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Screening of biological activity of various species of the genus Narcissus sp. IV
Valešová, Zuzana ; Suchánková, Daniela (advisor) ; Vrabec, Rudolf (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmacognosy and Pharmaceutical botany Author: Zuzana Valešová Supervisor: PharmDr. Daniela Suchánková, Ph.D. Title of thesis: Screening of biological activity of various species of the genus Narcissus sp. IV Key words: Narcisus sp., bulbs, alkaloidal extracts, GC/MS analysis, biological activity, acetylcholinesterase, butyrylcholinesterase Plants of the family Amaryllidaceae have a long history of using as traditional remedies. Plants of this family produce structurally unique isoquinoline compounds, which have been called "Amaryllidaceae alkaloids". Over 600 Amaryllidaceae alkaloids have been isolated, which are characterized by interesting biological activity. Cytotoxic, antimicrobial, antiparasitic, anti-inflammatory activity has been described, but the best known is the inhibitory activity against the enzymes acetylcholinesterase and butyrylcholinesterase, which is used in practice for therapy of Alzheimer's disease. [8, 9] The genus Narcissus is primarily known as decorative plants that blooms in early spring. However, daffodils are also used to isolate galanthamine or other alkaloids that are being studied for their effect. [13] The aim of this thesis was to screen the biological activity of extracts of the...
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Alkaloids of Zephyranthes citrina (Amaryllidaceae): isolation, determination of structure, biological activity
Čejdová, Aneta ; Vrabec, Rudolf (advisor) ; Cahlíková, Lucie (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: Aneta Čejdová Title of diploma thesis: Alkaloids of Zephyranthes citrina (Amaryllidaceae): isolation, determination of structure, biological activity Key words: Amaryllidaceae, alkaloids, Zephyranthes citrina, biological activity, isolation From the selected alkaloidal fractions obtained from the bulbs of Zephyranthes citrina, six different alkaloids were isolated by chromatographic methods. They were identified using standard analytical methods (NMR, MS, HRMS, and optical rotation). The obtained compounds belong to the lycorine structural type (lycorine, galanthine, 6-oxonarcissidine, narcissidine) and haemanthamine structural type (maritidine, zephyranine E). The alkaloid 6-oxonarcissidine has not been described in the literature yet. The inhibitory activity against human AChE and BuChE was measured for the isolated alkaloids. Lycorine, galanthine, narcissidine, and maritidine have already been measured in many studies before; therefore, the attention was focused on the two less-known alkaloids: zephyranine E and 6-oxonarcissidine. However, the resulting IC₅₀ values of both alkaloids against human AChE and BuChE were above 100 µM, which indicates their insignificant...
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Screening of biological activity of various species of the genus Narcissus sp. IV
Valešová, Zuzana ; Suchánková, Daniela (advisor) ; Vrabec, Rudolf (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department: Department of Pharmacognosy and Pharmaceutical botany Author: Zuzana Valešová Supervisor: PharmDr. Daniela Suchánková, Ph.D. Title of thesis: Screening of biological activity of various species of the genus Narcissus sp. IV Key words: Narcisus sp., bulbs, alkaloidal extracts, GC/MS analysis, biological activity, acetylcholinesterase, butyrylcholinesterase Plants of the family Amaryllidaceae have a long history of using as traditional remedies. Plants of this family produce structurally unique isoquinoline compounds, which have been called "Amaryllidaceae alkaloids". Over 600 Amaryllidaceae alkaloids have been isolated, which are characterized by interesting biological activity. Cytotoxic, antimicrobial, antiparasitic, anti-inflammatory activity has been described, but the best known is the inhibitory activity against the enzymes acetylcholinesterase and butyrylcholinesterase, which is used in practice for therapy of Alzheimer's disease. [8, 9] The genus Narcissus is primarily known as decorative plants that blooms in early spring. However, daffodils are also used to isolate galanthamine or other alkaloids that are being studied for their effect. [13] The aim of this thesis was to screen the biological activity of extracts of the...
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Alkaloids from Vinca minor L. and their biological activity.
Vrabec, Rudolf ; Opletal, Lubomír (advisor) ; Kokoška, Ladislav (referee) ; Lapčík, Oldřich (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: Mgr. Rudolf Vrabec Supervisor: prof. RNDr. Lubomír Opletal, CSc. Title of doctoral thesis: Alkaloids from Vinca minor L. and their biological activity Key words: Vinca, indole alkaloids, Alzheimer's disease, AChE, BuChE, POP, GSK-3β, cytotoxicity, docking study Twenty-three monoterpene indole alkaloids of different structural types were isolated by chromatographic techniques from aerial parts of Vinca minor L. (Apocynaceae). The alkaloids were identified by a combination of analytical methods (NMR, MS, HRMS, optical rotation). Among obtained compounds, one structure was undescribed so far and was named vincaminorudeine. Eleven alkaloids were isolated for the first time from this species. Obtained compounds that were isolated in sufficient amounts were subjected to in vitro tests for the inhibition of hAChE, hBuChE, POP, and GSK-3β - enzymes that play a key role in the pathophysiology of Alzheimer's disease. The most active alkaloid was (−)-2-ethyl-3[2-(3-ethylpiperidinyl)-ethyl]-1H- indole (VR-19) with IC50 = 0,65 µM for the inhibition of hBuChE, and with IC50 = 58 µM for the inhibition of POP. Other alkaloids which exhibited a significant inhibition against hBuChE (IC50 30...
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Alkaloids from Vinca minor L. and their biological activity.
Vrabec, Rudolf ; Opletal, Lubomír (advisor) ; Kokoška, Ladislav (referee) ; Lapčík, Oldřich (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: Mgr. Rudolf Vrabec Supervisor: prof. RNDr. Lubomír Opletal, CSc. Title of doctoral thesis: Alkaloids from Vinca minor L. and their biological activity Key words: Vinca, indole alkaloids, Alzheimer's disease, AChE, BuChE, POP, GSK-3β, cytotoxicity, docking study Twenty-three monoterpene indole alkaloids of different structural types were isolated by chromatographic techniques from aerial parts of Vinca minor L. (Apocynaceae). The alkaloids were identified by a combination of analytical methods (NMR, MS, HRMS, optical rotation). Among obtained compounds, one structure was undescribed so far and was named vincaminorudeine. Eleven alkaloids were isolated for the first time from this species. Obtained compounds that were isolated in sufficient amounts were subjected to in vitro tests for the inhibition of hAChE, hBuChE, POP, and GSK-3β - enzymes that play a key role in the pathophysiology of Alzheimer's disease. The most active alkaloid was (−)-2-ethyl-3[2-(3-ethylpiperidinyl)-ethyl]-1H- indole (VR-19) with IC50 = 0,65 µM for the inhibition of hBuChE, and with IC50 = 58 µM for the inhibition of POP. Other alkaloids which exhibited a significant inhibition against hBuChE (IC50 30...
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The antioxidant activity of St. John's wort explantate cultures
Vrabec, Rudolf ; Martin, Jan (advisor) ; Spilková, Jiřina (referee)
St. John's wort is a herbal medicine well known for its anti-depressant effect. It contains anthraquinone derivates, prenylated floroglucinols, tannins, hydroxycinnamic acids, and especially flavonoids, which have a wide range of biological effects on the body including antioxidant properties. Antioxidants are one of the possibilities to protect body from harmful influences of free radicals - highly reactive particles that damage biological structures. In this work, two methods (DPPH and superoxide radical) were used to determinate antioxidant activity of methanolic and aqueous extracts of dried St. John's wort - Hypericum Perforatum L. and its callus and suspension explant cultures. The results are processed into tables and graphs which compare the effectiveness of extracts to quench the radicals. EC50 for the methanolic extract was 0,064 mg/ml and for the aqueous extract 0,068 mg/ml. EC50 for the aqueous extract was 16,727 mg/ml, but unfortunatelly the other antioxidant activity values for EC50 were too low to evaluate. Determination of the content of flavonoids hyperoside and quercetin by high performance liquid chromatography shows that their highest content is in the drug extracts and that the explant cultures have negligible content of the flavonoids. There is no content of hypericin in all...
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