Although the medicinal plant Artemisia rupestris L. has been widely researched for several decades, its alkaloids have never been isolated before. To our surprise, the alkaloids in the plant were not detected in the stems but detected in the flowers. Herein, a novel and strange guaipyridine sesquiterpene alkaloid with a carboxyl group named rupestine was purified successfully from the total alkaloids extracted from the flowers by high-speed counter-current chromatography (HSCCC). The two-phase solvent system used was composed of ethyl acetate-methanol-water (8:1:7, v/v/v). Fifty six milligrams of rupestine was obtained at over 97% purity and 95% recovery from 200 mg of the total alkaloids in one-step separation. Its structure was elucidated by spectroscopic methods including high resolution ESI-MS, (1)H NMR, (13)C NMR, Heteronuclear Multiple Bond Correlation (HMBC), Heteronuclear Single Quantum Coherence (HSQC), and Nuclear Overhauser Enhancement Spectroscopy (NOESY).
The known compounds cappariloside A and stachydrin, an adenosine nucleoside, and for the first time from plants of the Capparidaceae family the known compounds hypoxanthine and uracil were isolated from Capparis spinosa (Capparidaceae) fruit.Capparis spinosa (Capparidaceae) is widely distributed throughout the whole world. Information on alkaloids, flavonoids, and glycosides [1][2][3][4][5] in addition to lipids and carbohydrates [6] from this plant has been published.Herein we report a study of alkaloids from fruit of C. spinosa growing in Xinjiang Autonomy Region of China. The alcohol extract of ground and defatted ripe fruit of C. spinosa produced total extracted substances containing also water-soluble alkaloids of the betaine type. The lipophilic components were removed by washing the acidic solution of extracted substances with ether. The total alkaloids were obtained by treatment of the acidic solution with conc. ammonia to adjust the pH to 9 and extraction with n-butanol (fraction A). The dried alkaloidal fraction A was chromatographed over a silica-gel column with elution by CHCl 3 , CHCl 3 :CH 3 OH, and CH 3 OH. Work up with CH 3 OH of the CHCl 3 :CH 3 OH (12:1) fractions isolated amorphous hypoxanthine (1) and uracil (2) [7,8], which were identified using PMR and 13 C NMR spectral data and authentic samples (spectral properties are given in Experimental).Crystalline 3, mp 228-229°C, was isolated from CHCl 3 :CH 3 OH (10:1) fractions. The UV spectrum of 3 had absorption maxima at 206.4 and 259.6 nm. The IR spectrum had absorption bands for active H at 3425, 3370 (NH 2 ), 3320, and 3143 (OH) cm −1 ; lactone ring (tetrahydrofuran), 1680; ether, 1100 and 1030; and tri-and disubstituted aromatic rings, 1600, 1577, 870, 822, 795, and 765. The mass spectrum of 3 gave a peak for the molecular ion with m/z 267 and fragments with m/z 148 and 119 produced by cleavage of the tetrahydrofuran ring. Peaks for ions with m/z 134 and 133 corresponded to fragments formed by cleavage of the C-N bond between the main part of the molecule and the tetrahydrofuran ring. NMR data ( 1 H and 13 C) are given in Experimental.The spectral data (UV, IR, mass, NMR) were reminiscent of those of adenosine (3) [9]. However, the lack of an authentic sample prohibited reliable identification of 3 as adenosine. As a result, a single-crystal x-ray structure analysis (XSA) of 3 showed that the isolated base was in fact the known nucleoside adenosine (C 10 H 13 N 5 O 4 ), which is constructed from D-ribose and a purine base in which the N-9 atom of the purine base adenine is bonded to C-1 of D-ribose [10][11][12][13]. Adenosine
A. Nabiev, and V. U. KhuzhaevA series of new convolvine derivatives based on the alkaloid from Convolvulus subhirsutus and C. pseudocanthabrica were synthesized using alkylhalides and aliphatic and aromatic acid chlorides. Results of biological tests showed that convolvine and its derivatives exhibited pronounced antihypoxic, immunomodulating, and anti-inflammatory activity.The aerial parts of Convolvulus subhirsutus and C. pseudocanthabrica growing in Uzbekistan [1] have previously yielded 10 alkaloids [2-7] that were tropane derivatives, the principal ones being convolvine and convolamine with a content of 45-50% of the total alkaloids. A quantitative determination found that the content of the alkaloid mixture in the aerial part was 0.6%; in the roots, 1.6% of the dry plant weight.The convolvine content in C. subhirsutus and C. pseudocanthabrica reaches 0.3% in the aerial part; 0.7%, in roots. As a result of the availability of convolvine, a series of its derivatives were prepared. Their pharmacological properties were studied in a search for compounds with valuable pharmacological activity. For this, convolvine (1) was reacted with alkyl halides (methyliodide, hexylbromide, amylbromide, nonylbromide, benzylchloride) to produce the corresponding derivatives N-methylconvolvine hydroiodide (2), N-amylconvolvine hydrobromide (3), N-hexylconvolvine hydrobromide (4), N-nonylconvolvine hydrobromide (5), and N-benzylconvolvine (6) according to the scheme:Convolvine was also reacted with aliphatic and aromatic acid chlorides to produce N-benzoylconvolvine (7), N-chloroacetylconvolvine (8), and N-4c-nitrobenzoylconvolvine (9), reduction of 9 produced N-4c-aminobenzoylconvolvine (10), and N-naphthoylconvolvine (11):
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.