Isochaihulactone analogues: synthesis and anti-proliferative activity of novel dibenzylbutyrolactones

Effective extracellular vesicles in glioma: Focusing on effective ncRNA exosomes and immunotherapy methods for treatment

This comprehensive article explores the complex field of glioma treatment, with a focus on the important roles of non-coding RNAsRNAs (ncRNAs) and exosomes, as well as the potential synergies of immunotherapy. The investigation begins by examining the various functions of ncRNAs and their involvement in glioma pathogenesis, progression, and as potential diagnostic biomarkers. Special attention is given to exosomes as carriers of ncRNAs and their intricate dynamics within the tumor microenvironment. The exploration extends to immunotherapy methods, analyzing their mechanisms and clinical implications in the treatment of glioma. By synthesizing these components, the article aims to provide a comprehensive understanding of how ncRNAs, exosomes, and immunotherapy interact, offering valuable insights into the evolving landscape of glioma research and therapeutic strategies.

Immune Checkpoint Inhibitors in Human Glioma Microenvironment

Gliomas are the most common primary brain tumors in adults. Despite the fact that they are relatively rare, they cause significant morbidity and mortality. High-grade gliomas or glioblastomas are rapidly progressing tumors with a very poor prognosis. The presence of an intrinsic immune system in the central nervous system is now more accepted. During the last decade, there has been no major progress in glioma therapy. The lack of effective treatment for gliomas can be explained by the strategies that cancer cells use to escape the immune system. This being said, immunotherapy, which involves blockade of immune checkpoint inhibitors, has improved patients' survival in different cancer types. This novel cancer therapy appears to be one of the most promising approaches. In the present study, we will start with a review of the general concept of immune response within the brain and glioma microenvironment. Then, we will try to decipher the role of various immune checkpoint inhibitors within the glioma microenvironment. Finally, we will discuss some promising therapeutic pathways, including immune checkpoint blockade and the body's effective anti-glioma immune response.

Optimization of asymmetric reduction conditions of 1-(benzo [d] [1,3] dioxol-5-yl) ethanone by Lactobacillus fermentum P1 using D-optimal experimental design-based model

The biocatalytic asymmetric reduction of prochiral ketones is a significant transformation in organic chemistry as chiral carbinols are biologically active molecules and may be used as precursors of many drugs. In this study, the bioreduction of 1-(benzo [d] [1,3] dioxol-5-yl) ethanone for the production of enantiomerically pure (S)-1-(1,3-benzodioxal-5-yl) ethanol was investigated using freeze-dried whole-cell of Lactobacillus fermentum P1 and the reduction conditions was optimized with a D-optimal experimental design-based optimization methodology. This is the first study using this optimization methodology in a biocatalytic asymmetric reduction. Using D-optimal experimental design-based optimization, optimum reaction conditions were predicted as pH 6.20, temperature 30 °C, incubation time 30 h, and agitation speed 193 rpm. For these operating conditions, it was estimated that the product could be obtained with 94% enantiomeric excess (ee) and 95% conversion rate (cr). Besides, the actual ee and cr were found to be 99% tested under optimized reaction conditions. These findings demonstrated that L. fermentum P1 as an effective biocatalyst to obtain (S)-1-(1,3-benzodioxal-5-yl) ethanol and with the D-optimal experimental design-based optimization, this product could be obtained with the 99% ee and 99% cr. Finally, the proposed mathematical optimization technique showed the applicability of the obtained results for asymmetric reduction reactions.

The Role of Bcl-xL Protein Research in Veterinary Oncology

Due to their significant impact on human and animal health, cancer diseases are an area of considerable concern for both human and veterinary medicine. Research on the cancer pathogenesis in companion animals, such as dogs, allows not only for improving canine cancer treatment, but also for translating the results into human oncology. Disruption of apoptosis in tumor-transformed cells is a well-known mechanism leading to the development of cancer. One of the main factors involved in this process are proteins belonging to the B-cell lymphoma 2 (Bcl-2) family, and the imbalance between pro-apoptotic and anti-apoptotic members of this family contributes to the development of cancer. Studies on the function of these proteins, including B-cell lymphoma-extra large (Bcl-xL), have also been intensively conducted in companion animals. The Bcl-xL gene was sequenced and found to share over 99% homology with the human protein. Research showed that the Bcl-2 family plays the same role in human and canine cells, and data from studies in dogs are fully translatable to other species, including humans. The role of this protein family in cancer development was also confirmed. The article presents the current state of knowledge on the importance of the Bcl-xL protein in veterinary oncology.

Reaction Mechanism of a Nonheme Iron Enzyme Catalyzed Oxidative Cyclization via C-C Bond Formation

A complementary study including design of mechanistic probes, biochemical assays, model analysis, and liquid chromatography coupled mass spectrometry was conducted to establish the reaction mechanism for a nonheme iron enzyme catalyzed (-)-podophyllotoxin formation. Our results indicate that the originally proposed hydroxylated intermediate is unlikely to be involved in this reaction. Instead, the formation of benzylic radical/carbocation intermediate can be utilized to trigger the C-C bond formation to construct the C-ring of (-)-podophyllotoxin.

Enantiomeric trans β-aryl-δ-iodo-γ-lactones derived from 2,5-dimethylbenzaldehyde induce apoptosis in canine lymphoma cell lines by downregulation of anti-apoptotic Bcl-2 family members Bcl-xL and Bcl-2

For many years, studies focused on developing new natural or synthetic compounds with antineoplastic activity have attracted the attention of researchers. An interesting group of such compounds seem to be those with both lactone moiety and an aromatic ring which, in addition to antimicrobial or antiviral activity, also exhibit antitumor properties. The study shows antitumor activity of two enantiomeric trans isomers of 5-(1-iodoethyl)-4-(2',5'-dimethylphenyl)dihydrofuran-2-one. Our aim was to determine their antitumor activity manifested as an ability to induce apoptosis in selected canine cancer cell lines as well as to evaluate differences in their strength depending on the configuration of their stereogenic centers. The enantiomers (+)-(4R,5S,6R)-1 and (-)-(4S,5R,6S)-2 were found to induce classical caspase-dependent apoptosis through downregulation of the expression of anti-apoptotic proteins Bcl-xL and Bcl-2. Although the mechanism of apoptosis induction was the same for both enantiomers, they differed in their strength, as stronger antineoplastic activity in vitro was exhibited by isomer (+)-(4R,5S,6R)-1.

Production of (R)-1-(1,3-benzodioxol-5-yl)ethanol in high enantiomeric purity by Lactobacillus paracasei BD101

Piperonyl ring is found in a number of naturally occurring compounds and possesses enormous biological activities. There are many studies in the literature with compounds containing a piperonyl ring, but there are very few studies on the synthesis of chiral piperonyl carbinol. The objective of this study was to determine the microbial reduction ability of bacterial strains and to reveal the effects of different physicochemical parameters on this reduction ability. A total of 15 bacterial isolates were screened for their ability to reduce 1-(benzo[d][1,3]dioxol-5-yl) ethanone 1 to its corresponding alcohol. Among these isolates Lactobacillus paracasei BD101 was found to be the most successful biocatalyst to reduce the ketone containing piperonyl ring to the corresponding alcohol. The reaction conditions were systematically optimized for the reducing agent L paracasei BD101, which showed high enantioselectivity and conversion for the bioreduction. The preparative scale study was performed, and a total of 3.72 g of (R)-1-(1,3-benzodioxol-5-yl) ethanol in high enantiomeric form (>99% enantiomeric excess) was produced in a mild, cheap, and environment-friendly process. This study demonstrates that L paracasei BD101 can be used as a biocatalyst to obtain chiral carbinol with excellent yield and selectivity.

Design, Synthesis and Structure-Activity Relationships of (±)-Isochaihulactone Derivatives

Z-K8 (2), the racemic form of isochaihulactone (1), previously showed significant antitumor effects in A549 and LNCaP tumor-bearing mice. In the present study, 17 derivatives of 2, were designed, synthesized and evaluated for anti-proliferative activity against four human tumor cell lines. All new derivatives exhibited high potency against A549 and P-glycoprotein (P-gp)-overexpressing KBvin. One of our new derivative exhibited greater activity against three tested tumor cells (A549, KB, and KB-VIN) than 2, and induced cell cycle arrest in the G₂/M phase. Moreover, SAR conclusions were first established for this series of compounds. Our study clearly identified a structural feature that should be retained for good activity and also a moiety that can tolerate various modifications and, thus, is ideal for further changes.

Chemoenzymatic Synthesis of trans-β-Aryl-δ-hydroxy-γ-lactones and Enzymatic Kinetic Resolution of Their Racemic Mixtures

Two novel and convenient routes to obtain enantiomerically enriched trans-β-aryl-δ-hydroxy-γ-lactones 5a–d with potential antifeedant and anticancer activity were developed. In the first method starting from corresponding enantiomers of γ,δ-unsaturated esters 4a–d derived from enzymatically resolved allyl alcohols 1a–d, both enantiomers of hydroxylactones 5a–d were synthesized with high enantiomeric excesses (73%–97%). Configurations of the stereogenic centers of the synthesized compounds were assigned based on the mechanism of acidic lactonization of esters 4a–d in the presence of m-chloroperbenzoic acid (m-CPBA). An alternative method for the production of optically active trans-β-aryl-δ-hydroxy-γ-lactones 5a–d was lipase-catalyzed kinetic resolution of their racemic mixtures by transesterification with vinyl propionate as the acyl donor. The most efficient enzyme in the screening procedure was lipase B from Candida antarctica. Its application on a preparative scale after 6 h afforded unreacted (+)-(4S,5R,6S)-hydroxylactones 5a–d and (+)-(4R,5S,6R)-propionates 6a–d, most of them with high enantiomeric excesses (92%–98%). Resolution of lactone 5d with bulky 1,3-benzodioxol ring provided products with significantly lower optical purity (ee = 89% and 84% for hydroxylactone 5d and propionate 6d, respectively). The elaborated methods give access to both enantiomers of trans-β-aryl-δ-hydroxy-γ-lactones 5a–d with the defined absolute configurations of stereogenic centers, which is crucial requirement for the investigations of relationship: spatial structure–biological activity.

Optically active stereoisomers of 5-(1-iodoethyl)-4-(4'-isopropylphenyl)dihydrofuran-2-one: The effect of the configuration of stereocenters on apoptosis induction in canine cancer cell lines

Four stereoisomers of δ-iodo-γ-lactones with p-isopropylphenyl substituent at β-position: cis-(4R,5R,6S)-1, cis-(4S,5S,6R)-2, trans-(4R,5S,6R)-3, trans-(4S,5R,6S)-4 with proved antiproliferative activity were subjected to in vitro tests for a better understanding of their anticancer activity. The subject of our interest was a possible relationship between a configuration of chiral centers of the studied lactones and their anticancer potency against a panel of canine cell lines representing hematopoietic (CLBL-1, GL-1, CL-1, CLB70) and mammary gland cancers (P114, CMT-U27, CMT-U309). To determine the anticancer activity of the tested compounds, cell viability and cell metabolic activity were checked using propidium iodide staining and the MTT test. To determine whether the studied compounds cause necrotic or apoptotic cell death, two assays for apoptosis evaluation were performed, annexin V staining and detection of caspase 3/7 activation. Simultaneously, the effects of the compounds on the cell cycle were also examined. The conducted research confirmed the anticancer potential of the tested lactones against canine cancers. The investigated isomers exerted higher activity against canine lymphoma/leukemia cell lines than against mammary tumors, whereas the configuration of stereogenic centers of the examined compounds affected their activity. It has been shown that stereoisomers with 4S configuration (2,4) were more active, and the most potent one was the cis-(4S,5S,6R)-2 isomer. The investigated lactones seemed to initiate the process of apoptosis rather than acting as typical cytostatic agents, as cell death via apoptosis, and no increase in G2-M population in the cell cycle analysis were observed. The presented study demonstrated that all four stereoisomers of δ-iodo-γ-lactones with p-isopropylphenyl substituent at β-position induced apoptosis via a mitochondrial-mediated, caspase-dependent pathway.

Natural product inspired design and synthesis of β-carboline and γ-lactone based molecular hybrids

β-Carboline and γ-lactone moieties have been selected by nature as privileged scaffolds and display a wide range of pharmacological properties. Following nature, we envisaged the preparation of new β-carboline and γ-lactone based molecular hybrids incorporating both the pharmacophores. In this regard, a water-assisted In-mediated environmentally benign and easy to execute single-step tandem Barbier type allylation-lactonisation process has been devised in order to afford the targeted molecular architectures. It is anticipated that aqueous medium plays the key role in allylation as well as in the subsequent lactonisation process for the diastereo-selective synthesis of these conjugates. It is believed that water drives the reaction pathway through dual activation, it increases the electrophilic character of formyl and ester functionalities and simultaneously enhances the nucleophilic potential of the hydroxyl group to facilitate the in situ intramolecular condensation. Importantly, during this synthetic strategy no column chromatographic purification was required at any stage.

Synthesis and anti-cancer activity evaluation of new dimethoxylated chalcone and flavanone analogs

A novel series of chalcones and flavanones discriminated by the presence of a 3,4-dimethoxyphenyl moiety in their structures were synthesized as anti-cancer agents. The cytotoxicity evaluation of the analogs against the MCF-7, MDA-MB-231 (human breast cancer), and SK-N-MC (human neuroblastoma) cell lines demonstrated that the introduction of a halogen on the 3,4-dimethoxyphenyl part of both series and the attachment of a pyrrolidinylethoxy group on the C-7 position of the flavanone derivatives increased their activity. Indeed, 3-halogenated chalcones (1c and 1d) were more potent than the standard drug etoposide against all tested cell lines. Fluorescence microscopy and flow cytometry analyses confirmed that the anti-cancer effect of the most potent compounds 1c and 1d occurs via apoptosis induction.

Halogenated flavanones as potential apoptosis-inducing agents: synthesis and biological activity evaluation

A series of halogenated flavanones were synthesized from 2-hydroxychalcones and tested for their cytotoxicity against a panel of human cancer cell lines. Among the synthesized compounds, 3',7-dichloroflavanone (2d) showed the highest activity against MCF-7, LNCaP, PC3, Hep-G2, KB and SK-N-MC cells. However, 3',6-dichloroflavanone (2g) with IC(50) value of 2.9 ± 0.9 μM was the most potent compound against MDA-MB-231 cells, being approximately 12 times more active than etoposide as reference drug. According to the flow-cytometric analysis, compound 2g can induce apoptosis by 66.19 and 21.37% in PC3 and MDA-MB-231 cells, respectively. The results of acridine orange/ethidium bromide staining and TUNEL assay suggested that the cytotoxic activity of this compound in PC3 and MDA-MB-231 cells occurs via apoptosis.

Asymmetrical 2,6-bis(benzylidene)cyclohexanones: Synthesis, cytotoxic activity and QSAR study

In order to develop novel anti-cancer agents, a series of asymmetrical 2,6-bis (benzylidene)cyclohexanone derivatives containing nitrobenzylidene moiety were synthesized and their cytotoxic activity were determined in vitro against MDA-MB 231, MCF-7 and SK-N-MC cell lines using MTT assay. Among the tested compounds, the highest activity against MDA-MB 231 cells was achieved by 2-(3-bromo-5-methoxy-4-propoxybenzylidene)-6-(2-nitrobenzylidene)cyclohexanone (compound 5d). Whereas, compound 5j (the 3-nitro analog of compound 5d) was the most potent compound against MCF-7 and SK-N-MC cell lines. The results indicated that the cytotoxic activity profile against different tumor cells can be optimized by desired 4-alkoxy-3-bromo-5-methoxybenzylidene scaffold.

Thiazolyl N-benzyl-substituted acetamide derivatives: synthesis, Src kinase inhibitory and anticancer activities

KX2-391 (KX-01/Kinex Pharmaceuticals), N-benzyl-2-(5-(4-(2-morpholinoethoxy)phenyl)pyridin-2-yl)acetamide, is a highly selective Src substrate binding site inhibitor. To understand better the role of pyridine ring and N-benzylsubstitution in KX2-391 and establish the structure-activity relationship, a number of N-benzyl substituted (((2-morpholinoethoxy)phenyl)thiazol-4-yl)acetamide derivatives containing thiazole instead of pyridine were synthesized and evaluated for Src kinase inhibitory activities. The unsubstituted N-benzyl derivative (8a) showed the inhibition of c-Src kinase with GI(50) values of 1.34 μM and 2.30 μM in NIH3T3/c-Src527F and SYF/c-Src527F cells, respectively. All the synthesized compounds were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), breast carcinoma (BT-20), and leukemia (CCRF-CEM) cells. 4-Fluorobenzylthiazolyl derivative 8b exhibited 64-71% inhibition in the cell proliferation of BT-20 and CCRF cells at concentration of 50 μM.