Cytotoxic effects of kinetin riboside and its selected analogues on cancer cell lines

N6-[(Furan-2-yl)methyl]adenosine (kinetin riboside) and its seven synthesized analogues were examined for the ability to inhibit the growth of five human carcinoma cell lines and for comparison of normal human lung fibroblast cell line (MRC-5). Out of the compounds evaluated, 8-azakinetin riboside was shown to exhibit significant cytotoxic activity for 72 h treatment against ovarian OVCAR-3 and pancreatic MIA PaCa-2 cancer cells (IC50 = 1.1 μM) with an observed weaker effect against MRC-5 cells (IC50 = 4.6 μM). Kinetin riboside, as well as its N6-[(furan-3-yl)methyl]- and N6-[(thien-2-yl)methyl]- counterparts, also exhibited cytotoxic activities at low micromolar levels but were non-selective over MRC-5 cells.

Novel esterquat-based herbicidal ionic liquids incorporating MCPA and MCPP for simultaneous stimulation of maize growth and fighting cornflower

Modern agricultural practices are often based on the use of mixtures of specific herbicides to achieve efficient crop protection. The major drawbacks of commercial herbicidal formulations include the necessity to incorporate toxic surfactants and high volatility of active substances. Transformation of herbicides into herbicidal ionic liquids (HILs) seems to be a promising alternative which allows to almost completely reduce volatility due to ionic interactions. In the scope of this research, we transformed (2-methyl-4-chlorophenoxy)acetic acid (MCPA) into a quaternary ester (esterquat) with the use of derivatives of 2-dimethylaminoethanol. The obtained esterquats were later coupled with (±)-2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) in the form of an anion. The combination of MCPA and MCPA is commonly applied in the UK, EU countries and also in the USA to increase the spectrum of targeted weed species. In the framework of this study, novel HILs with an esterquat moiety incorporating a long alkyl chain (C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₄) were prepared and characterized in terms of basic physicochemical properties (solubility and volatility) as well as biodegradability. Their phytotoxicity was assessed towards cornflower (Centaurea cyanus) as a model weed and maize (Zea mays) as a crop plant. The presence of the esterquat cation contributed to satisfactory solubility in water and other low polar solvents, which eliminates the need to add exogenous adjuvants. Further experiments indicated that the tested HILs stimulated the germination stage of maize and maintained high herbicidal activity towards cornflower. No significant differences in terms of properties were observed in case of HILs which included alkyl substituents with an odd number of carbon atoms. Future studies should be focused on structural modifications in order to improve the biodegradability as well as field studies for evaluation of commercial applications.

Biodegradation of ritalinic acid by Nocardioides sp. - Novel imidazole-based alkaloid metabolite as a potential marker in sewage epidemiology

The consumption of methylphenidate, a nootropic drug used to improve mental performance, is becoming increasingly serious. Methylphenidate is metabolized in human liver to ritalinic acid, which has been commonly detected in sewage and surface waters. Additionally, ritalinic acid serves as a biomarker in sewage epidemiology studies. Thus knowledge of the stability and microbial degradation pathways of ritalinic acid is essential for proper estimation of methylphenidate consumption. In the study reported here, we describe the fast formation of a previously unknown, dead-end metabolite of ritalinic acid by Nocardioides sp. strain MW5. HRMS and 2D NMR analyses allowed precisely identification of the compound as an imidazole-based alkaloid cation with chemical formula 11-[3-(formylamino)propyl]-1,2,3,4,6,7,8,9-octahydrodipyrido[1,2-a:1',2'-c]imidazole-5-ium. In experiments, Nocardioides sp. strain MW5 transformed 34% of ritalinic acid into this metabolite, while 52% was mineralized into CO₂. Alkaloid was not biodegraded during the OECD 301 F test. This study provides new insight into the environmental fate of methylphenidate and its metabolites. The data collected are essential for assessing nootropic drug consumption by sewage epidemiology and should lead to a better understanding of microbial degradation of ritalinic acid.

Transformation of herbicides into dual function quaternary tropinium salts

Quaternary tropinium salts as novel, efficient herbicides and plant-growth promoting agents in case of crops.

Nucleoside dimers analogs containing floxuridine and thymidine with unnatural linker groups: synthesis and cancer line studies. Part III

Two series of novel fluorinated nucleosides dimers with an unnatural 1,2,3-triazole linkage were synthesized. The obtained molecules were prepared using "click" chemistry approach based on copper(I) catalyzed Huisgen azide-alkyne cycloaddition. It was performed between 3'- and 5'-azido-nucleosides as the azide components, and the 3'-O- and 5'-O-propargyl-nucleosides as the alkyne components. Based on analysis of the ³ J_HH, ³ J_H1'C2 and ³ J_H1'C6 we estimated conformational preferences of sugar part and orientation around glycosidic bond. All described nucleosides dimers analogs were characterized by spectroscopic methods and evaluated for their in vitro cytotoxicity in three human cancer cell lines: cervical (HeLa), oral (KB) and breast (MCF-7).

Plant growth promoting N-alkyltropinium bromides enhance seed germination, biomass accumulation and photosynthesis parameters of maize (Zea mays)

N-Alkyltropinium bromides were synthesized and characterized as novel plant-growth promoting agents.

Impact of O-alkyl-pyridineamidoximes on the soil environment

Pyridine derivatives such as oximes and amidoximes are widely used in pharmaceutical, analytical and coordination chemistry. Increasing interest in this group of compounds as well as their complexing properties and surface activity resulted in their introduction into the environment and change of the ecosystem functioning. Based on this phenomenon, the evaluation of impact O-alkyl-pyridineamidoximes on the soil environment was determined by analysis of changes of metal mobility in soil and plant seed germination. The obtained results indicate that O-propyl-pyridineamidoximes may change the mobility of metals in soil and influence the germination and development of plants. The introduction of these compounds to soil resulted in the reduction of metal (Cu, Pb, Fe) mobility in the soil matrix. This effect resulted in the retention of metals in the soil and inhibition of their mobility. This phenomenon suggests the possibility of using the analyzed compounds in the remediation process as a stabilizing factor. Pyridineamidoximes at a concentration below 100 mg/kg of soil did not influence the seed germination and plant development.

Biodiversity of soil bacteria exposed to sub-lethal concentrations of phosphonium-based ionic liquids: Effects of toxicity and biodegradation

Little is known about the effect of ionic liquids (ILs) on the structure of soil microbial communities and resulting biodiversity. Therefore, we studied the influence of six trihexyl(tetradecyl)phosphonium ILs (with either bromide or various organic anions) at sublethal concentrations on the structure of microbial community present in an urban park soil in 100-day microcosm experiments. The biodiversity decreased in all samples (Shannon's index decreased from 1.75 down to 0.74 and OTU's number decreased from 1399 down to 965) with the largest decrease observed in the microcosms spiked with ILs where biodegradation extent was higher than 80%. (i.e. [P₆₆₆₁₄][Br] and [P₆₆₆₁₄][2,4,4]). Despite this general decrease in biodiversity, which can be explained by ecotoxic effect of the ILs, the microbial community in the microcosms was enriched with Gram-negative hydrocarbon-degrading genera e.g. Sphingomonas. It is hypothesized that, in addition to toxicity, the observed decrease in biodiversity and change in the microbial community structure may be explained by the primary biodegradation of the ILs or their metabolites by the mentioned genera, which outcompeted other microorganisms unable to degrade ILs or their metabolites. Thus, the introduction of phosphonium-based ILs into soils at sub-lethal concentrations may result not only in a decrease in biodiversity due to toxic effects, but also in enrichment with ILs-degrading bacteria.

New antiglioma zwitterionic pronucleotides with an FdUMP framework

We have designed and synthesized new 5-fluoro-2'-deoxyuridine 5'-phosphate pronucleotides which can function as potential agents against the glioblastoma multiforme tumor. Their anti-malignant potency has been tested against T98G, U-118 MG, U-87 MG gliomas, HeLa, and Caco-2 cancer cell lines, using MRC-5 healthy cells as a reference. Five of the sixteen compounds (4c, 4f-i) exhibited significant anticancer potency and high selectivity indices (SI 12-66). It is likely that these zwitterionic pronucleotides may function in a similar manner to zwitterionic phospholipids, by inducing cell membrane charge disorder, making the cell permeable to bioactive agents. The most promising therapeutic pronucleotides 4c, 4f-h, have high intestinal-blood uptake potency (Caco-2 cell line), and may be considered as potential, orally administrated, anticancer drugs.

Quantitative analysis of amphiphilic N-alkyloxypyridinecarboximidamide by liquid chromatography-tandem mass spectrometry

LC–MS/MS method to determine hydrophobic N-alkyloxy substituted amidines: N-(2-ethylhexyloxy)pyridine-2-carboximidamide, N-(2-ethylhexyloxy)pyridine-3-carboximidamide, N-(2-ethylhexyloxy)pyridine-4-carboximidamide, N-decyloxy pyridine-2-carboximidamide, N-decyloxypyridine-3-carboximidamide and N-decyloxypyridine-4-carboximidamide was developed and validated in terms of linearity, precision and accuracy. The developed method was successfully applied to monitor and control the synthesis process. The experimental data points indicated that the straight chain alkyl bromide reacted most rapidly than branched alkyl bromide and the enhancement of the reaction efficiency strongly depended on reaction temperature.

Searching for anti-glioma activity. Ribonucleoside analogues with modifications in nucleobase and sugar moieties

Several ribonucleoside analogues with modifications in the nucleobase and sugar moiety have been screened for anti-glioma activity in the T98G glioma cell line using cervical (HeLa) cell line as reference human malignant cells, and lung fibroblast (MCR-5) cell line as non-cancerous reference cells. Among the investigated compounds, ribonucleosides containing 6-chloropurine (3), 7-guanine (5) and a pyrrolopyrimidine (18) as nucleobases, show promising anti-glioma activity with good selectivity indices, and can be considered as lead structures for further anti-cancer studies.

New 3'-O-aromatic acyl-5-fluoro-2'-deoxyuridine derivatives as potential anticancer agents

New aromatic and aliphatic 3'-O-acyl-5-fluoro-2'-deoxyuridine derivatives were synthesized and evaluated as candidates for prodrugs against various cancer cell lines. As the most promising candidate for antimalignant therapeutics was found a dual-acting acyl derivative 7h, which apparently released not only the known anticancer nucleoside, 5-fluoro-2'-deoxyuridine (FdU), but also an additional active metabolite, acetylsalicylic acid, reinforcing thus therapeutic effect of FdU. Promising therapeutic indices showed also some aromatic dicarboxylic acids derivatives decorated with FdU esters (11 and 12).

Comparative study on the biodegradability of morpholinium herbicidal ionic liquids

This study focused on evaluating the toxicity as well as primary and ultimate biodegradability of morpholinium herbicidal ionic liquids (HILs), which incorporated MCPA, MCPP, 2,4-D or Dicamba anions. The studied HILs were also subjected to determination of surface active properties in order to assess their influence on toxicity and biodegradability. The study was carried out with microbiota isolated from different environmental niches: sediments from river channel, garden soil, drainage trench collecting agricultural runoff stream, agricultural soil and municipal waste repository. The obtained results revealed that resistance to toxicity and biodegradation efficiency of the microbiota increased in the following order: microbiota from the waste repository > microbiota from agricultural soil ≈ microbiota from an agricultural runoff stream > microbiota from garden soil > microbiota from the river sludge. It was observed that the toxicity of HILs increased with the hydrophobicity of the cation, however the influence of the anion was more notable. The highest toxicity was observed when MCPA was used as the anion (EC₅₀ values ranging from 60 to 190 mg L⁻¹). The results of ultimate biodegradation tests indicated that only HILs with 2,4-D as the anion were mineralized to some extent, with slightly higher values for HILs with the 4-decyl-4-ethylmorpholinium cation (10–31 %) compared to HILs with the 4,4-didecylmorpholinium cation (9–20 %). Overall, the cations were more susceptible (41–94 %) to primary biodegradation compared to anions (0–61 %). The obtained results suggested that the surface active properties of the studied HILs may influence their toxicity and biodegradability by bacteria in different environmental niches.

Genetic and chemical analyzes of transformations in compost compounds during biodegradation of oiled bleaching earth with waste sludge

Composting of oiled bleaching earth with waste sludge and corn straw was carried out to investigate the ability of microorganisms to synthesize biosurfactants that might decrease the surface tension of composts. Analytical results and changes in the surface tension suggest that biodegradation of fatty by-products was the consequence of emulsifying properties of higher fatty acids. The surface tension for isolates from all composting phases was between 37 and 43 mN m(-1). No substances synthesized by microorganisms that might be able to decrease the surface tension were detected in composts. Tensammetric, TLC and HPLC-MS results and changes in surface tension suggest that biodegradation of fatty by-products results from the emulsifying properties of higher fatty acids. A decrease in fatty content from 144 to 6 mg g(-1) dry matter was obtained.

Synthesis and antiviral activity of novel derivatives of 2'-beta-C-methylcytidine

A series of novel derivatives of 2'-C-beta-methylcytidine, involving nucleosides modified in the "upper part" of the pyrimidine base (N(4)- and/or 5-position), has been synthesized and evaluated for their inhibitory effect on in vitro replication of the hepatitis C virus and the yellow fever virus (both Flaviviridae).

Reaction of nucleosides with 2-acetoxyethyl acetoxymethyl ether

Application of 2-acetoxyethyl acetoxymethyl ether as a model of peracylated sugars (e.g. 1,2,3,5-tetra-O-acetyl-beta-D-ribofuranose) is a convenient way to study the mechanism and sequence of glycosyl exchange reactions in the nucleoside chemistry.