Semisynthetic Analogues Research Articles

Anticancer Effects of Abietane Diterpene 7α-Acetoxy-6β-hydroxyroyleanone from Plectranthus grandidentatus and Its Semi-Synthetic Analogs: An In Silico Computational Approach

The abietane diterpenoid 7α-acetoxy-6β-hydroxyroyleanone (Roy) isolated from Plectranthus grandidentatus demonstrates cytotoxicity across numerous cancer cell lines. To potentiate anticancer attributes, a series of semi-synthetic Roy derivatives were generated and examined computationally. ADMET predictions were used to evaluate drug-likeness and toxicity risks. The antineoplastic potential was quantified by PASS. The DFT models were used to assess their reactivity and stability. Molecular docking determined cancer-related protein binding. MS simulations examined ligand–protein stability. Additionally, network pharmacology was used to identify potential targets and signaling pathways. Favorable ADME attributes and acceptable toxicity profiles were determined for all compounds. Strong anticancer potential was shown across derivatives (Pa 0.819–0.879). Strategic modifications altered HOMO–LUMO gaps (3.39–3.79 eV) and global reactivity indices. Favorable binding was revealed against cyclin-dependent kinases, BCL-2, caspases, receptor tyrosine kinases, and p53. The ligand exhibited a stable binding pose in MD simulations. Network analysis revealed involvement in cancer-related pathways. In silico evaluations predicted Roy and derivatives as effective molecules with anticancer properties. Experimental progress is warranted to realize their chemotherapeutic potential.

Exploring the potential of semi-synthetic Swertiamarin analogues for GLUT facilitation and insulin secretion in NIT-1 cell lines: a molecular docking and in-vitro study

Synthesis, characterisation, and anti-diabetic potential of swertiamarin analogues against DPP-4 enzymatic inhibition was done prior to this study. However, swertiamarin and its analogues inhibited DPP-4 enzyme significantly. Semisynthetic swertiamarin analogues have been studied for antidiabetic potential and mechanism of action utilising molecular docking and in-vitro techniques. The mechanism of action for swertiamarin analogues was determined by in-silico molecular docking studies using glucose-transporters, GLUT-1 (PDB ID: 4PYP), GLUT-3 (PDB ID: 7SPS), and GLUT-4 (PDB ID: 7WSM) along with in-vitro glucose uptake and glucose-induced insulin secretion assays. These studies found that synthesised swertiamarin analogues SNIPERSV3, SNIPERSV4, and SNIPERSV7 shown better docking score against different GLUTs and better anti-diabetic effects on glucose uptake and insulin secretion in NIT-1 cell line than standard glibenclamide and swertiamarin. Thus, swertiamarin analogues might be studied for diabetes therapy in the future.

Investigating impacts of the mycothiazole chemotype as a chemical probe for the study of mitochondrial function and aging.

Small molecule inhibitors of the mitochondrial electron transport chain (ETC) hold significant promise to provide valuable insights to the field of mitochondrial research and aging biology. In this study, we investigated two molecules: mycothiazole (MTZ) - from the marine sponge C. mycofijiensis and its more stable semisynthetic analog 8-O-acetylmycothiazole (8-OAc) as potent and selective chemical probes based on their high efficiency to inhibit ETC complex I function. Similar to rotenone (Rote), MTZ, a newly employed ETC complex I inhibitor, exhibited higher cytotoxicity against cancer cell lines compared to certain non-cancer cell lines. Interestingly, 8-OAc demonstrated greater selectivity for cancer cells when compared to both MTZ and Rote, which has promising potential for anticancer therapeutic development. Furthermore, in vivo experiments with these small molecules utilizing a C. elegans model demonstrate their unexplored potential to investigate aging studies. We observed that both molecules have the ability to induce a mitochondria-specific unfolded protein response (UPRMT) pathway, that extends lifespan of worms when applied in their adult stage. We also found that these two molecules employ different pathways to extend lifespan in worms. Whereas MTZ utilizes the transcription factors ATFS-1 and HSF1, which are involved in the UPRMT and heat shock response (HSR) pathways respectively, 8-OAc only required HSF1 and not ATFS-1 to mediate its effects. This observation underscores the value of applying stable, potent, and selective next generation chemical probes to elucidate an important insight into the functional roles of various protein subunits of ETC complexes and their regulatory mechanisms associated with aging.

LC-MS/MS analysis of 11-nor-9-carboxy-hexahydrocannabinol (HHC-COOH) and 11-hydroxy-hexahydrocannabinol (HHC-OH) for verification of hexahydrocannabinol (HHC) intake

Natural and semi-synthetic cannabinoid analogs are getting increasing media attention for their recreative use as an alternative to traditional cannabis, in Sweden as well as internationally. To investigate an increasing number of urine samples incoming to our clinical laboratory that were screening positive, using a CEDIA THC-COOH immunoassay from ThermoFisher Scientific, but then testing negative using GC-MS based verification analysis, we developed an LC-MS/MS-method for verification of hexahydrocannabinol (HHC) and Δ8-tetrahydrocannabinol. Assessment of HHC intake was based on identification of the following four metabolites: 11-nor-9(R)-carboxy-hexahydrocannabinol (R-HHC-COOH), 11-nor-9(S)-carboxy-hexahydrocannabinol (S-HHC-COOH), 11-hydroxy-9(R)-hexahydrocannabinol (R-HHC-OH) and 11-hydroxy-9(S)-hexahydrocannabinol (S-HHC-OH). Out of 46 urine samples analysed in this study, 44 showed presence of HHC-metabolites, which indicate HHC as the main explanation for an increased number of negative verifications for THC-COOH. In these samples, the HHC-OH metabolites occurred at a higher concentration than R-HHC-COOH while S-HHC-COOH was only detected in few samples at low concentrations. R-HHC-COOH and S-HHC-COOH can easily be added to a pre-existing verification method for THC-COOH, and still show acceptable results, while HHC-OH requires an enzyme capable of hydrolysing the ether glucuronide bond.

Isolation of Fidaxomicin and Shunt Metabolites from Actinoplanes deccanensis

A protocol for the isolation of the antibiotic fidaxomicin (Fdx) from Actinoplanes deccanensis and the isolation of shunt metabolites from A. deccanensisfdxG2‐ is reported. We constructed the mutant strain A. deccanensisfdxG2‐ by genetic manipulation which enabled the isolation of shunt metabolites as useful starting points for semisynthetic analogues of Fdx. Furthermore, a synthetic protocol for the conversion of complex A. deccanensisfdxG2‐ extracts into the single compound FdxG2‐OH via methanolysis is presented. This synthetic procedure is complemented by images and practical notes. Full structure assignment is given in the SI and the characterization data files are published to aid experimentalists. The protocol is also suitable as an undergraduate laboratory project. We hope to facilitate research into new Fdx derivatives through the availability of this procedure.

DNA Interaction and Cleavage Modes of Anthraquinone-Fused Enediynes: A Study on Tiancimycins, Yangpumicins, and Their Semisynthetic Analogues.

Dynemicin A has been the sole prototypical anthraquinone-fused enediyne (AFE) explored since its discovery in 1989. This study investigates the distinct DNA binding and cleavage mechanisms of emerging AFEs, represented by tiancimycins and yangpumicins, along with semisynthetic analogues. Our findings reveal their potent cytotoxicity against various tumor cell lines, while 18-methoxy tiancimycin A treatment could significantly suppress breast tumor growth with minimal toxicity. One of the most potent AFEs, i.e., tiancimycin A, preferentially targets DNA sequences 5'-ATT, 5'-CTT, 5'-GAA, 5'-GAT, and 5'-TTA. Molecular dynamics simulations suggest that emerging AFEs intercalate deeper into AT-rich DNA base pairs compared to dynemicin A. Importantly, tiancimycin A may equilibrate between insertional and intercalative modes without deintercalation, enabling selective cleavage of T and A bases. This study underscores how subtle structural variations among AFEs significantly influence their DNA recognition and cleavage, facilitating future design of novel AFEs as potent and selective payloads for antibody-drug conjugates.

Recent Advances in the Development of Polymyxin Antibiotics: 2010-2023.

The polymyxins are nonribosomal lipopeptides produced by Paenibacillus polymyxa and are potent antibiotics with activity specifically directed against Gram-negative bacteria. While the clinical use of polymyxins has historically been limited due to their toxicity, their use is on the rise given the lack of alternative treatment options for infections due to multidrug resistant Gram-negative pathogens. The Gram-negative specificity of the polymyxins is due to their ability to target lipid A, the membrane embedded LPS anchor that decorates the cell surface of Gram-negative bacteria. Notably, the mechanisms responsible for polymyxin toxicity, and in particular their nephrotoxicity, are only partially understood with most insights coming from studies carried out in the past decade. In parallel, many synthetic and semisynthetic polymyxin analogues have been developed in recent years in an attempt to mitigate the nephrotoxicity of the natural products. Despite these efforts, to date, no polymyxin analogues have gained clinical approval. This may soon change, however, as at the moment there are three novel polymyxin analogues in clinical trials. In this context, this review provides an update of the most recent insights with regard to the structure-activity relationships and nephrotoxicity of new polymyxin variants reported since 2010. We also discuss advances in the synthetic methods used to generate new polymyxin analogues, both via total synthesis and semisynthesis.

Synthesis and invitro antitumor activity of galactosamine-docetaxel conjugates.

Docetaxel (DTX) is a semi-synthetic analogue of paclitaxel which has attracted extensive attention in the treatment of cancer. However, the current clinically used DTX formulations display low tumor targeting ability, leading to unsatisfactory therapeutic outcomes with adverse effects, which poses significant challenges to the clinical application. In this study, three galactosamine (Gal) and docetaxel conjugates with different linkers were synthesized, namely DTX-(suc-Gal)2, DTX-(DTDPA-Gal)2, and DTX-(DSeDPA-Gal)2. These three conjugates were characterized by 1H NMR, FT-IR and HRMS. The invitro drug release study shows that DTX-(DTDPA-Gal)2 and DTX-(DSeDPA-Gal)2 exhibit glutathione (GSH)-responsive drug release and DTX-(DSeDPA-Gal)2 displays higher GSH-responsiveness. The invitro antitumor activity study shows that DTX-(DTDPA-Gal)2 and DTX-(DSeDPA-Gal)2 exhibit enhanced cytotoxicity, cell apoptosis rate and G2/M phase arrest against HepG2 cells as compared to DTX-(suc-Gal)2, DTX-(DSeDPA-Gal)2 displays the highest cytotoxicity, cell apoptosis rate and G2/M phase arrest among these three conjugates. In addition, DTX-(DSeDPA-Gal)2 exhibits higher selectivity to HepG2 cells as compared to free DTX. The DTX-(DSeDPA-Gal)2 developed in this study has been proven to be an effective DTX conjugate for selective killing hepatoma cells.

Chemical and Antiplasmodial Investigations on Eremophila-Derived Alkaloids and Semisynthetic Ether Analogues.

Microthecaline A (1), the known antiplasmodial quinoline serrulatane alkaloid from the roots of Eremophila microtheca F. Muell. ex Benth. (Scrophulariaceae), was targeted for isolation and subsequent use in the generation of a semisynthetic ether library. A large-scale extraction and isolation yielded the previously undescribed quinoline serrulatane microthecaline B (2), along with crystalline 1 that enabled the first X-ray crystallographic analysis to be undertaken on this rare alkaloid structure class. The X-ray diffraction analysis of 1 supported the absolute configuration assignment of microthecaline A, which was originally assigned by ECD data analysis. Microthecaline A (1) was converted into 10 new semisynthetic ether derivatives (3-12) using a diverse series of commercially available alkyl halides. Chemical structures of the new serrulatane alkaloid and semisynthetic ether analogues were assigned by spectroscopic and spectrometric analyses. Antiplasmodial evaluations of 1-12 showed that the semisynthetic derivative 5 elicited the most potent activity with an IC50 value of 7.2 μM against Plasmodium falciparum 3D7 (drug-sensitive) strain.

Anticancer Effect by Combined Treatment of Artemisia annua L. Polyphenols and Docetaxel in DU145 Prostate Cancer Cells and HCT116 Colorectal Cancer Cells.

Docetaxel (DTX), a semi-synthetic analogue of paclitaxel (taxol), is known to exert potent anticancer activity in various cancer cells by suppressing normal microtubule dynamics. In this study, we examined how the anticancer effect of DTX is regulated by polyphenols extracted from Korean Artemisia annua L. (pKAL) in DU145 prostate cancer cells (mutant p53) and HCT116 colorectal cancer cells (wild-type p53). Here, we show that the anticancer effect of DTX was enhanced more significantly by pKAL in HCT116 cells than in DU145 cells via phase-contrast microscopy, CCK-8 assay, Western blot, and flow cytometric analysis of annexin V/propidium iodide-stained cells. Notably, mutant p53 was slightly downregulated by single treatment of pKAL or DTX in DU145 cells, whereas wild-type p53 was significantly upregulated by pKAL or DTX in HCT116 cells. Moreover, the enhanced anticancer effect of DTX by pKAL in HCT116 cells was significantly associated with the suppression of DTX-induced p53 upregulation, increase of DTX-induced phospho-p38, and decrease of DTX-regulated cyclin A, cyclin B1, AKT, caspase-8, PARP1, GM130, NF-κB p65, and LDHA, leading to the increased apoptotic cell death and plasma membrane permeability. Our results suggest that pKAL could effectively improve the anticancer effect of DTX-containing chemotherapy used to treat various cancers expressing wild-type p53.

(370) Overview of Nonclinical Studies of LIB-01, a Novel Promising Oral Drug Under Development for Treatment of Erectile Dysfunction

Abstract Introduction LIB-01 is a novel molecule being developed as an oral drug for the treatment of erectile dysfunction (ED). It is a semi-synthetic analog, developed based on research on active compounds identified in root bark that had been used for treatment of male sexual disability since time immemorial. Objective In preparation for clinical development, a number of nonclinical studies on erectile function were conducted in normal and diabetic rats with ED. Studies to investigate the mechanism supporting the pro-erectile effect of LIB-01 were also conducted. A summary of the results from the nonclinical research program is presented. Methods Erectile response elicited by electrical stimulation of the cavernous nerve (ES CN) in anaesthetized rats was assessed. Intracavernous and arterial blood pressures were monitored according to a standardized experimental procedure. Mechanism of action studies were conducted with rat cavernosal tissue samples using immunohistochemistry and in ex vivo/organ chamber experiments. The isometric tension studies were conducted on cavernosal strips from LIB-01 treated and untreated Wistar rats. Cavernosal strips from untreated rats were incubated with either LIB-01 or DMSO (control) and then pre-contracted by phenylephrine (PHE). Concentration- or frequency response curves were performed on PHE pre-contracted strips in 3 consecutive steps: (i) cumulative addition of increasing acetylcholine (ACh) concentrations, (ii) electrical field stimulation (EFS) with increasing frequencies, and (iii), cumulative addition of increasing sodium nitroprusside (SNP) concentrations. Results A statistically significant pro-erectile facilitatory effect of LIB-01 has been repeatedly evidenced in all the studies conducted in anaesthetized control Wistar rats, by oral or subcutaneous administration of LIB-01 at 15 mg/kg/d, with an effect in the similar range as iv sildenafil 0.3mg/kg, when compared. The pro-erectile effect of LIB-01 was not acute, instead, the effect gradually increased and remained for at least 7 days post treatment. In addition, LIB-01 significantly improved erectile responses in anaesthetized diabetic Goto-Kakizaki ED rats compared to vehicle-treated rats, demonstrating the pro-erectile effect of LIB-01 in a robust validated pathophysiological rat model of type 2 diabetes. Immunohistochemistry experiments on cavernosal tissue from LIB-01 treated normal rats showed that neither CD31 nor nNOS expression was altered, thus likely ruling out any effect of LIB-01 on cavernosal micro-vascularization or cavernosal nNOS. Furthermore, only at a high concentration (10-5 M) was there a slight increase in the endothelium dependent relaxations induced by ACh compared to vehicle while LIB-01 did not exert any effect neither on endothelium-independent relaxations induced by SNP nor on nitrergic relaxation induced by EFS of untreated cavernosal strips exposed ex-vivo to different concentrations of LIB-01. Conclusions LIB-01 is a novel molecule which displays a significant pro-erectile effect in anesthetized normal rats as well as in diabetic rats with ED. The pro-erectile effect of LIB-01 is not acute, instead, the effect gradually increases and remains for at least 7 days post-treatment. Results from several mechanistic studies lead to postulate that the mechanism of LIB-01 does not recruit the NO-cGMP pathway thereby differing from phosphodiesterase type 5 inhibitors. A first-in-human clinical trial with LIB-01 is planned to start in 2023. Disclosure Yes, this is sponsored by industry/sponsor: Dicot AB. Clarification: Industry initiated, executed and funded study. Any of the authors act as a consultant, employee or shareholder of an industry for: Dicot AB.

Overview of the New Bioactive Heterocycles as Targeting Topoisomerase Inhibitors Useful Against Colon Cancer.

Colorectal cancer (CRC) is the third most common worldwide cancer with high mortality. Factors such as more effective screening programs and improvements in treatment modalities have favored a decrease in the incidence and mortality rate of colorectal cancer in the last three decades. Metastatic CRC is incurable in most cases, and therapy using multiple drugs can increase patients' life expectancy by 2 to 3 years. Chemotherapy is the primary treatment, and fluoropyrimidines correspond to the first treatment line. They can be used in monotherapy or therapeutic schemes of oxaliplatin, FOLFOX (intravenous fluorouracil, leucovorin, and oxaliplatin), and CAPOX (oral capecitabine and oxaliplatin) or regimens based on Irinotecan, such FOLFIRI (fluorouracil, leucovorin, and Irinotecan) and CAPIRI (capecitabine and Irinotecan). Like Camptothecin, irinotecan and other analogs have a mechanism of action based on forming a ternary complex with Topoisomerase I and DNA by reversibly binding, providing DNA damage and consequent cell death. This way, topoisomerases are vital enzymes for DNA maintenance and cell viability. Thus, here we will review the main works demonstrating the correlation between the inhibition of different isoforms of topoisomerases and the in vitro cytotoxic activity in colon cancer. The findings revealed that natural compounds, semi-synthetic and synthetic analogs showed potential cytotoxicity against several colon cancer cell lines in vitro and that this activity was often accompanied by the ability to inhibit type I and II topoisomerases, demonstrating that these enzymes can be promising drug targets for the development of new chemotherapeutics against colon cancer.

Previously Uncharacterized Variants, OCF-E-OCF-J, of the Antifungal Occidiofungin Produced by Burkholderia contaminans MS14.

The rise of multidrug resistant fungal infections highlights the need to identify and develop novel antifungal agents. Occidiofungin is a nonribosomally synthesized glycolipopeptide that has a unique mechanism of action, disrupting actin-mediated functions and inducing cellular apoptosis. Antifungal activity has been observed in vitro against various fungal species, including multidrug resistant Candida auris, and in vivo efficacy has been demonstrated in a murine vulvovaginal candidiasis model. Occidiofungin, a cyclic glycolipopeptide, is composed of eight amino acids and in previous studies, an asparagine residue was assigned at position 7 (ASN7). In this study, new structural variants of occidiofungin have been characterized which have aspartic acid (ASP7), glutamine (GLN7), or glutamic acid (GLU7) at position 7. The side chain of the ASP7 variant contains the only terminal carboxylic acid in the peptide and provides a useful site for selective chemical modifications. Analogues were synthesized at the ASP7 position and tested for antifungal activity. These analogues were shown to be more active as compared to the ASP7 variant against a panel of Candida species. The naturally occurring variants of occidiofungin with a side chain containing a carboxylic acid at the seventh amino acid position can be used to develop semisynthetic analogues with enhanced therapeutic properties.

Lincosamide Antibiotics: Structure, Activity, and Biosynthesis.

Lincosamides are naturally occurring antibiotics isolated from Streptomyces sp. Currently, lincomycin A and its semisynthetic analogue clindamycin are used as clinical drugs. Due to their unique structures and remarkable biological activities, derivatizations of lincosamides via semi-synthesis and biosynthetic studies have been reported. This review summarizes the structures and biological activities of lincosamides, and the recent studies of lincosamide biosynthetic enzymes.

Site-selective synthesis and pharmacological elucidation of novel semi-synthetic analogues of koenimbine as a potential anti-inflammatory agent

Koenimbine (1), a carbazole alkaloid isolated from Murraya koenigii, belongs to the Rutaceae family. Various pharmacological effects such as anti-diabetic, melanogenesis inhibition, anti-diarrheal, anti-cancer, and anti-inflammatory properties of koenimbine have already been reported. In the current study, we investigated the anti-inflammatory role of koenimbine (1) and its novel semi-synthetic derivative 8-methoxy-3,3,5-trimethylpyrano[3,2-a] carbazole-11(3H)-yl) (3-(trifluoromethyl) phenyl) methanone (1G) in both in vitro and in vivo biological systems. Our results demonstrated that the anti-inflammatory activity of 1G significantly lowered the production of NO, pro-inflammatory cytokines (IL-6, TNF-α & IL-1β), LTB4 following LPS stimulation in RAW 264.7 macrophages. Furthermore, 1G significantly attenuated the expression levels of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose dependent manner and also decreased the production of reactive oxygen species (ROS) in LPS-activated RAW 264.7 cells. In addition, the oral administration of 1G reduced the inflammatory response in carrageenan-induced paw edema in BALB/C mice. Moreover, it effectively reduced NO, IL-6, IL-1β & TNF-α levels, liver markers (AST, ALT), and kidney markers (BUN, CRE, and Urea). Also, 1G reverted the infiltration of inflammatory cells and tissue damage in lungs, liver and kidney enhanced the survival rate in LPS-challenged mice. 1G blocks NF-κB p65 from translocating into the nucleus and activating inflammatory gene transcription. These results illustrated that 1G suppresses the inflammatory effects both in-vitro and in-vivo studies via downregulating the nuclear factor kappa-B (NF-κB) signaling pathway. In conclusion, our results demonstrate that semi-synthetic derivative 1G can effectively attenuate the inflammatory response via NF-κB and MAPK signaling pathways; suggesting 1G is a potential novel anti-inflammatory drug candidate in treating inflammatory disorders.

Synthesis and Structural Activity Relationship Study of Ursolic Acid Derivatives as Antitubercular Agent.

The chemical transformation of ursolic acid (UA) into novel C-3 aryl ester derivatives and in vitro and silico assessment of their antitubercular potential. UA is a natural pentacyclic triterpenoid with many pharmacological properties. Semisynthetic UA analogs have demonstrated enhanced anticancer, antimalarial, and antifilarial properties in our previous studies. The C-30 carboxylic group of previously isolated UA was protected, and various C-3 aryl ester derivatives were semi-synthesized. The agar dilution method was used to evaluate the in vitro antitubercular efficacy of Mycobacterium tuberculosis (Mtb) H37Ra. In silico docking studies of the active derivative were carried out against Mtb targets, catalase peroxidase (PDB: 1SJ2), dihydrofolate reductase (PDB: 4M2X), enoyl-ACP reductase (PDB: 4TRO), and cytochrome bc1 oxidase (PDB: 7E1V). The derivative 3-O-(2-amino,3-methyl benzoic acid)-ethyl ursolate (UA-1H) was the most active among the eight derivatives (MIC1 2.5 µg/mL) against Mtb H37Ra. Also, UA-1H demonstrated significant binding affinity in the range of 10.8-11.4 kcal/mol against the antiTb target proteins, which was far better than the positive control Isoniazid, Ethambutol, and co-crystallized ligand (HEM). Moreover, the predicted hit UA-1H showed no inhibition of Cytochrome P450 2D6 (CYP2D6), suggesting its potential for favorable metabolism in Phase I clinical studies. The ursolic acid derivative UA-1H possesses significant in vitro antitubercular potential with favorable in silico pharmacokinetics. Hence, further in vivo assessments are suggested for UA-1H for its possible development into a secure and efficient antitubercular drug.

Computer-assisted drug discovery (CADD) of an anti-cancer derivative of the theobromine alkaloid inhibiting VEGFR-2

VEGFR-2 is a significant target in cancer treatment, inhibiting angiogenesis and impeding tumor growth. Utilizing the essential pharmacophoric structural properties, a new semi-synthetic theobromine analogue (T-1-MBHEPA) was designed as VEGFR-2 inhibitor. Firstly, T-1-MBHEPA's stability and reactivity were indicated through several DFT computations. Additionally, molecular docking, MD simulations, MM-GPSA, PLIP, and essential dynamics (ED) experiments suggested T-1-MBHEPA's strong binding capabilities to VEGFR-2. Its computational ADMET profiles were also studied before the semi-synthesis and indicated a good degree of drug-likeness. T-1-MBHEPA was then semi-synthesized to evaluate the design and the in silico findings. It was found that, T-1-MBHEPA inhibited VEGFR-2 with an IC50 value of 0.121 ± 0.051 µM, as compared to sorafenib which had an IC50 value of 0.056 µM. Similarly, T-1-MBHEPA inhibited the proliferation of HepG2 and MCF7 cell lines with IC50 values of 4.61 and 4.85 µg/mL respectively - comparing sorafenib's IC50 values which were 2.24 µg/mL and 3.17 µg/mL respectively. Interestingly, T-1-MBHEPA revealed a noteworthy IC50 value of 80.0 µM against the normal cell lines exhibiting exceptionally high selectivity indexes (SI) of 17.4 and 16. 5 against the examined cell lines, respectively. T-1-MBHEPA increased the percentage of apoptotic MCF7 cells in early and late stages, respectively, from 0.71 % to 7.22 % and from 0.13 % to 2.72 %, while the necrosis percentage was increased to 11.41 %, in comparison to 2.22 % in control cells. Furthermore, T-1-MBHEPA reduced the production of pro-inflammatory cytokines TNF-α and IL-2 in the treated MCF7 cells by 33 % and 58 %, respectively indicating an additional anti-angiogenic mechanism. Also, T-1-MBHEPA decreased significantly the potentialities of MCF7 cells to heal and migrate from 65.9 % to 7.4 %. Finally, T-1-MBHEPA’s oral treatment didn’t show toxicity on the liver function (ALT and AST) and the kidney function (creatinine and urea) levels of mice.

Synthetic Strategies toward Lysergic Acid Diethylamide: Ergoline Synthesis via α-Arylation, Borrowing Hydrogen Alkylation, and C-H Insertion.

Lysergic acid diethylamide (LSD), a semisynthetic ergoline alkaloid analogue and hallucinogen, is a potent psychoplastogen with promising therapeutic potential. While a variety of synthetic strategies for accessing ergoline alkaloids have emerged, the complexity of the tetracyclic ring system results in distinct challenges in preparing analogues with novel substitution patterns. Methods of modulating the hallucinogenic activity of LSD by functionalization at previously inaccessible positions are of continued interest, and efficient syntheses of the ergoline scaffold are integral toward this purpose. Here, we report novel C-C bond forming strategies for preparing the ergoline tetracyclic core, focusing on the relatively unexplored strategy of bridging the B- and D-ring systems last. Following cross-coupling to first join the A- and D-rings, we explored a variety of methods for establishing the C-ring, including intramolecular α-arylation, borrowing hydrogen alkylation, and rhodium-catalyzed C-H insertion. Our results led to a seven-step formal synthesis of LSD and the first methods for readily introducing substitution on the C-ring. These strategies are efficient for forming ergoline-like tetracyclic compounds and analogues, though they each face unique challenges associated with elaboration to ergoline natural products. Taken together, these studies provide important insights that will guide future synthetic strategies toward ergolines.

Antiproliferative activity and apoptosis-inducing mechanism of Amaryllidaceae alkaloid montanine on A549 and MOLT-4 human cancer cells

The isoquinoline alkaloids found in Amaryllidaceae are attracting attention due to attributes that can be harnessed for the development of new drugs. The possible molecular mechanisms by which montanine exerts its inhibitory effects against cancer cells have not been documented. In the present study, montanine, manthine and a series of 15 semisynthetic montanine analogues originating from the parent alkaloid montanine were screened at a single test dose of 10 μM to explore their cytotoxic activities against a panel of eight cancer cell lines and one non-cancer cell line. Among montanine and its analogues, montanine and its derivatives 12 and 14 showed the highest cytostatic activity in the initial single-dose screening. However, the native montanine exhibited the greatest antiproliferative activity against cancer cells, with a lower mean IC50 value of 1.39 µM, compared to the displayed mean IC50 values of 2.08 µM for 12 and 3.57 µM for 14. Montanine exhibited the most potent antiproliferative activity with IC50 values of 1.04 µM and 1.09 µM against Jurkat and A549 cell lines, respectively. We also evaluated montanine’s cytotoxicity and cell death mechanisms. Our results revealed that montanine triggered apoptosis of MOLT-4 cells via caspase activation, mitochondrial depolarisation and Annexin V/PI double staining. The Western blot results of MOLT-4 cells showed that the protein levels of phosphorylated Chk1 Ser345 were upregulated with increased montanine concentrations. Our findings provide new insights into the mechanisms underlying the cytostatic, cytotoxic and pro-apoptotic activities of montanine alkaloids in lung adenocarcinoma A549 and leukemic MOLT-4 cancer cell types.

Scoparone chemical modification into semi-synthetic analogues featuring 3-substitution for their anti-inflammatory activity.

Natural products (NPs) continue to serve as a structural model for the development of new bioactive molecules and improve the process of identifying novel medicines. The biological effects of coumarins, one of the most researched compounds among NPs, are currently being thoroughly investigated. In the present investigation, we reported the synthesis of nineteen semi-synthetic 3-substituted scoparone analogues, followed by their characterization using analytical methods such as NMR, HPLC, and HRMS. All compounds screened for in vitro and in vivo study for their ability to reduce inflammation. The SAR study worked effectively for this particular scoparone 3-substitution, as compounds 3, 4, 9, 16, 18, and 20 displayed improved in vitro results for TNF-α than the parent molecule. Similarly, compounds 3, and 17 showed a higher percentage of IL-6 inhibition. Compounds 3, 4, and 12 have also been identified by in vivo studies as promising candidates with higher percent inhibition than the parent scoparone molecule. As evident from all in vitro and in vivo studies, compound 3 showed the most potent anti-inflammatory activity among all.