Lysicamine Reduces Protein Kinase B (AKT) Activation and Promotes Necrosis in Anaplastic Thyroid Cancer.

Anaplastic thyroid cancer (ATC) is an aggressive form of thyroid cancer (TC), accounting for 50% of total TC-related deaths. Although therapeutic approaches against TC have improved in recent years, the survival rate remains low, and severe adverse effects are commonly reported. However, unexplored alternatives based on natural compounds, such as lysicamine, an alkaloid found in plants with established cytotoxicity against breast and liver cancers, offer promise. Therefore, this study aimed to explore the antineoplastic effects of lysicamine in papillary TC (BCPAP) and ATC (HTH83 and KTC-2) cells. Lysicamine treatment reduced cell viability, motility, colony formation, and AKT activation while increasing the percentage of necrotic cells. The absence of caspase activity confirmed apoptosis-independent cell death. Necrostatin-1 (NEC-1)-mediated necrosome inhibition reduced lysicamine-induced necrosis in KTC-2, suggesting necroptosis induction via a reactive oxygen species (ROS)-independent mechanism. Additionally, in silico analysis predicted lysicamine target proteins, particularly those related to MAPK and TGF-ß signaling. Our study demonstrated lysicamine's potential as an antineoplastic compound in ATC cells with a proposed mechanism related to inhibiting AKT activation and inducing cell death.

High Selectivity of 8-Hydroxyquinoline on Leishmania (Leishmania) and Leishmania (Viannia) Species Correlates with a Potent Therapeutic Activity In Vivo.

Leishmaniasis is a neglected disease caused by protozoa of the genus Leishmania, which causes different clinical manifestations. Drugs currently used in the treatment such as pentavalent antimonial and amphotericin B cause severe side effects in patients, and parasite resistance has been reported. Thus, it is necessary and urgent to characterize new and effective alternative drugs to replace the current chemotherapy of leishmaniasis. In this regard, it has been experimentally demonstrated that quinoline derivatives present significative pharmacological and parasitic properties. Thus, the aim of this work was to demonstrate the leishmanicidal activity of 8-hydroxyquinoline (8-HQ) in vitro and in vivo. The leishmanicidal activity (in vitro) of 8-HQ was assayed on promastigote and intracellular amastigote forms of L. (L.) amazonensis, L. (L.) infantum chagasi, L. (V.) guyanensis L. (V.) naiffi, L. (V.) lainsoni, and L. (V.) shawi. Additionally, the levels of nitric oxide and hydrogen peroxide were analyzed. The therapeutic potential of 8-HQ was analyzed in BALB/c mice infected with a strain of L. (L.) amazonensis that causes anergic cutaneous diffuse leishmaniasis. In vitro data showed that at 24 and 72 h, 8-HQ eliminated promastigote and intracellular amastigote forms of all studied species and this effect may be potentialized by nitric oxide. Furthermore, 8-HQ was more selective than miltefosine. Infected animals treated with 8-HQ by the intralesional route dramatically reduced the number of tissue parasites in the skin, and it was associated with an increase in IFN-γ and decrease in IL-4, which correlated with a reduction in inflammatory reaction in the skin. These results strongly support the idea that 8-HQ is an alternative molecule that can be employed in the treatment of leishmaniasis, given its selectivity and multispectral action in parasites from the Leishmania genus.

Unsaturation pattern of phosphatidylglycerols modulating the interaction of lysicamine with cells membrane models at the air-water interface.

Lysicamine, an alkaloid with tumorigenic activity, was incorporated in cell membrane models made of lipid Langmuir monolayers. Dipalmitoylphosphocholine (DPPC), dioleoylphosphocholine (DOPC), and palmitoyloleoylcholine (POPC) represented non-tumorigenic cell membranes, and dipalmitoylphosphoserine (DPPS), dioleoylphosphoserine (DOPS), and palmitoyloleoylserine (POPS), tumorigenic ones. The monolayers were characterized by tensiometry, infrared spectroscopy, and Brewster Angle Microscopy (BAM). No significant shifts of the isotherms were observed for the saturated lipids (DPPC and DPPS), while for the others (DOPC, POPS, DOPS, and POPS), more significant changes were observed not only in the compression isotherms but also in the surface pressure-time curve for pre-compressed monolayers. The molecular organization, as well as the morphology of the drug-lipid monolayers, could be inferred with infrared spectroscopy and BAM. While the first revealed that the alkyl chain ordering changed upon lysicamine incorporation, the second showed how the drug could distinctly change the state of aggregation of molecular domains at the air-water interface. In conclusion, lysicamine could interact distinctly with each lipid at the air-water interface, showing the dependence not only on the lipid polar groups but also on the level of unsaturation of the alkyl chains.

The composition of fusogenic lipid mixtures at the air-water modulates the physicochemical properties changes upon interaction with lysicamine.

Knowing how a bioactive compound interacts with cell membranes is important to understand its effect at the molecular level. In this sense, this work aimed to study the interaction of lysicamine, an alkaloid with action against lung cancer cell lines, with lipid monolayers as cell membrane models. We employed two lipid mixtures: the first composed of 35% DOPC, 30% DOPE, 20% sphingomyelin, and 15% cholesterol as healthy cell membranes models (MM1), and the second replacing DOPC with DOPS as cancer cells models (MM2). The interaction of lysicamine with the monolayers was evaluated using tensiometry, Brewster angle microscopy (BAM), and polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS). Lysicamine had interfacial effects in both membrane models. For MM 1, it expanded the lipid monolayer and changed the interfacial rheological properties, increasing the in-plane elasticity of the films. PM-IRRAS spectra suggested a higher conformational disorder of the alkyl chains of the lipids. For MM 2, lysicamine also shifted the isotherms to higher areas, expanding the monolayers, but with no significant alteration in their interfacial rheological properties. PM-IRRAS spectra also suggested higher disorder in the orientation of the lipid alkyl chains upon lysicamine incorporation. For both models, BAM did not show alteration in interfacial aggregation upon drug incorporation. In conclusion, changes in some interfacial properties of membrane models caused by lysicamine depend on the monolayer composition, which can be associated with its bioactivity in cellular membranes.

Aporphine and isoquinoline derivatives block glioblastoma cell stemness and enhance temozolomide cytotoxicity.

Glioblastoma (GBM) is the most aggressive and common primary malignant brain tumor with limited available therapeutic approaches. Despite improvements in therapeutic options for GBM patients, efforts to develop new successful strategies remain as major unmet medical needs. Based on the cytotoxic properties of aporphine compounds, we evaluated the biological effect of 12 compounds obtained through total synthesis of ( ±)-apomorphine hydrochloride (APO) against GBM cells. The compounds 2,2,2-trifluoro-1-(1-methylene-3,4-dihydroisoquinolin-2(1H)-yl)ethenone (A5) and ( ±)-1-(10,11-dimethoxy-6a,7-dihydro-4H-dibenzo[de,g]quinolin-6(5H)-yl)ethenone (C1) reduced the viability of GBM cells, with 50% inhibitory concentration ranging from 18 to 48 µM in patient-derived GBM cultures. Our data show that APO, A5 or C1 modulate the expression of DNA damage and apoptotic markers, impair 3D-gliomasphere growth and reduce the expression of stemness markers. Potential activity and protein targets of A5, C1 or APO were predicted in silico based on PASS and SEA software. Dopamine receptors (DRD1 and 5), CYP2B6, CYP2C9 and ABCB1, whose transcripts were differentially expressed in the GBM cells, were among the potential A5 or C1 target proteins. Docking analyses (HQSAR and 3D-QSAR) were performed to characterize possible interactions of ABCB1 and CYP2C9 with the compounds. Notably, A5 or C1 treatment, but not temozolomide (TMZ), reduced significantly the levels of extracellular ATP, suggesting ABCB1 negative regulation, which was correlated with stronger cytotoxicity induced by the combination of TMZ with A5 or C1 on GBM cells. Hence, our data reveal a potential therapeutic application of A5 and C1 as cytotoxic agents against GBM cells and predicted molecular networks that can be further exploited to characterize the pharmacological effects of these isoquinoline-containing substances.

Advances Towards the Synthesis of Aporphine Alkaloids: C-Ring Formation via Approaches Based on One- and Two-Bond Disconnections.

Aporphine compounds constitute a class of substances with important pharmacological properties, including anticancer, antiviral, anti-HIV, anti-inflammatory, and leishmanicidal activities. Consequently, several strategies to obtain the aporphine core have been reported. Herein this review, we provide an overview of two relevant approaches used to construct the C-ring in the synthetic routes developed. The first approach, which is based on a one-bond disconnection, allows C-ring formation using a 1-benzyl-1,2,3,4-tetrahydroisoquinoline intermediate (mainly) employing cyclization reactions catalyzed by metals or promoted by light. The second approach, which is derived from a two-bond disconnection, leads to C-ring formation via a sequence of reactions starting with [4+2] cycloadditions. Through these approaches, aporphinoids with a diverse range of substitution patterns and biological activities can be synthesized.

Exploring Possible Surrogates for Kobayashi's Aryne Precursors.

A class of aryne precursors, that is, 2-(trimethylsilyl)aryl 4-chlorobenzenesulfonates, has been developed through well-established synthetic routes, which allow the formation of arynes under relatively mild conditions. All the aryne precursors were obtained from phenols and 4-chlorobenzenesulfonyl chloride, an inexpensive and easy-to-handle reagent with relatively low toxicity, and subjected to nucleophilic addition reactions, providing addition products in yields of 24 to 92%, and to cycloaddition reactions, affording cycloadducts in yields up to 80%. This work provides interesting insights into the mechanisms of aryne generation. In addition, 2-(trimethylsilyl)phenyl 4-chlorobenzenesulfonate was successfully employed in the total synthesis of (±)-aporphine.

Assessment of the cytotoxic effects of aporphine prototypes on head and neck cancer cells.

Purpose Among alkaloids, abundant secondary metabolites in plants, aporphines constitute a class of compounds with interesting biological activities, including anticancer effects. The present study evaluated the anticancer activities of 14 substances, including four aporphine derivatives acquired through the biomonitoring of (±)-apomorphine hydrochloride total synthesis from 2-phenethylamine and 3,4-dimethoxybenzaldehyde against head and neck squamous cell carcinoma (HNSCC). Methods The cytotoxic effects of compounds against a panel of HNSCC cell lines were determined by PrestoBlue cell viability assay, while the genotoxicity of substances was evaluated by micronucleus test. Cell death was detected by flow cytometry (Annexin V/7AAD) and western blot analysis was used to detect the presence of cleaved Caspase-3 molecules. Results The aporphine and isoquinoline derivatives APO, C1, and A5 significantly reduced HNSCC cell viability and promoted DNA damages in these cells. Further, by activating the Caspase-3 pathway, these substances were able to induce apoptosis. Conclusion Our results revealed that APO, C1, and A5 exhibit cytotoxic effects in HNSCC cells. The mechanisms of action appear to be partly via the generation of DNA damages and apoptosis induction through Caspase-3 pathway activation. This study provides preclinical data that suggest a potential therapeutic role for APO, C1, and A5 against head and neck cancer cells.

Synthesis, leishmanicidal activity, structural descriptors and structure-activity relationship of quinoline derivatives.

AIM: Considering the epidemiology of leishmaniasis, the emergence of resistant parasites to the approved drugs, and severe clinical manifestations, the development of novel leishmanicidal molecules has become of considerable importance. RESULTS: In this work, three commercially available and 19 synthesized quinoline derivatives were evaluated against promastigote and amastigote forms of Leishmania (Leishmania) amazonensis. In addition, structural parameters and molecular electrostatic potentials were obtained by theoretical calculations, allowing statistical (principal component analyses and hierarchical cluster analyses) and comparative (molecular electrostatic potentials vs leishmanicidal activities) studies, respectively. CONCLUSION: Principal component analyses and hierarchical cluster analyses suggested volume and polar surface area as possible structural descriptors for the leishmanicidal activity. Furthermore, a comparison between molecular electrostatic potentials and leishmanicidal activities afforded a reasonable structure-activity relationship.

Total Syntheses of Aporphine Alkaloids via Benzyne Chemistry: An Approach to the Formation of Aporphine Cores.

Total syntheses of lysicamine, (±)-nuciferine, (±)-nornuciferine, (±)-zanthoxyphylline iodide, (±)-O-methylisothebaine, and (±)-trimethoxynoraporphine were accomplished by an approach that involves the formation of aporphine cores through reactions between an isoquinoline derivative and silylaryl triflates promoted by CsF. Unprecedented formations of aporphine cores proceeded in good yields presumably through [4 + 2] cycloaddition reactions followed by hydrogen migrations.

Bioconversion of iodoacetophenones by marine fungi.

Nine marine fungi (Aspergillus sclerotiorum CBMAI 849, Aspergillus sydowii Ce19, Beauveria felina CBMAI 738, Mucor racemosus CBMAI 847, Penicillium citrinum CBMAI 1186, Penicillium miczynskii Ce16, P. miczynskii Gc5, Penicillium oxalicum CBMAI 1185, and Trichoderma sp. Gc1) catalyzed the asymmetric bioconversion of iodoacetophenones 1-3 to corresponding iodophenylethanols 6-8. All the marine fungi produced exclusively (S)-ortho-iodophenylethanol 6 and (S)-meta-iodophenylethanol 7 in accordance to the Prelog rule. B. felina CBMAI 738, P. miczynskii Gc5, P. oxalicum CBMAI 1185, and Trichoderma sp. Gc1 produced (R)-para-iodophenylethanol 8 as product anti-Prelog. The bioconversion of para-iodoacetophenone 3 with whole cells of P. oxalicum CBMAI 1185 showed competitive reduction-oxidation reactions.

Synthesis of indazoles by the [3+2] cycloaddition of diazo compounds with arynes and subsequent acyl migration.

The [3+2] cycloaddition of a variety of diazo compounds with o-(trimethylsilyl)aryl triflates in the presence of CsF or TBAF at room temperature provides a very direct, efficient approach to a wide range of potentially biologically and pharmaceutically interesting substituted indazoles in good to excellent yields under mild reaction conditions. Simple diazomethane derivatives afford N-unsubstituted indazoles or 1-arylated indazoles, depending upon the stoichiometry of the reagents and the reaction conditions, while dicarbonyl-containing diazo compounds undergo carbonyl migration to afford 1-acyl or 1-alkoxycarbonyl indazoles selectively.

Regioselective synthesis of 3-(2-hydroxyaryl)pyridines via arynes and pyridine N-oxides.

A variety of substituted 3-(2-hydroxyphenyl)pyridines have been prepared regioselectively by a transition-metal-free, mild, one-step route, which involves the reaction of pyridine N-oxides with silylaryl triflates in the presence of CsF in acetonitrile at room temperature. These reactions proceed in good yields through what appears to be a series of rearrangements.