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91.
Dihydrocyclocitral, a useful reagent in organic synthesis, has been synthesized in high yield and with high stereoselectivity from citronellal under microwave irradiation in two steps, involving acetic anhydride under base catalysis, then p-toluenesulfonic acid adsorbed on silica gel under solventless conditions (80% yield, reaction time 22 min). 相似文献
92.
93.
Ai Doan Thi Thuy Van Trinh Thi Thanh Huong Doan Thi Mai Huyen Tram Le Marc Litaudon Van Minh Chau Van Cuong Pham 《Tetrahedron letters》2018,59(20):1909-1912
Two novel alkaloids, with an unprecedented carbon skeleton, pileamartines A (1) and B (2), together with the known alkaloid, julandine (I-a) were isolated from the alkaloidal fraction of Pilea aff. martinii leaves. Their structures were established by spectral data analysis, including MS and 2D NMR. The absolute configurations of 1 and 2 were suggested by comparison of their experimental and calculated electronic circular dichroism spectra. Compound 2 exhibited weak inhibitory activity against the α-glucosidase enzyme with an inhibition of 11% at a concentration of 200?µM. These compounds were not cytotoxic against several cancer cell lines even at a concentration of 150?µM. 相似文献
94.
Ai Doan Thi Thuy Ngan Truong Bich Hien Nguyen Thi Linh Nguyen Thuy Van Cuong Pham Huyen Vu Thi Huong Doan Thi Mai 《Chemistry of Natural Compounds》2021,57(2):360-363
Chemistry of Natural Compounds - 相似文献
95.
Tien Doan Phan Thao My Trinh Thi Thu Khiem Le Hong Frontasyeva Marina Zinicovscaia Inga Son Nguyen An Van Dung Do 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(6):2743-2750
Journal of Radioanalytical and Nuclear Chemistry - Forty-five moss samples were collected at the end of the 2019 rainy season in Hanoi capital and some other cities in Red River Delta and the south... 相似文献
96.
Thi Dao Phi Huong Doan Thi Mai Van Hieu Tran Van Loi Vu Bich Ngan Truong Tuan Anh Tran Van Minh Chau Van Cuong Pham 《Tetrahedron letters》2017,58(19):1830-1833
A series of bengamide E analogues were prepared from the corresponding polyketide chain and amino acids via amide coupling reactions. Opening of the polyketide chain lactone ring with α-aminolactams was successfully achieved under microwave irradiation in the presence of sodium 2-ethyl hexanoate. A cytotoxic activity evaluation against a panel of cancer cell lines (KB, HepG-2, Lu-1, MCF-7, HL-60 and Hela) indicated that the 2′R analogues were generally more cytotoxic than the 2′S analogues. Additionally, several analogues exhibited selective inhibition against various cancer cell lines: compounds 32a and 32b selectively inhibited MCF-7 cells, while 33b and 35b were more sensitive toward Lu-1 and HepG-2, respectively. Notably, some of the synthetic analogues possess cytotoxic activities with IC50 values less than 1 µM. 相似文献
97.
In this paper, we establish new formulae for computing and/or estimating the Fréchet subdifferential of the efficient point multifunction of a parametric vector optimization problem. These formulae are presented in a broad class of conventional vector optimization problems with the presence of geometric, operator and (finite and infinite) functional constraints. 相似文献
98.
Miho Motoyama Dr. Thu-Hong Doan Paulina Hibner-Kulicka Ryo Otake Malgorzata Lukarska Jean-Francois Lohier Kota Ozawa Prof. Dr. Shinkoh Nanbu Dr. Carole Alayrac Prof. Dr. Yumiko Suzuki Prof. Dr. Bernhard Witulski 《化学:亚洲杂志》2021,16(15):2087-2099
2-N-aminoquinazolines were prepared by consecutive SNAr functionalization. X-ray structures display the nitrogen lone pair of the 2-N-morpholino group in conjugation with the electron deficient quinazoline core and thus representing electronic push-pull systems. 2-N-aminoquinazolines show a positive solvatochromism and are fluorescent in solution and in solid state with quantum yields up to 0.73. Increase in electron donor strength of the 2-amino substituent causes a red-shift of the intramolecular charge transfer (ICT) band (300–400 nm); whereas the photoluminescence emission maxima (350–450 nm) is also red-shifted significantly along with an enhancement in photoluminescence efficiency. HOMO-LUMO energies were estimated by a combination of electrochemical and photophysical methods and correlate well to those obtained by computational methods. ICT properties are theoretically attributed to an excitation to Rydberg-MO in SAC-CI method, which can be interpreted as n-π* excitation. 7-Amino-2-N-morpholino-4-methoxyquinazoline responds to acidic conditions with significant increases in photoluminescence intensity revealing a new turn-on/off fluorescence probe. 相似文献
99.
Doan Pham Minh Jocelyn Ramaroson Ange Nzihou Patrick Sharrock Guy Depelsenaire 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):112-120
Abstract Thermal synthesis of sodium cyclotriphosphate (SCTP) – Na3P3O9 was investigated in the temperature range of 150 °C to 750 °C using sodium chloride (NaCl) and 85 wt% orthophosphoric acid (H3PO4) as economical starting materials. Reaction temperature had a crucial impact on the chloride elimination rate and the formation of SCTP. The best result was obtained at 600 °C with 96% of elimination of the initial chloride as hydrochloric acid and 84% of selectivity in SCTP. At lower temperatures, residual chloride contents were high. At higher temperatures (650 °C and 750 °C), SCTP was melted and transformed into glassy products. 相似文献
100.
Doan Pham Minh Ange Nzihou Patrick Sharrock Jocelyn Ramaroson 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):1132-1140
Abstract Direct synthesis of sodium cyclotriphosphate, Na3P3O9 (SCTP), from sodium chloride and orthophosphoric acid as economical starting materials was investigated. Reaction conditions including the heating rate, reaction plateau time, air flow rate, and Na/P molar ratio were found to be key parameters for the elimination of chloride and for the selectivity in SCTP. High yields in SCTP (94–99%) were obtained. The results are very interesting with respect to a potential industrial application for the synthesis of SCTP from point of view of the low cost of the starting materials. 相似文献