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1.
A ruthenium-catalyzed ring opening-ring closing metathesis reaction serves as the key step in the stereoselective synthesis of a new enantiopure 2-substituted-4,5-dehydropiperidine skeleton, a valuable intermediate for the synthesis of piperidine alkaloids (such as (−)-halosaline) and of hydroxylated quinolizidines (such as (2R,9aR)-(+)-2-hydroxy-quinolizidine). 相似文献
2.
3.
E. V. Boltukhina F. I. Zubkov A. V. Varlamov 《Chemistry of Heterocyclic Compounds》2006,42(8):971-1001
Data for 1966–2004 on methods for the construction of tetracyclic systems in which an isoindole ring is condensed with quinoline
and isoquinoline fragments on the [1,2] side are reviewed. Methods and conditions for the synthesis of isoindoloquinolines
and isoindoloisoquinolines are examined. Examples of the synthesis of physiologically active natural alkaloids possessing
the structure of these condensed isoindoles are presented.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1123–1157, August, 2006. 相似文献
4.
M. N. Sultankhodzhaev B. Tashkhodzhaev B. B. Averkiev M. Yu. Antipin 《Chemistry of Natural Compounds》2002,38(1):78-82
The known diterpenoid alkaloids karacoline, karakanine, songorine, napelline, 12-acetylnapelline, cammaconine, and a new 7,17-secoalkaloid of the lycoctonine type, secokaraconitine, were isolated from tubers of Aconitum karacolicum. An x-ray structure analysis of the new alkaloid was performed. 相似文献
5.
The first total synthesis of (±)-cyclooroidin, a member of the pyrrole-imidazole alkaloid family recently isolated from the sponge Agelas oroides in optically pure form, is described. The synthesis was achieved in nine linear steps, with an overall yield of 10%. Key step was a Wolff bromoketone synthesis performed on the intermediate longamide B. 相似文献
6.
Khairitdinova E. D. Tsirlina E. M. Spirikhin L. V. Fedorov N. I. Efremov Yu. Ya. Yunusov M. S. 《Russian Chemical Bulletin》2003,52(9):2078-2080
A new norditerpenoid alkaloid has been isolated from the roots of Delphinium cuneatum. On the basis of 1H, 13C NMR, IR, and mass spectra, the structure of the alkaloid was established as 1,6,14-trimethoxy-7,8-dihydroxy-18-(2-methyl)succinylanthranoyloxyaconane (16-demethoxymethyllycaconitine). The roots of Delphinium cuneatum also contain the known alkaloid methyllycaconitine and N,N"-di(methoxycarbonyl)-3,4-diaminotoluene. 相似文献
7.
Boris Pejin Kristina Tešanović Dragica Jakovljević Sonja Kaišarević Filip Šibul Milena Rašeta 《Natural product research》2019,33(5):750-754
The polysaccharide (PSH) extracts from the edible mushroom species Coprinus comatus and Coprinellus truncorum were screened in liquid for their acetylcholinesterase inhibitory (AChE) activity. Both extracts were found to display inhibition of the aforementioned enzyme reaching similar IC50 values of 0.62 ± 0.07 and 0.61 ± 0.03 mg/mL, respectively. According to the means of FTIR spectroscopy, these PSH extracts mostly contained β-glucans. However, the presence of some proteins and polyphenolics as minor ingredients were also detected. Compared with existing literature data for anti-AChE activity of the sugar samples, the findings within this study may be treated as a profound bioactivity. Consequently, this study puts some light on the possible use of the screened macrofungi in the palliative treatment of Alzheimer’s disease. 相似文献
8.
A new procedure for determining nitrogenated bases by forming ion pairs with Fe(SCN)63– is studied. The method consists of extracting the ion pair formed by a nitrogenated base and the inorganic complex Fe(SCN)63– into an organic phase, and measuring the iron in the organic phase by AAS at 248.3 nm. The optimal experimental conditions for determining amylocaine, avacan, bromhexine, diphenhydramine and papaverine are studied. The organic phase used is 1,2-dichloroethane. The standard deviation of the method varies between 10–1 and 10–2. The interferences produced by various substances are studied. 相似文献
9.
A. E. Goncharov A. A. Politov N. A. Pankrushina O. I. Lomovskii 《Chemistry of Natural Compounds》2006,42(3):336-339
Extracts of Aconitum septentrionale Koelle roots obtained using chloroform, isopropanol, and ethanol were purified using chloroform and basic γ-Al2O3. Ballast materials were selectively adsorbed by γ-Al2O3, increasing the mass fraction of lappaconitine in the extract. The ethanol extract was purified most. The degree of lappaconitine
extraction by chloroform was unaffected by the presence of γ-Al2O3. However, the mass fraction in the extract and lappaconitine extraction from Aconitum septentrionale were increased more than twice.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 274–276, May–June, 2006. 相似文献
10.
D. M. Turdybekov K. M. Turdybekov E. V. Burdel'naya A. Zh. Turmukhambetov S. M. Adekenov Yu. V. Gatilov 《Chemistry of Natural Compounds》2003,39(1):19-21
The structure of lappacontine hydrobromide hydrate was solved by an x-ray structure analysis. 相似文献