Trimethyl Ester Research Articles

Cationic photosensitizers and potassium iodide: an innovative approach for enhanced photodynamic inactivation of pathogenic bacteria in aquaculture

Aquaculture is a rapidly growing industry, accounting for more than half of the worldwide fish production. However, this sector is often affected by bacterial infections, threatening farmed animals and consumer safety. This study explored the potential of Photodynamic Inactivation (PDI) as an innovative antimicrobial approach for the inactivation of Gram-negative bacteria relevant to the aquaculture sector: Vibrio parahaemolyticus, Vibrio anguillarum, and Escherichia coli. The experiments were conducted in the presence of the cationic photosensitizers (PSs) 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin (TMPyP) and methylene blue (MB). For V. parahaemolyticus, the protocol was extended to the neutral and anionic PSs curcumin (CUR), chlorin e6 trimethyl ester (Ce6Me), and 5,10,15,20-tetrakis(4-sulfophenyl)porphyrin (TPPS4). The assays were performed in the absence or presence of potassium iodide, well-known to improve PDI effect, while its potential for aquaculture application is yet to be studied. These evaluations were performed in phosphate-buffered saline (PBS) and in artificial seawater (ASW) to simulate aquaculture water disinfection. The cationic PSs TMPyP and MB were the most efficient in the bacterial inactivation. Although higher concentrations of PS were required to achieve effective bacterial inactivation in ASW compared to PBS, the application of KI enhanced the effectiveness of all PSs, reducing the treatment time at least by threefold. The bacterial inactivation profiles revealed higher susceptibility of Vibrionaceae bacteria which may be linked to the differential PDI impact on the outer cell membranes of these bacteria. These findings indicate that treatments with PSs, particularly TMPyP and MB, in combination with KI constitute a potential approach for bacteria control in the aquaculture sector.

Bioactive metabolites, antioxidant, and antidiabetic activities of fermented local rice (Pare ambo) by Pleurotus spp.: In-vitro and in-silico approach

Pare ambo, a local black rice variety popular in Tana Toraja (South Sulawesi), is recognized for its health benefits, especially for those managing diabetes or aiming to prevent obesity due to its antioxidant-rich composition. This study explored the impact of Pleurotus spp. Fermentation on pare ambo, examining its nutritional transformation. Proximate analysis indicated higher levels of crude protein (9.67 ± 0.73%), crude fat (3.36 ± 0.84%), and fiber (1.67 ± 0.33%) in P. cystidiosus fermentation compared to P. ostreatus and P. djamor. Antioxidant and antidiabetic activities significantly improved in all fermentations at 500 ppm concentration. Pare ambo fermented by all three Pleurotus species contained citric acid and trimethyl ester compounds, displaying superior antioxidant and antidiabetic activities, interacting with antioxidant receptor 5O0x (−7.2 kcal/mol) and antidiabetic receptor 3w37 (−8.2 kcal/mol) compared to the unfermented sample. Fatty acid profiling identified 32 compounds, predominantly FAMEs with ester groups. Pleurotus cystidiosus and P. djamor fermentations contributed 20 compounds, while P. ostreatus contributed 18 compounds. Prominent interactions were visualized between naphthalene, and decahydro-2,6-dimethyl, with 5O0x and 3w37. Anthocyanins were detected through HPLC separation in P. cystidiosus and P. ostreatus fermentation outputs. This study shows pare ambo as a promising functional food, abundant in natural antioxidants and antidiabetic compounds, highlighting the potential of Pleurotus spp. Fermentation to enhance the nutritional profile and bioactivity of indigenous rice varieties.

PERBANDINGAN RENDEMEN EKSTRAKSI KECOMBRANG (Etlingera elatior) MENGGUNAKAN METODE MASERASI DAN SOKLETASI

Torch ginger (Etlingera elatior) contains secondary metabolites that have antibacterial potential. The production of torch ginger extract in Indonesia is still limited. However, market demand increase because pharmaceutical industry is starting to use the torch ginger extract. Furthermore, the growing utilization of torch ginger will enhance the economy of torch ginger farmers. This study aims to compare the extraction efficiency of maceration and soxhletation methods in obtaining bioactive compounds from torch ginger using ethanol, methanol and n-hexane as solvents. The results showed that in the maceration method, ethanol solvent produced the highest yield of 15%, methanol 7% and n-hexane 3%. In soxhletation method, ethanol and methanol solvents produced yields of 15% and 13% respectively, higher than n-hexane only 1%. Overall, soxhletation method with ethanol solvent was the best condition for torch ginger extraction. GC-MS characterization showed the presence of bioactive compounds such as 2-Chloropropionic acid, Boric acid trimethyl ester, Silane dimethoxymethyl and Octadecanoic acid methyl ester which contribute to the antibacterial activity in torch ginger essential oil.

IDENTIFIKASI SENYAWA AKTIF EKSTRAK DAUN JARAK KEPYAR (Ricinus communis) DENGAN ANALISIS FITOKIMIA DAN GC-MS SEBAGAI KANDIDAT SENYAWA OBAT

As a tropical country with biodiversity, Indonesia is rich with flora especially those with potential as medicinal plants such as Jarak Kepyar (Ricinus communis). Leaves of jarak kepyar (Ricinus communis) are used as a medicine for wounds, rash, abscess, and fever. Therefore, the purpose of this study was to determine the active compound in ethanol and n-hexane extract of jarak kepyar (Ricinus communis) leaves using phytochemical analysis and GC-MS. The research method used is the experimental method in the laboratory. The steps of the research were extraction of jarak kepyar (Ricinus communis) leaves using 96% ethanol and n-hexane with the maceration method. Furthermore, jarak kepyar (Ricinus communis) leaves extract was analyzed qualitative and quantitatively by phytochemical screening and GC-MS analysis. The results of the phytochemical screening showed that the chemical compounds contained in the ethanol extract of jarak kepyar (Ricinus communis) leaves were flavonoids, alkaloids, terpenoids, tannins and phenolics. While the chemical compounds contained in the n-hexane extract of jarak kepyar (Ricinus communis) leaves are alkaloids. GC-MS analysis of the ethanol and n-hexane extracts of jarak kepyar (Ricinus communis) leaves showed that several compounds that are found in the extract of jarak kepyar (Ricinus communis) leaves such as 2-ethoxycarbonyl-5-oxo-pyrolidine, delta-octalactone, trimethyl ester or trimethyl citrate, quinic acid, 2,3- Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one and methyl oleate have potential as medicinal compounds.

Ultra‐Broadband Random Laser and White‐Light Emissive Carbon Dots/Crystal In‐Situ Hybrids (Small 41/2022)

Multicolor Lasers In article number 2203152, Wenfei Zhang, Hailong Zhang, Zheng Xie, and co-workers report a strategy to realize the in-situ hybridization of carbon nanodots and 1,3,5-benzenetricarboxylic acid trimethyl ester crystals. The hybrid crystals exhibit ultra-broadband multicolor random laser over the near ultraviolet-visible region and continuous white-light fluorescence. The structure of the hybrid crystals is just like the wolf's fangs mace weapon in the hands of oriental mythical figure Kuimu Wolf, who is one of the 28 constellations of Ancient Chinese myths and legends. The colorful triumphant glitter represents the multicolor laser of the hybrid crystals.

Ultra-Broadband Random Laser and White-Light Emissive Carbon Dots/Crystal In-Situ Hybrids.

The continuous white-light emission of carbon dots (CDs) can be applied to producing multicolor laser emissions by one single medium. Meanwhile, the solid-state emission greatly contributes to its practical application. In this work, a strategy to realize the in-situ hybridization of silane-functionalized CDs (SiCDs) and 1,3,5-benzenetricarboxylic acid trimethyl ester (Et3BTC) by a one-pot solvothermal method is reported. Significantly, the SiCDs/Et3BTC hybrid crystals exhibit ultra-broadband random laser emission over the near ultraviolet-visible region under 265nm nanosecond pulsed laser excitation. The wavelength region of laser emission is achieved from 315 to 600nm within an emission band of CDs-based materials. It is worth noting that the wavelength range of the laser is wider than the previously reported works. It is proposed that the continuous white-light emission of SiCDs caused by multiple fluorescence centers mainly gives rise to the broadband random laser emission. Moreover, the crystals are conducive to forming resonance and realizing solid-state laser emission. This in-situ method is expected to enable a more convenient, cheaper, and greener approach to prepare luminescent hybrids for application in multicolor laser displays, multi-level laser anti-counterfeiting, supercontinuum light sources, and so on.

Indium complexes of chlorin e6 trimethyl ester and methylpyropheophorbide a: Synthesis and photophysical characterization

Complexes of chlorin e6 trimethyl ester (H2Chl-e6,), methylpyropheophorbidea (H2MePyroPheo) with indium(III) (InChl-e6, and InMePyroPheo) were obtained from the corresponding macrocyclic ligands by complexation reaction with InIII trisacetylacetonate in acetic acid. In the case of methylpheophorbidea (H2MePheo) the complexation reaction is accompanied by side-process of exo-cyclic ring oxidation leading to inseparable mixture of InMePheo, its 13(2)-hydroxy derivative and InMePyroPheo. Spectral-luminescence and photophysical properties of H2Chl-e6 and H2MePyroPheo and their InIII complexes were studied in DMF. Metal free chlorins have relatively long fluorescence lifetimes (τf ∼ 5.4–7.5 ns) and moderate fluorescence and singlet oxygen quantum yields (ФF ∼ 0.39 and 0.29, ФΔ ∼ 0.47 and 0.60, for H2Chl-e6 and H2MePyroPheo, respectively). It was revealed that insertion of the indium atom into the macrocyclic core strongly diminishes the fluorescence lifetimes (τf ∼ 0.5–0.9 ns) and quantum yields (ФF ∼ 0.04–0.06), but facilitates the conversion to the triplet state leading to enhanced singlet oxygen quantum yields. Therefore, InChl-e6 and InMePyroPheo having intense Q-band absorption in the therapeutic window (638 and 661 nm) and high values of ФΔ (0.84 and 0.76) can be considered as promising photosensitizers for PDT.

Is 18α-Glycyrrhizin a real natural product? Improved preparation of 18α-Glycyrrhizin from 18β-Glycyrrhizin as a positive standard for HPLC analysis of licorice extracts.

18α-Glycyrrhizin is an epimer of 18β-glycyrrhizin, a major component of licorice (Glycyrrhiza sp.), which is widely used as a traditional medicine. Whether 18α-glycyrrhizin is a real natural product has been debated in the long history of glycyrrhizin chemistry because 18β-glycyrrhizin is epimerizable to a more thermodynamically stable 18α-glycyrrhizin under aqueous alkali conditions. We improved the preparation of 18α-glycyrrhizin from 18β-glycyrrhizin by successive epimerization reactions of 18β-glycyrrhizin, trimethyl esterification of the resulting epimerized mixture, and alkaline hydrolysis of a purified 18α-glycyrrhizin trimethyl ester. Approaches to the possible presence of 18α-glycyrrhizin in licorice extracts by HPLC using synthetic 18α-glycyrrhizin as a positive standard strongly suggested that 18α-glycyrrhizin could naturally exist as a minor congener of glycyrrhizin derivatives in Glycyrrhiza species.

A new megastigmane, known porphyrinic and galloylated bioactive derivatives from the leaves of Gymnosporia senegalensis

Investigation of the non-polar (rich in chlorophyll) and polar fractions of the ethyl acetate extract of Gymnosporia senegalensis (Lam.) Loes. leaves led to the isolation of nine compounds, including one new megastigmane derivative, (3 R*,5 S*,6 R*,7 E,9ξ)-7-megastigmene-3,6,9-triol-3- O-β-D-(6′- O-galloyl)glucopyranoside (1), four known galloylated derivatives (2, 3, 8, 9), three known chlorophyll derivatives (4–6), and one known fatty acid (7). The structures of the isolates were determined by means of spectroscopic and spectrometric data, as well as by comparison with literature values. The extracts and isolated compounds were tested for their antibacterial, antifungal, and antioxidant activities. The isolates showed weak to high antimicrobial activities with phaeophytin A (4) being the most active one whereas phaeophorbide-a (5) and Chlorine e6 trimethyl ester (6) exhibited the highest antioxidant activities.

Biodegradation Study of an Organophosphorus Insecticide–Quinalphos by Novel Sphingobacterium mizutaii strain DSM 11724.

Organophosphate pesticides are now the most popular commercial pesticides in vineyards, with widespread use across the globe. They are recalcitrant, have acute toxicity at higher concentrations and irreversibly inactive acetylcholine esterase in insects, humans and other animals. Sphingobacterium mizutaii was isolated from the vineyard dump region, which was found to break down Organophosphate pesticides in-vitro conditions. The degradation efficiency was found by spectral analysis in U.V visible spectra through pre and post degradation. Gas chromatography with Mass spectroscopy identified the breakdown products as Amine bis 2-phosphoethyl, butyric acid 3-amino 4-methoxy, Acetamide and phosphoric acid trimethyl ester. These compounds have never been previously reported. This bacterium provided a suitable bioremediation entity in these yards to overcome the pesticide pollution of soils. The Sphingobacterium mizutaii has never been previously reported to be used in the bioremediation of organophosphate pesticides. The application of this bacteria in the agricultural sector can have substantial use in sustainable agriculture.

Pharmacokinetics and tissue distribution characteristics of the novel photosensitizer 32-(4-methoxyphenyl)-152-aspartyl-chlorin e6

二氢卟吩类衍生物32-(4-甲氧基苯基)-152-天冬氨酸-二氢卟吩e6(DYSP-C34)是从程海湖螺旋藻中提取并合成的新型光敏剂。研究DYSP-C34在生物体内的药代动力学及组织分布过程对光动力疗法(PDT)的有效性和安全性至关重要。该文运用高效液相色谱-紫外(HPLC-UV)检测技术,建立了大鼠血浆中DYSP-C34的检测方法。采用沉淀蛋白-液液萃取法处理血浆和组织样品,采用Unitary C18色谱柱(250 mm×4.6 mm, 5 μm)分离,流动相为甲醇-5 mmol/L四丁基磷酸氢铵缓冲盐溶液(70:30, v/v),流速为1.0 mL/min,进样量为20 μL,检测波长为400 nm,柱温为40 ℃。实验结果表明,大鼠血浆药物质量浓度在1~200 μg/mL范围内线性良好,判定系数(r2)为0.9941。在低、中、高(8、40、120 μg/mL)3个添加水平下的提取回收率分别为74.39%、69.71%和65.89%,日内和日间相对标准偏差(RSD)均在5%以内。运用此方法测定静脉注射DYSP-C34(16 mg/kg)后大鼠血浆中以及荷瘤小鼠组织中的药物浓度,采用DAS 2.0计算出药物半衰期t1/2z为6.98 h,药-时曲线下面积AUC(0-∞)为1025.01 h·mg/L,平均驻留时间MRT(0-∞)为9.19 h。DYSP-C34在荷瘤小鼠体内的分布结果显示,DYSP-C34可以在肿瘤组织中蓄积,并具有一定的滞留作用。综上,该文建立了大鼠血浆中DYSP-C34的HPLC-UV测定方法,并进行了方法学验证,此方法简便、快速,结果准确。阐明了DYSP-C34在静脉给药方式下大鼠体内药代动力学和荷瘤小鼠组织中的分布特征,对临床合理用药和药效学研究具有重要意义。

Total Synthesis of Kadcoccinic Acid A Trimethyl Ester.

The first total synthesis of the trimethyl ester of kadcoccinic acid A is described. The central structural element of our synthesis is a cyclopentenone motif that allows the assembly of the natural product skeleton. A gold(I)-catalyzed cyclization of an enynyl acetate led to efficient construction of the cyclopentenone scaffold. In this step, optimization studies revealed that the stereochemistry of the enynyl acetate dictates regioisomeric cyclopentenone formation. The synthesis further highlights an efficient copper-mediated conjugate addition, merged with a gold(I)-catalyzed Conia-ene reaction to connect the two fragments, thereby forging the D-ring of the natural product. The synthetic strategy reported herein can provide a general platform to access the skeleton of other members of this family of natural products.

Precise Assembly and Supramolecular Catalysis of Tetragonal- and Trigonal-Elongated Octahedral Coordination Containers

The construction of distorted or irregular coordination polyhedrons with specific shapes and functionalities is highly challenging. Here, we demonstrate a viable strategy for attaining a severely d...

Разработка способа получения триметилового эфира фосфонуксусной кислоты

In the recent years the methods of synthesis and biological activity of phosphorus-containing analogues of biogenic carboxylic acids that are potential anti-metabolites of corresponding endogenous ligands in metabolic processes have been intensively studied. Phosphonacetic (PAA) and phosphonformic acids are the most important biological active phosphorus-containing carboxylic acids. Antiviral activity of phosphonacetic acid and some it’s derivates via inhibition of replication of viral DNA is proven by a number of studies, but searching of efficient and economical method of synthesis of PAA for industrial manufacturing still going on. In this paper, development of the method of synthesis of trimethyl ester of PAA that is the most convenient initial compound for further PAA synthesis is considered. The basis of this development was taken the reaction of interphase alkylation of dimethylphophite by methylchloroacetate without any solvents. Potassium carbonate or sodium carbonate in presence of appropriate phase transfer catalyst was used as a base in this reaction. In the course of the work, the kinetics and selectivity of this reaction were investigated using different bases and the corresponding kinetic curves were obtained. In case of sodium carbonate as a base the effect of using different phase transfer catalysts on yield and selectivity of this reaction was shown. As part of the study, a series of experiments were carried out and optimal process conditions were determined that allow it to be scaled using commercially available substrates and without the use of labor-intensive and high-cost technological methods.

Inverse electron demand Diels–Alder reaction as a novel method for functionalization of natural chlorins

The addition of 3-aryl-1,2,4,5-tetrazines at the vinyl group of chlorin e6 trimethyl ester affords the corresponding pyridazine–porphyrin conjugates. The study of spectral properties of the obtained compounds revealed insignificant changes in the absorbance and fluorescence spectra as compared to those of chlorin.

Chlorophyll-based organic solar cells with improved power conversion efficiency

Abstract Chlorophylls (Chls), and associated chlorophyll derivatives, are one of the oldest, most versatile organic semiconductors found in nature. Herein, we present two easily semi-synthesized chlorophyll derivatives, namely, chlorin e6 trimethyl ester (Ce6Me3) and its copper complex (Cu–Ce6Me3), as the p-type dopants for organic semiconductors and their impact in organic solar cells (OSCs). In our study, both Chls showed intense Soret and Qy bands in the UV-visible spectra, leading to an effect means for capturing solar light and energy. Chls also exhibited high carrier mobility owing to the partial formation of aggregates through the spin-coating process. Using Chls, we fabricated OSCs in both planar-heterojunction (PHJ) and bulk-heterojunction (BHJ) solar cell configurations, together with C70/PC70BM as electron acceptors. In PHJ solar cells, we received solar power conversion efficiencies (PCEs) of only 0.85% and 0.93% for Cu–Ce6Me3- and Ce6Me3-based devices, respectively, with the thickness of the donor layer at 5 nm. In BHJ cells, we achieved much higher PCEs of 1.53% and 2.05% for Cu–Ce6Me3:PC70BM and Ce6Me3:PC70BM respectively, where both blending ratios were set to 1:8. The improvement on PCE in BHJ cells may be attributed to the better charge separation increase at the donor–acceptor interface.

An optimized method for an (2R,3S)-isocitric acid building block

An optimized method for (2R,3S)-isocitric acid lactone-2,3-dicarboxylic acid dimethyl ester as an (2R,3S)-isocitric acid building block based on a fermentation solution containing both (2R,3S)-isocitric acid (ICIT) and citric acid is described. The number of operations needed until now has been reduced; some steps have been modified, making altogether the method distinctly faster. During the course of this investigation, crystal structures have been determined of (2R,3S)-isocitric acid lactone-2,3-dicarboxylic acid dimethyl ester, (2R,3S)-isocitric acid lactone-2,3-dicarboxylic acid, and (2R,3S)-isocitric acid lactone-2,3-dicarboxylic acid anhydride. For the first time, full NMR data are given for ICIT trimethyl ester and ICIT lactone-2,3-dicarboxylic acid dimethyl ester. The multigram amounts of the three ICIT lactone compounds open the way for the synthetic use of ICIT generated in a biotechnological process.

Improved Isolation of Microbiologically Produced (2R,3S)-Isocitric Acid by Adsorption on Activated Carbon and Recovery with Methanol

A new, efficient method for the isolation of (2R,3S)-isocitric acid (ICA) from its fermentation solution was developed. It is noteworthy that this method is based on selective adsorption directly from the fermentation solution on activated carbon, followed by the release of both ICA and citric acid by means of elution with methanol and their final separation by known methods. Thereby, several disadvantages were overcome: Electrodialysis is no longer necessary to remove cations such as Na+ from the fermentation solution. Also, several hitherto accompanying dyestuffs were not observed with this method. Furthermore, removal of water by distillation is expendable. Eventually, the new crude product is of a quality that also avoids the use of a tedious slide vane rotary vacuum pump distillation of the trimethyl esters of both acids, which hitherto was the basis for the separation of ICA. In summary, the new method distinctly spares energy as well as time.

Trans-Aconitic acid-based hetero-Diels-Alder reaction in the synthesis of thiopyrano[2,3-d][1,3]thiazole derivatives

The hetero-Diels-Alder reaction of 5-arylideneisorhodanines with trans-aconitic acid proceeds as a regio- and diastereoselective process with spontaneous decarboxylation of the [4+2]-adduct to furnish thiopyrano[2,3-d][1,3]thiazole (2) and chromeno[4′,3′:4,5]thiopyrano[2,3-d]thiazole (3) derivatives analogously to the use of itaconic acid as a dienophile. Conversely, the one-pot, three-component reaction of 5-arylideneisorhodanines, trans-aconitic acid and anilines proceeded without decarboxylation, leading to novel rel-(5′R,6′R,7′R)-5′-carboxy-7′-aryl-1-aryl-3′,7′-dihydro-2H,2′H,5H-spiro[pyrrolidin-3,6′-thiopyrano[2,3-d]thiazol]-2,2′,5-triones 4. Interestingly, the use of trans-aconitic acid trimethyl ester led to the opposite regioselectivity, yielding rel-(5R,6S,7S)-5-methyloxycarbonylmethyl-2-oxo-7-aryl-3,5,6,7-tetrahydro-2H-thiopyrano[2,3-d]thiazol-5,6-dicarboxylates 5. Selected compounds were examined for trypanocide activity against the bloodstream forms of Trypanosoma brucei where compound 4e showed the highest activity (IC50=6.74μM).

Bioassay-Guided Isolation of Cytotoxic Isocryptoporic Acids from Cryptoporus volvatus.

The present work constitutes a contribution to the phytochemical investigation of Cryptoporus volvatus aiming to search for effective cytotoxic constituents against tumor cell lines in vivo. Bioassay-guided separation of the ethylacetate extract of C. volvatus afforded four new isocryptoporic acid (ICA) derivatives, ICA-B trimethyl ester (1), ICA-E (2), ICA-E pentamethyl ester (3), and ICA-G (4), together with nine known cryptoporic acids. These isocryptoporic acids are isomers of the cryptoporic acids with drimenol instead of albicanol as the terpenoid fragment; their structures were elucidated on the basis of spectroscopic evidences (UV, IR, HRMS, and NMR) and comparison with literature values. All isolates show certain cytotoxic activities against five tumor cell lines. Among them, compound 4 showed an comparable activity to that of the positive control cis-platin, while other compounds exhibited weak cytotoxic activities.