Synthesis,characterization, and antimicrobial evaluation of some new hydrazinecarbothioamide, 1,2,4-triazole and 1,3,4-thiadiazole derivatives

In this work, we reported the synthesis and evaluation of antibacterial and antifungal activities of three new compound series obtained from 6-(phenyl/4-chlorophenyl)imidazo[2,1-b]thiazole-3-acetic acid hydrazide: 2-{[6-(phenyl/4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl]acetyl}-N-alkyl/arylhydrazinecarbothioamides (2a–d), 4-alkyl/aryl-2,4-dihydro-5-{[6-(phenyl/4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl]methyl}-3H-1,2,4-triazole-3-thiones (3a–n), and 2-alkyl/arylamino-5-{[6-(phenyl/4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl]methyl}-1,3,4-thiadiazoles (4a–g). The newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR (APT), mass and elemental analysis. Their antibacterial and antifungal activities were evaluated against Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Candida albicans ATCC 10231, C. parapsilosis ATCC 22019, C. krusei ATCC 6258, Trichophyton mentagrophytes var. erinacei NCPF 375, Microsporum gypseum NCPF 580, and T. tonsurans NCPF 245. 3c, 3f, 3m, 3n, and 4e showed the highest antibacterial activity. Particularly 3c, 3f, 3g, 3k, 3n, 4a, 4e, and 4g showed the highest antifungal activity against tested fungi.     

Microwave-Assisted Synthesis and Anti-HIV Activity of New Acyclic C-Nucleosides of 3-(D-Ribo-Tetritol-1-yl)-5-Mercapto-1,2,4-Triazoles. Part 1

Microwave-assisted synthesis of novel acyclic C-nucleosides of 6-alkyl/aryl-3-(1,2-O-isopropylidene-D-ribo-tetritol-1-yl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles (5–12) and the 6-aryl-thiomethyl analogues 25–27 has been described. Deblocking of 5–12 and 25–27 afforded the free acyclic C-nucleosides 13–20, and 28–30, respectively. All of the synthesized compounds showed no inhibition against HIV-1 and HIV-2 replication in MT-4 cells. However, 6-(3,4-dichlorophenyl)-3-(1,2-O-isopropylidene-D-ribo-tetritol-1-yl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole (6) is a potent inhibitor, in vitro, of the replication of HIV-2. These results suggest that compound 6 should be considered as a new lead in the development of antiviral agent.     

Synthesis and pharmacological evaluation of condensed heterocyclic 6-substituted 1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazole and 1,3,4-oxadiazole derivatives of isoniazid

The significance of this study was to prepare various isoniazid derivatives by introducing the isoniazid core into several molecules to explore the possibilities of some altered biological activities. Series of 6-substituted-1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazole (3a–g) and 1,3,4-oxadiazole (4a–g and 5) derivatives of isoniazid were synthesized in satisfactory yield and pharmacologically evaluated for their anti-inflammatory, analgesic, ulcerogenic, and lipid peroxidation activities by known experimental models.     

Synthesis and biological activity of pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidin-4-one derivatives: in silico approach

Xanthine oxidase (XO) is responsible for the pathological condition called gout. Inhibition of XO activity by various pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidine-4-one derivatives was assessed and compared with the standard inhibitor allopurinol. Out of 10 synthesized compounds, two compounds, viz. 3-amino-6-(2-hydroxyphenyl)-1H-pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidin-4-one (3b) and 3-amino-6-(4-chloro-2-hydroxy-5-methylphenyl)-1H-pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidin-4-one (3g) were found to have promising XO inhibitory activity of the same order as allopurinol. Both compounds and allopurinol inhibited competitively with comparable Ki (3b: 3.56?µg, 3g: 2.337?µg, allopurinol: 1.816?µg) and IC₅₀ (3b: 4.228?µg, 3g: 3.1?µg, allopurinol: 2.9?µg) values. The enzyme–ligand interaction was studied by molecular docking using Autodock in BioMed Cache V. 6.1 software. The results revealed a significant dock score for 3b (?84.976?kcal/mol) and 3g (?90.921?kcal/mol) compared with allopurinol (?55.01?kcal/mol). The physiochemical properties and toxicity of the compounds were determined in silico using online computational tools. Overall, in vitro and in silico study revealed 3-amino-6-(4-chloro-2-hydroxy-5-methylphenyl)-1H-pyrazolo[3,4-d]thiazolo[3,2–a]pyrimidin-4-one (3g) as a potential lead compound for the design and development of XO inhibitors.     

Synthesis,physiochemical property and antimicrobial activity of novel quaternary ammonium salts

Twenty-four novel 5-phenyl-1,3,4-oxadiazole-2-thiol (POT) analogues, benzo[d]oxazole-2-thiol, benzo[d]thiazole-2-thiol and 5-methyl-1,3,4-thiadiazole-2-thiol-substituted N,N-bis(2-hydroxyethyl) quaternary ammonium salts (QAS) (5a-d, 6a-d, 7a-d, 10a-d, 13a-d, 16a-d) were prepared and characterised by FTIR, NMR and elemental analysis. Part of target compounds (5d, 6d, 7d, 10d, 13d, 16d) displayed potent antimicrobial effect against ten common pathogens (S. aureus, α-H-tococcus, β-H-tococcus, E. coli, P. aeruginosa, Proteus vulgaris, Canidia Albicans, Cytospora mandshurica, Physalospora piricola, Aspergillus niger) and had relatively low cytotoxity against two human cell lines (HaCat and LO2). TEM and SEM images of E. coli and S. aureus morphologies treated with 7d showed that the antibacterial mechanism might be the QAS fixing on cell wall surfaces and puncturing to result in the release of bacterial cytoplasm. This study provides new information of QAS, which could be used to design novel antimicrobial agents applied in clinic or agriculture.     

Synthesis and Antiviral Activities of New Pyrazolo[4,3‐c]quinolin‐3‐ones and Their Ribonucleoside Derivatives

Several new pyrazolo[4,3‐c]quinolin‐3‐one ribonucleosides (5a–g) and their corresponding heterocycle moieties (3a–g) were synthesized and evaluated against vaccinia virus (VV) and herpes simplex virus type 1 (HSV‐1). The derivatives 3c and 3d showed modest inhibitory activity against vaccinia virus reaching 70% at a concentration of 100 µM. All heterocyclic compounds (3a–f) showed a modest inhibition against HSV‐1, reaching the maximal inhibitory effect around 20–30%. The antiviral effects of most of the pyrazolo[4,3‐c]quinolin‐3‐one ribonucleosides (5a–f) on VV and HSV were not impressive.     

VEGFR-2 inhibitors and apoptosis inducers: synthesis and molecular design of new benzo[g]quinazolin bearing benzenesulfonamide moiety

Two series of novel 4-(2-(2-(2-(substituted) hydrazinyl)-2-oxoethylthio)-4-oxobenzo[g]quinazolin-3(4H)-yl) benzenesulfonamide 5–17 and 4-(2-(2-(substituted-1H-pyrazol-1-yl)-2-oxoethylthio)-4-oxobenzo[g]quinazolin-3(4H)-yl) benzenesulfonamide 18–24 were synthesised from the starting material 4-(2-(2-hydrazinyl-2-oxoethylthio)-4-oxobenzo[g]quinazolin-3(4H)-yl) benzenesulfonamide 5, to be evaluated for their inhibitory activity towards VEGFR-2. The target compounds 5–24, were screened for their cytotoxic activity against MCF-7 breast cancer cell line and the percentage inhibition against VEGFR-2. Compounds 9, 20, 22 and 23, showed excellent VEGFR-2 inhibitory activity with IC₅₀ ranging from 0.64 to 1.04?µm. Being the most potent, compound 9 was evaluated for its apoptotic inducer effect by studying the effect on caspase-3, it was found to increase its level. Compound 9 boosted the level of Bax and reduced the level of BCl2, compared to the control. Cell cycle analysis was conducted, compound 9 showed cell cycle arrest at G2/M phase. Moreover, mild cytotoxic effect (IC₅₀?=?29.41?µm, respectively) in normal breast cells MCF-12?A, was observed when treated with the same compound. Finally, a molecular docking study was performed to investigate the possible binding interaction inside the active site of the VEGFR-2 enzyme.     

Synthesis,antimicrobial activity and molecular modeling study of substituted 5-aryl-pyrimido[5,4-c]quinoline-2,4-diones

A series of pyrimido[5,4-c]quinoline-2,4-dione derivatives 5a–k were synthesized in moderate yields via a thermolysis reaction of equimolar ratio of 5-arylidine-1,3-dimethylbarbituric acid derivatives 3a–d with aniline derivatives 4a–d at 150–180 °C for 1–2?h. Eight of the synthesized compounds were chosen for a primary in vitro one-dose anticancer assay performed using the full NCI 60 cell panel. Only compound 5b showed moderate GI% at the used dose (10 μM) against four of the tested cell lines corresponding to leukemia SR (GI%: 51), non small-cell lung cancer HOP-92 (GI%: 63), melanoma UACC-62 (GI%: 53) and renal cancer UO-31 (GI%: 69). On the other hand, antimicrobial screening of the whole set of the synthesized compounds was performed against three Gram +ve and two Gram ?ve bacterial strains. Results of the antimicrobial screening showed that compounds 5d, 5e, 5f, 5h and 5k have broad-spectrum antibacterial efficacy being moderately active against all the tested Gram +ve and two Gram ?ve bacteria. Also, compound 5a showed interesting results being only active against Streptococcus faecalis and both tested Gram ?ve strains viz. E. coli and P. aeruginosa. In order to compare the binding mode of the most active compounds 5e and 5f along with the inactive compound 5c we docked these compounds into the empty binding site of topoisomerase II DNA gyrase (PDB ID: 1KZN), and results were compared with the bound inhibitor Clorobiocin.     

Synthesis and Antimicrobial Evaluation of Novel Chiral 2‐Amino‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine Derivatives

New N‐substituted‐2‐amino‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine derivatives were synthesized employing a convenient one‐pot three‐component method and their structures were characterized by ¹H‐NMR and single crystal X‐ray diffraction analysis. All the synthesized compounds were in vitro screened for antimicrobial activity against Gram‐positive (Sarcina lutea) and Gram‐negative bacteria (Escherichia coli). In this work, we introduced a chiral residue on the tetrahydropyridine nitrogen, the hitherto the less investigated position on this pharmacophore in order to explore the effect. The antibacterial results showed that the synthesized compounds were active only against Gram‐positive bacteria and the (R)‐enantiomers displayed a greater antimicrobial potency than their (S)‐counterparts. The structure–activity relationship here investigated may provide some interesting clues for future development of tetrahydrothienopyridine derivatives with higher antimicrobial activity.     

Synthesis of a novel class of some 1,3,4-oxadiazole derivatives as antimicrobial agents

In an effort to discover new candidates with improved antimicrobial activities we report here the synthesis and in vitro biological evaluation of various series of 2-{(3,4,5-trimethoxy phenyl-1,3,4-oxadiazolyl)-5-thio}-4-(morpholino)-6-(phenyl ureido)-s-triazine (7a-i) and 2-{(3,4,5-trimethoxy phenyl-1,3,4-oxadiazolyl)-5-thio}-4-(morpholino)-6-(phenyl thioureido)-s-triazine (8a-g). Antimicrobial properties of the title compounds were investigated against two Gram ( + ve) bacteria (S. aureus, B. subtilis), two Gram ( ? ve) bacteria (P. aeruginosa, E. coli) and yeast-like fungi (C. albicans) using the broth microdilution method.     

NOVEL SYNTHESIS OF seco TYPE OF ACYCLO C-NUCLEOSIDES OF 1,2,4-TRIAZOLE AND 1,2,4-TRIAZOLO[3,4-b][1,3,4]THIADIAZINE

The seco C-nucleosides 3-(1,2,3,4,5-penta-O-acetyl-D-gluco- and D- galacto-pentitol-1-yl)-1H-1,2,4-triazoles (8 and 9) were obtained in a one pot by deamination and dethiolation of 4-amino-3-(D-gluco- and D-galacto-pentitol-1-yl)-5-mercapto-1,2,4-triazoles (1 and 2), respectively, using sodium nitrite in orthophosphoric acid and subsequent acetylation. Condensation of 1, 2, and 4-amino-3-(D-glycero-D-gulo-hexitol-1-yl)-5-mercapto-1,2,4-triazole (12) with phenacylbromide (11) afforded the corresponding 3-(D-gluco-, D-galacto-pentitol-1-yl) and 3-(D-glycero-D-gulo-hexitol-1-yl)-6-phenyl-7H-1,2,4- triazolo[3,4-b][1,3,4] thiadiazines (15, 16, and 17). Acetylation of 15–17 gave the penta- and hexa-O-acetyl derivatives 18–20, respectively. The structures were confirmed by using ¹H, ¹³C, and 2D NMR spectra, DQFCOSY, HMQC, and HMBC experiments. The favored conformational structures were deduced from the vicinal coupling constants of the protons.     

Synthesis of new 4-[2-(alkylamino)ethylthio]pyrrolo[1,2-a]quinoxaline and 5-[2-(alkylamino)ethylthio]pyrrolo[1,2-a]thieno[3,2-e]pyrazine derivatives,as potential bacterial multidrug resistance pump inhibitors

The synthesis of new 4-[2-(alkylamino)ethylthio]pyrrolo[1,2-a]quinoxaline derivatives 1a-l is described in five or six steps starting from various substituted nitroanilines 2a-e. The bioisostere 5-[2-(alkylamino)ethylthio]pyrrolo[1,2-a]thieno[3,2-e]pyrazine 1m was also prepared. The new derivatives were evaluated as efflux pump inhibitors (EPIs) in a model targeting the NorA system of Staphylococcus aureus. The antibiotic susceptibility of two strains overproducing NorA, SA-1199B and SA-1, was determined alone and in combination with the neo-synthesised compounds by the agar diffusion method and MIC determination, in comparison with reserpine and omeprazole taken as reference EPIs. A preliminary structure-activity relationship study firstly allowed to clarify the influence of the substituents at positions 7 and/or 8 of the pyrrolo[1,2-a]quinoxaline nucleus. Methoxy substituted compounds, 1b and 1g, were more potent EPIs than the unsubstituted compounds (1a and 1f), followed by chlorinated derivatives (1c-d and 1h). Moreover, the replacement of the N,N-diethylamino group (compounds 1a-e) by a bioisostere such as pyrrolidine (compounds 1f-h) enhanced the EPI activity, in contrast with the replacement by a piperidine moiety (compounds 1i-k). Finally, the pyrrolo[1,2-a]thieno[3,2-e]pyrazine compound 1m exhibited a higher EPI activity than its pyrrolo[1,2-a]quinoxaline analogue 1a, opening the way to further pharmacomodulation.     

Design,synthesis, neuroprotective,antibacterial activities and docking studies of novel thieno[2,3-d]pyrimidine-alkyne Mannich base and oxadiazole hybrids

A series of thieno[2,3-d]pyrimidine alkyne Mannich base derivatives (7a-e, 8a-e) and thieno[2,3-d]pyrimidine 1,3,4-oxadiazole derivatives (9a-e, 10a-e) have been synthesized and evaluated for their neuroprotective and neurotoxicity activities where 9a, 10d displayed good neuroprotection 10.6 and 11.88?µg/mL respectively against the H₂O₂ induced cell death at the EC₅₀ values and 9b, 9d showed respective toxic effects on PC12 cells at CC₅₀ 86.12 and 94.16?µg/mL. Compounds 9a, 9e, 10a and 10b showed strong antibacterial activity against two gram positive (S. aureus, B. subtilis) and two gram-negative strains (E. coli, P. aeruginosa) and showed good binding affinities with C(30) carotenoid dehydrosqualene synthase, Gyrase A and LpxC. This is the first report for the demonstration of thieno[2,3-d] pyrimidine derivatives as promising neuroprotective agents against H₂O₂ induced neurotoxicity on PC12 cells.     

Design,synthesis and biological evaluation of tricyclic pyrazolo[1,5-c][1,3]benzoxazin-5(5H)-one scaffolds as selective BuChE inhibitors

Based on the structural analysis of tricyclic scaffolds as butyrylcholinesterase (BuChE) inhibitors, a series of pyrazolo[1,5-c][1,3]benzoxazin-5(5H)-one derivatives were designed, synthesized and evaluated for their acetylcholinesterase (AChE) and BuChE inhibitory activity. Compounds with 5-carbonyl and 7- or/and 9-halogen substitutions showed potential BuChE inhibitory activity, among which compounds 6a, 6c and 6g showed the best BuChE inhibition (IC₅₀?=?1.06, 1.63 and 1.63?µM, respectively). The structure–activity relationship showed that the 5-carbonyl and halogen substituents significantly influenced BuChE activity. Compounds 6a and 6g were found nontoxic, lipophilic and exhibited remarkable neuroprotective activity and mixed-type inhibition against BuChE (K_i?=?7.46 and 3.09?µM, respectively). Docking studies revealed that compound 6a can be accommodated into BuChE via five hydrogen bonds, one Pi–Sigma interaction and three Pi–Alkyl interactions.     

Design,synthesis of novel pyranotriazolopyrimidines and evaluation of their anti-soybean lipoxygenase,anti-xanthine oxidase,and cytotoxic activities

The synthesis of 14-(aryl)-14H-naphto[2,1-b]pyrano[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine-2-yl) acetamidoximes 2a–e has been accomplished by reaction of 2-acetonitrile derivatives 1a–e with hydroxylamine. Cyclocondensation reaction of precursors 2a–e with some elctrophilic species such as ethylorthoformate, acetic anhydride, and methyl-acetoacetate provided the new oxadiazole derivatives 3a–e, 4a–e, and 5a–e, respectively. On the other hand, the reaction of precursors 2a–e with 2-chloropropanoyl chloride afforded the new acetimidamides 6a–e which evolve under reflux of toluene to the new oxadiazoles 7a–e. The synthetic compounds were screened for their anti-xanthine oxidase, anti-soybean lipoxygenase, and cytotoxic activities. Moderate to weak xanthine oxidase and soybean lipoxygenase inhibitions were obtained but significant cytotoxic activities were noted. The most cytotoxic activities were recorded mainly (i) 5a was the most active (IC_50?=_?4.0?μM) and selective against MCF-7 and (ii) 2a was cytotoxic against the four cell lines with selectivity for MCF-7 and OVCAR-3 (IC_50?=_?17 and 12?μM, respectively) while 2e is highly selective against OVCAR-3 (IC_50?=_?10?μM).     

Synthesis of new thieno[2,3-b]pyridine derivatives as pim-1 inhibitors

Three series of 5-bromo-thieno[2,3-b]pyridines bearing amide or benzoyl groups at position 2 were prepared as pim-1 inhibitors. All the prepared compounds were tested for their pim-1 enzyme inhibitory activity. Two compounds (3c and 5b) showed moderate pim-1 inhibitory activity with IC₅₀ of 35.7 and 12.71?μM, respectively. Three other compounds (3d, 3g and 6d) showed poor pim-1 inhibition. The most active compounds were tested for their cytotoxic activity on five cell lines [MCF7, HEPG2, HCT116, A549 and PC3]. Compound 3g was the most potent cytotoxic agent on almost all the cell lines tested.     

Synthesis of 3-Aminoimidazo[4,5-c]pyrazole Nucleoside via the N-N Bond Formation Strategy as a [5:5] Fused Analog of Adenosine

3-Amino-6-(β-D-ribofuranosyl)imidazo[4,5-c]pyrazole (2) was synthesized via an N-N bond formation strategy by a mononuclear heterocyclic rearrangement (MHR). A series of 5-amino-1-(5-O-tert-butyldimethylsilyl-2,3-O-isopropylidene-β-D-ribofuranosyl-4-(1,2,4-oxadiazol-3-yl)imidaz-oles (6a-d), with different substituents at the 5-position of the 1,2,4-oxadiazole, were synthesized from 5-amino-1-(β-D-ribofuranosyl)imidazole-4-carboxamide (AICA Ribose, 3). It was found that 5-amino-1-(5-O-tert-butyldimethylsilyl-2,3-O-isopropylidene-β-D-ribofuranosyl)-4-(5-methyl-1,2,4-oxadiazol-3-yl)imidazole (6a) underwent the MHR with sodium hydride in DMF or DMSO to afford the corresponding 3-acetamidoimidazo[4,5-c]pyrazole nucleoside(s) (7b and/or 7a) in good yields. A direct removal of the acetyl group from 3-acetamidoimidazo[4,5-c]pyrazoles under numerous conditions was unsuccessful. Subsequent protecting group manipulations afforded the desired 3-amino-6-(β-D-ribofuranosyl)imidazo[4,5-c]pyrazole (2) as a 5:5 fused analog of adenosine (1).     

Synthesis and in vitro antimicrobial activity of new 4-phenyl-5-methyl-4H-1,2,4-triazole-3-thione derivatives

This study presents the synthesis, spectral analysis and antimicrobial evaluation of a new series of substituted 1,2,4-triazole (5a–i) and 1,3,4-thiadiazole derivatives (9a, c, g, h). New compounds were obtained by cyclization reaction of acyl thiosemicarbazide derivatives in the presence of alkaline and acidic media. All synthesized compounds were screened for their in vitro antimicrobial activities. Nine of the compounds had potential activity against Gram-positive bacteria (MIC?=?3.91–500 µg/mL). Some compounds showed good activity especially against: Micrococcus luteus ATCC 10240 (MIC?=?3.91?31.25 µg/mL), Bacillus subtilis ATCC 6633 (MIC?=?15.63? 62.5 µg/mL), and Staphylococcus aureus ATCC 25923 (MIC?=?15.63?125 µg/mL).     

Synthesis of new pyridothienopyrimidinone derivatives as Pim-1 inhibitors

Four series of pyridothienopyrimidin-4-one derivatives were designed and prepared to improve the pim-1 inhibitory activity of the previously reported thieno[2,3-b]pyridines. Significant improvement in the pim-1 inhibition and cytotoxic activity was achieved using structure rigidification strategy via ring closure. Six compounds (6c, 7a, 7c, 7d, 8b and 9) showed highly potent pim-1 inhibitory activity with IC₅₀ of 4.62, 1.18, 1.38, 1.97, 8.83 and 4.18?μM, respectively. Four other compounds (6b, 6d, 7b and 8a) showed moderate pim-1 inhibition. The most active compounds were tested for their cytotoxic activity on three cell lines [MCF7, HCT116 and PC3]. Compounds 7a [the 2-(2-chlorophenyl)-2,3-dihydro derivative] and 7d [the 2-(2-(trifluoromethyl)-phenyl)-2,3-dihydro derivative] displayed the most potent cytotoxic effect on the three cell lines tested consistent with their highest estimated pim-1 IC₅₀ values.     

Synthesis,antitumor screening and cell cycle analysis of novel benzothieno[3,2-b]pyran derivatives

Abstract

Three series of benzothiophene derivatives were designed and synthesized as cytotoxic agents. The compounds were subjected to in vitro antitumor screening at the National Cancer Institute (NCI), Bethesda, MD. The results of the single dose screening indicated that only the benzothieno[3,2-b]pyran series 3a–f exhibited potent and broad spectrum cytotoxic activity and was subjected to five dose cytotoxic screening. The most active compound in this study was 2-amino-6-bromo-4-(4-nitrophenyl)-4H-[1]benzothieno[3,2-b]pyran-3-carbonitrile (3e) with MG-MID GI₅₀, TGI, and LC₅₀ values of 0.11, 7.94 and 42.66?μM, respectively. Compound 3e exhibited broad spectrum anticancer activity against a panel of 59 cell lines. To elucidate the underlying mechanism of compound 3e cytotoxic activity, we examined its effect on cell cycle progression and its ability to induce apoptosis using human colon adenocarcinoma cell line (HCT-116). The effect of compound 3e on the cell cycle progression indicated that exposure of HCT-116 cells to compound 3e for 24 and 48?h, induced a significant disruption in the cell cycle profile including time dependent decrease in cell population at G1 phase with concomitant increase in pre-G and G2/M cell population. Moreover, compound 3e induced time dependent increase in the percentage of early and late apoptotic and necrotic cell population. In conclusion, we were able to successfully design a new series of benzothieno[3,2-b]pyran derivatives with potent cytotoxic activity and their mechanism of cytotoxicity was examined.