The results obtained indicate that the dried and powdered pomace of unripe apples can be used as a health-promoting natural product for the reduction of postprandial glycaemia and to improve the health of patients with diabetes.

The cyclization of arylalkynes under selenobromination conditions, combined with an acid-induced 3,2-aryl shift, was elaborated as a general synthetic pathway for the preparation of polyhydroxy-2- and -3-arylbenzo[b]selenophenes from the same starting materials. The redox properties, free-radical-scavenging ability, and cytotoxicity against malignant cell lines (MCF-7, MDA-MB-231, HepG2, and 4T1) of the synthesized compounds were explored, and the obtained results were used to consider the structure-activity relationships (SARs) in these compounds. Consequently, the structural features that were responsible for the highly potent peroxyl-radical-scavenging activity were established.

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The design of nanoparticle delivery materials possessing biological activities is an attractive strategy for the development of various therapies. In this study, 11 cationic amphiphilic 4-(N-alkylpyridinium)-1,4-dihydropyridine (1,4-DHP) derivatives differing in alkyl chain length and propargyl moiety/ties number and position were selected for the study of their self-assembling properties, evaluation of their cytotoxicity in vitro and toxicity on microorganisms, and the characterisation of their interaction with phospholipids. These lipid-like 1,4-DHPs have been earlier proposed as promising nanocarriers for DNA delivery. We have revealed that the mean diameter of freshly prepared nanoparticles varied from 58 to 513 nm, depending upon the 4-(N-alkylpyridinium)-1,4-DHP structure. Additionally, we have confirmed that only nanoparticles formed by 4-(N-dodecylpyridinium)-1,4-DHP derivatives 3 and 6, and by 4-(N-hexadecylpyridinium)-1,4-DHP derivatives 10 and 11 were stable after two weeks of storage. The nanoparticles of these compounds were found to be homogenous in size distribution, ranging from 124 to 221 nm. The polydispersity index (PDI) values of 1,4-DHPs samples 3, 6, 10, and 11 were in the range of 0.10 to 0.37. We also demonstrated that the nanoparticles formed by 4-(N-dodecylpyridinium)-1,4-DHP derivatives 3, 6, and 9, and 4-(N-hexadecylpyridinium)-1,4-DHP derivatives 10 and 11 had zeta-potentials from +26.07 mV (compound 6) to +62.80 mV (compound 11), indicating a strongly positive surface charge and confirming the relative electrostatic stability of these nanoparticle solutions. Transmission electron microscopy (TEM) images of nanoaggregates formed by 1,4-DHPs 3 and 11 confirmed liposome-like structures with diameters around 70 to 170 nm. The critical aggregation concentration (CAC) value interval for 4-(N-alkylpyridinium)-1,4-DHP was from 7.6 µM (compound 11) to 43.3 µM (compound 6). The tested 4-(N-alkylpyridinium)-1,4-DHP derivatives were able to quench the fluorescence of the binary 1,6-diphenyl-1,3,5-hexatriene (DPH)—1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) system, demonstrating hydrophobic interactions of 1,4-DHPs with phospholipids. Thus, 4-(N-dodecylpyridinium)-1,4-DHP derivative 3 quenched the fluorescence of the DPH–DPPC system more efficiently than the other 4-(N-alkylpyridinium)-1,4-DHP derivatives. Likewise the compound 3, also 4-(N-dodecylpyridinium)-1,4-DHP derivative 9 interacted with the phospholipids. Moreover, we have established that increasing the length of the alkyl chain at the quaternised nitrogen of the 4-(N-alkylpyridinium)-1,4-DHP molecule or the introduction of propargyl moieties in the 1,4-DHP molecule significantly influences the cytotoxicity on HT-1080 (human fibrosarcoma) and MH-22A (mouse hepatocarcinoma) cell lines, as well as the estimated basal cytotoxicity. Additionally, it was demonstrated that the toxicity of the 4-(N-alkylpyridinium)-1,4-DHP derivatives on the Gram-positive and Gram-negative bacteria species and eukaryotic microorganism depended on the presence of the alkyl chain length at the N-alkyl pyridinium moiety, as well as the number of propargyl groups. These lipid-like compounds may be proposed for the further development of drug formulations to be used in cancer treatment.

It has been found that the nature of the substituent, its position in the quinoline ring, and the nature of the metal significantly affect the antitumor activity and toxicity of metal 8-quinolinethiolates. The most cytotoxic towards human fibrosarcoma HT-1080 and mouse hepatoma MG-22A tumor cells are the 6-methoxy-8-quinolinethiolates of rhodium, osmium, iridium, indium, antimony, and bismuth, however these are highly toxic towards normal mouse embryonic NIH 3T3 fibroblasts. The iridium 5-methyl-8-quinolinethiolate is somewhat less active to MG-22A cells but shows quite good selectivity of action because of its markedly lower toxicity.Keywords: metal 3-and 5-methyl-8-quinolinethiolates, metal 2-and 6-methoxy-8-quinolinethiolates, synthesis, toxicity, cytotoxicity.After more than 40 years, platinum complexes occupy a high profile place in the arsenal of antitumor agents [1-3]. During this time there have appeared problems connected with their use, i.e. high overall toxicity leading to unwanted side effects and resistance to platinum preparations in a series of tumors which can develop during the time of chemotherapy. Attempts have been made to overcome these observations by changing the ligands in the platinum complexes and, more recently, by exchanging the metal [4,[7][8][9][10][11].In this respect the most promising proved to be ruthenium complexes which have low overall toxicity and are selectively accumulated in the tumor cells [4,7,[12][13][14][15][16][17][18]. Two of them have carried on to clinical investigation [14,19,20]. At the same time their rhodium and osmium analogs have shown even greater cytotoxicity towards A549 lung and T47D mammary gland carcinoma cells [21].We have shown that not only ruthenium, rhodium, and osmium but also iridium complexes [22,23] with an 8-quinolinethiol [22,23] or 8-quinolineselenol [24,25] ligand show high cytotoxicity to HT-1080 human fibrosarcoma and MG-22A mouse hepatoma tumor cells. However, all of these compounds showing high activity towards tumor cells are also toxic to normal NIH 3T3 mouse embryonic fibroblasts [22]. The toxicity of the highly active rhodium and iridium 8-quinolinethiolates can be markedly decreased by the introduction into their molecules of a methyl group at the 4 position of the quinoline ring [23]. It was also found that substituents in different positions of the quinoline ring can increase the selectivity of action of di(8-quinolyl) disulfides [26]. __________________________________________________________________________________________