Superbanone,A New 2‐Aryl‐3‐benzofuranone and Other Bioactive Constituents from the Tube Roots of Butea superba

Phytochemical investigation from the tube roots of Butea superba, led to the isolation and identification of a new 2‐aryl‐3‐benzofuranone named superbanone ( 1 ), one benzoin, 2‐hydroxy‐1‐(2‐hydroxy‐4‐methoxyphenyl)‐2‐(4‐methoxyphenyl)ethanone ( 2 ), eight pterocarpans ( 3  –  10 ), and eleven isoflavonoids ( 11  –  21 ). Compound 2 was identified for the first time as a natural product. The structure of the isolated compounds was elucidated using spectroscopic methods, mainly 1D‐ and 2D‐NMR. The isolated compounds and their derivatives were evaluated for α‐glucosidase inhibitory and antimalarial activities. Compounds 3 , 7 , 8 , and 11 showed promising α‐glucosidase inhibitory activity (IC₅₀ = 13.71 ± 0.54, 23.54 ± 0.75, 28.83 ± 1.02, and 12.35 ± 0.36 μm , respectively). Compounds 3 and 11 were twofold less active than the standard drug acarbose (IC₅₀ = 6.54 ± 0.04 μm ). None of the tested compounds was found to be active against Plasmodium falciparum strain 94. On the basis of biological activity results, structure–activity relationships are discussed.     

Homochiral bifunctional L‐prolinamide‐ and L‐bis‐prolinamide‐catalyzed asymmetric aldol reactions performed in wet solvent‐free conditions

In this study, the novel bifunctional homochiral thiourea‐L‐prolinamides 1–4 , tertiary amino‐L‐prolinamide 5 , and bis‐L‐prolinamides 6 and 7 were prepared from enantiomerically pure (11R,12R)‐11,12‐diamino‐9,10‐dihydro‐9,10‐ethanoanthracene 8 and (11S,12S)‐11,12‐diamino‐9,10‐dihydro‐9,10‐ethanoanthracene ent‐8 . Highly enantioselective and diastereoselective aldolic intermolecular reactions (up to 95% enantiomeric excess, 93:7 anti/syn) between aliphatic ketones (20 equiv) and a range of aromatic aldehydes (1 equiv) were successfully carried out in the presence of water (10 equiv) and monochloroacetic acid (10 mol%), solvent‐free conditions, at room temperature over 24 h using organocatalysts 1–7 (5 mol%). Stereoselective induction using density functional theory–based methods was consistent with the experimental data.     

Synthesis of the N‐methyl Derivatives of 2‐Aminothiazol‐4(5H)‐one and Their Interactions with 11βHSD1‐Molecular Modeling and in Vitro Studies

11β‐Hydroxysteroid dehydrogenase type 1 (11β‐HSD1) is an enzyme that affects the body's cortisol levels. The inhibition of its activity can be used in the treatment of Cushing's syndrome, metabolic syndrome and type 2 diabetes. In this study, we synthesized new derivatives of 2‐(methylamino)thiazol‐4(5H)‐one and tested their activity towards inhibition of 11β‐HSD1 and its isoform – 11β‐HSD2. The results were compared with the previously tested allyl derivatives. We found out that methyl derivatives are weaker inhibitors of 11β‐HSD1 in comparison to their allyl analogs. Due to significant differences in the activity of the compounds, molecular modeling was performed, which was aimed at comparing the interactions between 11β‐HSD1 and ligands differing by substituent at the amine group (allyl vs. methyl). Modeling showed that the absence of the allyl group can lead to the rotation of whole ligand molecule which affects its interaction with the enzyme.     

Out‐of‐season production of 17,20β‐dihydroxypregn‐4‐en‐3‐one in the roach Rutilus rutilus

In this study, although the highest production of two physiologically significant progestins in teleosts [17,20β‐dihydroxypregn‐4‐en‐3‐one (17,20β‐P) and 17,20β,21‐trihydroxypregn‐4‐en‐3‐one (17,20β,21‐P)] was observed in the period just prior to spawning in both male and female roach Rutilus rutilus, there was also a substantial production (mean levels of 5–10 ng ml^?1 in blood; and a rate of release of 5–20 ng fish^?1 h^?1 into the water) in males and females in the late summer and early autumn (at least 7 months prior to spawning). During this period, the ovaries were increasing rapidly in size and histological sections were dominated by oocytes in the secondary growth phase [i.e. incorporation of vitellogenin (VTG)]. At the same time, the testes were also increasing rapidly in size and histological sections were dominated by cysts containing mainly spermatogonia type B. Measurements were also made of 11‐ketotestosterone (11‐KT) in males and 17β‐oestradiol and VTG in females. The 3 months with the highest production of 11‐KT coincided with the period that spermatozoa were present in the testes. In females, the first sign of a rise in 17β‐oestradiol concentrations coincided with the time of the first appearance of yolk globules in the oocytes (in August). The role of the progestins during the late summer and autumn has not been established.     

13,14‐seco‐Withanolides from Physalis minima with Potential Anti‐inflammatory Activity

Four new 13,14‐seco‐withanolides, minisecolides A – D ( 1  –  4 ), together with three known analogues 5  –  7 , were isolated from the whole plants of Physalis minima. The structures of new compounds were determined on the basis of spectroscopic analysis, including ¹H‐, ¹³C‐NMR, 2D‐NMR (HMBC, HSQC, ROESY), and HR‐ESI‐MS. Evaluation of all isolates for their inhibitory effects on nitric oxide (NO) production was conducted on lipopolysaccaride‐activated RAW264.7 macrophages. Compounds 2 , 3 , 5 , and 6 showed inhibitory activities, especially for compound 5 with IC₅₀ value of 3.87 μm .     

Regulation of with‐no‐lysine kinase signaling by Kelch‐like proteins

In 2001, with‐no‐lysine (WNK) kinases were identified as the genes responsible for the human hereditary hypertensive disease pseudohypoaldosteronism type II (PHAII). It took a further 6 years to clarify that WNK kinases participate in a signaling cascade with oxidative stress‐responsive gene 1 (OSR1), Ste20‐related proline‐alanine‐rich kinase (SPAK), and thiazide‐sensitive NaCl cotransporter (NCC) in the kidney and the constitutive activation of this signaling cascade is the molecular basis of PHAII. Since this discovery, the WNK–OSR1/SPAK–NCC signaling cascade has been shown to be involved not only in PHAII but also in the regulation of blood pressure under normal and pathogenic conditions, such as hyperinsulinemia. However, the molecular mechanisms of WNK kinase regulation by dietary and hormonal factors and by PHAII‐causing mutations remain poorly understood. In 2012, two additional genes responsible for PHAII, Kelch‐like 3 (KLHL3) and Cullin3, were identified. At the time of their discovery, the molecular mechanisms underlying the interaction between these genes and their involvement in PHAII were unknown. Here we review the pathophysiological roles of the WNK signaling cascade clarified to date and introduce a new mechanism of WNK kinase regulation by KLHL3 and Cullin3, which provides insight on previously unknown mechanisms of WNK kinase regulation.     

Determination of manganese‐ and manganese‐containing fungicides with lucigenin–Tween‐20‐enhanced chemiluminescence detection

A flow‐injection (FI) method is reported for the determination of Mn(II), maneb and mancozeb fungicides based on the catalytic effect of Mn(II) on the oxidation of lucigenin and dissolved oxygen in a basic solution. The Tween‐20 surfactant has been reported for first time to enhance lucigenin chemiluminescence (CL) intensity in the presence of Mn(II) (53%) and maneb and mancozeb (89%). The calibration graphs were linear in the concentration range of 0.001–1.5 mg L^–1 (R² = 0.9982 (n = 11) with a limit of detection (S/N = 3) of 0.1 µg L^–1 for Mn(II) and 0.01–3.0 mg L^–1 [R² = 0.9989 and R² = 0.9992 (n = 6)] with a limit of detection (S/N =3) of 1.0 µg L^–1 for maneb and mancozeb respectively. Injection throughputs of 90 and 120 h^–1 for Mn(II) and maneb and mancozeb respectively, and relative standard deviations of 1.0–3.4% were obtained in the concentration range studied. The experimental variables, e.g., reagents concentrations, flow rates, sample volume, and photomultiplier tube voltage, were optimized and potential interferences were investigated. The analysis of Mn(II) in river water reference materials (SLRS‐4 and SLRS‐5) showed good agreement with the certified values incorporating an on‐line 8‐hydroxyquinoline chelating column in the manifold for removing interfering metal ions. Recoveries for maneb and mancozeb were in the range of 92 ± 5 to 104 ± 3% and 91 ± 2 to 100 ± 4% (n = 3) respectively. The effect of 30 other pesticides (fungicides, herbicides and insecticides) was also examined in the lucigenin–Tween‐20 CL system. Copyright © 2015 John Wiley & Sons, Ltd.     

New Alkaloids and α‐Glucosidase Inhibitory Flavonoids from Ficus hispida

Two new pyrrolidine alkaloids, ficushispimines A ( 1 ) and B ( 2 ), a new ω‐(dimethylamino)caprophenone alkaloid, ficushispimine C ( 3 ), and a new indolizidine alkaloid, ficushispidine ( 4 ), together with the known alkaloid 5 and 11 known isoprenylated flavonoids 6  –  16 , were isolated from the twigs of Ficus hispida. Their structures were elucidated by spectroscopic methods. Isoderrone ( 8 ), 3′‐(3‐methylbut‐2‐en‐1‐yl)biochanin A ( 11 ), myrsininone A ( 12 ), ficusin A ( 13 ), and 4′,5,7‐trihydroxy‐6‐[(1R*,6R*)‐3‐methyl‐6‐(1‐methylethenyl)cyclohex‐2‐en‐1‐yl]isoflavone ( 14 ) showed inhibitory effects on α‐glucosidase in vitro.     

Peptide–peptoid hybrids based on (1–11)‐parathyroid hormone analogs

A series of peptide–peptoid hybrids, containing N‐substituted glycines, were synthesized based on the H‐Aib‐Val‐Aib‐Glu‐Ile‐Gln‐Leu‐Nle‐His‐Gln‐Har‐NH₂ (Har = Homoarginine) as the parent parathyroid hormone (1–11) analog. The compounds were pharmacologically characterized in their agonistic activity at the parathyroid hormone 1 receptor. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.     

Drimane Sesquiterpenoids from the Aspergillus oryzae QXPC‐4

Three new drimane sesquiterpenoids, astellolides C–E ( 1 – 3 , resp.), four new drimane sesquiterpenoid p‐hydroxybenzoates, astellolides F–I ( 4 – 7 , resp.), together with two known compounds astellolides A and B ( 8 and 9 , resp.), have been isolated from the liquid culture of Aspergillus oryzae (strain No. QXPC‐4). Their structures were established by comprehensive analysis of spectroscopic data. The relative and absolute configurations were determined on the basis of NOESY and CD data, together with single‐crystal X‐ray diffraction analyses of compounds 1 – 3 . The metabolites were evaluated for their cytotoxic activities, however, no compounds showed a significant cytotoxicity against the tested cell lines at a concentration of 20 μM .     

Synthesis of 3‐Methylidene‐1‐tosyl‐2,3‐dihydroquinolin‐4(1H)‐ones as Potent Cytotoxic Agents

An efficient synthetic strategy to 3‐methylidene‐2,3‐dihydroquinolin‐4(1H)‐ones variously substituted in position 2 has been developed. The title compounds were synthesized in the reaction sequence involving reaction of diethyl methylphosphonate with methyl 2‐(tosylamino)benzoate, condensation of thus formed diethyl 2‐oxo‐2‐(2‐N‐tosylphenyl)ethylphosphonate with various aldehydes followed by successful application of the obtained 3‐(diethoxyphosphoryl)‐1,2‐dihydroquinolin‐4‐ols as Horner–Wadsworth–Emmons reagents for the olefination of formaldehyde. Also, enantioselective approach to the target compounds has been evaluated using 3‐dimenthoxyphosphoryl group as a chiral auxiliary. Single X‐ray crystal analysis of (2S)‐3‐(dimenthoxyphosphoryl)‐2‐phenyl‐1‐tosyldihydroquinolin‐4‐ol revealed the presence of strong resonance‐assisted hydrogen bond (RAHB). The obtained 3‐methylidene‐2,3‐dihydroquinolin‐4(1H)‐ones were then tested for their cytotoxic activity against two leukemia cell lines NALM‐6 and HL‐60 and a breast cancer MCF‐7 cell line. All compounds showed very high cytotoxic activity with the IC₅₀ values mostly below 1 μm in all three cancer cell lines. The selected analogs were also tested on human umbilical vein endothelial cells (HUVEC) and on human mammary gland/breast cells (MCF‐10A) to evaluate their influence on normal cells. Since one of the most serious problems in cancer chemotherapy is the development of drug resistance, the mRNA levels and activity of ABCB1 transporter considered to be the most important factor engaged in drug resistance, were evaluated in MCF‐7 cells treated with two selected analogs. Both compounds were strong ABCB1 transporter inhibitors that could prevent efflux of anticancer drugs from cancer cells.     

Characterizing the release of bioactive N‐glycans from dairy products by a novel endo‐β‐N‐acetylglucosaminidase

Endo‐β‐N‐acetylglucosaminidase isolated from B. infantis ATCC 15697 (EndoBI‐1) is a novel enzyme that cleaves N‐N′‐diacetyl chitobiose moieties found in the N‐glycan core of high mannose, hybrid, and complex N‐glycans. These conjugated N‐glycans are recently shown as a new prebiotic source that stimulates the growth of a key infant gut microbe, Bifidobacterium longum subsp. Infantis. The effects of pH (4.45–8.45), temperature (27.5–77.5°C), reaction time (15–475 min), and enzyme/protein ratio (1:3,000–1:333) were evaluated on the release of N‐glycans from bovine colostrum whey by EndoBI‐1. A central composite design was used, including a two‐level factorial design (2⁴) with four center points and eight axial points. In general, low pH values, longer reaction times, higher enzyme/protein ratio, and temperatures around 52°C resulted in the highest yield. The results demonstrated that bovine colostrum whey, considered to be a by/waste product, can be used as a glycan source with a yield of 20 mg N‐glycan/g total protein under optimal conditions for the ranges investigated. Importantly, these processing conditions are suitable to be incorporated into routine dairy processing activities, opening the door for an entirely new class of products (released bioactive glycans and glycan‐free milk). The new enzyme's activity was also compared with a commercially available enzyme, showing that EndoBI‐1 is more active on native proteins than PNGase F and can be efficiently used during pasteurization, streamlining its integration into existing processing strategies. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1331–1339, 2015     

Efficient blue organic light‐emitting diodes using N2,N2,N11,N11,5,6,7,8‐octaphenyltriphenylene‐2,11‐diamine derivatives

In this study, we have synthesized phenyl‐substituted triphenylene derivatives, using the Diels–Alder reaction and the Buchwald–Hartwig reaction. To investigate electroluminescence properties of these materials, multilayer organic light‐emitting diode (OLED) devices were fabricated with a structure of indium–tin–oxide (ITO) (180 nm)/4,4′‐bis(N‐(1‐naphthyl)‐N‐phenylamino)biphenyl (NPB) (50 nm)/blue‐emitting materials (1–3) (30 nm)/bathophenanthroline (Bphen) (35 nm)/lithium quinolate (Liq) (2 nm)/Al (100 nm). A device using N²,N²,N¹¹,N¹¹,5,6,7‐heptaphenyltriphenylene‐2,11‐diamine (2) exhibited efficient blue emission with luminous, power, and external quantum efficiencies of 0.92 cd/A, 0.67 lm/W, and 1.17% at 20 mA/cm², respectively. The Commission International de L'Éclairage coordinates of this device were (x = 0.15, y = 0.09) at 6.0 V. Copyright © 2015 John Wiley & Sons, Ltd.     

Melanogenesis‐Inhibitory and Cytotoxic Activities of Diarylheptanoids from Acer nikoense Bark and Their Derivatives

Nine cyclic diarylheptanoids, 1 – 9 , including two new compounds, i.e., 9‐oxoacerogenin A ( 8 ) and 9‐O‐β‐D ‐glucopyranosylacerogenin K ( 9 ), along with three acyclic diarylheptanoids, 10 – 12 , and four phenolic compounds, 13 – 16 , were isolated from a MeOH extract of the bark of Acer nikoense (Aceraceae). Acid hydrolysis of 9 yielded acerogenin K ( 17 ) and D ‐glucose. Two of the cyclic diarylheptanoids, acerogenin A ( 1 ) and (R)‐acerogenin B ( 5 ), were converted to their ether and ester derivatives, 18 – 24 and 27 – 33 , respectively, and to the dehydrated derivatives, 25, 26, 34 , and 35 . Upon evaluation of compounds 1 – 16 and 18 – 35 for their inhibitory activities against melanogenesis in B16 melanoma cells, induced with α‐melanocyte‐stimulating hormone (α‐MSH), eight natural glycosides, i.e., six diarylheptanoid glycosides, 2 – 4, 6, 9 , and 12 , and two phenolic glycosides, 15 and 16 , exhibited inhibitory activities with 24–61% reduction of melanin content at 100 μM concentration with no or almost no toxicity to the cells (88–106% of cell viability at 100 μM ). In addition, when compounds 1 – 16 and 18 – 35 were evaluated for cytotoxic activity against human cancer cell lines, two natural acyclic diarylheptanoids, 10 and 11 , ten ether and ester derivatives, 18 – 22 and 27 – 31 , and two dehydrated derivatives, 34 and 35 , exhibited potent cytotoxicities against HL60 human leukemia cell line (IC₅₀ 8.1–19.3 μM ), and five compounds, 10, 11, 20, 29 , and 30 , against CRL1579 human melanoma cell line (IC₅₀ 10.1–18.4 μM ).     

Anticonvulsant Activity of Enantiomeric N‐trans‐Cinnamoyl Derivatives of 2‐Aminopropan‐1‐ols and 2‐Aminobutan‐1‐ols

Epilepsy, one of the most frequent neurological disorders, is still insufficiently treated in about 30% of patients. As a consequence, identification of novel anticonvulsant agents is an important issue in medicinal chemistry. In the present article we report synthesis, physicochemical, and pharmacological evaluation of N‐trans‐cinnamoyl derivatives of R and S‐2‐aminopropan‐1‐ol, as well as R and S‐2‐aminobutan‐1‐ol. The structures were confirmed by spectroscopy and for derivatives of 2‐aminopropan‐1‐ols the configuration was evaluated by means of crystallography. The investigated compounds were tested in rodent models of seizures: maximal electroshock (MES) and subcutaneous pentetrazol test (scPTZ), and also in a rodent model of epileptogenesis: pilocarpine‐induced status prevention. Additionally, derivatives of 2‐aminopropan‐1‐ols were tested in benzodiazepine‐resistant electrographic status epilepticus rat model as well as in vitro for inhibition of isoenzymes of cytochrome P450. All of the tested compounds showed promising anticonvulsant activity in MES. For R(–)‐(2E)‐N‐(1‐hydroxypropan‐2‐yl)‐3‐phenylprop‐2‐enamide pharmacological parameters were found as follows: ED₅₀ = 76.7 (68.2–81.3) mg/kg (MES, mice i.p., time = 0.5 h), ED₅₀ = 127.2 (102.1–157.9) mg/kg (scPTZ, mice i.p., time = 0.25 h), TD₅₀ = 208.3 (151.4–230.6) mg/kg (rotarod, mice i.p., time = 0.25 h). Evaluation in pilocarpine status prevention proved that all of the reported compounds reduced spontaneous seizure activity and act as antiepileptogenic agents. Both enantiomers of 2‐aminopropan‐1‐ols did not influence cytochrome P450 isoenzymes activity in vitro and are likely not to interact with CYP substrates in vivo. Chirality 28:482–488, 2016. © 2016 Wiley Periodicals, Inc.     

New 4,5‐seco‐20(10→5)‐abeo‐Abietane Diterpenoids with Anti‐Inflammatory Activity from Isodon lophanthoides var. graciliflorus (Benth.) H.Hara

Three new 4,5‐seco‐20(10→5)‐abeo‐abietane diterpenoids, 16‐hydroxysalvilenone ( 1 ), 15‐hydroxysalprionin ( 2 ), and 11β,15‐dihydroxysalprionin‐12‐one ( 3 ), and nine known abietane diterpenoids, 4 – 12 , along with one known sempervirane diterpenoid, hispidanol A ( 13 ), were isolated from the aerial parts of Isodon lophanthoides var. graciliflorus. The structures of compounds 1 – 3 were determined on the basis of spectroscopic methods including extensive analysis of NMR and mass spectroscopic data. All diterpenoids were tested for their TNF‐α inhibitory effects on LPS‐induced RAW264.7 cells. Compound 9 (16‐acetoxyhorminone) was the most potent with an IC₅₀ value of 3.97±0.70 μm .     

Cytotoxic and Anti‐inflammatory Sesquiterpenes from Ainsliaea henryi

Three new sesquiterpenoids, 4α‐hydroxyeudesm‐11(13)‐en‐12‐yl 3‐methylbutanoate ( 1 ), diaspanolide E ( 2 ), and (13α)‐germacra‐1(10),4‐dien‐12,8α‐olid‐15‐oic acid ( 3 ), along with eight known sesquiterpenoids ( 4 – 11 ), were isolated from the aerial parts of Ainsliaea henryi. The chemical structures of compounds 1 – 3 were elucidated by spectroscopic analysis (1D‐, 2D‐NMR, MS and HR/MS). All isolates were evaluated for their inhibitory activities against nitric oxide (NO) production in lipopolysaccharide‐induced RAW264.7 macrophage cells. Compound 10 exhibited significantly inhibition against NO release with an IC₅₀ value of 6.54 ± 0.16 μm . Also, all isolated compounds were tested for cytotoxicity against three human tumor cell lines A549, MGC803, and HCT116, among which compound 5 significantly inhibited the proliferation of MGC803 cell lines with an IC₅₀ value of 2.2 ± 0.2 μm .     

Potent and Selective Monoamine Oxidase‐B Inhibitory Activity: Fluoro‐ vs. Trifluoromethyl‐4‐hydroxylated Chalcone Derivatives

For various neurodegenerative disorders like Alzheimer's and Parkinson’s diseases, selective and reversible MAO‐B inhibitors have a great therapeutic value. In our previous study, we have shown that a series of methoxylated chalcones with F functional group exhibited high binding affinity toward human monoamine oxidase‐B (hMAO‐B). In continuation of our earlier study and to extend the understanding of the structure–activity relationships, a series of five new chalcones were studied for their inhibition of hMAO. The results demonstrated that these compounds are reversible and selective hMAO‐B inhibitors with a competitive mode of inhibition. The most active compound, (2E)‐1‐(4‐hydroxyphenyl)‐3‐[4‐(trifluoromethyl)phenyl]prop‐2‐en‐1‐one, exhibited a K_i value of 0.33 ± 0.01 μm toward hMAO‐B with a selectivity index of 26.36. A molecular docking study revealed that the presence of a H‐bond network in hydroxylated chalcone with the N(5) atom of FAD is crucial for MAO‐B selectivity and potency.     

Statistical Inference for a Two‐Stage Outcome‐Dependent Sampling Design with a Continuous Outcome

Summary The two‐stage case–control design has been widely used in epidemiology studies for its cost‐effectiveness and improvement of the study efficiency ( White, 1982 , American Journal of Epidemiology 115, 119–128; Breslow and Cain, 1988 , Biometrika 75, 11–20). The evolution of modern biomedical studies has called for cost‐effective designs with a continuous outcome and exposure variables. In this article, we propose a new two‐stage outcome‐dependent sampling (ODS) scheme with a continuous outcome variable, where both the first‐stage data and the second‐stage data are from ODS schemes. We develop a semiparametric empirical likelihood estimation for inference about the regression parameters in the proposed design. Simulation studies were conducted to investigate the small‐sample behavior of the proposed estimator. We demonstrate that, for a given statistical power, the proposed design will require a substantially smaller sample size than the alternative designs. The proposed method is illustrated with an environmental health study conducted at National Institutes of Health.     

Synthesis of Novel Chiral Sulfonamide‐Bearing 1,2,4‐Triazole‐3‐thione Analogs Derived from D‐ and L‐Phenylalanine Esters as Potential Anti‐Influenza Agents

Novel enantiopure 1,2,4‐trizole‐3‐thiones containing a benzensulfonamide moiety were synthesized via multistep reaction sequence starting with D‐phenylalanine methyl ester and L‐phenylalanine ethyl ester as a source of chirality. The chemical structures of all compounds were characterized by elemental analysis, UV, IR, ¹H NMR, ¹³C NMR, 2D NMR (HETCOR), and mass spectral data. All compounds were tested in vitro antiviral activity against a broad variety of DNA and RNA viruses and in vitro cytostatic activity against murine leukemia (L1210), human T‐lymphocyte (CEM) and human cervix carcinoma (HeLa) cell lines. Although enantiopure 1,2,4‐triazole‐3‐thione analogs in (R) configuration emerged as promising anti‐influenza A H1N1 subtype in Madin Darby canine kidney cell cultures (MDCK), their enantiomers exhibited no activity. Especially compounds 18a , 21a , 22a , 23a , and 24a (EC₅₀: 6.5, 6.1, 2.4, 1.6, 1.7 μM, respectively) had excellent activity against influenza A H1N1 subtype compared to the reference drug ribavirin (EC₅₀: 8.0 μM). Several compounds have been found to inhibit proliferation of L1210, CEM and HeLa cell cultures with IC₅₀ in the 12–53 μM range. Compound 5a and 27a in (R) configuration were the most active compounds (IC₅₀: 12–22 μM for 5a and IC₅₀: 19–23 μM for 27a ). Chirality 28:495–513, 2016. © 2016 Wiley Periodicals, Inc.