Search

A new, validated, sensitive and cheap method for preliminary quantitative evaluation of acetylcholine esterase inhibitory activity is presented. The proposed method combines HPTLC with data analysis by means of image processing software. An in-situ TLC autobiographic method was employed in which regions of the TLC plate which contain acetylcholinesterase inhibitors show up as white spots against the yellow background. Bleaching of the yellow color, caused by substances with acetylcholinesterase inhibitory activity was observed and recorded using a digital camera. ImageJ, JustTLC and Sorbfil, three image processing programs were evaluated for quantitative measurements. For evaluation of the assay efficiency, acetylcholinesterase inhibitory activity of different Amaryllidaceae plant extracts was expressed as Standard Activity Coefficients (SACs), which are relative measures of the activity to the well known acetylcholinesterase inhibitor eserine. We attempted to validate the method according to the ICH guideline. Different statistical data revealed that all image analysis software are able to detect the acetylcholine esterase inhibitory activity at very low concentration levels with the ImageJ program being the best of all three tested software regarding sensitivity, linearity and precision.

A rapid, accurate, specific, repeatable and robust HPTLC method for the determination of lycorine in different Amaryllidaceae plant extracts is presented in this work. No article related to the HPTLC determination of lycorine in plant extracts has been reported in literature. Lycorine, a common alkaloid of family Amaryllidaceae, moreover, there have been some recent reports which reveal the interaction of lycorine with DNA and tRNA. It has, therefore, been to the interest of phytochemists to determine the content of this alkaloid in Amaryllidaceaous plants.

In this article, we report on the alkaloid profile and dynamic of alkaloid content and diversity in two Narcissus plants at different stages of development. The alkaloid profile of the two Narcissus species was investigated by GC/MS and HPTLC. Fifty eight Amaryllidaceae alkaloids were detected, and 25 of them were identified in the different organs of N. tazetta and N. papyraceus. The alkaloid 3-O-methyl-9-O-demethylmaritidine is tentatively identified here for the first time from the Amaryllidaceae family, and four alkaloids (tazettamide, sternbergine, 1-O-acetyllycorine, 2,11-didehydro-2-dehydroxylycorine) are tentatively identified for the first time in the genus Narcissus. The different organs of the two species analyzed showed remarkable differences in their alkaloid pattern, type of biosynthesis, main alkaloid and number of alkaloids. Lycorine-type alkaloids dominated the alkaloid, metabolism in N. papyraceus, while alkaloids of narciclasine-, galanthamine- and homolycorine-types were found only in the species N. tazetta L. Fil: Shawky, Eman. Alexandria University; Egipto Fil: Abou-Donia, Amina H.. Alexandria University; Egipto Fil: Darwish, Fikria A.. Alexandria University; Egipto Fil: Toaima, Soad M.. Alexandria University; Egipto Fil: Takla, Sarah S.. Alexandria University; Egipto Fil: Pigni, Natalia Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina Fil: Bastida, Jaume. Universidad de Barcelona; España

The work presented in this paper demonstrates the use of HPTLC-UV to quantify rutin in the alcoholic extract of Amaryllis belladonna L. (Family Amaryllidaceaea) flowers which was detected, isolated and identified in previous work. The results obtained by HPTLC showed excellent accuracy and precision when compared to the spectrophotometric method.

A new lycorine-type alkaloid, named ())-amarbellisine, was isolated from the bulbs of Egyptian Amaryllis belladonna L. together with the well known alkaloids ())-lycorine, ())-pancracine, (+)-vittatine, (+)-11-hydroxyvittatine, and (+)-hippeastrine. The new alkaloid, containing the pyrrolo[de]phenanthridine ring system, was essentially characterised by spectroscopic and optical methods, and proved to be the 2-methoxy-3a,4,5,7,11b,11c-hexahydro-1H-[1,3]dioxolo[4,5-j]pyrrolo[3,2,1-de]phenanthridinol. By using HPTLC technique we also carried out a comparative study of the relative and total alkaloidal content at two different stages of plant growth. Finally, the antimicrobial activity of the isolated alkaloids was assayed. 2004 Elsevier Ltd. All rights reserved.

This study compares the chloroform extracts of bulbs and roots of Narcissus papyraceus Ker Gawl. and Narcissus tazetta L. The cytotoxicity of the plant extracts was evaluated against human hepatocellular carcinoma cell line (HEPG2) and colon carcinoma cell line (HCT116) in comparison to doxorubicin. The extracts from the after-flowering (AF) bulbs of N. tazetta L. and N. papyraceus exhibited strong cytotoxic activity against HEPG2 (IC50: 2.2, 3.5 μg mL(-1)) and HCT116 (IC50: 4.2, 3.9 μg mL(-1)) cell lines, respectively. N. tazetta L. bulbs exhibited the least cell viability percentage in HepG-2 cell line (5.32%), while the AF root extracts of N. papyraceus exhibited the least cell viability percentage in HCT116 cell line (4.93%), when applied at a concentration of 50 μg mL(-1), thereby being more active than doxorubicin at the same concentration.

Two masanane-type lactone alkaloids, named nobilisitine A and B, were isolated from Egyptian Clivia nobilis and characterized by spectroscopic and chemical methods. Both compounds showed contain the same [2]benzopyrano [3,4- g ]indole ring system and therefore belong to the same subgroup of Amaryllidaceae alkaloids. In particular, nobilisitine A and B, reported as two new alkaloids, proved to be the 5 β -hydroxy-3a,11c- epi -masan-7-one and the 3-hydroxybutanoyl ester of clivonine (5a-hydroxy-5a- epi -masan-7-one), the alkaloid previously extracted from Clivia miniata and belonging to the same alkaloid subgroup. Nobilisitine B appears to be an epimer at the acyl side chain of clivatine.

Bulbs of Pancratium maritimum were found to contain a new glucosyloxy phenolic metabolise as well as 14 known Amaryllidaceae alkaloids. The structure of the phenolic metabolite was elucidated by spectroscopic and chemical methods, and it was identified as narciclasine-4- O -β- d -glucopyranoside. When tested in Artemia salina and potato disc assays the new glucoside showed cytotoxic and antitumour activity very similar to narciclasine.

The work reported in this paper aims at developing an accurate, specific, repeatable and robust HPTLC method for the determination of galanthamine in different Amaryllidaceae plant extracts.

A phytochemical investigation of the bulbs and flowers of Hymenocallis littoralis SALISB., cultivated in Egypt, was carried out, which resulted in the isolation of four alkaloids, lycorine (1), hippeastrine (2), 11-hydroxyvittatine (3), and (+)-8-O-demethylmaritidine (4), and of two flavonoids, quercetin 3'-O-glucoside (5), and rutin (6). The volatile constituents of the plant flowers were analyzed for the first time by GC/MS, which led to the identification of 26 known compounds (Table 1). Finally, the antimicrobial activity of the petroleum ether extract of the flowers of H. littoralis was investigated.

Two new alkaloids; ent-6alpha/6beta-hydroxybuphanisine, (-)-8-demethylmaritidine and seven known alkaloids were isolated from Pancratium sickenbergeri grown in Egypt. Three of the known alkaloids were tested in the NCI cytotoxicity screen, but were found to be inactive.

Two 2-oxyphenanthridinium alkaloids have been isolated from Egyptian Pancratium maritimum and identified as ungeremine and zefbetaine using spectroscopic and chemical methods. The identification of zefbetaine was supported by its partial synthesis from pseudolycorine and by comparison with its unnatural isomer, iso -zefbetaine, which was in turn prepared from sternbergine.

The investigation of the aerial parts of Centaurea glomerata afforded four new sesquiterpene lactones of the germacradienolide type and the lignan lactone arctigenin. Their structures were elucidated by spectroscopic methods.

Hydrastine, canadine, and berberine were determined by the acid-dye technique. At pH 5.6, both the tertiary and the quaternary hydrastis alkaloids formed ion-pairs with bromcresol purple. The liberated hydrastine and canadine from the alkaloid-dye complexes were determined spectrophotometrically in the presence of berberine by the three-wavelength method of analysis. However, berberine could not be assayed successfully by this method due to significant partitioning in the aqueous phase during extraction. At pH 7.2, only berberine could ion-pair with bromcresol purple to form a chloroform-extractable complex. Consequently, the berberine content was analyzed selectively through the colorimetric determination of the combined dye at 580 nm. The suitability of the proposed methods was examined through the analyses of synthetic mixtures of hydrastis alkaloids and samples of hydrastis tincture and liquid extract. Percentage recoveries were 98.2-101.4 for the synthetic mixtures and 98.4-101.7 for the tincture and liquid extract spiked with berberine.

The flower heads of Chrysanthemum coronarium afforded a new sesquiterpene lactone, dihydrocumambrin A, in addition to the known cumambrin A.