Search Results (8)

The photosensitive properties of smart photoactive polymers give them a wide range of potential applications across various fields. This study focuses on designing polymeric systems that incorporate hydrophilic polymers, with the primary goal of adapting these materials for biological applications. Specifically, it aims to contribute to the development of photochromic materials for optical processing, utilizing both molecular and macromolecular components. Additionally, this study evaluates the effectiveness of photoactive polymers in photodynamic therapy (PDT). It details the synthesis and characterization of photoactive copolymers derived from maleic anhydride (MAn) combined with vinyl monomers such as 2-methyl-2-butene (MB) and 1-octadecene (OD), as well as the organic compound 1-(2-hydroxyethyl)-3,3-dimethylindoline-6-nitrobenzopyran (SP). The two novel optically active alternating polymeric systems, poly(maleic anhydride-alt-octadecene) and poly(maleic anhydride-alt-2-methyl-2-butene), were functionalized with SP through an esterification process in a 1:1 monomer feed ratio, using pyridine as a catalyst. This methodology incorporated approximately 100% of the photoactive molecules into the main acrylic chain to prepare the alternating copolymers. These copolymers were characterized by UV-visible, FTIR, and 1H-NMR spectroscopy and analysis of their optical and thermal properties. When exposed to UV light, the photoactive polymer films can develop a deep blue color (566 nm in the absorption spectra). Finally, the study also assesses their capacity for photodynamic antimicrobial action in organic film. Notably, the photoactive P(MAn-alt-2MB)-PS significantly enhances the photodynamic antimicrobial activity of the photosensitizer Ru(bpy) against two bacterial strains of Staphylococcus aureus, reducing the minimum inhibitory concentration (MIC) from 2 µg/mL to 0.5 µg/mL. Therefore, 4 times less photosensitizer is required when mixed with the photoactive polymer to inhibit the growth of antibiotic-sensitive and -resistant bacteria. Full article

The nun moth, Lymantria monacha L. (Linnaeus, 1758), is one of the most important defoliators of coniferous forests in Europe and Asia. In sexual communication, females produce three epoxides and an alkene: (−)-disparlure [(7S,8R)-cis-7,8-epoxy-2-methyloctadecane], (+)-monachalure [(7R,8S)-cis-7,8-epoxyoctadecane], (−)-monachalure [(7S,8R)-cis-7,8-epoxyoctadecane], and their corresponding olefins. This study aimed to develop a green synthesis pathway for all pheromonal components, emphasizing the use of common raw materials, a simplified three-step process, lower costs, and an environmentally friendly approach compared to existing methods. The proposed method introduces a novel synthetic route employing an innovative improvement alkylation step catalyzed by lithium iodide in diglyme. The synthesized compounds were characterized using GC-MS, ¹H NMR, and ¹³C NMR spectroscopy. Six synthetic blends were formulated for field testing, with the goal of identifying the most attractive composition. Field trials demonstrated that a blend with a 10:10:1 ratio of (±)-Disparlure, (±)-Monachalure, and (Z)-2-Methyl-7-octadecene exhibited the highest attraction efficiency. Full article

Secondary metabolites, bioactive compounds produced by living organisms, can unveil symbiotic relationships in nature. In this study, soilborne entomopathogenic nematodes associated with symbiotic bacteria (Xenorhabdus stockiae and Photorhabdus luminescens) were extracted from solvent supernatant containing secondary metabolites, demonstrating significant inhibitory effects against E. coli, S. aureus, B. subtilus, P. mirabilis, E. faecalis, and P. stutzeri. The characterization of these secondary metabolites by Fourier transforms infrared spectroscopy revealed amine groups of proteins, hydroxyl and carboxyl groups of polyphenols, hydroxyl groups of polysaccharides, and carboxyl groups of organic acids. Furthermore, the obtained crude extracts were analyzed by high-performance liquid chromatography for the basic identification of potential bioactive peptides. Gas chromatography–mass spectrometry analysis of ethyl acetate extracts from Xenorhabdus stockiae identified major compounds including nonanoic acid derivatives, proline, paromycin, octodecanal derivatives, trioxa-5-aza-1-silabicyclo, 4-octadecenal, methyl ester, oleic acid, and 1,2-benzenedicarboxylicacid. Additional extraction from Photorhabdus luminescens yielded functional compounds such as indole-3-acetic acid, phthalic acid, 1-tetradecanol, nemorosonol, 1-eicosanol, and unsaturated fatty acids. These findings support the potential development of novel natural antimicrobial agents for future pathogen suppression. Full article

Genus Salsola (family Amaranthaceae) is one of the most prevailing genera in Saudi Arabia. Although several species were reported for their traditional uses, the majority of Salsola species still need to be phytochemically and biologically explored. The current study presents the GC-MS profiling as well as an in vitro investigation of the bioactivities of the n-hexane extracts from the five Salsola species: Salsola arabica, S. cyclophylla, S. imbricata, S. incanescens and S. villosa. Additionally, the compounds identified in the most active extracts were screened for their interaction with the active sites of cyclooxygenase enzyme isoforms (COX-1 and COX-2). GC-MS analysis of the n-hexane extracts from the five species resulted in the identification of 67 constituents. Oleic acid (75.57%), 1-octadecene (14.46%), cinnamaldehyde α-hexyl (57.15%), octacosyl heptafluorobutyrate (25.36%) and hexadecanoic acid methyl ester (26.15%) represent the major constituents in S. arabica, S. cyclophylla, S. imbricata, S. inscanescence and S. villosa, respectively. Results of bioactivity testing highlighted S. villosa as having the highest anti-oxidant activity (IC₅₀ 0.99 ± 0.05 mg/mL), which was closely followed by S. cyclophylla (IC₅₀ 1.36 ± 0.06 mg/mL) compared to the IC₅₀ of 0.16 ± 0.01 mg/mL recorded by ascorbic acid. S. villosa was further noted for having the strongest COX-2 inhibitory activity (IC₅₀ 4.6 ± 0.13 µg/mL) among the tested extracts followed by S. arabica (IC₅₀ 13.1 ± 0.37 µg/mL) and S. cyclophylla (IC₅₀ 20.1 ± 0.57 µg/mL). On the other hand, S. imbricata extract displayed the most characteristic inhibition activity against COX-1 (IC₅₀ 10.2 ± 0.52 µg/mL), which was non-significant from the standard drug celecoxib. Based upon bioactivity results, the phytoconstituents identified in S. villosa and S. imbricata extracts were investigated for their capability to interact with the active sites of both cyclooxygenase enzyme isoforms adopting molecular docking. Results indicated the possibility to incorporate the compounds to active sites of the enzymes where some of them bind with their polar end into the cavity beyond Arg120 and their aliphatic chain oriented to the catalytically important Tyr385 similar to the natural substrate arachidonic acid, indicating that they could be promising candidates for the future development of selective COX inhibitors. Full article

Agarwood is a resinous wood of great economic value produced by trees from the Thymelaeaceae family in response to stress. The natural formation of agarwood can take decades after exposure to the stressors. Artificial agarwood induction by inoculating the stem with fungi has been successfully demonstrated, but resin accumulation occurs very slowly. Cell suspension and callus cultures may serve as an alternative solution to provide a fast-growing plant material to produce artificial agarwood in a short period. Here, we induced agarwood formation in callus cultures of Aquilaria malaccensis by application of crude mycelial extracts of Fusarium solani strains GSL1 or GSL2, or methyl jasmonate (MeJA). After 20 days of treatment with elicitors, all treated calluses had less dry weight than the control group. The gas chromatography–mass spectrometry analysis identified 33 different secondary metabolites among all samples, four of which were present in all treatments and control, i.e., 1-docosene and 1-octadecene (alkenes), 4-di-tert-buthylphenol (phenolic), and benzenepropanoic acid (fatty acid). The 6-methoxy-2-(4-methoxyphenethyl)-4H-chromene-4-one, a chromone derivative, was only detected in callus elicited with the F. solani strain GSL2 and MeJA. All treated calli produced more fatty acid derivatives than the control group. We conclude that elicitors used in this study can induce the production of agarwood-related chemicals such as chromone and fatty acid in callus culture. Full article

This work is the continuation of a series of studies focused on establishing the relationship between the surface thermodynamic properties of polyelectrolyte matrix tablets and drug release mechanisms. In this case, two model drugs with different polarity features, such as carbamazepine (non-polar) and metoprolol succinate (polar) were used in combination with polymeric material hydroxypropyl-methyl cellulose (HPMC) and two polyelectrolytes derived from maleic anhydride corresponding to the sodium salts of poly(maleic acid-alt-ethylene) and poly(maleic acid-alt-octadecene) named PAM-0Na and PAM-18Na, respectively. The polymers were obtained and characterized as reported previously. Surface studies were performed by the sessile drop method, whilst the surface free energy was determined through Owens, Wendt, Rable and Kaeble (OWRK) semi-empirical model. By contrast, the drug release studies were performed by in vitro dissolution tests, where data were analyzed through dissolution efficiency. The results showed that, depending on the drug polarity, type and polymer proportion, surface properties and drug release processes are significantly affected. Full article

This work is the continuation of a study focused on establishing relations between surface thermodynamic properties and in vitro release mechanisms using a model drug (ampicillin trihydrate), besides analyzing the granulometric properties of new polymeric materials and thus establishing the potential to be used in the pharmaceutical field as modified delivery excipients. To do this, we used copolymeric materials derived from maleic anhydride with decreasing polarity corresponding to poly(isobutylene-alt-maleic acid) (hydrophilic), sodium salt of poly(maleic acid-alt-octadecene) (amphiphilic), poly(maleic anhydride-alt-octadecene) (hydrophobic) and the reference polymer hydroxyl-propyl-methyl-cellulose (HPMC). Each material alone and in blends underwent spectroscopic characterization by FTIR, thermal characterization by DSC and granulometric characterization using flow and compaction tests. Each tablet was prepared at different polymer ratios of 0%, 10%, 20%, 30% and 40%, and the surface properties were determined, including the roughness by micro-visualization, contact angle and water absorption rate by the sessile drop method and obtaining W_adh and surface free energy (SFE) using the semi-empirical models of Young–Dupré and Owens-Wendt-Rabel-Käelbe (OWRK), respectively. Dissolution profiles were determined simulating physiological conditions in vitro, where the kinetic models of order-zero, order-one, Higuchi and Korsmeyer–Peppas were evaluated. The results showed a strong relationship between the proportion and nature of the polymer to the surface thermodynamic properties and kinetic release mechanism. Full article

An asymmetric synthesis of 14-methyl-1-octadecene, the sex pheromone of the peach leafminer moth has been achieved. The target molecule was synthesized in six linear steps and in 30.3% overall yield from commercially available hexanoyl chloride, (S)-4-benzyloxazolidin-2-one and 1,9-nonanediol. The hexanoyl chloride was connected with (S)-4-benzyloxazolidin-2-one, and with the induction of the chiral oxazolidinone auxiliary, after chiral methylation, LAH reduction and then tosylation gave the chiral key intermediate 5 in high stereoselectivity. 1,9-Nonanediol, was selectively brominated, THP protected and subjected to Li₂CuCl₄-mediated C-C coupling to afford a C₁₂ intermediate. The target molecule, (S)-14-methyl-1-octadecene, was obtained after the two parts were subjected to a second Li₂CuCl₄-mediated C-C coupling. Our synthetic approach represents the first time a substrate-control asymmetric synthesis of (S)-14-methyl-1-octadecene has been reported. Full article