ABSTRACT Salinity stress profoundly affects crop plants’ morphological structures and physiological processes, decreasing plant growth and development. The application of phytohormones has been proved an efficient way to alleviate salinity stress. This study was done to evaluate the effects of exogenous application of gibberellic acid (GA3; 0.288 mM), salicylic acid (SA; 0.362 mM), indole acetic acid (IAA; 0.285 mM) and control (0 mM) on seedling growth and physiological parameters of hargel (Solenostemma argel Hayne) seedlings under different salinity levels (0, 50 and 100 mM NaCl). Significant decreases due to salinity stress were observed in all the seedling growth parameters shoot and root length, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, chlorophyll a and b content, and antioxidant enzymes activities such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). In contrast, soluble protein and carotenoid content increased with increasing salinity. At high salinity level, GA3 increased carotenoid content and APX activity by 56.4% and 53.4%, respectively, while SA increased shoot dry weight, SOD, POD and soluble protein by 1.3-fold, 1.3-fold, 1.95-fold and 93.2%, compared with the control, IAA increased root length and fresh root weight at the same salinity level by 1.58-fold and 2-fold, respectively. In conclusion, seed priming with an appropriate dosage of exogenous hormones successfully mitigates the adverse effects of NaCl by increasing photosynthetic pigment, antioxidant enzyme activity and seedling growth parameters. Furthermore, SA exhibited the best mitigating effects compared to IAA and GA3.

ABSTRACT Salinity is a growing problem worldwide and techniques are needed to mitigate this problem. The experiment was conducted to examine if biochar could improve growth, physiological response, and DM yield of forage sorghum (Sorghum bicolor (L.) Moench) under saline conditions. Sorghum seedlings were transplanted in sandy loam soil (0-20 cm layer of a Typic Fluvaquents Entisols) treated with sodium chloride at rates of 0.26, 5.8, and 12.6 dS m-1. The saline soil was treated with four biochar rates, 0%, 2.5%, 5%, and 10% (w/w). Plant height, fresh weight, photosynthetic rate (A), stomatal conductance (gs), transpiration rate (E), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) were affected by the interaction between salinity and biochar. At the 12.6 dS m-1 salinity rate, 5% biochar increased plant height, leaf area, fresh weight, DM yields, A, gs, and E by 20.1%, 16.5%, 26.2%, 27.4%, 14.5%, 31.1%, and 26.7%, respectively. At the 12.6 dS m-1 salinity rate, 5% biochar decreased CAT, POD, and SOD by 56.8%, 44.8%, and 18.9%, respectively. Furthermore, among all biochar rates used in this investigation, the 5% rate had a better result for forage sorghum production. These findings demonstrated that the lowest biochar soil amendment application could alleviate the harmful impact of salinity; a high biochar application rate can have a negative influence.

Owing to valuable biological activities of 1,3,4-oxadiazole, sulfamoyl and piperidine functionalities, some new 1-(4-{[(5-substituted-1,3,4-oxadiazol-2-yl) thio]methyl}benzene sulfonyl)-4-methylpiperidine (6a-o) derivatives have been introduced. The target molecules were synthesized from different aralkyl/aryl carboxylic acids, 1a-o, through a series of steps. First the compounds, 1a-o, were converted to heterocyclic 1,3,4-oxadiazole nucleophiles, 4a-o. Second an electrophile as 1-(4-bromomethylbenzenesulfonyl)-4-methylpiperidine (5) was synthesized from 4-methylpiperidine. Finally the target compounds, 6a-o, were prepared by reacting 4a-o with 5 in DMF and LiH. The final compounds were structurally elucidated by spectral data of IR, ¹H-NMR and EI-MS. All the compounds were screened for their antibacterial evaluation and found to exhibit valuable results.

Abstract In the study presented here, a new series of 2-furyl(4-{4-[(substituted)sulfonyl]benzyl}-1-piperazinyl)methanone derivatives was targeted. The synthesis was initiated by the treatment of different secondary amines (1a-h) with 4-bromomethylbenzenesulfonyl chloride (2) to obtain various 1-{[4-(bromomethyl)phenyl]sulfonyl}amines (3a-h). 2-Furyl(1-piperazinyl)methanone (2-furoyl-1-piperazine; 4) was then dissolved in acetonitrile, with the addition of K2CO3, and the mixture was refluxed for activation. This activated molecule was further treated with equi-molar amounts of 3a-h to form targeted 2-furyl(4-{4-[(substituted)sulfonyl]benzyl}-1-piperazinyl)methanone derivatives (5a-h) in the same reaction set up. The structure confirmation of all the synthesized compounds was carried out by EI-MS, IR and 1H-NMR spectral analysis. The compounds showed good enzyme inhibitory activity. Compound 5h showed excellent inhibitory effect against acetyl- and butyrylcholinesterase with respective IC50 values of 2.91±0.001 and 4.35±0.004 μM, compared to eserine, a reference standard with IC50 values of 0.04±0.0001 and 0.85±0.001 μM, respectively, against these enzymes. All synthesized molecules were active against almost all Gram-positive and Gram-negative bacterial strains tested. The cytotoxicity of the molecules was also checked to determine their utility as possible therapeutic agents.

RESUMO Tendo em vista a importância farmacológica da porção 1,3,4-oxadiazol, sintetizou-se uma série de novos derivados S-substituídos, 5a-h, de 5-(1-(4-tosi)piperidin-4-il)-1,3,4-oxadiazol-2-tiol (3). A reação do cloreto de p-toluenossulfonila (a), com isonipecotato de (b) etila forneceu 1-(4-tosil)piperidin-4-carboxilato de metila (1), que foi, em seguida, transformado em 1-(4-tosil)piperidin-4-carbo-hidrazida (2) por reação com hidrato de hidrazina em metanol. O composto 2 foi submetido a refluxo com CS2 na presença de KOH para se obter 5-(1-(4-tosil)piperidin-4-il)-1,3,4-oxadiazol-2-tiol (3). Os compostos desejados, 5a-h, foram obtidos por agitação de 3 com haletos de aralquila, 4a-h, em DMF, na presença de NaH. As estruturas dos compostos sintetizados foram elucidadas através de análise dos espectros de 1H-MNR, IR e EI-MS. Estes compostos foram, ainda, avaliados quanto à inibição das enzimas lipoxigenase e alfa-glucosidase, juntamente com a atividade antibacteriana contra bactérias Gram positivas e Gram negativas.

ABSTRACT Keeping in mind the pharmacological importance of the 1,3,4-oxadiazole moiety, a series of new S-substituted derivatives, 5a-h, of 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol (3) were synthesized. The reaction of p-toluenesulfonyl chloride (a) and ethyl isonipecotate (b) produced ethyl 1-(4-tosyl)piperidin-4-carboxylate (1) which was further transformed into 1-(4-tosyl)piperidin-4-carbohydrazide (2) by hydrazine hydrate in methanol. Compound 2 was refluxed with CS2 in the presence of KOH to synthesize 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol (3). The desired compounds, 5a-h, were synthesized by stirring 3 with aralkyl halides, 4a-h, in DMF using NaH as an activator. The structures of synthesized compounds were elucidated by 1H-NMR, IR and EI-MS spectral studies. These compounds were further evaluated for enzyme inhibitory activity against lipoxygenase and alpha-glucosidase, along with antibacterial activity against Gram-negative and Gram-positive bacteria.

The synthesis of poly-functional moieties as one unit has been under consideration by the synthetic chemists to search out new potent molecules. 2-Chlorobenzoic acid (1) was converted to 5-(2-chlorophenyl)-1,3,4-Oxadiazol-2-thiol (4) through a series of steps. This nucleophile was attached with different electrophiles, prepared by the reaction of aryl/alkyl amines with 2-bromoacetylbromide, in NaH/DMF to synthesize N-substituted-2-((5-(2-chlorophenyl)-1,3,4-Oxadiazol-2-yl)sulfanyl)acetamide, 7a-f. The molecule 4 was stepped to ethyl ester and carbohydrazide. The carbohydrazide was made to react with aryl carboxaldehydes in methanol to synthesize N'-substituted-2-(5-(2-chlorophenyl)-1,3,4-Oxadiazol-2-ylthio)acetohydrazide, 11a-i. The structures of all the molecules were corroborated through IR, ¹H-NMR and EI-MS spectral data. Both the series were screened for antibacterial and enzyme inhibition activity.

resumo Uma série de acetamidas 2-{[5-(1H-indol-3-ilmetil)-1,3,4-oxadiazol-2-il]sulfanila} N-substituídas (8a-w) foi sintetizada em três fases. A primeira etapa envolveu a conversão sequencial de ácido 2-(1H-indol-3-il)acético (1) a éster (2), seguido por hidrazida (3) e, finalmente, a e ciclização na presença de CS2 e KOH alcoólico produziu 5-(1H-indol-3-il- metil)-1,3,4-oxadiazole-2-tiol (4). Na segunda etapa, aminas arílicas/aralquílicas(5a-w) reagiram com brometo de 2-bromoacetila (6), em meio básico, para se obter acetamidas 2-bromo-N-substituídas (7a-w). Na terceira etapa, estes eletrófilos (7a- w) reagiram com 4, para se obter os compostos alvo (8a-w). A elucidação estrutural de todos os derivados sintetizados foi realizada por 1H-NMR, IR e técnicas de espectrometria de EI-MS. Além disso, eles foram submetidos a triagem de atividade antibacteriana e hemolítica. Análise da inibição enzimática foi bem apoiada pelos resultados de docking molecular. Por exemplo, o composto 8q exibiu melhor potencial inibitório contra α-glicosidase, e os compostos 8g e 8b exibiram, comparativamente, melhor inibição contra butirilcolinesterase (BChE) elipoxigenase (LOX), respectivamente. Do mesmo modo os compostos 8b e 8c mostraram excelente potencial antibacteriano contra SalmonellaTyphi, semelhante ao do ciprofloxacino, antibiótico padrão usado neste estudo. Os compostos 8c e 8l também mostraram excelente potencial antibacteriano contra Staphylococcus aureus . Quase todos os compostos mostraram pequena atividade hemolítica, sendo que o composto 8p apresentou menor atividade. Assim, as moléculas sintetizadas podem ter a sua utilidade como agentes terapêuticos adequados.

abstract A series of N-substituted 2-{[5-(1H-indol-3-ylmethyl)-1,3,4-oxadiazol-2-yl]sulfanyl}acetamides (8a-w) was synthesized in three steps. The first step involved the sequential conversion of 2-(1H-indol-3-yl)acetic acid (1) to ester (2) followed by hydrazide (3) formation and finally cyclization in the presence of CS2 and alcoholic KOH yielded 5-(1H-indole-3-yl-methyl)-1,3,4-oxadiazole-2-thiol (4). In the second step, aryl/aralkyl amines (5a-w) were reacted with 2-bromoacetyl bromide (6) in basic medium to yield 2-bromo-N-substituted acetamides (7a-w). In the third step, these electrophiles (7a-w) were reacted with 4 to afford the target compounds (8a-w). Structural elucidation of all the synthesized derivatives was done by 1H-NMR, IR and EI-MS spectral techniques. Moreover, they were screened for antibacterial and hemolytic activity. Enzyme inhibition activity was well supported by molecular docking results, for example, compound 8q exhibited better inhibitory potential against α-glucosidase, while 8g and 8b exhibited comparatively better inhibition against butyrylcholinesterase and lipoxygenase, respectively. Similarly, compounds 8b and 8c showed very good antibacterial activity against Salmonella typhi, which was very close to that of ciprofloxacin, a standard antibiotic used in this study. 8c and 8l also showed very good antibacterial activity against Staphylococcus aureus as well. Almost all compounds showed very slight hemolytic activity, where 8p exhibited the least. Therefore, the molecules synthesized may have utility as suitable therapeutic agents.

Halophilic bacteria are commonly found in natural environments containing significant concentration of NaCl such as inland salt lakes and evaporated sea-shore pools, as well as environments such as curing brines, salted food products and saline soils. Dependence on salt is an important phenotypic characteristic of halophilic bacteria, which can be used in the polyphasic characterization of newly discovered microorganisms. In this study the diversity of halophilic bacteria in foreshore soils of Daecheon, Chungnam, and Saemangeum, Jeonbuk, was investigated. Two types of media, namely NA and R2A supplemented with 3%, 5%, 9%, 15%, 20% and 30% NaCl were used. More than 200 halophilic bacteria were isolated and BOX-PCR fingerprinting analysis was done for the typing of the isolates. The BLAST identification results showed that isolated strains were composed of 4 phyla, Firmicutes (60%), Proteobacteria (31%), Bacteriodetes (5%) and Actinobacteria (4%). Isolates were affiliated with 16 genera and 36 species. Bacillus was the dominant genus in the phylum Firmicutes, comprising 24% of the total isolates. Halomonas (12%) and Shewanella (12%) were also found as the main genera. These findings show that the foreshore soil of Daecheon Beach and Saemangeum Sea of Korea represents an untapped source of bacterial biodiversity.

1. The present study describes a direct and an alternative HPLC method for the determination of etoposide in injectable dosage forms. Etoposide, an antineoplastic drug, was eluted through C18 ODS Hypersil column of 250 ÷ 4.6 mm id with 5 ìçé particle size using simple mobile phase of methanol: water (1:1, v/v) at a flow rate of 1.0 mL min¹ and detected at 204 nm. The limit of detection of etoposide was 0.03 µg mL-1. The proposed method was found linear in the range of 0.25 µg mL¹ to 62.5 µg mL¹ and CV was 1.3% at 0.25 µg mL¹ , 0.48% at 3.90 µg mL¹ and 0.13% at 62.5 µg mL¹. The accuracy of the developed method for two injectable dosage forms was 99.4 and 99.7% with RSD of 0.3%. The validation results and statistical data demonstrate that the method is simple, cost effective, reproducible and suitable in quality analysis of the active ingredient and dosage form.