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Zsoldos B, Nagy N, Donkó-Tóth V, Keglevich P, Weber M, Dékány M, Nehr-Majoros A, Szőke É, Helyes Z, Hazai L. Novel Piperazine Derivatives of Vindoline as Anticancer Agents. Int J Mol Sci 2024; 25:7929. [PMID: 39063170 PMCID: PMC11277489 DOI: 10.3390/ijms25147929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
A series of novel vindoline-piperazine conjugates were synthesized by coupling 6 N-substituted piperazine pharmacophores at positions 10 and 17 of Vinca alkaloid monomer vindoline through different types of linkers. The in vitro antiproliferative activity of the 17 new conjugates was investigated on 60 human tumor cell lines (NCI60). Nine compounds presented significant antiproliferative effects. The most potent derivatives showed low micromolar growth inhibition (GI50) values against most of the cell lines. Among them, conjugates containing [4-(trifluoromethyl)benzyl]piperazine (23) and 1-bis(4-fluorophenyl)methyl piperazine (25) in position 17 of vindoline were outstanding. The first one was the most effective on the breast cancer MDA-MB-468 cell line (GI50 = 1.00 μM), while the second one was the most effective on the non-small cell lung cancer cell line HOP-92 (GI50 = 1.35 μM). The CellTiter-Glo Luminescent Cell Viability Assay was performed with conjugates 20, 23, and 25 on non-tumor Chinese hamster ovary (CHO) cells to determine the selectivity of the conjugates for cancer cells. These compounds exhibited promising selectivity with estimated half-maximal inhibitory concentration (IC50) values of 2.54 μM, 10.8 μM, and 6.64 μM, respectively. The obtained results may have an impact on the design of novel vindoline-based anticancer compounds.
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Ferenczi E, Keglevich P, Tayeb BA, Minorics R, Papp D, Schlosser G, Zupkó I, Hazai L, Csámpai A. Synthesis and Antiproliferative Effect of New Alkyne-Tethered Vindoline Hybrids Containing Pharmacophoric Fragments. Int J Mol Sci 2024; 25:7428. [PMID: 39000534 PMCID: PMC11242353 DOI: 10.3390/ijms25137428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/26/2024] [Accepted: 07/04/2024] [Indexed: 07/16/2024] Open
Abstract
In the frame of our diversity-oriented research on multitarget small molecule anticancer agents, utilizing convergent synthetic sequences terminated by Sonogashira coupling reactions, a preliminary selection of representative alkyne-tethered vindoline hybrids was synthesized. The novel hybrids with additional pharmacophoric fragments of well-documented anticancer agents, including FDA-approved tyrosine-kinase inhibitors (imatinib and erlotinib) or ferrocene or chalcone units, were evaluated for their antiproliferative activity on malignant cell lines MDA-MB-231 (triple negative breast cancer), A2780 (ovarian cancer), HeLa (human cervical cancer), and SH-SY5Y (neuroblastoma) as well as on human embryonal lung fibroblast cell line MRC-5, which served as a reference non-malignant cell line for the assessment of the therapeutic window of the tested hybrids. The biological assays identified a trimethoxyphenyl-containing chalcone-vindoline hybrid (36) as a promising lead compound exhibiting submicromolar activity on A2780 cells with a marked therapeutic window.
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Mayer S, Nagy N, Keglevich P, Szigetvári Á, Dékány M, Szántay Junior C, Hazai L. Synthesis of Novel Vindoline-Chrysin Hybrids. Chem Biodivers 2021; 19:e202100725. [PMID: 34874114 DOI: 10.1002/cbdv.202100725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/15/2021] [Indexed: 11/05/2022]
Abstract
Vinca alkaloids are well-known microtubule targeting agents, which are used against some types of cancer. Vindoline is one of the monomeric Vinca alkaloids which does not have anti-tumor effect, although its derivatives have serious impact on the field of these indole alkaloids. Chrysin is a secondary plant metabolite, which has broad-spectrum biological activity, among others anticancer activity. Chrysin had shown synergic effect with several antiproliferative compounds (e. g., doxorubicin, cisplatin and ciglitazone), therefore, we attempted the synthesis of a novel vindoline-chrysin hybrid molecule. However, in the first case a diphenylamine structure was isolated. The mechanism of the unexpected reaction was studied, and then the originally targeted hybrid was synthesized by a reverse route coupling. A further hybrid was produced using a different site of the molecule. The antitumor activities were determined against 60 human tumor cell lines (NCI60), where the aimed hybrid showed low micromolar GI50 values on most of the cell lines.
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Für CS, Horváth EJ, Szigetvári Á, Dékány M, Hazai L, Keglevich G, Bölcskei H. Synthesis of Spiro[cycloalkane-pyridazinones] with High Fsp3 Character Part 2*. LETT ORG CHEM 2021. [DOI: 10.2174/1570178617999200728214211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
An extended compound library of spiro[cycloalkane-pyridazinones] with a high Fsp3 character
is targeted. There are two possibilities to improve the physicochemical parameters of a drug candidate
molecules or building blocks, either to replace the aromatic systems with bioisoster heteroaromatic
moieties, e.g. with one or two nitrogen containing ring systems (pyridines, pyridazines, pyrimidines,
etc.), or to increase the Fsp3 character of the compounds. Using a new synthetic approach,
the Grignard reaction of 2-oxaspiro[4.5]decane-1,3-dione and 2-oxaspiro[4.4]nonane-1,3-dione with
p-halophenyl- or p-alkylphenyl-magnesium bromide resulted in the formation of the corresponding
2-oxoethyl-cycloalkanecarboxylic acids, which served as starting materials for the pyridazinones by
reaction with hydrazine or phenylhydrazine. The pyridazinones obtained were alkylated with methyliodide
or benzylbromide. 16 Novel 4-tolyl- or 4-halophenyl-2,3-diazaspiro[5.5]undec-3-en-1-one and
4-tolyl- or 4-halopyhenyl-7,8-diazaspiro[4.5]dec-8-en-6-one, and their N-methyl, N-benzyl, and
N-phenyl derivatives were synthetized. The physicochemical parameters and the Fsp3 character of the
novel compounds obtained were studied. A few of them showed excellent logP and clogP values, but
the introduction of a further phenyl group seemed to be disadvantageous.
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Mayer S, Keglevich P, Keglevich A, Hazai L. New Anticancer Vinca Alkaloids in the Last Decade - A Mini-Review. CURR ORG CHEM 2021. [DOI: 10.2174/1385272825666210216123256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The chemistry and pharmacology of the important Vinca alkaloids such as vinblastine
and vincristine used in anticancer therapy are still investigated widely. Several new
derivatives, e.g., vinflunine, vinorelbine, and vindesine, have been synthesized and become
successful medicines in anti-cancer therapy. In 2012, we published a paper that reviewed the
Vinca derivatives. Nevertheless, the interest in the preparation of new modified structures is
not decreasing either in recent years. In this review, the vinblastine-type molecules with several
substituents, e.g., amide, nitrile, hydrazide, substituted side chains, etc. in different positions
of catharanthine and/or vindoline cores are presented. An important part of the review is
the derivatization of the monomer alkaloid vindoline, which possesses no antitumor effect.
Additionally, new hybrid molecules of these alkaloids are also discussed in this mini-review.
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Nagy S, Szigetvári Á, Ilkei V, Krámos B, Béni Z, Szántay C, Hazai L. Synthesis of aminal-type Lilium candidum alkaloids and lilaline; determination of their relative configuration by the concerted use of NMR spectroscopy and DFT conformational analysis. Tetrahedron 2021. [DOI: 10.1016/j.tet.2020.131827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Für CS, Riszter G, Gerencsér J, Szigetvári Á, Dékány M, Hazai L, Keglevich G, Bölcskei H. Synthesis of Spiro[cycloalkane-pyridazinones] with High Fsp3 Character. LETT DRUG DES DISCOV 2020. [DOI: 10.2174/1570180816666190710130119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
owadays, in course of the drug design and discovery much attention is
paid to the physicochemical parameters of a drug candidate, in addition to their biological activity.
Disadvantageous physicochemical parameters can hinder the success of a drug candidate.
Objective:
Lovering et al. introduced the Fsp3 character as a measure of carbon bond saturation,
which is related to the physicochemical paramethers of the drug. The pharmaceutical research focuses
on the synthesis of compounds with high Fsp3 character.
Methods:
To improve the physicochemical properties (clogP, solubility, more advantageous ADME
profile, etc.) of drug-candidate molecules one possibility is the replacement of all-carbon aromatic
systems with bioisoster heteroaromatic moieties, e.g. with one or two nitrogen atom containing systems,
such as pyridines and pyridazines, etc. The other option is to increase the Fsp3 character of the
drug candidates. Both of these aspects were considered in the design the new spiro[cycloalkanepyridazinones],
the synthesis of which is described in the present study.
Results:
Starting from 2-oxaspiro[4.5]decane-1,3-dione or 2-oxaspiro[4.4]nonane-1,3-dione, the
corresponding ketocarboxylic acids were obtained by Friedel-Crafts reaction with anisole or veratrole.
The ketocarboxylic acids were treated by hydrazine, methylhydrazine or phenylhydrazine to form
the pyridazinone ring. N-Alkylation reaction of the pyridazinones resulted in the formation of further
derivatives with high Fsp3 character.
Conclusion:
A small compound library was obtained incorporating compounds with high Fsp3 characters,
which predicts advantageous physico-chemical parameters (LogP, ClogP and TPSA) for potential
applications in medicinal chemistry.
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Mayer S, Keglevich P, Ábrányi-Balogh P, Szigetvári Á, Dékány M, Szántay C, Hazai L. Synthesis and In Vitro Anticancer Evaluation of Novel Chrysin and 7-Aminochrysin Derivatives. Molecules 2020; 25:molecules25040888. [PMID: 32079315 PMCID: PMC7070641 DOI: 10.3390/molecules25040888] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/13/2020] [Accepted: 02/13/2020] [Indexed: 01/24/2023] Open
Abstract
Chrysin is a naturally occurring flavonoid with mild anticancer activity. In this paper we report the synthesis of new chrysin derivatives alkylated with N-phenylchloroacetamides in position 7. A novel method was developed for the preparation of 7-aminochrysin derivatives via the Smiles rearrangement, resulting in diphenylamine-type compounds. In silico studies of the Smiles rearrangement were performed. We also present the in vitro antiproliferative activity of the synthesized compounds against 60 human tumor cell lines (NCI60). The most potent derivative exhibited nanomolar antitumor activity on the MCF7 cell line of breast cancer (GI50 = 30 nM) and on the HCT-15 cell line of colon cancer (GI50 = 60 nM).
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Keglevich A, Zsiros V, Keglevich P, Szigetvári Á, Dékány M, Szántay C, Mernyák E, Wölfling J, Hazai L. Synthesis and In Vitro Antitumor Effect of New Vindoline-steroid Hybrids. CURR ORG CHEM 2019. [DOI: 10.2174/1385272823666190614113218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
10-Aminovindoline and 17-desacetylvindoline were coupled with 5α-
dihydrotestosterone hemisuccinate and 19-nortestosterone hemisuccinate. As a result,
four vindoline-steroid hybrids were synthesized via a succinate linker. One of the new
hybrid compounds showed significant anticancer effect in vitro in the case of colon cancer
and melanoma cell lines.
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Keglevich A, Szigetvári Á, Dékány M, Szántay C, Keglevich P, Hazai L. Synthesis and in vitro Antitumor Effect of New Vindoline Derivatives Coupled with Triphenylphosphine. CURR ORG CHEM 2019. [DOI: 10.2174/1385272823666190524083236] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An important approach to the development of new antitumor agents is the synthesis of conjugates containing two or more structural units. Taking this into consideration, vindoline derivatives were coupled with triphenylphosphine, to afford the expected phosphonium salts. The new hybrid entities were characterized by NMR spectroscopy, and their anticancer activity was also evaluated.
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Keglevich A, Szigetvári Á, Dékány M, Szántay Jr. C, Keglevich P, Hazai L. Synthesis of vinca alkaloid–triphenylphosphine derivatives having potential antitumor effect. PHOSPHORUS SULFUR 2019. [DOI: 10.1080/10426507.2018.1550780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Keglevich A, Mayer S, Pápai R, Szigetvári Á, Sánta Z, Dékány M, Szántay C, Keglevich P, Hazai L. Attempted Synthesis of Vinca Alkaloids Condensed with Three-Membered Rings. Molecules 2018; 23:molecules23102574. [PMID: 30304796 PMCID: PMC6222653 DOI: 10.3390/molecules23102574] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/17/2018] [Accepted: 10/02/2018] [Indexed: 11/16/2022] Open
Abstract
Our successful work for the synthesis of cyclopropanated vinblastine and its derivatives by the Simmons⁻Smith reaction was followed to build up further three-membered rings into the 14,15-position of the vindoline part of the dimer alkaloid. Halogenated 14,15-cyclopropanovindoline was prepared by reactions with iodoform and bromoform, respectively, in the presence of diethylzinc. Reactions of dichlorocarbene with vindoline resulted in the 10-formyl derivative. Unexpectedly, in the case of the dimer alkaloids vinblastine and vincristine, the rearranged products containing an oxirane ring in the catharanthine part were isolated from the reactions. The attempted epoxidation of vindoline and catharanthine also led to anomalous rearranged products. In the epoxidation reaction of vindoline, an o-quinonoid derivative was obtained, in the course of the epoxidation of catharanthine, a hydroxyindolenine type product and a spiro derivative formed by ring contraction reaction, were isolated. The coupling reaction of vindoline and the spiro derivative obtained in the epoxidation of catharanthine did not result in a bisindole alkaloid. Instead, two surprising vindoline trimers were discovered and characterized by NMR spectroscopy and mass spectrometry.
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Bánóczi Z, Keglevich A, Szabó I, Ranđelović I, Hegedüs Z, Regenbach FL, Keglevich P, Lengyel Z, Gorka-Kereskényi Á, Dubrovay Z, Háda V, Szigetvári Á, Szántay C, Hazai L, Tóvári J, Hudecz F. The effect of conjugation on antitumor activity of vindoline derivatives with octaarginine, a cell-penetrating peptide. J Pept Sci 2018; 24:e3118. [PMID: 30084214 DOI: 10.1002/psc.3118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/05/2018] [Accepted: 07/06/2018] [Indexed: 12/19/2022]
Abstract
Some Vinca alkaloids (eg, vinblastine, vincristine) have been widely used as antitumor drugs for a long time. Unfortunately, vindoline, a main alkaloid component of Catharanthus roseus (L.) G. Don, itself, has no antitumor activity. In our novel research program, we have prepared and identified new vindoline derivatives with moderate cytostatic activity. Here, we describe the effect of conjugation of vindoline derivative with oligoarginine (tetra-, hexa-, or octapeptides) cell-penetrating peptides on the cytostatic activity in vitro and in vivo. Br-Vindoline-(l)-Trp-OH attached to the N-terminus of octaarginine was the most effective compound in vitro on HL-60 cell line. Analysis of the in vitro activity of two isomer conjugates (Br-vindoline-(l)-Trp-Arg8 and Br-vindoline-(d)-Trp-Arg8 suggests the covalent attachment of the vindoline derivatives to octaarginine increased the antitumor activity significantly against P388 and C26 tumour cells in vitro. The cytostatic effect was dependent on the presence and configuration of Trp in the conjugate as well as on the cell line studied. The configuration of Trp notably influenced the activity on C26 and P388 cells: conjugate with (l)-Trp was more active than conjugate with the (d)-isomer. In contrast, conjugates had very similar effect on both the HL-60 and MDA-MB-231 cells. In preliminary experiments, conjugate Br-vindoline-(l)-Trp-Arg8 exhibited some inhibitory effect on the tumor growth in P388 mouse leukemia tumor-bearing mice. Our results indicate that the conjugation of modified vindoline could result in an effective compound even with in vivo antitumor activity.
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Ilkei V, Hazai L, Antus S, Bölcskei H. Flavonoid Alkaloids: Isolation, Bioactivity, and Synthesis. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2018. [DOI: 10.1016/b978-0-444-64058-1.00008-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
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Mayer S, Keglevich P, Ábrányi-Balogh P, Szigetvári Á, Dékány M, Szántay, Jr. C, Hazai L. Attempted Diels-Alder Reactions on Vindoline Derivatives. PERIODICA POLYTECHNICA-CHEMICAL ENGINEERING 2017. [DOI: 10.3311/ppch.11087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The Diels-Alder reaction of vindoline and methyl vinyl ketone resulted in a Friedel-Crafts reaction product. In the reaction between the ortho-quinone derivative of vindoline and N-phenylmaleimide, two anomalous products were obtained, a vindoline dimer, and a condensed vindoline derivative.
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Ilkei V, Spaits A, Prechl A, Müller J, Könczöl Á, Lévai S, Riethmüller E, Szigetvári Á, Béni Z, Dékány M, Martins A, Hunyadi A, Antus S, Szántay C, Balogh GT, Kalaus G, Bölcskei H, Hazai L. C8-selective biomimetic transformation of 5,7-dihydroxylated flavonoids by an acid-catalysed phenolic Mannich reaction: Synthesis of flavonoid alkaloids with quercetin and (–)-epicatechin skeletons. Tetrahedron 2017. [DOI: 10.1016/j.tet.2017.01.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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17
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Ilkei V, Spaits A, Prechl A, Szigetvári Á, Béni Z, Dékány M, Szántay C, Müller J, Könczöl Á, Szappanos Á, Mándi A, Antus S, Martins A, Hunyadi A, Balogh GT, Kalaus G, Bölcskei H, Hazai L, Kurtán T. Biomimetic synthesis and HPLC-ECD analysis of the isomers of dracocephins A and B. Beilstein J Org Chem 2016; 12:2523-2534. [PMID: 28144321 PMCID: PMC5238559 DOI: 10.3762/bjoc.12.247] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/02/2016] [Indexed: 11/23/2022] Open
Abstract
Starting from racemic naringenin ((±)-1), a mixture of dracocephin A stereoisomers 6-(2”-pyrrolidinone-5”-yl)naringenin (±)-2a–d and its regioisomer, dracocephin B 8-(2”-pyrrolidinone-5”-yl)naringenin (±)-3a–d originally isolated from Dracocephalum rupestre, have been synthesized in a one-pot reaction. The separation of 2a–d and 3a–d was achieved by preparative HPLC. The four stereoisomers of each natural product were separated by analytical chiral HPLC and their absolute configuration was studied by the combination of HPLC–ECD measurements and TDDFT–ECD calculations. The synthesized flavonoid alkaloids were further characterized by physicochemical and in vitro pharmacological studies.
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Keglevich P, Szántay C, Hazai L. The Chemistry of Galanthamine. Classical Synthetic Methods and Comprehensive Study on its Analogues. Mini Rev Med Chem 2016; 16:1450-1461. [DOI: 10.2174/1389557516666160321114556] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 01/07/2016] [Accepted: 03/01/2016] [Indexed: 11/22/2022]
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Keglevich A, Hegedus L, Péter L, Gyenese J, Szántay C, Dubrovay Z, Dékány M, Szigetvári Á, Martins A, Molnár J, Hunyadi A, Keglevich P, Hazai L. Anomalous Products in the Halogenation Reactions of Vinca Alkaloids. CURR ORG CHEM 2016. [DOI: 10.2174/1385272820666160617080202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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20
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Keglevich P, Ábrányi-Balogh P, Szigetvári Á, Szántay C, Szántay C, Hazai L. Studies on the mechanism of quaternization of the catharanthine part of vinblastine and vincristine. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Ilkei V, Bana P, Tóth F, Palló A, Holczbauer T, Czugler M, Sánta Z, Dékány M, Szigetvári Á, Hazai L, Szántay C, Szántay C, Kalaus G. A simple synthesis of bannucine and 5′-epibannucine from (−)-vindoline. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.10.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Keglevich P, Hazai L, Kalaus G, Szántay C. Cyclopropanation of Some Alkaloids. PERIODICA POLYTECHNICA-CHEMICAL ENGINEERING 2015. [DOI: 10.3311/ppch.7257] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Szántay C, Keglevich P, Hazai L, Dubrovay Z, Sánta Z, Dékány M, Szántay C, Kalaus G. Bisindole Alkaloids Condensed with a Cyclopropane Ring, Part 2. Cyclopropano-vinorelbine and Its Derivatives. HETEROCYCLES 2015. [DOI: 10.3987/com-14-s(k)20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Szántay C, Keglevich P, Hazai L, Dubrovay Z, Szántay C, Kalaus G. Bisindole Alkaloids Condensed with a Cyclopropane Ring, Part 1. 14,15-Cyclopropanovinblastine and -vincristine. HETEROCYCLES 2014. [DOI: 10.3987/com-13-12918] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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25
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Ilkei V, Faragó K, Sánta Z, Dékány M, Hazai L, Szántay Jr. C, Szántay C, Kalaus G. The First Synthesis of Sessiline. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ijoc.2014.45033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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