Molecules

Editorial

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3 pages, 205 KiB

Open AccessEditorial

Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications

by Éva Frank and György Szőllősi

Molecules 2021, 26(15), 4617; https://doi.org/10.3390/molecules26154617 - 30 Jul 2021

Cited by 14 | Viewed by 2072

Abstract

Most of the organic compounds applied as pharmaceuticals or intermediates utilized in their synthesis contain heterocyclic motifs [...] Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

Research

Jump to: Editorial, Review

9 pages, 6412 KiB

Open AccessCommunication

Synthesis and Properties of Pentafluorosulfanyl Group (SF₅)-Containing Meta-Diamide Insecticides

by Jae Gon Kim, On-Yu Kang, Sang Mee Kim, Guldana Issabayeva, In Seok Oh, Yaeji Lee, Won Hyung Lee, Hwan Jung Lim and Seong Jun Park

Molecules 2020, 25(23), 5536; https://doi.org/10.3390/molecules25235536 - 25 Nov 2020

Cited by 9 | Viewed by 3823

Abstract

Herein, we describe novel pentafluorosulfanyl (SF₅) group-containing meta-diamide insecticides. For the facile preparation of the SF₅-based compounds 4a–d, practical synthetic methods were applied. Among newly synthesized compounds, 3-benzamido-N-(2,6-dimethyl-4-(pentafluoro-λ⁶-sulfanyl)phenyl)-2-fluorobenzamide 4d showed (i) a [...] Read more.

Herein, we describe novel pentafluorosulfanyl (SF₅) group-containing meta-diamide insecticides. For the facile preparation of the SF₅-based compounds 4a–d, practical synthetic methods were applied. Among newly synthesized compounds, 3-benzamido-N-(2,6-dimethyl-4-(pentafluoro-λ⁶-sulfanyl)phenyl)-2-fluorobenzamide 4d showed (i) a high insecticidal activity, (ii) an excellent selectivity to insects, and (iii) good levels of water solubility and log P values. In this study, we demonstrated that the pentafluorosulfanyl moiety could serve as an attractive functionality for the discovery of a new scope of crop-protecting agents. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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15 pages, 2816 KiB

Open AccessArticle

Synthesis and Antibacterial Evaluation of New Pyrazolo[3,4-d]pyrimidines Kinase Inhibitors

by Chiara Greco, Rosa Catania, Dario Leonardo Balacco, Vincenzo Taresco, Francesca Musumeci, Cameron Alexander, Alan Huett and Silvia Schenone

Molecules 2020, 25(22), 5354; https://doi.org/10.3390/molecules25225354 - 16 Nov 2020

Cited by 10 | Viewed by 2708

Abstract

Pyrazolo[3,4-d]pyrimidines represent an important class of heterocyclic compounds well-known for their anticancer activity exerted by the inhibition of eukaryotic protein kinases. Recently, pyrazolo[3,4-d]pyrimidines have become increasingly attractive for their potential antimicrobial properties. Here, we explored the activity of a [...] Read more.

Pyrazolo[3,4-d]pyrimidines represent an important class of heterocyclic compounds well-known for their anticancer activity exerted by the inhibition of eukaryotic protein kinases. Recently, pyrazolo[3,4-d]pyrimidines have become increasingly attractive for their potential antimicrobial properties. Here, we explored the activity of a library of in-house pyrazolo[3,4-d]pyrimidines, targeting human protein kinases, against Staphylococcus aureus and Escherichia coli and their interaction with ampicillin and kanamycin, representing important classes of clinically used antibiotics. Our results represent a first step towards the potential application of dual active pyrazolo[3,4-d]pyrimidine kinase inhibitors in the prevention and treatment of bacterial infections in cancer patients. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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18 pages, 3992 KiB

Open AccessArticle

Design of Anticancer 2,4-Diaminopyrimidines as Novel Anoctamin 1 (ANO1) Ion Channel Blockers

by Taewoo Kim, Sinyoung Cho, Haejun Oh, Joonseong Hur, Haedong Kim, Young-Ho Choi, Seongho Jeon, Young Duk Yang and Seok-Ho Kim

Molecules 2020, 25(21), 5180; https://doi.org/10.3390/molecules25215180 - 06 Nov 2020

Cited by 6 | Viewed by 2210

Abstract

Pyrimidine is a privileged scaffold in many synthetic compounds exhibiting diverse pharmacological activities, and is used for therapeutic applications in a broad spectrum of human diseases. In this study, we prepared a small set of pyrimidine libraries based on the structure of two [...] Read more.

Pyrimidine is a privileged scaffold in many synthetic compounds exhibiting diverse pharmacological activities, and is used for therapeutic applications in a broad spectrum of human diseases. In this study, we prepared a small set of pyrimidine libraries based on the structure of two hit compounds that were identified through the screening of an in-house library in order to identify an inhibitor of anoctamin 1 (ANO1). ANO1 is amplified in various types of human malignant tumors, such as head and neck, parathyroid, and gastrointestinal stromal tumors, as well as in breast, lung, and prostate cancers. After initial screening and further structure optimization, we identified Aa3 as a dose-dependent ANO1 blocker. This compound exhibited more potent anti-cancer activity in the NCI-H460 cell line, expressing high levels of ANO1 compared with that in A549 cells that express low levels of ANO1. Our results open a new direction for the development of small-molecule ANO1 blockers composed of a pyrimidine scaffold and a nitrogen-containing heterocyclic moiety, with drug-like properties. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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17 pages, 1117 KiB

Open AccessArticle

Skin Damages—Structure Activity Relationship of Benzimidazole Derivatives Bearing a 5-Membered Ring System

by Ernestine Nicaise Djuidje, Elisa Durini, Sabrina Sciabica, Elena Serra, Jan Balzarini, Sandra Liekens, Stefano Manfredini, Silvia Vertuani and Anna Baldisserotto

Molecules 2020, 25(18), 4324; https://doi.org/10.3390/molecules25184324 - 21 Sep 2020

Cited by 13 | Viewed by 2825

Abstract

In the search for scaffolds for multifunctional compounds we investigated the structure activity relationship of a class of benzimidazole derivatives bearing 5-membered ring. The newly synthesized and the already known compounds were divided into three classes that present different substituent at 5 position [...] Read more.

In the search for scaffolds for multifunctional compounds we investigated the structure activity relationship of a class of benzimidazole derivatives bearing 5-membered ring. The newly synthesized and the already known compounds were divided into three classes that present different substituent at 5 position of the benzimidazole ring (-H, -COOH or –SO₃H) and different heterocycle at position 2 (thiophene, furan or pyrrole). All the derivatives were synthesized and tested to determine their photoprotective profile against UV rays, in vitro antioxidant capacity against different radicals (DPPH and FRAP test), antifungal inhibitory activity (dermatophytes and Candida albicans), antiviral and antiproliferative activity. A Structure-Activity Relationship study indicated compound 10, bearing a pyrrole heterocycle on the benzimidazole ring, as the best multifunctional derivative of the series and as potential candidate for the development of drugs especially in case of melanoma. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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20 pages, 2116 KiB

Open AccessArticle

Multistep Synthesis and In Vitro Anticancer Evaluation of 2-Pyrazolyl-Estradiol Derivatives, Pyrazolocoumarin-Estradiol Hybrids and Analogous Compounds

by Barnabás Molnár, Mohana Krishna Gopisetty, Dóra Izabella Adamecz, Mónika Kiricsi and Éva Frank

Molecules 2020, 25(18), 4039; https://doi.org/10.3390/molecules25184039 - 04 Sep 2020

Cited by 12 | Viewed by 2724

Abstract

Although the hormone independent cytotoxic activity of several estradiol derivatives endowed with a simple substituent at C-2 has been reported so far, 2-heterocyclic and 2,3-condensed analogs are less investigated from both synthetic and pharmacological points of view. Therefore, novel A-ring-connected 2-pyrazoles of estradiol [...] Read more.

Although the hormone independent cytotoxic activity of several estradiol derivatives endowed with a simple substituent at C-2 has been reported so far, 2-heterocyclic and 2,3-condensed analogs are less investigated from both synthetic and pharmacological points of view. Therefore, novel A-ring-connected 2-pyrazoles of estradiol and, for comparison, their structurally simplified non-steroidal pairs were synthesized from estradiol 3-methyl ether and 6-methoxy-1,2,3,4-tetrahydronaphthalene. Friedel-Crafts acetylation of the protected phenolic compounds and subsequent O-demethylation led to ortho-substituted derivatives regioselectively, which were converted to arylhydrazones with phenylhydrazine, 4-tolylhydrazine and 4-chloro-phenylhydrazine, respectively, under microwave conditions. The hydrazones were subjected to cyclization with the Vilsmeier-Haack reagent immediately after preparation and the ring closure/formylation sequence resulted in steroidal and non-steroidal 4′-formylpyrazoles in moderate to good yields. During reductive transformations, 4-hydroxymethyl-pyrazoles were obtained, while oxidative lactonization of the 4-formylpyrazole moiety with the phenolic OH in the presence of the Jones reagent afforded A-ring-integrated pyrazolocoumarin hybrids and related analogs. Steroidal pyrazoles, which were produced as C-17 acetates due to acetylation of C-17 OH during the primary Friedel-Crafts reaction, underwent deacetylation in alkaline methanol to furnish 2-heterocyclic estradiol derivatives. Pharmacological studies revealed the overall and cancer cell-specific cytotoxicity of the derivatives and the half maximal inhibitory concentrations were obtained for the most promising compounds. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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20 pages, 9637 KiB

Open AccessArticle

Stabilisation of Exotic Tribromide (Br₃⁻) Anions via Supramolecular Interaction with a Tosylated Macrocyclic Pyridinophane. A Serendipitous Case

by Álvaro Martínez-Camarena, Matteo Savastano, Carla Bazzicalupi, Antonio Bianchi and Enrique García-España

Molecules 2020, 25(14), 3155; https://doi.org/10.3390/molecules25143155 - 10 Jul 2020

Cited by 13 | Viewed by 2629

Abstract

Tetraaza-macrocyclic pyridinophane L-Ts, decorated with a p-toluenesulfonyl (tosyl; Ts) group, appear to be a useful tool to provide evidence on how the interplay of various supramolecular forces can help stabilise exotic anionic species such as tribromide (Br₃⁻) anions. Indeed, [...] Read more.

Tetraaza-macrocyclic pyridinophane L-Ts, decorated with a p-toluenesulfonyl (tosyl; Ts) group, appear to be a useful tool to provide evidence on how the interplay of various supramolecular forces can help stabilise exotic anionic species such as tribromide (Br₃⁻) anions. Indeed, crystals of (H₂L-Ts)(Br₃)_1.5(NO₃)_0.5 unexpectedly grew from an acidic (HNO₃) aqueous solution of L-Ts in the presence of Br⁻ anions. The crystal structure of this compound was determined by single crystal XRD analysis. Hydrogen bonds, salt-bridges, anion-π, π-π stacking, and van der Waals interactions contribute to stabilising the crystal lattice. The observation of two independent Br₃⁻ anions stuck over the π-electron densities of pyridine and tosyl ligand groups, one of them being sandwiched between two pyridine rings, corroborates the significance of anion-π interactions for N-containing heterocycles. We show herein the possibility of detecting anion-π contacts from fingerprint plots generated by Hirshfeld surface analysis, demonstrating the effective usage of this structural investigation technique to further dissect individual contributions of stabilising supramolecular forces. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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30 pages, 12393 KiB

Open AccessArticle

New Paracyclophanylthiazoles with Anti-Leukemia Activity: Design, Synthesis, Molecular Docking, and Mechanistic Studies

by Ashraf A Aly, Stefan Bräse, Alaa A. Hassan, Nasr K. Mohamed, Lamiaa E. Abd El-Haleem, Martin Nieger, Nesrin M. Morsy and Elshimaa M. N. Abdelhafez

Molecules 2020, 25(13), 3089; https://doi.org/10.3390/molecules25133089 - 07 Jul 2020

Cited by 13 | Viewed by 2827

Abstract

A new series of methyl 2-(2-(4′-[2.2]paracyclophanyl)-hydrazinylidene)-3-substituted-4-oxothiazolidin-5-ylidene)acetates 3a–f were synthesized from the reaction of paracyclophanyl-acylthiosemicarbazides 2a–f with dimethyl acetylenedicarboxylate. Based upon nuclear magnetic resonance (NMR), infrared (IR), and mass spectra (HRMS), the structure of the obtained products was elucidated. X-ray [...] Read more.

A new series of methyl 2-(2-(4′-[2.2]paracyclophanyl)-hydrazinylidene)-3-substituted-4-oxothiazolidin-5-ylidene)acetates 3a–f were synthesized from the reaction of paracyclophanyl-acylthiosemicarbazides 2a–f with dimethyl acetylenedicarboxylate. Based upon nuclear magnetic resonance (NMR), infrared (IR), and mass spectra (HRMS), the structure of the obtained products was elucidated. X-ray structure analysis was also used as unambiguous tool to elucidate the structure of the products. The target compounds 3a–f were screened against 60 cancer cell lines. They displayed anticancer activity against a leukemia subpanel, namely, RPMI-8226 and SR cell lines. The activity of compound 3a was found as the most cytotoxic potency against 60 cancer cell lines. Consequently, it was selected for further five doses analysis according to National Cancer Institute (NCI) protocol. The cytotoxic effect showed selectivity ratios ranging between 0.63 and 1.28 and between 0.58 and 5.89 at the GI₅₀ and total growth inhibition (TGI) levels, respectively. Accordingly, compound 3a underwent further mechanistic study against the most sensitive leukemia RPMI-8226 and SR cell lines. It showed antiproliferation with IC50 = 1.61 ± 0.04 and 1.11 ± 0.03 µM against RPMI-8226 and SR cell lines, respectively. It also revealed a remarkable tubulin inhibitory activity, compared to colchicine with IC50 = 4.97 µM/mL. Caspase-3, BAX, and Bcl-2 assays for 3a using annexin V-FITC staining revealed significant pro-apoptotic activity. Furthermore, multidrug-resistant leukemia SR cells were used to show better resistance indices (1.285 ng/mL, 1.15-fold) than the reference. Docking studies with β-tubulin indicate that most of the tested compounds illustrated good binding at the colchicine binding site of the enzyme, especially for compound 3a, which made several interactions better than that of the reference colchicine. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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11 pages, 695 KiB

Open AccessArticle

Synthesis and Characterization of New Series of 1,3-5-Triazine Hydrazone Derivatives with Promising Antiproliferative Activity

by Hessa H. Al H. Al Rasheed, Azizah M. M. Malebari, Kholood A. A. Dahlous and Ayman El-Faham

Molecules 2020, 25(11), 2708; https://doi.org/10.3390/molecules25112708 - 11 Jun 2020

Cited by 10 | Viewed by 3096

Abstract

A new series of s-triazine hydrazone derivatives was prepared based on the reaction of 6-hydrazino-2,4-disubstituted-s-triazine with p-substituted benzaldehyde derivatives using a straightforward synthetic pathway. The antiproliferative activity of all synthesized compounds was evaluated against two human cancer cell lines; [...] Read more.

A new series of s-triazine hydrazone derivatives was prepared based on the reaction of 6-hydrazino-2,4-disubstituted-s-triazine with p-substituted benzaldehyde derivatives using a straightforward synthetic pathway. The antiproliferative activity of all synthesized compounds was evaluated against two human cancer cell lines; breast cancer MCF-7 and colon carcinoma HCT-116 using MTT assay. Among all, 11 compounds have shown strong to moderate antiproliferative activity with IC₅₀ values in the range 1.01–18.20 µM in MCF-7 and 0.97–19.51 µM in HCT-116. The best results were obtained with 4,4’-(6-(2-(pyridin-2-ylmethylene)hydrazinyl)-1,3,5-triazine-2,4-diyl) dimorpholine 11 (IC₅₀ = 1.0 µM and 0.98 µM in MCF-7 and HCT-116 cell lines, respectively). The substituents on the s-triazine core as well as the substituent at the benzylidene moiety have a great effect on the antiproliferative activity. Whereas compounds containing dimorpholino-s-triazine derivatives 8a–e showed more potent antiproliferative in MCF-7 compared to their analogs 7a–f (compounds containing two-piperidine rings), compounds containing one piperidine and one morpholine ring 9a–f showed better IC₅₀values in the range 10.4–22.2 µM. On the other hand, compounds containing two-piperidine rings 7a–f showed more potent antiproliferative in HCT-116 (IC₅₀ values in the range 8.8–19.5 µM) than their analogs 8a–e and 9a–f. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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23 pages, 5714 KiB

Open AccessArticle

Synthesis, Molecular Recognition Study and Liquid Membrane-Based Applications of Highly Lipophilic Enantiopure Acridino-Crown Ethers

by Ádám Golcs, Bálint Árpád Ádám, Viola Horváth, Tünde Tóth and Péter Huszthy

Molecules 2020, 25(11), 2571; https://doi.org/10.3390/molecules25112571 - 31 May 2020

Cited by 10 | Viewed by 3145

Abstract

New highly lipophilic enantiopure crown ethers containing a heterocyclic unit have been synthesized. Phase transport, UV-Vis- and fluorescence spectrophotometric investigations as well as electrochemical studies on the complexation of the new macrocycles with several amine and amino acid derivatives were also carried out. [...] Read more.

New highly lipophilic enantiopure crown ethers containing a heterocyclic unit have been synthesized. Phase transport, UV-Vis- and fluorescence spectrophotometric investigations as well as electrochemical studies on the complexation of the new macrocycles with several amine and amino acid derivatives were also carried out. Achiral amines were used for studying the structural preference of the new macrocycles. Among the studied structural features of the guest molecules, the intermolecular π-π interaction showed the most significant effect on complexation, which made the aralkylamine-type compounds the most preferable guest molecules. The studied liquid membrane-based applications and photophysical investigations showed appreciable enantiomeric recognition toward some aralkylamine model compounds with homochiral preferences. New crown ether derivatives (R,R)-2 and (S,S)-2 were successfully applied as enantioselective carrier and sensor molecules. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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25 pages, 16563 KiB

Open AccessArticle

Discovery of New Apoptosis-Inducing Agents for Breast Cancer Based on Ethyl 2-Amino-4,5,6,7-Tetra Hydrobenzo[b]Thiophene-3-Carboxylate: Synthesis, In Vitro, and In Vivo Activity Evaluation

by Emad M. Gad, Mohamed S. Nafie, Elsayed H. Eltamany, Magdy S. A. G. Hammad, Assem Barakat and Ahmed T. A. Boraei

Molecules 2020, 25(11), 2523; https://doi.org/10.3390/molecules25112523 - 28 May 2020

Cited by 62 | Viewed by 3722

Abstract

A multicomponent synthesis was empolyed for the synthesis of ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate 1. An interesting cyclization was obtained when the amino-ester 1 reacted with ethyl isothiocyanate to give the benzo[4,5]thieno[2,3-d][1,3]thiazin-4-one 3. Acylation of the amino-ester 1 with chloroacetyl [...] Read more.

A multicomponent synthesis was empolyed for the synthesis of ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate 1. An interesting cyclization was obtained when the amino-ester 1 reacted with ethyl isothiocyanate to give the benzo[4,5]thieno[2,3-d][1,3]thiazin-4-one 3. Acylation of the amino-ester 1 with chloroacetyl chloride in DCM and Et₃N afforded the acylated ester 4. The amino-ester 1 was cyclized to benzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one 8, which was reacted with some alkylating agents leading to alkylation at nitrogen 9–13. Hydrazide 14 was utilized as a synthon for the synthesis of the derivatives 15–19. Chloro-thieno[2,3-d]pyrimidine 20 was synthesized and reacted with the hydrazine hydrate to afford the hydrazino derivative 21, which was used as a scaffold for getting the derivatives 22–28. Nucleophilic substitution reactions were used for getting the compounds 29–35 from chloro-thieno[2,3-d]pyrimidine 20. In the way of anticancer therapeutics development, the requisite compounds were assessed for their cytotoxicity in vitro against MCF-7 and HepG-2 cancer cell lines. Twelve compounds showed an interesting antiproliferative potential with IC₅₀ from 23.2 to 95.9 µM. The flow cytometric analysis results showed that hit 4 induces the apoptosis in MCF-7 cells with a significant 26.86% reduction in cell viability. The in vivo study revealed a significant decrease in the solid tumor mass (26.6%) upon treatment with compound 4. Moreover, in silico study as an agonist for inhibitors of JAK2 and prediction study determined their binding energies and predicted their physicochemical properties and drug-likeness scores. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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Review

Jump to: Editorial, Research

25 pages, 6192 KiB

Open AccessReview

Pentacyclic Triterpenoids with Nitrogen-Containing Heterocyclic Moiety, Privileged Hybrids in Anticancer Drug Discovery

by Vuyolwethu Khwaza, Sithenkosi Mlala, Opeoluwa O. Oyedeji and Blessing A. Aderibigbe

Molecules 2021, 26(9), 2401; https://doi.org/10.3390/molecules26092401 - 21 Apr 2021

Cited by 34 | Viewed by 3707

Abstract

Pentacyclic triterpenoids are well-known phytochemicals with various biological activities commonly found in plants as secondary metabolites. The wide range of biological activities exhibited by triterpenoids has made them the most valuable sources of pharmacological agents. A number of novel triterpenoid derivatives with many [...] Read more.

Pentacyclic triterpenoids are well-known phytochemicals with various biological activities commonly found in plants as secondary metabolites. The wide range of biological activities exhibited by triterpenoids has made them the most valuable sources of pharmacological agents. A number of novel triterpenoid derivatives with many skeletal modifications have been developed. The most important modifications are the formation of analogues or derivatives with nitrogen-containing heterocyclic scaffolds. The derivatives with nitrogen-containing heterocyclic compounds are among the most promising candidate for the development of novel therapeutic drugs. About 75% of FDA-approved drugs are nitrogen-containing heterocyclic moieties. The unique properties of heterocyclic compounds have encouraged many researchers to develop new triterpenoid analogous with pharmacological activities. In this review, we discuss recent advances of nitrogen-containing heterocyclic triterpenoids as potential therapeutic agents. This comprehensive review will assist medicinal chemists to understand new strategies that can result in the development of compounds with potential therapeutic efficacy. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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54 pages, 37321 KiB

Open AccessReview

Recent Advances in the Synthesis of β-Carboline Alkaloids

by Tímea Szabó, Balázs Volk and Mátyás Milen

Molecules 2021, 26(3), 663; https://doi.org/10.3390/molecules26030663 - 27 Jan 2021

Cited by 45 | Viewed by 9013

Abstract

β-Carboline alkaloids are a remarkable family of natural and synthetic indole-containing heterocyclic compounds and they are widely distributed in nature. Recently, these alkaloids have been in the focus of interest, thanks to their diverse biological activities. Their pharmacological activity makes them desirable as [...] Read more.

β-Carboline alkaloids are a remarkable family of natural and synthetic indole-containing heterocyclic compounds and they are widely distributed in nature. Recently, these alkaloids have been in the focus of interest, thanks to their diverse biological activities. Their pharmacological activity makes them desirable as sedative, anxiolytic, hypnotic, anticonvulsant, antitumor, antiviral, antiparasitic or antimicrobial drug candidates. The growing potential inherent in them encourages many researchers to address the challenges of the synthesis of natural products containing complex β-carboline frameworks. In this review, we describe the recent developments in the synthesis of β-carboline alkaloids and closely related derivatives through selected examples from the last 5 years. The focus is on the key steps with improved procedures and synthetic approaches. Furthermore the pharmacological potential of the alkaloids is also highlighted. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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41 pages, 20200 KiB

Open AccessReview

Cytotoxic Properties of 1,3,4-Thiadiazole Derivatives—A Review

by Sara Janowska, Agata Paneth and Monika Wujec

Molecules 2020, 25(18), 4309; https://doi.org/10.3390/molecules25184309 - 20 Sep 2020

Cited by 43 | Viewed by 5878

Abstract

During recent years, small molecules containing five-member heterocyclic moieties have become the subject of considerable growing interest for designing new antitumor agents. One of them is 1,3,4-thiadiazole. This study is an attempt to collect the 1,3,4-thiadiazole and its derivatives, which can be considered [...] Read more.

During recent years, small molecules containing five-member heterocyclic moieties have become the subject of considerable growing interest for designing new antitumor agents. One of them is 1,3,4-thiadiazole. This study is an attempt to collect the 1,3,4-thiadiazole and its derivatives, which can be considered as potential anticancer agents, reported in the literature in the last ten years. Full article

(This article belongs to the Special Issue Nitrogen-Containing Heterocycles as Significant Molecular Scaffolds for Medicinal and Other Applications)

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