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Gold nanoparticles (AuNPs) have been synthesized directly inside liposomes using honey as a reducing agent. The obtained aggregates, named Cassyopea® Gold due to the method used for their preparation, show remarkable properties as reactors and carriers of the investigated AuNPs. A mean size of about 150 nm and negative surface charge of -46 mV were measured for Cassyopea® Gold through dynamic light scattering and zeta potential measurements, respectively. The formation of the investigated gold nanoparticles into Cassyopea® liposomes was spectroscopically confirmed by the presence of their typical absorption band at 516 nm. The catalytic activity of the combined liposome–AuNP nanocomposites was tested via the thermal cis–trans isomerization of resonance-activated 4-methoxyazobenzene (MeO-AB). The kinetic rate constants (kobs) determined at 25 °C in the AuNP aqueous solution and in the Cassyopea® Gold samples were one thousand times higher than the values obtained when performing MeO-AB cis–trans conversion in the presence of pure Cassyopea®. The results reported herein are unprecedented and point to the high versatility of Cassyopea® as a reactor and carrier of metal nanoparticles in chemical, biological, and technological applications. [ABSTRACT FROM AUTHOR]

Autocatalysis has been recognized to be involved in the emergence of life and intrinsic to biomolecular replication. Recently, an efficient template autocatalysis driven by solvent‐free crystallization has been reported. Herein, we unveil the role of intermolecular hydrogen bonds formed by amides in crystallization‐driven template autocatalysis (CDTA), which involves the autocatalytic activity, template selectivity, and thermal responsiveness. We found that the thermal‐induced cis‐trans isomerization of amides possibly affects the H‐bonding‐mediated template ability of products for autocatalytic transformation. As a result, CDTA can be reversibly inhibited and activated by tuning the reaction temperatures. Our work sheds light on the significance of noncovalent H‐bonding interactions in artificial self‐replicators. [ABSTRACT FROM AUTHOR]

Flexible and highly ultraviolet (UV) sensitive materials garner considerable attention in wearable devices, adaptive sensors, and light‐driven actuators. Herein, a type of nanofilms with unprecedented fully reversible UV responsiveness are successfully constructed. Building upon this discovery, a new system for ultra‐fast, sensitive, and reliable UV detection is developed. The system operates by monitoring the displacement of photoinduced macroscopic motions of the nanofilms based composite membranes. The system exhibits exceptional responsiveness to UV light at 375 nm, achieving remarkable response and recovery times of < 0.3 s. Furthermore, it boasts a wide detection range from 2.85 µW cm−2 to 8.30 mW cm−2, along with robust durability. Qualitative UV sensing is accomplished by observing the shape changes of the composite membranes. Moreover, the composite membrane can serve as sunlight‐responsive actuators for artificial flowers and smart switches in practical scenarios. The photo‐induced motion is ascribed to the cis–trans isomerization of the acylhydrazone bonds, and the rapid and fully reversible shape transformation is supposed to be a synergistic result of the instability of the cis‐isomers acylhydrazone bonds and the rebounding property of the networked nanofilms. These findings present a novel strategy for both quantitative and qualitative UV detection. [ABSTRACT FROM AUTHOR]

Controlling amide bond geometries and the secondary structures of β‐peptoids is a challenging task as they contain several rotatable single bonds in their backbone. Herein, we describe the synthesis and conformational properties of novel "β‐azapeptoids" with confined dihedrals. We discuss how the acylhydrazide sidechains in these molecules enforce trans amide geometries (ω ~180°) via steric and stereoelectronic effects. We also show that the Θ(Cα‐Cβ) and Ψ(OC‐Cα) backbone torsions of β‐azapeptoids occupy a narrow range (170–180°) that can be rationalized by the staggered conformational preference of the backbone methylene carbons and a novel backbone nO→σ*Cβ‐N interaction discovered in this study. However, the ϕ (Cβ‐N) torsion remains freely rotatable and, depending on ϕ, the sidechains can be parallel, perpendicular, and anti‐parallel relative to each other. In fact, we observed parallel and perpendicular relative orientations of sidechains in the crystal geometries of β‐azapeptoid dimers. We show that ϕ of β‐azapeptoids can be controlled by incorporating a bulky substituent at the backbone β‐carbon, which could provide complete control over all the backbone dihedrals. Finally, we show that the ϕ and Ψ dihedrals of β‐azapeptoids resemble that of a PPII helix and they retain PPII structure when incorporated in Host–guest proline peptides. [ABSTRACT FROM AUTHOR]

Abstract Flexible and highly ultraviolet (UV) sensitive materials garner considerable attention in wearable devices, adaptive sensors, and light‐driven actuators. Herein, a type of nanofilms with unprecedented fully reversible UV responsiveness are successfully constructed. Building upon this discovery, a new system for ultra‐fast, sensitive, and reliable UV detection is developed. The system operates by monitoring the displacement of photoinduced macroscopic motions of the nanofilms based composite membranes. The system exhibits exceptional responsiveness to UV light at 375 nm, achieving remarkable response and recovery times of < 0.3 s. Furthermore, it boasts a wide detection range from 2.85 µW cm−2 to 8.30 mW cm−2, along with robust durability. Qualitative UV sensing is accomplished by observing the shape changes of the composite membranes. Moreover, the composite membrane can serve as sunlight‐responsive actuators for artificial flowers and smart switches in practical scenarios. The photo‐induced motion is ascribed to the cis–trans isomerization of the acylhydrazone bonds, and the rapid and fully reversible shape transformation is supposed to be a synergistic result of the instability of the cis‐isomers acylhydrazone bonds and the rebounding property of the networked nanofilms. These findings present a novel strategy for both quantitative and qualitative UV detection.

This study presents the results of comparative hydrogenation of sunflower oil over a platinum catalyst supported on activated diatomite and an industrial nickel catalyst (Pricat-9910). Catalysts are characterized using physical methods, such as transmission electron microscopic, temperature programmed hydrogen desorption, Brunauer–Emmett–Teller and inductively coupled plasma atomic emission spectrometry, enabling the determination of the size of catalyst particles, forms of adsorbed hydrogen, and specific surface area. Depending on the process conditions, hydrogenation reaction rates on platinum catalysts have been found to be 2–5 times higher than cis-trans isomerization reaction rates. Using a nickel catalyst, the hydrogenation and isomerization rates at low temperatures (110°C-130 °C) and 0.5 MPa pressure are almost similar, while, the hydrogenation rate is 1.4–1.8 times lower than the isomerization rate at high temperatures and pressures, leading to the formation of a large number of trans isomers. The difference in catalysts selectivity may be attributed the speciation and different adsorption energies of surface hydrogen, leading to the possibility of simultaneous hydrogenation of linoleic and oleic acids on the nickel catalyst.

Phototransformations of 6-nitro-8-methoxy-substituted indoline spiropyran in acetonitrile have been studied by laser kinetic spectroscopy (laser photolysis) with single- and double-pulse excitation. The role of the triplet state in the kinetics of photocoloration of spiropyran has been revealed. It has been shown that photochromic transformations of spiropyran involve unstable trans-isomers (conformers) of the open merocyanine form of spiropyran. Data on the transformation kinetics of the trans-isomers are presented. [ABSTRACT FROM AUTHOR]

Geometrical mono-trans isomers of arachidonic acid (mtAA) are endogenous products of free radical-induced cis-trans double bond isomerization occurring to natural fatty acids during cell metabolism, including lipid peroxidation (LPO). Very little is known about the functional roles of mtAA and in general on the effects of mono-trans isomers of polyunsaturated fatty acids (mtPUFA) in various types of programmed cell death, including ferroptosis. Using HT1080 and MEF cell cultures, supplemented with 20 μM PUFA (i.e., AA, EPA or DHA) and their mtPUFA congeners, ferroptosis occurred in the presence of RSL3 (a direct inhibitor of glutathione peroxidase 4) only with the PUFA in their natural cis configuration, whereas mtPUFA showed an anti-ferroptotic effect. By performing the fatty acid-based membrane lipidome analyses, substantial differences emerged in the membrane fatty acid remodeling of the two different cell fates. In particular, during ferroptosis mtPUFA formation and their incorporation, together with the enrichment of SFA, occurred. This opens new perspectives in the role of the membrane composition for a ferroptotic outcome. While pre-treatment with AA promoted cell death for treatment with H 2 O 2 and RSL3, mtAA did not. Cell death by AA supplementation was suppressed also in the presence of either ferroptosis inhibitors, such as the lipophilic antioxidant ferrostatin-1, or NADPH oxidase (NOX) inhibitors, including diphenyleneiodonium chloride and apocynin. Our results confirm a more complex scenario for ferroptosis than actually believed. While LPO processes are active, the importance of environmental lipid levels, balance among SFA, MUFA and PUFA in lipid pools and formation of mtPUFA influence the membrane phospholipid turnover, with crucial effects in the occurrence of cell death by ferroptosis. [Display omitted] • mtPUFA induce different membrane lipid remodeling with SFA enrichment than PUFA. • mtPUFA do not have pro-ferroptotic activity as PUFA do. • Mono-trans isomers of arachidonic acid (mtAA) were formed upon lipid peroxidation. • Isomerization of AA to mtAA works as a negative feedback mechanism for ferroptosis. [ABSTRACT FROM AUTHOR]

Photoresponsive molecular devices can be a valuable tool to promote chemical changes in response to multiple signals, such as photons and pH, to deliver drugs or to detect physiological conditions in vivo. For example, trans-chalcones (Ct) from 4′-hydroxyflavylium (F1) and 7-hydroxyflavylium (F2) can undergo cis-trans isomerization by photoreaction into many different structures. The isomerization takes place at a slow rate in response to pH change; however, it can be done in seconds by photoreaction. In the investigation, as confirming the previous reports, 3-(2-hydroxy-phenyl)-1-(4-hydroxy-phenyl)-propenone, the trans-chalcone (CtF1) from F1, produces flavylium ions in pH = 1–4.5. Then, we further discovered that the flavylium quickly releases protons to yield the corresponding quinoidal base (A) in a solution of pH = 5.2 during irradiation with 350 nm. Meanwhile, the photolysis of 3-(2,4-dihydroxy-phenyl)-1-phenyl-propenone, the trans-chalcone (CtF2) from F2 at pH = 5.6, induces photoacid behavior by losing a proton from the trans-chalcone to generate Ct2−. The different outcomes of these nearly colorless chalcones under similar pH conditions and with the same photochemical conditions can be useful when yielding colored AH+, A, or Ct2− in a mildly acidic pH environment with temporal and spatial control using photochemical means.

Cis‐trans isomerization of amide bonds impedes de novo design of folded peptoids (poly‐N‐substituted glycines) with precise secondary structures and affects peptoid‐biomolecule binding affinity. Herein, from X‐ray, NMR and DFT studies of azapeptoids, we have discovered a tetrel bonding interaction that stabilizes trans‐peptoids. We show that peptoids having α‐heteroatoms and N‐aryl groups in the sidechain adopt trans‐amide geometries due to the presence of a nX/πAr→σ*Cα−N tetrel bonding interaction between the sidechain α‐heteroatom lone pair (nX) or π‐electrons (πAr) and the σ* orbital of the backbone Cα−N bond. Further, CD spectroscopic studies of oligo‐proline host–guest model peptides showed that azapeptoid residues stabilize polyproline II helical conformation. These data indicate that the sidechain‐backbone tetrel bonding could be leveraged to design peptoids with precise secondary structures for a wide range of biological and material applications. [ABSTRACT FROM AUTHOR]

Plasmalogens are membrane phospholipids with two fatty acid hydrocarbon chains linked to L-glycerol, one containing a characteristic cis-vinyl ether function and the other one being a polyunsaturated fatty acid (PUFA) residue linked through an acyl function. All double bonds in these structures display the cis geometrical configuration due to desaturase enzymatic activity and they are known to be involved in the peroxidation process, whereas the reactivity through cis-trans double bond isomerization has not yet been identified. Using 1-(1Z-octadecenyl)-2-arachidonoyl-sn-glycero-3-phosphocholine (C18 plasm-20:4 PC) as a representative molecule, we showed that the cis-trans isomerization can occur at both plasmalogen unsaturated moieties, and the product has characteristic analytical signatures useful for omics applications. Using plasmalogen-containing liposomes and red blood cell (RBC) ghosts under biomimetic Fenton-like conditions, in the presence or absence of thiols, peroxidation, and isomerization processes were found to occur with different reaction outcomes due to the particular liposome compositions. These results allow gaining a full scenario of plasmalogen reactivity under free radical conditions. Moreover, clarification of the plasmalogen reactivity under acidic and alkaline conditions was carried out, identifying the best protocol for RBC membrane fatty acid analysis due to their plasmalogen content of 15–20%. These results are important for lipidomic applications and for achieving a full scenario of radical stress in living organisms. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) is a plant hormone that regulates numerous plant processes, including plant growth, development, and stress physiology. ABA plays an important role in enhancing plant stress tolerance. This involves the ABA-mediated control of gene expression to increase antioxidant activities for scavenging reactive oxygen species (ROS). ABA is a fragile molecule that is rapidly isomerized by ultraviolet (UV) light and catabolized in plants. This makes it challenging to apply as a plant growth substance. ABA analogs are synthetic derivatives of ABA that alter ABA's functions to modulate plant growth and stress physiology. Modifying functional group(s) in ABA analogs alters the potency, selectivity to receptors, and mode of action (i.e., either agonists or antagonists). Despite current advances in developing ABA analogs with high affinity to ABA receptors, it remains under investigation for its persistence in plants. The persistence of ABA analogs depends on their tolerance to catabolic and xenobiotic enzymes and light. Accumulated studies have demonstrated that the persistence of ABA analogs impacts the potency of its effect in plants. Thus, evaluating the persistence of these chemicals is a possible scheme for a better prediction of their functionality and potency in plants. Moreover, optimizing chemical administration protocols and biochemical characterization is also critical in validating the function of chemicals. Lastly, the development of chemical and genetic controls is required to acquire the stress tolerance of plants for multiple different uses. [ABSTRACT FROM AUTHOR]

The peptidyl prolyl cis-trans isomerase Pin1 plays vital roles in diverse cellular processes and pathological conditions. NeuroD is a differentiation and survival factor for a subset of neurons and pancreatic endocrine cells. Although multiple phosphorylation events are known to be crucial for NeuroD function, their mechanisms remain elusive. In this study, we demonstrate that zebrafish embryos deficient in Pin1 displayed phenotypes resembling those associated with NeuroD depletion, characterized by defects in formation of mechanosensory hair cells. Furthermore, zebrafish Pin1 interacts with NeuroD in a phosphorylation-dependent manner. In Pin1-deficient cell lines, NeuroD is rapidly degraded. However, the protein stability of NeuroD is restored upon overexpression of Pin1. These findings suggest that Pin1 functionally regulates NeuroD protein levels by post-phosphorylation cis-trans isomerization during neuronal specification.

Photoresponsive molecular devices can be a valuable tool to promote chemical changes in response to multiple signals, such as photons and pH, to deliver drugs or to detect physiological conditions in vivo. For example, trans-chalcones (Ct) from 4′-hydroxyflavylium (F1) and 7-hydroxyflavylium (F2) can undergo cis-trans isomerization by photoreaction into many different structures. The isomerization takes place at a slow rate in response to pH change; however, it can be done in seconds by photoreaction. In the investigation, as confirming the previous reports, 3-(2-hydroxy-phenyl)-1-(4-hydroxy-phenyl)-propenone, the trans-chalcone (CtF1) from F1, produces flavylium ions in pH = 1–4.5. Then, we further discovered that the flavylium quickly releases protons to yield the corresponding quinoidal base (A) in a solution of pH = 5.2 during irradiation with 350 nm. Meanwhile, the photolysis of 3-(2,4-dihydroxy-phenyl)-1-phenyl-propenone, the trans-chalcone (CtF2) from F2 at pH = 5.6, induces photoacid behavior by losing a proton from the trans-chalcone to generate Ct2−. The different outcomes of these nearly colorless chalcones under similar pH conditions and with the same photochemical conditions can be useful when yielding colored AH+, A, or Ct2− in a mildly acidic pH environment with temporal and spatial control using photochemical means. [ABSTRACT FROM AUTHOR]

The c subunits, which constitute the c‐ring apparatus of the F1FO‐ATPase, could be the main components of the mitochondrial permeability transition pore (mPTP). The well‐known modulator of the mPTP formation and opening is the cyclophilin D (CyPD), a peptidyl‐prolyl cis‐trans isomerase. On the loop, which connects the two hairpin α‐helix of c subunit, is present the unique proline residue (Pro40) that could be a biological target of CyPD. Indeed, the proline cis‐trans isomerization might provide the switch that interconverts the open/closed states of the pore by pulling out the c‐ring lipid plug. [ABSTRACT FROM AUTHOR]

Disease-related tau protein in Alzheimer's disease is hyperphosphorylated and aggregates into neurofibrillary tangles. The cis -proline isomer of the pSer/Thr-Pro sequence has been proposed to act as a precursor of aggregation ('Cistauosis' hypothesis), but this aggregation scheme is not yet entirely accepted. Hence to investigate isomer-specific-aggregation of tau, proline residues at the RTPPK motif were replaced by alanine residues (with permanent trans configuration) employing genetic engineering methods. RTPAK, RTAPK, and RTAAK mutant variants of tau were generated, and their in vitro aggregation propensity was investigated using multi-spectroscopic techniques. Besides, the cell toxicity of oligomers/fibrils was analyzed and compared to those of the wild-type (WT) tau. Analyses of mutant variants have shown to be in agreement (to some degree) to the theory of the 'cistauosis' hypothesis. The results showed that the trans isomer in the 232-rd residue (P232A mutant rather than P233A) had reduced aggregation propensity. However, this study did not illustrate any statistically significant difference between the wild and the mutant protein aggregations concerning cell toxicity. [ABSTRACT FROM AUTHOR]

Mycro 3 is a synthetic pyrazolo[1,5‐a]pyrimidine amide with interesting bioactivity having exhibited promising results in in vivo studies against pancreatic cancer. Even though it is a known compound, no data concerning its conformations have been reported before. The aim of this work is to investigate the formation of its trans‐ and cis‐ isomers, the photophysical processes of the isomerization, and the solvent effect via a DFT study. We found that this isomerization is a thermodynamically favourable reaction, having a small barrier of 10.3 kcal/mol in DMSO. Additionally, the calculated 1H and 13C NMR spectra of the two isomers revealed measurable differences. Furthermore, the S0→S1 excitation was found in vis area at 413 nm (trans‐isomer), while the S2→S0 and S1→S0 excitations are charge transfer (CT) and partially CT state in near‐infrared and vis spectra, showing that mycro 3 also has the potential to be used as a photosensitizer. Finally, its synthesis and its NMR analysis revealed a good agreement with the proposed trans conformation. [ABSTRACT FROM AUTHOR]

Plasmalogens are membrane phospholipids with two fatty acid hydrocarbon chains linked to L-glycerol, one containing a characteristic cis-vinyl ether function and the other one being a polyunsaturated fatty acid (PUFA) residue linked through an acyl function. All double bonds in these structures display the cis geometrical configuration due to desaturase enzymatic activity and they are known to be involved in the peroxidation process, whereas the reactivity through cis-trans double bond isomerization has not yet been identified. Using 1-(1Z-octadecenyl)-2-arachidonoyl-sn-glycero-3-phosphocholine (C18 plasm-20:4 PC) as a representative molecule, we showed that the cis-trans isomerization can occur at both plasmalogen unsaturated moieties, and the product has characteristic analytical signatures useful for omics applications. Using plasmalogen-containing liposomes and red blood cell (RBC) ghosts under biomimetic Fenton-like conditions, in the presence or absence of thiols, peroxidation, and isomerization processes were found to occur with different reaction outcomes due to the particular liposome compositions. These results allow gaining a full scenario of plasmalogen reactivity under free radical conditions. Moreover, clarification of the plasmalogen reactivity under acidic and alkaline conditions was carried out, identifying the best protocol for RBC membrane fatty acid analysis due to their plasmalogen content of 15–20%. These results are important for lipidomic applications and for achieving a full scenario of radical stress in living organisms.

Polyfunctional macrocycles have been studied extensively for their responsive properties. In this study, three electron- deficient novel azo-containing crown ethers were successfully synthesized. The synthesized macrocycles were characterized and their photophysical along with photoisomerization were studied. The results were compared with their acyclic derivative. It was found that these compounds did not convert to their cis-isomer completely due to the rigidity of the cycles. The fluorescence studies revealed that the macrocycles were fluorescent while the acyclic azo derivative was found not to show fluorescence. The macrocycles were also tested for alkali metal cation-binding abilities. It was shown with DFT calculations that not only the ring size of macrocycles but also the conformation places an important role in recognition of these cations. [ABSTRACT FROM AUTHOR]

Trimethylamine N-Oxide (TMAO) is an important metabolite, which is derived from choline, betaine, and carnitine in various organisms. In humans, it is synthesized through gut microbiota and is abundantly found in serum and cerebrospinal fluid (CSF). Although TMAO is a stress protectant especially in urea-rich organisms, it is an atherogenic agent in humans and is associated with various diseases. Studies have also unveiled its exceptional role in protein folding and restoration of mutant protein functions. However, most of these data were obtained from studies carried on fast-folding proteins. In the present study, we have investigated the effect of TMAO on the folding behavior of a well-characterized protein with slow folding kinetics, carbonic anhydrase (CA). We discovered that TMAO inhibits the folding of this protein via its effect on proline cis–trans isomerization. Furthermore, TMAO is capable of inducing cell cycle arrest. This study highlights the potential role of TMAO in developing proteopathies and associated diseases. [ABSTRACT FROM AUTHOR]

Cis-trans isomerization of the peptide bond prior to proline is an intrinsically slow process but plays an essential role in protein folding. In vivo cis-trans isomerization reaction is catalyzed by Peptidyl-prolyl isomerase (PPIases), a category of proteins widely distributed among all the three domains of life. The present study is majorly focused on the distribution of different types of PPIases in the archaeal domain. All the three hitherto known families of PPIases (namely FKBP, Cyclophilin and parvulin) were studied to identify the evolutionary conservation across the phylum archaea. The basic function of cyclophilin, FKBP and parvulin has been conserved whereas the sequence alignment suggested variations in each clade. The conserved residues within the predicted motif of each family are unique. The available protein structures of different PPIase across various domains were aligned to ascertain the structural variation in the catalytic site. The structural alignment of native PPIase proteins among various groups suggested that the apo-protein may have variable conformations but when bound to their specific inhibitors, they attain similar active site configuration. This is the first study of its kind which explores the distribution of archaeal PPIases, along with detailed structural and functional analysis of each type of PPIase found in archaea.

Here, we report on the fabrication of light-switchable and light-responsive membranes based on graphene oxide (GO) modified with azobenzene compounds. Azobenzene and para-aminoazobenzene were grafted onto graphene oxide layers by covalent attachment/condensation reaction prior to the membranes’ assembly. The modification of GO was proven by the UV-vis, IR, Raman and photoelectron spectroscopy. The membrane’s light-responsive properties were investigated in relation to the permeation of permanent gases and water vapors under UV and IR irradiation. Light irradiation does not influence the permeance of permanent gases, while it strongly affected that of water vapors. Both switching and irradiation-induced water permeance variation is described, and they were attributed to over 20% of the initial permeance. According to in situ diffraction studies, the effect is ascribed to the change to the interlayer distance between the graphene oxide nanoflakes, which increases under UV irradiation to ~1.5 nm while it decreases under IR irradiation to ~0.9 nm at 100% RH. The last part occurs due to the isomerization of grafted azobenzene under UV irradiation, pushing apart the GO layers, as confirmed by semi-empirical modelling.

Photolabile protecting groups offer synthetic routes with facile deprotection by photolysis, providing higher yields with less workup. Protecting groups producing only gaseous byproducts upon removal are particularly desirable as sustainable reagents. Cheletropic reactions provide just this combination of photocleavable groups with gaseous byproducts. However, only few protecting groups for cheletropic reactions have been described and little is known about their photochemistry and associated stereochemistry. Here we show that the sulfolene protecting group, used for diene protection and functionalization, can be photochemically removed. First, using TD‐DFT, we conclude that the photochemical ring‐opening occurs conrotatorily in a concerted process, consistent with the Woodward‐Hoffmann rules. Experimentally, we demonstrate that this process can be photoinitiated by radiation between 180 and 300 nm and confirm the proposed stereochemistry in solution. Using time‐resolved photoelectron spectroscopy, we determine that the first steps in the photochemical ring‐opening of sulfolene occur on ultrafast timescales (≤84 fs), consistent with a fully concerted process. Our findings expand applications of the sulfolene protecting group and promise an easy strategy for control of cis‐trans isomerization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Seven undescribed compounds were identified from Aglaia odorata. • The cis – trans isomerization equilibrium of tertiary amides was conducted. • Compounds 2–6, 8, 10, and 12 inhibited NO production at the nanomolar concentration. • The anti-neuroinflammatory effects of rocaglaol (12) were investigated in vivo. Fifty compounds including seven undescribed (1 , 13 , 18 – 20 , 30 , 31) and forty-three known (2 – 12 , 14 – 17 , 21 – 29 , 32 – 50) ones were isolated from the extract of the twigs and leaves of Aglaia odorata with anti-neuroinflammatory activities. Their structures were determined by a combination of spectral analysis and calculated spectra (ECD and NMR). Among them, compounds 13 – 25 were found to possess tertiary amide bonds, with compounds 16 , 17 , and 19 – 21 existing detectable cis / trans mixtures in 1H NMR spectrum measured in CDCl 3. Specifically, the analysis of the cis – trans isomerization equilibrium of tertiary amides in compounds 19 – 24 was conducted using NMR spectroscopy and quantum chemical calculations. Bioactivity evaluation showed that the cyclopenta[ b ]benzofuran derivatives (2 – 6 , 8 , 10 , 12) could inhibit nitric oxide production at the nanomolar concentration (IC 50 values ranging from 2 to 100 nM) in lipopolysaccharide-induced BV-2 cells, which were 413–20670 times greater than that of the positive drug (minocycline, IC 50 = 41.34 μM). The cyclopenta[ bc ]benzopyran derivatives (13 – 16), diterpenoids (30 – 35), lignan (40), and flavonoids (45 , 47 , 49 , 50) also demonstrated significant inhibitory activities with IC 50 values ranging from 1.74 to 38.44 μM. Furthermore, the in vivo anti-neuroinflammatory effect of rocaglaol (12) was evaluated via immunofluorescence, qRT-PCR, and western blot assays in the LPS-treated mice model. The results showed that rocaglaol (12) attenuated the activation of microglia and decreased the mRNA expression of iNOS, TNF- α , IL-1 β , and IL-6 in the cortex and hippocampus of mice. The mechanistic study suggested that rocaglaol might inhibit the activation of the NF-κB signaling pathway to relieve the neuroinflammatory response. [ABSTRACT FROM AUTHOR]

Recently, it has been shown that the thermochemical cis→trans isomerization of azobenzenes is accelerated by a factor of more than 1000 by electronic coupling to a gold surface via a conjugated system with 11 bonds and a distance of 14 Å. The corresponding molecular architecture consists of a platform (triazatriangulenium (TATA)) which adsorbs on the gold surface, with an acetylene spacer standing upright, like a post in the middle of the platform and the azobenzene unit mounted on top. The rate acceleration is due to a very peculiar thermal singlet–triplet–singlet mechanism mediated by bulk gold. To investigate this mechanism further and to examine scope and limitation of the “spin-switch catalysis” we now prepared analogous diazocine systems. Diazocines, in contrast to azobenzenes, are stable in the cis-configuration. Upon irradiation with light of 405 nm the cis-configuration isomerizes to the trans-form, which slowly returns back to the stable cis-isomer. To investigate the thermal trans→cis isomerization as a function of the conjugation to the metal surface, we connected the acetylene spacer in meta (weak conjugation) and in para (strong conjugation) position. Both isomers form ordered monolayers on Au(111) surfaces.

The post-synaptic density protein 95 (PSD-95) plays a central role in excitatory synapse development and synaptic plasticity. Phosphorylation of the N-terminus of PSD-95 at threonine 19 (T19) and serine 25 (S25) decreases PSD-95 stability at synapses; however, a molecular mechanism linking PSD-95 phosphorylation to altered synaptic stability is lacking. Here, we show that phosphorylation of T19/S25 recruits the phosphorylation-dependent peptidyl-prolyl cis–trans isomerase (Pin1) and reduces the palmitoylation of Cysteine 3 and Cysteine 5 in PSD-95. This reduction in PSD-95 palmitoylation accounts for the observed loss in the number of dendritic PSD-95 clusters, the increased AMPAR mobility, and the decreased number of functional excitatory synapses. We find the effects of Pin1 overexpression were all rescued by manipulations aimed at increasing the levels of PSD-95 palmitoylation. Therefore, Pin1 is a key signaling molecule that regulates the stability of excitatory synapses and may participate in the destabilization of PSD-95 following the induction of synaptic plasticity.

Phosphorylation-dependent peptidyl-prolyl cis-trans isomerization plays key roles in cell cycle progression, the pathogenesis of cancer, and age-related neurodegeneration. Most of our knowledge about the role of phosphorylation-dependent peptidyl-prolyl cis-trans isomerization and the enzyme catalyzing this reaction, the peptidyl-prolyl isomerase (Pin1), is largely limited to proteins not present in neurons. Only a handful of examples have shown that phosphorylation-dependent peptidyl-prolyl cis-trans isomerization, Pin1 binding, or Pin1-mediated peptidyl-prolyl cis-trans isomerization regulate proteins present at excitatory synapses. In this work, I confirm previous findings showing that Pin1 binds postsynaptic density protein-95 (PSD-95) and identify an alternative binding site in the phosphorylated N-terminus of the PSD-95. Pin1 associates via its WW domain with phosphorylated threonine (T19) and serine (S25) in the N-terminus domain of PSD-95 and this association alters the local conformation of PSD-95. Most importantly, I show that proline-directed phosphorylation of the N-terminus domain of PSD-95 alters the local conformation of this region. Therefore, proline-directed phosphorylation of the N-terminus of PSD-95, Pin1 association, and peptidyl-prolyl cis-trans isomerization may all play a role in excitatory synaptic function and synapse development.

Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) is an evolutionally conserved and unique enzyme that specifically catalyzes the cis-trans isomerization of phosphorylated serine/threonine-proline (pSer/Thr-Pro) motif and, subsequently, induces the conformational change of its substrates. Mounting evidence has demonstrated that Pin1 is widely overexpressed and/or overactivated in cancer, exerting a critical influence on tumor initiation and progression via regulation of the biological activity, protein degradation, or nucleus-cytoplasmic distribution of its substrates. Moreover, Pin1 participates in the cancer hallmarks through activating some oncogenes and growth enhancers, or inactivating some tumor suppressors and growth inhibitors, suggesting that Pin1 could be an attractive target for cancer therapy. In this review, we summarize the findings on the dysregulation, mechanisms, and biological functions of Pin1 in cancer cells, and also discuss the significance and potential applications of Pin1 dysregulation in human cancer.

The cis-trans isomerization of a metal-centred molecular gear was investigated by density functional theory (DFT). The gear uses Pt(II) as stator, the azaphospha-triptycene as rotor, and the ligand introduces chlorine atoms. Under the conditions driven by light and heat, the gear can undergo switchable motion through the meshing and disengaging of two rotators. To be specific, the geometry optimization of cis-[PtCl2(Tp)2] and trans-[PtCl2(Tp)2] isomers were performed via the M06-2X functional in conjunction with def2-SVP basis set. Through rotating around the Pt-P single bond, the potential energy surface was scanned to explore the different rotational modes of the cis- and trans- isomers. In addition, time-dependent density functional theory (TD-DFT) was used to calculate molecular excitation energy and ultraviolet absorption properties. The reaction transition state of cis→trans isomerization was calculated to study the isomerization process and the motion correlation between the two rotors during rotation. [ABSTRACT FROM AUTHOR]

Phosphorylation-dependent peptidyl-prolyl cis-trans isomerization plays key roles in cell cycle progression, the pathogenesis of cancer, and age-related neurodegeneration. Most of our knowledge about the role of phosphorylation-dependent peptidyl-prolyl cis-trans isomerization and the enzyme catalyzing this reaction, the peptidyl-prolyl isomerase (Pin1), is largely limited to proteins not present in neurons. Only a handful of examples have shown that phosphorylation-dependent peptidyl-prolyl cis-trans isomerization, Pin1 binding, or Pin1-mediated peptidyl-prolyl cis-trans isomerization regulate proteins present at excitatory synapses. In this work, I confirm previous findings showing that Pin1 binds postsynaptic density protein-95 (PSD-95) and identify an alternative binding site in the phosphorylated N-terminus of the PSD-95. Pin1 associates via its WW domain with phosphorylated threonine (T19) and serine (S25) in the N-terminus domain of PSD-95 and this association alters the local conformation of PSD-95. Most importantly, I show that proline-directed phosphorylation of the N-terminus domain of PSD-95 alters the local conformation of this region. Therefore, proline-directed phosphorylation of the N-terminus of PSD-95, Pin1 association, and peptidyl-prolyl cis-trans isomerization may all play a role in excitatory synaptic function and synapse development. [ABSTRACT FROM AUTHOR]

The post-synaptic density protein 95 (PSD-95) plays a central role in excitatory synapse development and synaptic plasticity. Phosphorylation of the N-terminus of PSD-95 at threonine 19 (T19) and serine 25 (S25) decreases PSD-95 stability at synapses; however, a molecular mechanism linking PSD-95 phosphorylation to altered synaptic stability is lacking. Here, we show that phosphorylation of T19/S25 recruits the phosphorylation-dependent peptidyl-prolyl cis–trans isomerase (Pin1) and reduces the palmitoylation of Cysteine 3 and Cysteine 5 in PSD-95. This reduction in PSD-95 palmitoylation accounts for the observed loss in the number of dendritic PSD-95 clusters, the increased AMPAR mobility, and the decreased number of functional excitatory synapses. We find the effects of Pin1 overexpression were all rescued by manipulations aimed at increasing the levels of PSD-95 palmitoylation. Therefore, Pin1 is a key signaling molecule that regulates the stability of excitatory synapses and may participate in the destabilization of PSD-95 following the induction of synaptic plasticity. [ABSTRACT FROM AUTHOR]

Self-healing materials are considered intelligent materials capable of recovering their original shapes from damaged or distorted forms after exposure to specific stimuli, such as chemicals, heat, moisture, or light. The utilization of thermoreversible crosslinks in polymer networks has garnered increasing interest as a method to create such materials. In these polymers, damage can be repaired simply by heating them above a gel-liquid transition temperature. Upon cooling, the material regains its previous cross-linked properties. However, finding alternative external stimuli other than heat presents an intriguing challenge. Among the various possibilities, light is the preferred choice due to its potential for remote and spatially-controlled activation. Additionally, the process can be easily paused and resumed by turning the excitation light on and off. Furthermore, the photo-switching of the glass transition temperature (Tg) in azobenzene-containing polymers induces reversible transitions from a solid to a liquid state. These reversible trans -to- cis transitions are triggered by UV and visible light irradiation. This phenomenon offers a novel approach to designing healable polymers and allows for precise control over the mechanical properties of polymers with spatio-temporal resolution. The main objective of this study is to investigate the feasibility of using light as a self-healing trigger in a recyclable polymer based on physically cross-linked epoxy/amine formulations. To achieve this goal, the matrix was modified with 4-phenylazophenol (PAP), which forms homogeneous blends with the polymer through hydrogen bond interactions. Films were prepared and characterized using various experimental techniques. Polymerization kinetics of samples with and without PAP was determined using FTIR, which was also employed for characterizing the final materials. Tg of the resulting products was measured using DSC, revealing a decrease in its value for PAP-modified samples. The transition from a solid to a liquid state during UV light irradiation was observed using rheometric analysis. The reversible photoisomerization behaviour of epoxy/amine/PAP was investigated using UV–visible spectroscopy in films prepared by spin-coating THF solutions. The ability of the material to self-heal at room temperature using light as a remote source was confirmed through TOM (Transmission Optical Microscopy) observations and quantified by profilometric measurements. In addition, surface mechanical properties were evaluated in order to determine the effect of the incorporation of the PAP, and the ability of the repaired material to recover its properties. Promising findings indicate that this recyclable polymer holds significant potential for multiple applications where its self-healing ability will be of great importance. [Display omitted] • Inclusion of PAP in DGEBA-DA polymer permitted the successful preparation of a photoresponsive azobenzene-modified material. • A marked acceleration in the polymerization rate of the PAP-modified sample with respect to the neat polymer is observed. • Photoswitching of the glass transition temperature (Tg) of azobenzene-containing polymers induces reversible solid-to-liquid transitions. • Self-healing can be induced a room temperature in the material, using a remote source as is light. [ABSTRACT FROM AUTHOR]

Alkene dipeptide isosteres (ADIs) are promising surrogates of peptide bonds that enhance the bioactive peptide resistance to enzymatic hydrolysis in medicinal chemistry. In this study, we investigated the substitution effects of an ADI on the energy barrier of cis-trans isomerization in the acetyl proline methyl ester (Ac-Pro-OMe) model. The (E)-alkene-type proline analog, which favors a cis-amide conformation, exhibits a lower rotational barrier than native Ac-Pro-OMe. A van't Hoff analysis suggests that the energy barrier is primarily reduced by enthalpic repulsion. It was concluded that although carbon-carbon double bonds and pyrrolidine rings individually increase the rigidity of the incorporation site, their combination can provide structural flexibility and disrupt bioactive conformations. This work provides new insights into ADI-based drug design.

A series of ruthenium hydride compounds containing substituted bidentate pyrrole‐imine ligands were synthesized and characterized. Reacting RuHCl(CO)(PPh3)3 with one equivalent of [C4H3NH(2‐CH=NR)] in ethanol in the presence of KOH gave compounds {RuH(CO)(PPh3)2[C4H3N(2‐CH=NR)]} where trans‐Py‐Ru‐H 1, R = CH2CH2C6H9; cis‐Py‐Ru‐H 2, R = Ph‐2‐Me; and cis‐Py‐Ru‐H 3, R = C6H11. Heating trans‐Py‐Ru‐H 1 in toluene at 70°C for 12 hr resulted a thermal conversion of the trans‐Py‐Ru‐H 1 into its cis form, {RuH(CO)(PPh3)2[C4H3N(2‐CH=NCH2CH2C6H9)]} (cis‐Py‐Ru‐H 1) in very high yield. The 1H NMR spectra of trans‐Py‐Ru‐H 1, cis‐Py‐Ru‐H 2, cis‐Py‐Ru‐H 3, and cis‐Py‐Ru‐H 1 all show a typical triplet at ca. δ–11 for the hydride. The trans and cis form indicate the relative positions of pyrrole ring and hydride. The geometries of trans‐Py‐Ru‐H 1, cis‐Py‐Ru‐H 1, and cis‐Py‐Ru‐H 3 are relatively similar showing typical octahedral geometries with two PPh3 fragments arranged in trans positions. [ABSTRACT FROM AUTHOR]

Peptidyl Prolyl Isomerases (PPIases) accelerate cis–trans isomerization of prolyl peptide bonds. In rice, the PPIase LRT2 is essential for lateral root initiation. LRT2 displays in vitro isomerization of a highly conserved W–P peptide bond (104W–P105) in the natural substrate OsIAA11. OsIAA11 is a transcription repressor that, in response to the plant hormone auxin, is targeted to ubiquitin-mediated proteasomal degradation via specific recognition of the cis isomer of its 104W–P105 peptide bond. OsIAA11 controls transcription of specific genes, including its own, that are required for lateral root development. This auxin-responsive negative feedback circuit governs patterning and development of lateral roots along the primary root. The ability to tune LRT2 activity via mutagenesis is crucial for understanding and modeling the role of this bimodal switch in the auxin circuit and lateral root development. We present characterization of the thermal stability and isomerization rates of several LRT2 mutants acting on the OsIAA11 substrate. The thermally stable mutants display activities lower than that of wild-type (WT) LRT2. These include binding diminished but catalytically active P125K, binding incompetent W128A, and binding capable but catalytically incompetent H133Q mutations. Additionally, LRT2 homologs hCypA from human, TaCypA from Triticum aestivum (wheat) and PPIB from E. coli were shown to have 110, 50 and 60% of WT LRT2 activity on the OsIAA11 substrate. These studies identify several thermally stable LRT2 mutants with altered activities that will be useful for establishing relationships between cis–trans isomerization, auxin circuit dynamics, and lateral root development in rice. [ABSTRACT FROM AUTHOR]

Abstract Biodiesel is a renewable fuel source comprising of fatty acid methyl esters (FAMEs). However, biodiesel (FAMEs) is susceptible to autoxidation. Therefore, structural modification of FAMEs through decreasing the number of double bonds (e.g., hydrogenation) or trans isomerization of original double bonds in the cis configuration, could improve the oxidative stability of FAMEs. In this work, the trans isomerization of carbon-carbon double bonds in unsaturated FAMEs obtained from edible oils has been successfully achieved using simple and safe p -toluenesulfinic acid as catalyst. And the effects of reaction time, temperature, catalyst loading, amount of water and antioxidants on the trans isomerization were investigated systematically. The results indicated that the amount of water (0–20 wt%) and antioxidants (<200 ppm) had no significant effect on the trans isomerization of unsaturated FAMEs. And the final product (trans FAMEs) was characterized by both GC and FT-IR. The conversion of trans double bonds of the isomerized lard FAMEs could reach 79.9% after heating at 100 °C for only 30 min without changing both the double bonds location and unsaturation degree. In addition, this convenient method was successfully applied in a variety of FAMEs prepared from different vegetable oils (e.g., safflower seed oil, camellia seed oil, high oleic sunflower oil and soybean oil) and approximately 80.0% selectivity of trans isomerization for all FAMEs were obtained. The present study showed a promising method to provide trans -FAMEs products for producing biodiesels with better oxidative stability (for high oleic FAMEs) and without adding of antioxidants. [ABSTRACT FROM AUTHOR]

Calcineurin is an essential calcium‐activated serine/threonine phosphatase. The six NMR‐observable methionine methyl groups in the catalytic domain of human calcineurin Aα (CNA) were assigned and used as reporters of the presence of potential cis‐trans isomers in solution. Proline 84 is found in the cis conformation in most calcineurin X‐ray structures, and proline 309, which is part of a highly conserved motif in phosphoprotein phosphatases, was modeled with a cis peptide bond in one of the two molecules present in the asymmetric unit of CNA. We mutated each of the two prolines to alanine to force the trans conformation. Solution NMR shows that the P84A CNA mutant exists in two forms, compatible with cis‐trans isomers, while the P309A mutant is predominantly in the trans conformation. Database: PDB depositions mentioned PDB 5C1V and 2JOG. 13C‐enriched methyl groups of methionine residues in calcineurin can be selectively observed by NMR and are sensitive probes of their environment. The P84A calcineurin mutant, introduced to enforce a trans amide bond, shows a duplicated signal for methionine 191, compatible with the partial conservation of the natural cis conformation in the alanine mutant. [ABSTRACT FROM AUTHOR]

The energy barrier for cis-to-trans isomerization is among the key parameters for photoswitchable molecules such as azobenzene. Recently, we introduced a well-defined model system based on thin films of crystalline, nanoporous metal-organic frameworks, MOFs. The system enables the precise investigation of the thermal cis-to-trans relaxation of virtually isolated azobenzene pendant groups by means of infrared spectroscopy in vacuum. Here, this approach is extended by using localized surface plasmon resonance spectroscopy. This simple and relatively inexpensive setup enables the investigation of the thermal cis-to-trans isomerization in different environments, here in argon gas or in liquid butanediol. The energy barrier for the cis-to-trans-relaxation in argon, 1.17±0.20eV, is identical to the barrier in vacuum, while the energy barrier in liquid butanediol is slightly larger, 1.26±0.15eV. [ABSTRACT FROM AUTHOR]

Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) specifically binds and isomerizes the phosphorylated serine/threonine-proline (pSer/Thr-Pro) motif, which leads to changes in protein conformation and function. Pin1 is widely overexpressed in cancers and plays an important role in tumorigenesis. Mounting evidence has revealed that targeting Pin1 is a potential therapeutic approach for various cancers by inhibiting cell proliferation, reducing metastasis, and maintaining genome stability. In this review, we summarize the underlying mechanisms of Pin1-mediated upregulation of oncogenes and downregulation of tumor suppressors in cancer development. Furthermore, we also discuss the multiple roles of Pin1 in cancer hallmarks and examine Pin1 as a desirable pharmaceutical target for cancer therapy. We also summarize the recent progress of Pin1-targeted small-molecule compounds for anticancer activity.

Cyclosporin is an 11-amino acid cyclic peptide with pharmacologically valuable properties which has a variety of actual and potential applications. Its activity relies on the cell membrane permeability which, in turn, depends on the structure of cyclosporin and its ability to change the conformation. In this work, conformational exchange processes occurring in cyclosporin C were studied using one- and two-dimensional nuclear magnetic resonance spectroscopy. The free energy barrier separating two major conformers observed in polar solution (acetonitrile) was found to be 77 ± 2 kJ/mol. Less populated conformation states are also present in the solution, which agrees with the ease of formation of multiple forms revealed by MD simulations of cyclosporin C. • Cyclosporin variant C in a polar solvent (acetonitrile) was studied by NMR. • Two distinct conformers were found to prevail in the solution. • Parameters of the chemical exchange between two main conformers were obtained. [ABSTRACT FROM AUTHOR]

To achieve structurally rigid pentamethine cyanine dyes with worthful photophysical properties for biological applications, five series of symmetrical meso-substituted bis(benzothiazolium) pentamethine cyanine dyes were synthesized via an efficient and simple triethylamine-promoted approach involved condensation of various N -substituted benzothiazolium salts with preformed β-substituted vinamidinium salts in high yield and purity without the nontrivial chromatographic separation. The chemical structures of the synthesized dyes were confirmed by HPLC-MS, 1H NMR, 13C NMR, and FTIR techniques. The photophysical properties of the new dyes were investigated in methanol, recognizing that the dyes demonstrate excellent fluorescent brightness. The solutions of the dyes exhibited maximum absorption and fluorescence emission in the range of 600–650 nm with high molar absorption coefficients (around 1-3 × 105 dm3 mol−1 cm−1) and 610–670 nm with remarkable fluorescence quantum yield, respectively. In addition, the photostabilities and photoluminescent stabilities of the synthetic dyes were studied in methanol, revealing their outstanding stability and resistance to photodecomposition. Examining the photochemical behavior (UV light) of the dyes in organic solvents with different polarities verified the main role of various meso substitutions on the rigidity of molecular structures and cis -trans isomerization to improve the photophysical properties. The presence of the pyridinium substituent rings into the polymethine chain makes the dyes rigid and more water-soluble because of their bulky form and positive charge, respectively. [Display omitted] • Rigid meso-substituted pentamethine cyanine dyes were synthesized, with worth photophysical properties and water solubility. • The efficient synthetic route involved condensation of benzothiazolium salts with vinamidinium salts in the presence of Et3N. • The new pyridinium substituent dyes in methanol absorb/emission at 590-660 nm and 620-670 nm, with high brightness. • New pyridinium dyes showed high stability and resistance to photodecomposition when studied for PL/Photo stabilities in MeOH. • UV test in various solvents showed meso substitutions' impact on molecular rigidity, isomerization, and optical properties. [ABSTRACT FROM AUTHOR]

Free-radical-mediated processes, such as peroxidation, isomerization and hydrogenation affecting fatty acid integrity and biological functions, have a trans-disciplinary relevance. Cardiolipins (CL, (1,3-diphosphatidyl-sn-glycerol)) and tetra-linoleoyl-CL are complex phospholipids, exclusively present in the Inner Mitochondrial Membrane (IMM) lipids, where they maintain membrane integrity and regulate enzyme functionalities. Peroxidation pathways and fatty acid remodeling are known causes of mitochondrial disfunctions and pathologies, including cancer. Free-radical-mediated isomerization with the change of the cis CL into geometrical trans isomers is an unknown process with possible consequences on the supramolecular membrane lipid organization. Here, the formation of mono-trans CL (MT-CL) and other trans CL isomers (T-CL) is reported using CL from bovine heart mitochondria and thiyl radicals generated by UV-photolysis from 2-mercaptoethanol. Analytical approaches for CL isomer separation and identification via 1H/13C NMR are provided, together with the chemical study of CL derivatization to fatty acid methyl esters (FAME), useful for lipidomics and metabolomics research. Kinetics information of the radical chain isomerization process was obtained using γ-irradiation conditions. The CL isomerization affected the structural organization of membranes, as tested by the reduction in unilamellar liposome diameter, and accompanied the well-known process of oxidative consumption induced by Fenton reagents. These results highlight a potential new molecular modification pathway of mitochondrial lipids with wide applications to membrane functions and biological consequences.

Trans fats, unsaturated fatty acids with at least one double bond in the trans configuration, have received a great amount of attention in the field of oleo chemistry and safety. In this work, the cis-trans isomerization of unsaturated fatty acids in edible oils has been successfully developed using simple and cheap p-toluenesulfinic acid as catalyst. The effects of reaction time, temperature, catalyst loading, and the amounts of water and antioxidants on the cis-trans isomerization have been systematically investigated. The results indicate that the amount of water (0–20 wt %) and antioxidants (0–200 mg/kg) had no significant effect on this cis-trans isomerization of unsaturated fatty acids in edible oils. The final products (trans fats) from the cis-trans isomerization reaction were characterized by both GC and React IR. The yield of trans double bonds from the isomerized fat can reach 79.6% after heating at 100 oC for 90 min without changing either the location of the double bonds or the degree of unsaturation. In addition, this convenient method has been applied to various vegetable oils (e.g., olive oil, camellia seed oil, corn oil, sesame oil, sunflower oil and soybean oil) and nearly 80.0% yields of TFA were generated, which shows a promising method to provide trans-fat products for research related to oleo and food chemistry.