Structurally diverse design and synthesis of novel 2-phenylindole amide derivatives with anti-canine breast cancer activity.

Breast cancer stands as the cancer with the highest incidence and mortality rates among women globally, in which triple-negative breast cancer has been ranked as the most difficult one. Bazedoxifene (BZA), a third-generation selective estrogen receptor modulator (SERM), has been exhibited notable inhibitory effect on both hormone-dependent breast cancer cells and triple-negative breast cancer cells, but showing very low in vivo effeacy. In order to obtain more effective antitumor derivatives than BZA, we have employed a structurally diverse design and synthesis of 57 novel 2-phenylindole amides for detecting their cytotoxities against triple-negative mammary cancer cell line, CMT-7364. Among them, 21 compounds demonstrated significant inhibitory activity against CMT-7364 cells (IC50 < 20 µM). Notably, compound 49 stood out, displaying both similar tumor cell inhibition (20 % reduce in IC50 value) and higher selectivity (4.6 times higher in SI value), compared to Bazedoxifene. Additionally, compound 49 exhibited desirable antitumor effects in a CMT-7364 cell-derived mouse in vivo model, achieving the best inhibition rate of 43.1 % and establishing strong molecular bonding with GP130. Our findings are also supported by comprehensive SAR and 3D-QSAR analyses. Furthermore, the best potent compound 49 was determined to block the cell cycle of canine breast cancer cells in the G0G1 phase in a time-dependent manner, by inducing apoptosis and autophagy. In conclusion, this work presents a valuable lead compound as a potential GP130 inhibitor against triple-negative breast cancer cell lines, laying the foundation for further antitumor drug development.

Preparation, structural characterization, and biological activities of lotus polysaccharides: A review.

Lotus (Nelumbo nucifera), belonging to the family of Nelumbonaceae, is a beautiful aquatic perennial plant. It has been used as an ancient horticulture plant and famous agricultural crop for thousands of years. Modern phytochemical and pharmacological experiments have proved that polysaccharide is one of the most pivotal bioactive constituents of lotus. Hence, the systematic review covering the fundamental research advances and developing prospects of N. nucifera polysaccharides (NNPs) is an urgent demand to provide theoretical basis for their further research and application. The present review summarizes current emerging research progresses on the polysaccharides isolated from lotus, and it focuses on advanced extraction and purification methods, unique structural features, engaging biological activities, potential molecular mechanisms, as well as the relationship of structure and activity of NNPs. This review sheds light on the potential values of NNPs in affording functionally bioactive agents in food industry or therapeutically effective medicines for health care. In addition, this review will provide valuable insights for further commercial product development and promising industrial application of NNPs in both of the fundamental research communities and food or pharmaceutical industries in future.

Design, semi-synthesis and bioevaluation of koumine-like derivatives as potential antitumor agents in vitro and in vivo.

Aims: Five series of novel koumine-like compounds were designed, semi-synthesized and systematically evaluated for antitumor activities.Methods: All compounds were evaluated for antiproliferative activity against four human cancer cell lines, including HT-29, HCT-116, HCT-15 and Caco-2.Results: Most compounds exhibited much higher antiproliferation activities (IC50 <10 µM) than koumine. Two selected compounds A4 and C5 showed comparable antitumor effects to 5-FU in vivo, as well as better safety profiles. Further studies suggested that A4 and C5 could arrest HT-29 cell cycle in G2 phase and raise reactive oxygen species level, thus inducing cell apoptosis related to Erk MAPK and NF-κB signaling pathways inhibition.Conclusion: These results will greatly promote the druggability study of these koumine-like compounds.

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Glyco-conjugation in 3-ß-anhydroicaritine.

A convenient method has been developed for the glycol-conjugation in 3-position of ß-anhydroicaritine in a reasonable yield. The structure of the 3-glycosylated ß-anhydroicaritine derivatives was confirmed to be correct by 1H NMR, 13C NMR and HRMS spectrum. These compounds are less soluble than icaritin, but more soluble than icariside II in CCl4. The screening results showed that compounds 12h, 12i and 12j had higher cytotoxicity to HepG2 and MCF-7 at a concentration of 50 µM.

Enhanced antihypertensive potential of fermented pomegranate juice: The contribution of phenolic compounds biotransformation and the resultant angiotensin-I-converting enzyme inhibition mechanism.

Current research on plant food-derived phenolic compounds as angiotensin-I-converting enzyme (ACE) inhibitors has been well documented. Pomegranate juice (PJ) has been reported positively contributed to ACE inhibition. Microbial fermentation is a preferable technique to regulate the biotransformation of phenolic compounds and their bioaccessibility, therefore promoting the ACE inhibitory activity in plant food with antihypertension potential. In this study, the remarkable improvements of ACE inhibitory activity and antioxidant capacity in Lactobacillus plantarum fermented PJ were observed. A consecutive study of phenolic compounds biotransformation, ACE inhibition kinetics and structure-activity relationship were performed. This study firstly highlights the relationship between the enhanced ACE inhibitory activity in fermented PJ and the biotransformation of phenolic compounds, providing a new way to reinforce plant food ACE inhibition potential by microbial fermentation.

Expedient Synthesis of a Library of Heparan Sulfate-Like "Head-to-Tail" Linked Multimers for Structure and Activity Relationship Studies.

Heparan sulfate (HS) plays important roles in many biological processes. The inherent complexity of naturally existing HS has severely hindered the thorough understanding of their structure-activity relationship. To facilitate biological studies, a new strategy has been developed to synthesize a HS-like pseudo-hexasaccharide library, where HS disaccharides were linked in a "head-to-tail" fashion from the reducing end of a disaccharide module to the non-reducing end of a neighboring module. Combinatorial syntheses of 27 HS-like pseudo-hexasaccharides were achieved. This new class of compounds bound with fibroblast growth factor 2 (FGF-2) with similar structure-activity trends as HS oligosaccharides bearing native glycosyl linkages. The ease of synthesis and the ability to mirror natural HS activity trends suggest that the new head-to-tail linked pseudo-oligosaccharides could be an exciting tool to facilitate the understanding of HS biology.

Identification of SARS-CoV-2 Main Protease Inhibitors from a Library of Minor Cannabinoids by Biochemical Inhibition Assay and Surface Plasmon Resonance Characterized Binding Affinity.

The replication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is mediated by its main protease (Mpro), which is a plausible therapeutic target for coronavirus disease 2019 (COVID-19). Although numerous in silico studies reported the potential inhibitory effects of natural products including cannabis and cannabinoids on SARS-CoV-2 Mpro, their anti-Mpro activities are not well validated by biological experimental data. Herein, a library of minor cannabinoids belonging to several chemotypes including tetrahydrocannabinols, cannabidiols, cannabigerols, cannabichromenes, cannabinodiols, cannabicyclols, cannabinols, and cannabitriols was evaluated for their anti-Mpro activity using a biochemical assay. Additionally, the binding affinities and molecular interactions between the active cannabinoids and the Mpro protein were studied by a biophysical technique (surface plasmon resonance; SPR) and molecular docking, respectively. Cannabinoids tetrahydrocannabutol and cannabigerolic acid were the most active Mpro inhibitors (IC50 = 3.62 and 14.40 µM, respectively) and cannabigerolic acid had a binding affinity KD=2.16×10-4 M). A preliminary structure and activity relationship study revealed that the anti-Mpro effects of cannabinoids were influenced by the decarboxylation of cannabinoids and the length of cannabinoids' alkyl side chain. Findings from the biochemical, biophysical, and computational assays support the growing evidence of cannabinoids' inhibitory effects on SARS-CoV-2 Mpro.

Relationship Between the Structure of Alkylpsoralens and Their Antiproliferative Activity in HL60 Cells.

BACKGROUND/AIM: As part of our continuing investigation in coumarin derivatives as potential anticancer substances, a series of alkylpsoralens were synthesized, and their antiproliferative activity was evaluated in leukemic HL60 cells. MATERIALS AND METHODS: Alkylpsoralens were systematically synthesized from the combination of several chloroketones and 7-hydroxycoumarin derivatives. RESULTS: Among the compounds synthesized, 4,4',8-trimethylpsoralen demonstrated the most potent activity (IC50=6.6 µM). CONCLUSION: The correlation between the alkylation pattern and antiproliferative activity showed the importance of the C4-methyl and C8-methyl moieties in the psoralen nucleus as well as the importance of lipophilicity for their antiproliferative activity.

Effect of hydrophobicity on distinct anticancer mechanism of antimicrobial peptide chensinin-1b and its lipoanalog PA-C1b in breast cancer cells.

Chensinin-1b and its lipoanalogs demonstrate different anticancer activities against selected cancer cells, and the anticancer activity of PA-C1b is improved up to 3-fold compared with that of the parent peptide chensinin-1b. However, detailing the mechanism of action of these peptides is required to better understand the structure-function relationship. In this study, chensinin-1b and PA-C1b were selected as the representative peptides to investigate the mode of action in cancer cells. The results indicated that the boundary of the cell membrane was broken when the cells were treated with chensinin-1b, while that of cells treated with PA-C1b remained intact based on morphological changes. Apoptosis assays indicated that PA-C1b induced MCF-7 cancer cell apoptosis, while chensinin-1b mainly damaged the cell membrane. MCF-7 cancer cells treated with the peptides induced the loss of mitochondrial membrane potential, and cytochrome c was released from mitochondria, but PA-C1b enhanced ROS generation. Additionally, PA-C1b uptake occurred via an energy-dependent pathway and was inhibited by selected endocytosis inhibitors. Furthermore, treatment of MCF-7 cells with PA-C1b suppressed Bcl-2 mRNA levels and increased Bax mRNA levels, upregulated the expression of the proapoptotic protein Bax and downregulated the expression of the antiapoptotic protein Bcl-2. These results indicate that the anticancer mechanism of AMPs may be considerably affected by only a slight difference in the hydrophobicity of the two peptides; and such a study may facilitate the design of novel peptide-based anticancer agents.

Antihypertensive Potential of Plant Foods: Research Progress and Prospect of Plant-Derived Angiotensin-Converting Enzyme Inhibition Compounds.

Global health concerns are clearly evidenced by cardiovascular disease, kidney damage, and heart attacks. Antihypertensive synthetic drugs, including angiotensin-converting enzyme (ACE) inhibitors, effectively control hypertension but with unpleasant side effects. In recent decades, studies on the role of food-derived compounds have provided a positive contribution to ACE regulation. Here, the research progress of plant food-derived phenolic compounds as ACE inhibitors is reviewed. A survey of bioactive compounds of plant food is presented to broaden the source scope of natural ACE inhibitors. A consecutive understanding of plant-derived ACE inhibitors classification, inhibition mechanism, structure-activity relationship, and bioavailability are scientifically organized. The emerging evidence highlights areas that need further research, including those related to molecular structure, bioaccessibility, and interactions with gut microflora. Future research on such topics may encourage basic research and clinic application to exploit these plant food constituents as novel ACE inhibitors.

Overview of piperlongumine analogues and their therapeutic potential.

Natural products have long been an important source for discovery of new drugs to treat human diseases. Piperlongumine (PL) is an amide alkaloid isolated from Piper longum L. (long piper) and other piper plants and has received widespread attention because of its diverse biological activities. A large number of PL derivatives have been designed, synthesized and assessed in many pharmacological functions, including antiplatelet aggregation, neuroprotective activities, anti-diabetic activities, anti-inflammatory activities, anti-senolytic activities, immune activities, and antitumor activities. Among them, the anti-tumor effects and application of PL and its derivatives are most extensively studied. We herein summarize the development of PL derivatives, the structure and activity relationships (SARs), and their therapeutic potential on the treatments of various diseases, especially against cancer. We also discussed the challenges and future directions associated with PL and its derivatives in these indications.

Characterisation of twelve newly synthesised N-(substituted phenyl)-2-chloroacetamides with QSAR analysis and antimicrobial activity tests.

In this study we screened twelve newly synthesised N-(substituted phenyl)-2-chloroacetamides for antimicrobial potential relying on quantitative structure-activity relationship (QSAR) analysis based on the available cheminformatics prediction models (Molinspiration, SwissADME, PreADMET, and PkcSM) and verified it through standard antimicrobial testing against Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Candida albicans. Our compounds met all the screening criteria of Lipinski's rule of five (Ro5) as well as Veber's and Egan's methods for predicting biological activity. In antimicrobial activity tests, all chloroacetamides were effective against Gram-positive S. aureus and MRSA, less effective against the Gram-negative E. coli, and moderately effective against the yeast C. albicans. Our study confirmed that the biological activity of chloroacetamides varied with the position of substituents bound to the phenyl ring, which explains why some molecules were more effective against Gram-negative than Gram-positive bacteria or C. albicans. Bearing the halogenated p-substituted phenyl ring, N-(4-chlorophenyl), N-(4-fluorophenyl), and N-(3-bromophenyl) chloroacetamides were among the most active thanks to high lipophilicity, which allows them to pass rapidly through the phospholipid bilayer of the cell membrane. They are the most promising compounds for further investigation, particularly against Gram-positive bacteria and pathogenic yeasts.

The impact of structural modification of sulfated polysaccharides on bone morphogenic protein 2 and inhibition of endothelial cell angiogenesis.

Sulfated polysaccharides play important roles in angiogenesis. However, the impact of structural alteration of sulfated polysaccharide on the bioactivity is still vague. In this study, binding between different sulfated polysaccharides and bone morphogenic protein 2 (BMP2) was measured to understand the sense of this motif transformation. The results showed that binding between sulfated α-1,4-glucan and BMP2 was the most intensive. The branch of α-1,4-glucan was important for the binding. The affinity of sulfated polysaccharides to BMP2 increased as the molecular weight (MW) and degree of substitution (DS) increased. DS that exceeded 1.05 impaired binding and played more important role in polysaccharide BMP2 interaction than MW. The reservation of partial 6-OH would benefit its binding ability to BMP2. Further, we showed that sulfated polysaccharides with strong binding to BMP2 blocked phosphorylation of Smad 1/5/8 and expression of Id1 to a greater extent than those not strongly bind to BMP2. The binding strength of polysaccharides to BMP2 increased, so did the potency of the anti-angiogenesis effects.

Discovery and synthesis of novel beesioside I derivatives with potent anti-HIV activity.

In this study, 12 known cycloartane triterpenoids (1-12) with four different skeletons isolated from the roots of Souliea vaginata were screened for the first time for in vitro anti-HIV activity using AZT as a standard. Among the compounds, beesioside I (1) showed the highest potency against HIV-1NL4-3 with an EC50 value of 2.32 µM (CC50 > 40 µM). Preliminary structure-activity relationship (SAR) studies on 1 indicated that simple modification of its aglycone (13) could significantly influence the antiviral activity. Particularly, the introduction of an acyl group at the C-3 position of 13 led to significant improvement in both anti-HIV potency and selectivity index. Among all synthetically modified derivatives, compound 13g was the most potent compound with an EC50 value of 0.025 µM and TI value greater than 800, comparable to those of 3-O-(3',3'-dimethylsuccinyl)-betulinic acid (DSB, bevirimat). Other analogues exhibited strong to weak inhibition of HIV-1 replication in MT-4 cells. The length, carboxylic terminus, and C-3' dimethyl substitution of the C-3 side chain substantially affected the anti-HIV activity. Finally, compound 13g was an effective agent against HIV with high potential for further investigation.

Role of Cytokinins in Senescence, Antioxidant Defence and Photosynthesis.

Cytokinins modulate a number of important developmental processes, including the last phase of leaf development, known as senescence, which is associated with chlorophyll breakdown, photosynthetic apparatus disintegration and oxidative damage. There is ample evidence that cytokinins can slow down all these senescence-accompanying changes. Here, we review relationships between the various mechanisms of action of these regulatory molecules. We highlight their connection to photosynthesis, the pivotal process that generates assimilates, however may also lead to oxidative damage. Thus, we also focus on cytokinin induction of protective responses against oxidative damage. Activation of antioxidative enzymes in senescing tissues is described as well as changes in the levels of naturally occurring antioxidative compounds, such as phenolic acids and flavonoids, in plant explants. The main goal of this review is to show how the biological activities of cytokinins may be related to their chemical structure. New links between molecular aspects of natural cytokinins and their synthetic derivatives with antisenescent properties are described. Structural motifs in cytokinin molecules that may explain why these molecules play such a significant regulatory role are outlined.

Relationship Between the Structure of Methoxylated and Hydroxylated Flavones and Their Antiproliferative Activity in HL60 Cells.

As part of our continuing investigation on flavonoid derivatives as potential anticancer substances, a series of methoxylated and hydroxylated flavones was synthesized, and their cytotoxic and anti-proliferative activity was evaluated in leukemic HL60 cells. Their structure-activity relationship was also investigated. The correlation between the methoxylation/hydroxylation pattern and antiproliferative activity revealed the importance of the 5,4'- and 3',4'-dihydroxyl moieties in flavone nucleus.

ß-glucans as potential immunoadjuvants: A review on the adjuvanticity, structure-activity relationship and receptor recognition properties.

ß-glucans, a group of polysaccharides exist in many organism species such as mushrooms, yeasts, oats, barley, seaweed, but not mammalians, have a variety of biological activities and applications in drugs and other healthcare products. In recent years, ß-glucans have been studied as adjuvants in anti-infection vaccines as well as immunomodulators in anti-cancer immunotherapy. ß-glucans can regulate immune responses when administered alone and can connect innate and adaptive immunity to improve immunogenicity of vaccines. When ß-glucans act as immunostimulants or adjuvants, a set of receptors have been revealed to recognize ß-glucans, including dectin-1, complement receptor 3 (CR3), CD5, lactosylceramide, and so on. Therefore, this review is mainly focused on the application of ß-glucans as immune adjuvants, the receptors of ß-glucans, as well as their structure and activity relationship which will benefit future research of ß-glucans.

Anti-Differentiation Effect of B, D-Seco limonoids of Swietenia mahogani.

BACKGROUND: Obesity is a pathological state caused by abnormal or excessive accumulation of fat. Swietenia mahogani JACQ., known as West Indian mahogany, is a medium-sized semi-evergreen tree belonging to Meliaceae. Their seeds are used in Indonesian folk medicine as a treatment for hypertension, diabetes, malaria, and it also has anti-feedant activities. The major components of S. mahogani are B, D-seco limonoids, a type of irregular triterpenes are well known. OBJECTIVE: We tried to find the bioactive components, which have the inhibitory activity on adipocyte differentiation from the seeds of S. mahogani. MATERIAL AND METHODS: 3T3-L1 cells, derived from mouse preadipocyte, are widely used in studying adipogenesis process. In this study, we used 3T3-L1 cells to find natural products with the inhibitory activity on adipocyte differentiation. S. mahogani seeds were dried and extracted with 100% MeOH. RESULTS: The methanolic extract was fractionated by bioassay-guided method to give nine B, D-seco limonoids (1-9) with slight structural modifications. Among nine compounds, compounds 4, 6 and 8 exhibited significant inhibitory effects of cell differentiation on 3T3-L1 cells. Those compounds have tigloyl residue at C-3 in common. Besides, compounds with no tigloyl residue at C-3 showed insignificant effect. Nevertheless, not all compounds with tigloyl residue at C-3 exerted significant inhibitory effect. CONCLUSION: These results suggested that tigloyl residue at C-3 may play a role in the anti-proliferative activity on a dipogenesis and the refined extract of S. mahogani may have a potential to be developed as a therapeutic agent to treat obesity. SUMMARY: Nine irregular seco-limonoids were isolated from Swietenia mahogani.Total extract and CHCl3 fraction of S. mahogani showed the significant inhibitory activities on 3T3-L1 cell differentiation.A tigloyl residue at C-3 in an aglycone may play a role in the anti-proliferative activity on adipogenesis.

Microbial hydroxylation and glycosylation of pentacyclic triterpenes as inhibitors on tissue factor procoagulant activity.

To discover new inhibitors on tissue factor procoagulant activity, 20 pentacyclic triterpenes were semi-synthetized through microbial transformation and assayed on the model of human THP-1 cells stimulated by lipopolysaccharide. In the biotransformation two types of reactions were observed, regio-selective hydroxylation and glycosylation. The bioassay results showed that most of tested compounds were significant effective on this model and two of the biotransformation products 23-hydroxy-28-O-ß-d-glucopyranosyl betulinic acid (3d) and 28-O-ß-d-glucopyranosyl oleanic acid (1a) exhibited most potential activities with the IC50 values of 0.028, 0.035nM respectively. The preliminary structure and activity relationship analysis revealed that the aglycones with single free hydroxyl group on the skeleton (1, 1j) were less effective than that with more free hydroxyl groups (1d, 1f, 2), mono-glycosylation can significantly enhance their inhibitory effects. Our findings also provide some potential leading compounds for tissue factor-related diseases, such as cancer and cardiovascular diseases.

Design, Synthesis and Evaluation of Indene Derivatives as Retinoic Acid Receptor α Agonists.

A series of novel indene-derived retinoic acid receptor α (RARα) agonists have been designed and synthesized. The use of receptor binding, cell proliferation and cell differentiation assays demonstrated that most of these compounds exhibited moderate RARα binding activity and potent antiproliferative activity. In particular, 4-((3-isopropoxy-2,3-dihydro-1H-inden-5-yl)-carbamoyl)benzoic acid (36d), which showed a moderate binding affinity, exhibited a great potential to induce the differentiation of NB4 cells (68.88% at 5 µM). Importantly, our work established indene as a promising skeleton for the development of novel RARα agonists.