Parent Skeleton Research Articles

Asymmetric structural strategy enables efficient MR-TADF emitters with low efficiency roll-off and doping-concentration insensitivity

Multiple resonance (MR) thermally activated delayed fluorescence (TADF) materials containing B/N hold great promise for application in efficient narrowband organic light-emitting diodes (OLEDs). However, overcoming the challenges of reducing efficiency roll-off while minimizing aggregation-caused quenching to achieve highly efficient, low efficiency roll-off and doping concentration-insensitive MR-TADF emitters remains a formidable task. To this end, we designed two asymmetric B/N MR-TADF emitters by integrating a twisted heptagonal tribenzo[b,d,f]azepine (TBA) unit with a bulky substituted carbazole unit. The new compounds inherit the excellent properties of both parent skeletons. BN-TPCzTBA achieves a high photoluminescence quantum yield of up to 98.6 % and attains a maximum external quantum efficiency (EQE) of up to 36.8 % without the use of a sensitizer. The EQE remains at 22.8 % at a high brightness of 1000 cd m−2, demonstrating a low efficiency roll-off (37 %). Importantly, the twisted, bulky, and asymmetrical structure of these molecules allows them to sustain over 30 % of the EQEmax with a consistent full width at half maximum (FWHM) even at doping concentrations of up to 30 %. This thereby presents an innovative molecular design strategy that addresses critical issues in MR-TADF material engineering, combining low efficiency roll-off with doping concentration insensitivity.

Phosphine oxide balanced charge transfer hybridization in multi-resonance emitters: towards ∼40% external quantum efficiency and preserved color purity

Introducing long-range charge transfer (LRCT) effect to optimize thermally activated delayed fluorescence (TADF) properties without reducing color purities is one of the key challenges for developing high-performance multi-resonance (MR) emitters. Herein, we construct two B,N-doped polycyclic emitters of MR-Acceptor (A) type DPPO-BN and the MR-π-A type TPPO-BN through incorporating P=O groups into BCz-BN skeleton. Compared to the parent skeleton, the insulating feature of P=O averts the color purity reduction. However, the strongest LRCT markedly enhances TADF properties of DPPO-BN, making its rate constants of prompt and delayed fluorescence, singlet radiation and reverse intersystem crossing (RISC) doubled. But, intermolecular charge transfer of DPPO-BN is simultaneously strengthened. In contrast, TPPO-BN reveals the balanced MR and LRCT and enhanced vibrational coupling, leading to ∼100% RISC efficiency and two orders of magnitude decreased nonradiative rate constants. As consequence, TPPO-BN-based devices realized the state-of-the-art external quantum efficiency up to 39.8% among nonsensitized MR diodes to present.

Debromination of novel brominated flame retardants using Zn-based additives: A viable thermochemical approach in the mitigation of toxic effects during e-waste recycling

Brominated flame retardants (BFRs) are bromine-bearing additives added to the polymeric fraction in various applications to impede fire ignition. The Stockholm Convention and various other legislations abolished legacy BFRs usage and hence, the so-called novel BFRs (NBFRs) were introduced into the market. Recent studies spotlighted their existence in household dust, aquifers and aquatic/aerial species. Co-pyrolysis of BFRs with metal oxides has emerged as a potent chemical recycling approach that produces a bromine-free stream of hydrocarbon. Herein, we investigate the debromination of two prominent two NBFRs; namely tetrabromobisphenol A 2,3-dibromopropyl ether (TD) and tetrabromobisphenol A diallyl ether (TAE) through their co-pyrolysis with zinc oxide (ZnO) and franklinite (ZnFe2O4). Most of the zinc content in electrical arc furnace dust (EAFD) exists in the form of these two metal oxides. Conversion of these metal oxides into their respective bromides could also assist in the selective extraction of the valuable zinc content in EAFD. The debromination potential of both oxides was unveiled via a multitude of characterization studies to analyze products (char, gas and condensates). The thermogravimetric analysis suggested a pyrolytic run up to 500 °C and the TAE treatment with ZnO produced only a trivial amount of brominated compounds (relative area, 0.83%). Phenol was the sole common compound in condensable products; potentially formed by the β-scission debromination reaction from the parental molecular skeleton. Inorganic compounds and methane were the major constituents in the gaseous products. The pyrochar analyses confirmed the presence of metal bromides retained in the residue, averting the bromine release into the atmosphere. The ion chromatography analysis portrayed <8% of HBr gas release into the atmosphere upon pyrolysis with ZnO. The ZnO dominance herein envisaged further probes into other spinel ferrites in combating brominated polymers.

AnnoSM: An Automated Annotation Tool for Determining the Substituent Modes on the Parent Skeleton Based on a Characteristic MS/MS Fragment Ion Library.

Mass spectrometry (MS) is a powerful technology for the structural elucidation of known or unknown small molecules. However, the accuracy of MS-based structure annotation is still limited due to the presence of numerous isomers in complex matrices. There are still challenges in automatically interpreting the fine structure of molecules, such as the types and positions of substituents (substituent modes, SMs) in the structure. In this study, we employed flavones, flavonols, and isoflavones as examples to develop an automated annotation method for identifying the SMs on the parent molecular skeleton based on a characteristic MS/MS fragment ion library. Importantly, user-friendly software AnnoSM was built for the convenience of researchers with limited computational backgrounds. It achieved 76.87% top-1 accuracy on the 148 authentic standards. Among them, 22 sets of flavonoid isomers were successfully differentiated. Moreover, the developed method was successfully applied to complex matrices. One such example is the extract of Ginkgo biloba L. (EGB), in which 331 possible flavonoids with SM candidates were annotated. Among them, 23 flavonoids were verified by authentic standards. The correct SMs of 13 flavonoids were ranked first on the candidate list. In the future, this software can also be extrapolated to other classes of compounds.

Luminescence mechanism analysis of a TADF molecule showing peculiar thermal behavior.

In recent years, much attention has been paid to the development of thermally activated delayed fluorescence (TADF) materials with short delayed-fluorescence lifetimes to improve the device performances of OLEDs. In principle, by reducing the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) overlap, while the energy difference between S1-T1 (ΔEST) and activation energy (Ea) can be reduced, and the reverse intersystem crossing rate constant (kRISC) can be accelerated, a decrease in the radiative rate constant happens, necessitating an advanced molecular design. Furthermore, a molecule based on heptazine as a parent skeleton has recently been found to have a peculiar temperature dependence of luminescence decay, suggesting a negative gap (NG) material. In this report, we show that 9-[1,4]benzoxaborino[2,3,4-kl]phenoxaborine-7-yl-1,3,6,8-tetramethyl-9H-carbazole (TMCz-BO), a donor-acceptor linked TADF molecule with a very short delay lifetime of 750 ns, exhibits a peculiar thermal behavior similar to that of NG materials based on the temperature dependence of its luminescence decay in solution.

Novel mono substituted pyridoimidazoisoquinoliniums via a silver-catalyzed intramolecular cyclization and their applications in cellular imaging.

Cationic heterocycles, an important class of organic compounds soluble in polar solvents, have been gaining attention in the construction of fluorescent probes. This paper reports the quick synthesis of novel pyrido[1',2';2,3]imidazo[5,1-a]isoquinoliniums starting from 2-(2-ethynylphenyl)imidazo[1,2-a]pyridines at room temperature via intramolecular cyclization by employing a catalytic amount of silver trifluoromethanesulfonate in addition to lithium trifluoromethanesulfonate and silica gel as the counter anion source and additive, respectively. The designed pyridoimidazoisoquinoliniums consisted of an imidazo[1,2-a]pyridine fused isoquinolinium. The X-ray diffraction results revealed that pyrido[1',2';2,3]imidazo[5,1-a]isoquinolinium trifluoromethanesulfonate contained considerable planar parent skeletons and interacted by π-π stacking with neighbouring molecules. Furthermore, in a methanol solution the designed 6-phenyl derivative exhibited strong fluorescence in the 420-450 nm region in addition to strong mitochondrial specificity in a cell staining assay.

Deciphering the molecular mechanistic paths describing the chemotherapeutic potential and epigenetic regulation of curcumin in lung cancer: a mini review.

In an uncontrolled inflammatory environment, the complex process of lung carcinogenesis occurs. Lung cancer remains the leading cause of cancer-related mortality worldwide. The average 5-year survival rate is still low despite significant advancements in our knowledge of lung carcinogenesis and the development of innovative therapies in recent decades. Research on adjuvant treatment, lung carcinogenesis pathways, and possible prognostic indicators has to be refocused using an innovative approach. The majority of lung cancers are discovered at an advanced stage when there is little chance of recovery. It has grown in popularity in recent years to supplement already available chemotherapeutic therapies with adjuvant herbal medications, which may lessen toxicity and adverse effects without sacrificing therapeutic efficiency. One such prospective contender is curcumin. In-depth research has been done on curcumin as a multi-target anti-tumor and anti-inflammatory molecule. A pharmacologically active polyphenol produced from turmeric is called curcumin. Over the past few decades, curcumin's therapeutic potential has been thoroughly studied, and data indicate that curcumin may play a part in a variety of biological processes, most notably its potent anticancer activity. Being a pleiotropic chemical, curcumin regulates a variety of molecules that are key players in many cell signaling pathways. It has been shown to stifle transformation, restrain proliferation, and trigger apoptosis. Curcumin can reduce the development of non-small cell LC by downregulating Circular RNA hsa_circ_0007580, which in turn controls the expression of integrin subunit beta 1 by adsorbing miR-384. Nevertheless, despite all these advantages, curcumin's effectiveness is still restricted because of its weak bioavailability, poor absorption within the systemic circulation, and quick removal from the body. In an effort to overcome these constraints, scientists from all around the world are working to develop a synthetic and improved curcuminoid by appropriately altering the parent skeleton structurally. These curcuminoids will simultaneously improve the physicochemical properties and efficacy. This review presents evidence from the most recent clinical trials coupled with the molecular mechanisms of curcumin in LC.

Cage-Space-Partitioned Metal–Organic Frameworks for Efficient Carbon Dioxide Capture and Conversion

Metal–organic frameworks (MOFs) have demonstrated potential for CO2 capture and conversion, which are of great importance to alleviate current global environmental problems. Considering that MOFs with large pores are not conducive to adsorption under atmospheric environments, it is critical to control MOF materials with suitable pore sizes and catalytic sites to facilitate CO2 adsorption and fixation. Based on this, cage space partition (CSP), a new strategy to precisely regulate the pore sizes of MOFs, is proposed herein. The feasibility of the CSP strategy is demonstrated in an extra-large metal–organic cage ([M60(BTC)24], M = Co or Ni, BTC = benzene-1,3,5-tricarboxylate), which connects adjacent small cages ([M12(BTC)12]) to form a parent skeleton. For the first CSP process, four typical pyridine-based triangular ligands (TPT, 2,4,6-tris(4-pyridyl)-1,3,5-triazine) are symmetrically inserted into the M60-cage via open metal sites, which transfer the parent skeleton into a novel CSP-MOF (SNNU-337). Furthermore, two larger tri-pyridine ligands (TPHAP, 2,5,8-tri(40-pyridyl)-1,3,4,6,7,9-hexaazaphenalene) are involved to fulfill the second CSP process through residue open metal sites distributed on the inner cage surface, which lead to another isostructural CSP-MOF material (SNNU-338). Oriented by the continuous π–π interactions, the trapped TPT and TPHAP partitioners are divided into two groups, which finally divided the whole large pore into seven small sections. Benefiting from the two-step CSP process, the low-pressure CO2 adsorption capacity of MOFs is remarkably enhanced. Grand canonical Monte Carlo simulations clearly indicate that the introduction of partition agents successfully regulates the internal aperture of the cage and thus enhances the interactions between the MOF skeleton and CO2 molecules. Moreover, the synergistic effects of CSP in large M60-cages and open metal sites in M12-cages make SNNU-337/338 MOFs excellent catalysts to catalyze CO2 cycloaddition with various epoxides.

Facile Synthesis of Helicene-Containing Arenes for Optical Limiting Devices.

A helicene-containing arene and its linear analogue have been successfully synthesized and characterized, where the single-crystal X-ray diffraction analysis indicates that the former can arrange in an offset packing style with a π-π overlap. The introduction of pentagon-rings into the parent skeletons in the resulting compounds can boost the stability, and such helicene-containing molecule possesses higher solubility in organic solvent than the linear analogue. The structural difference has significantly influenced the optical limiting performance. The former in solution and in doped gel glass presents higher optical limiting response towards 532 nm laser than the latter. This study can enrich the functionalization of helicene, which can possess a positive effect in terms of nonlinear optical property.

Synthesis, Photophysics and Optical Limiting Properties of Functionalized Benzofuran Derivatives

AbstractA series of functionalized benzofuran derivatives (2,3,4) have been strategically synthesized and characterized via NMR spectra and high resolution mass spectrometry. To enhance the solubility in organic common solvents, long alkyl groups were introduced into the parent skeletons in compounds2 b,3 b,4 b. The photophysical properties were examined in a comparative manner. The self‐assembly behaviors were further studied, indicating that the regular nanostructures could be tuned by the change of the ratio of THF and cetyltrimethylammonium bromide (CTAB) aqueous solution. Moreover,3 bpresented nonlinear optical (NLO) response recorded through open‐aperture Z‐scan way. The threshold of3 bwas 2.08 J/cm2, which is lower than that of the state‐of‐the‐art material C60(4.01 J/cm2) under the similar operation condition, implying that such molecule might be promising optical limiting (OL) materials.

Standards-Based UPLC-Q-Exactive Orbitrap MS Systematically Identifies 36 Bioactive Compounds in Ampelopsis grossedentata (Vine Tea)

Ampelopsis grossedentata (vine tea) has been used as a detoxifying beverage in China for centuries. To systematically identify its bioactive compounds, the study adopted standards-based ultra-high-performance liquid chromatography coupled with quadrupole/electrostatic field orbitrap high-resolution mass spectrometry (UPLC-Q-Exactive Orbitrap MS) analysis. The analysis was conducted under a negative ion model and the data were collected using the Xcalibur 4.1 software package. Based on comparisons with authentic standards, 36 bioactive compounds were putatively identified by four parameters: retention time, molecular ion peak, MS/MS profile, and characteristic fragments. These bioactive compounds include two chromones (noreugenin and 3,5,7-trihydroxychromone), 15 flavonoids (S-eriodictyol, S-naringenin, luteolin, ampelopsin, taxifolin, myricetin, quercetin, viscidulin I, kaempferol, myricetin 3-O-galactoside, myricitrin, avicularin, quercitrin, isorhamnetin-3-O-β-D-glucoside, and afzelin), four phenolic acids (gallic acid, 3,4-dihydroxy-5-methoxybenzoic acid, syringic acid, and ellagic acid), five tea polyphenols (epigallocatechin, epigallocatechin gallate, gallocatechin gallate, epicatechin gallate, and catechin gallate), three chalcones (phloridzin, phloretin, and naringenin chalcone), one stilbene (polydatin), two lipids (myristic acid and ethyl stearate), one sugar (D-gluconic acid), one amino acid (L-tryptophan), one triterpenoid (oleanolic acid) and one alkaloid (jervine). Notably, the jervine identification is the first report regarding the occurrence of alkaloid in the plant. Two chromones may be the parent skeleton to biosynthesize the flavonoid in A. grossedentata.

Rhodium catalyzed asymmetric synthesis of Chiraphos derivatives

Herein, we report a highly efficient versatile synthetic route to Chiraphos derivatives through Rh/Ph-bod catalyzed asymmetric addition of aryl boronic acids to phosphinyl dienes. Various substituted phosphinyl dienes, both on the parent skeleton and the phosphine atoms, were well tolerated with this method and provided chiral phosphine oxides in satisfied yield and up to 95% ee. The corresponding Chiraphos derivative displayed an advantage over Chiraphos in the representative Pd-catalyzed asymmetric 1,4-addition reaction.

Fundamental Chemistry of Essential Oils and Volatile Organic Compounds, Methods of Analysis and Authentication.

The current text provides a comprehensive introduction to essential oils, their biosynthesis, naming, analysis, and chemistry. Importantly, this text quickly brings the reader up to a level of competence in the authentication of essential oils and their components. It gives detailed descriptions of enantiomers and other forms of stereoisomers relevant to the study of natural volatiles and essential oils. The text also describes GC-MS work and provides tips on rapid calculation of arithmetic indices, how to interpret suggested names from the NIST mass spectral library, and what additional efforts are required to validate essential oils and defeat sophisticated adulteration tactics. In brief, essential oils are mixtures of volatile organic compounds that were driven out of the raw plant material in distillation, condensed into an oil that is strongly aroma emitting, and collected in a vessel as the top layer (uncommonly bottom layer) of two phase separated liquids: oil and water. Essential oils commonly include components derived from two biosynthetic groups, being terpenes (monoterpenes, sesquiterpenes and their derivatives) and phenylpropanoids (aromatic ring with a propene tail). The current text provides details of how terpenes and phenylpropanoids are further categorised according to their parent skeleton, then recognised by the character of oxidation, which may be from oxygen, nitrogen, or sulphur, or the presence/absence of a double bond. The essential oil’s science niche is an epicentre of individuals from diverse backgrounds, such as aromatherapy, pharmacy, synthetic and analytical chemistry, or the hobbyist. To make the science more accessible to the curious student or researcher, it was necessary to write this fundamentals-level introduction to the chemistry of essential oils (i.e., organic chemistry in the context of essential oils), which is herein presented as a comprehensive and accessible overview. Lastly, the current review constitutes the only resource that highlights common errors and explains in simplistic detail how to correctly interpret GC-MS data then accurately present the respective chemical information to the wider scientific audience. Therefore, detailed study of the contents herein will equip the individual with prerequisite knowledge necessary to effectively analyse an essential oil and make qualified judgement on its authenticity.

Fine-tuning of pore-space-partitioned metal-organic frameworks for efficient C2H2/C2H4 and C2H2/CO2 separation

Acetylene (C2H2) and ethylene (C2H4) both are important chemical raw materials and energy fuel gasses. But the effective removement of trace C2H2 from C2H4 and the purification of C2H2 from carbon dioxide (CO2) are particularly challenging in the petrochemical industry. As a class of porous physical adsorbent, metal-organic frameworks (MOFs) have exhibited great success in separation and purification of light hydrocarbon gas. Herein, we rationally designed four novel MOFs by the strategy of pore space partition (PSP) via introducing triangular tri(pyridin-4-yl)-amine (TPA) into the 1D hexagonal channels of acs-type parent skeleton. By modulating the functional groups of linear dicarboxylate linkers for the parent skeleton, a series of isoreticular PSP-MOFs (SNNU-278−281) were successfully obtained. The synergistic effects of suitable pore size and Lewis basic functional groups make these MOFs ideal C2H2 adsorbents. The gas adsorption experimental results show that all MOFs have excellent C2H2 uptakes. Specially, SNNU-278 demonstrates a high C2H2 uptake of 149.7 cm3/g at 273 K and 1 atm. Meanwhile, SNNU-278−281 MOFs also show extremely great C2H2 separation from CO2 and C2H4. The optimized SNNU-281 with high-density hydroxy groups exhibits extraordinary C2H2/CO2 and C2H2/C2H4 dynamic breakthrough interval times up to 31 min/g and 17 min/g under 298 K and 1 bar.

Phyto-Carbazole Alkaloids from the Rutaceae Family as Potential Protective Agents against Neurodegenerative Diseases.

Plant-derived (phyto) carbazole alkaloids are an important class of compounds, presented in the family of Rutaceae (Genera Murraya, Clausena, Glycosmis, Micromelum and Zanthoxylum). Due to several significant biological activities, such as antitumor, antibacterial, antiviral, antidiabetic, anti-HIV and neuroprotective activities of the parent skeleton (3-methylcarbazole), carbazole alkaloids are recognized as an important class of potential therapeutic agents. Neurodegenerative diseases (NDs) may exhibit a vast range of conditions, affecting neurons primarily and leading ultimately to the progressive losses of normal motor and cognitive functions. The main pathophysiological indicators of NDs comprise increasing atypical protein folding, oxidative stresses, mitochondrial dysfunctions, deranged neurotransmissions and neuronal losses. Phyto-carbazole alkaloids can be investigated for exerting multitarget approaches to ameliorating NDs. This review presents a comprehensive evaluation of the available scientific literature on the neuroprotective mechanisms of phyto-carbazole alkaloids from the Rutaceae family in ameliorating NDs.

Pentagon-Containing π-Expanded Systems: Synthesis and Photophysical Properties.

We have designed and synthesized three novel twistacene-modified enlarged pentagon-containing π-systems (6 and 9) with mismatched structures. The introduction of electron-withdrawing cyclopenta rings in the parent skeleton effectively stabilizes the electron-rich arenes. Their optoelectronic properties were studied via ultraviolet-visible (UV-vis) absorption spectra, fluorescence spectra, cyclic voltammetry, and density functional theory (DFT) calculation. In addition, chemical oxidation of the as-prepared compounds with nitrosonium hexafluoroantimonate could form the corresponding cationic radicals.

Biological Activity and Solubility of 5-Methoxy-1,4-Benzoquinone Having Bromoheptyl and Bromodecyl Substituents in the n-Octanol/Water System

The biological activity and solubility of compounds are influenced by its chemical structure. These properties can be improved by substituting alkyl, alkoxy, and/or haloalkane in the parent skeleton. In this research, the synthesis of 3-(7-bromoheptyl)-2-methyl-5-methoxy-1,4-benzoquinone (3a) and 3-(10-bromodecyl)-2-methyl-5-methoxy-1,4-benzoquinone (3b) was achieved through the decarboxylation reaction. The solubility and biological activity of 3a and 3b were compared with that of thymoquinone (TQ), which acts as an anti-inflammatory agent. Compounds 3a and 3b were successfully synthesized and analyzed using Fourier Transform Infra-Red (FTIR) and Nuclear Magnetic Resonance (NMR). The FTIR spectrum showed the increasing intensity of C-H sp3 and the absorption of C-Br because of the presence of the bromoheptyl and bromodecyl substituents. 1H-NMR showed the prominent chemical shift of olefinic methylene at δ 1.29–3.40 ppm. The solubility test showed the differences in the partition coefficient (log P) of 3a and 3b in the n-octanol/water system. The log P values of 3a and 3b are higher than those of TQ, indicating that methoxy, bromoheptyl, and bromodecyl support the increase in solubility. Biological activity test using the in silico approach showed that 3a and 3b have a higher tendency to bind with the translocator protein (TSPO) macromolecule than the phosphatase and tensin homolog (PTEN) macromolecule. The binding interactions of TSPO-3a and TSPO-3b, similar to that of TSPO-TQ, showed that both synthesized compounds have comparable activity. The binding energy of TSPO-3a is lower than that of TSPO-3b, indicating that 3a has a higher activity for anti-inflammatory drug candidates than 3b.

Design, Synthesis, and SAR of Novel 1,3-Disubstituted Imidazolidine or Hexahydropyrimidine Derivatives as Herbicide Safeners.

Herbicide safeners enhance herbicide detoxification in crops without reducing their herbicidal efficacy against target weeds. To alleviate maize injury caused by the sulfonylurea herbicide nicosulfuron, a series of 1,3-disubstituted imidazolidine or hexahydropyrimidine derivatives were rationally designed via bioisosterism and active subunit combinations. Thirty novel compounds were synthesized using an efficient one-pot method and low-cost raw materials and characterized by IR, 1H NMR, 13C NMR, and high-resolution mass spectrometer (HRMS). Bioactivity and structure-activity relationship (SAR) were evaluated for herbicide safeners tested against nicosulfuron injury. Most of the compounds effectively protected sensitive maize against nicosulfuron damage. The parent skeletons and substituents of the target compounds both substantially influenced their safener activity. Compound I-3 exhibited superior bioactivity compared to the safener isoxadifen-ethyl. Molecular docking simulations disclosed that compound I-3 competed with nicosulfuron for the acetolactate synthase active site and demonstrated that this is the protective mechanism of safeners. The target compound I-3 presented with strong herbicide safener activity in maize and is, therefore, a potential candidate for the development of a novel herbicide safener.

Synthesis of azachalcones, their α-amylase, α-glucosidase inhibitory activities, kinetics, and molecular docking studies

Diabetes being a chronic metabolic disorder have attracted the attention of medicinal chemists and biologists. The introduction of new and potential drug candidates for the cure and treatment of diabetes has become a major concern due to its increased prevelance worldwide. In the current study, twenty-seven azachalcone derivatives 3–29 were synthesized and evaluated for their antihyperglycemic activities by inhibiting α-amylase and α-glucosidase enzymes. Five compounds 3 (IC50 = 23.08 ± 0.03 µM), (IC50 = 26.08 ± 0.43 µM), 5 (IC50 = 24.57 ± 0.07 µM), (IC50 = 27.57 ± 0.07 µM), 6 (IC50 = 24.94 ± 0.12 µM), (IC50 = 27.13 ± 0.08 µM), 16 (IC50 = 27.57 ± 0.07 µM), (IC50 = 29.13 ± 0.18 µM), and 28 (IC50 = 26.94 ± 0.12 µM) (IC50 = 27.99 ± 0.09 µM) demonstrated good inhibitory activities against α-amylase and α-glucosidase enzymes, respectively. Acarbose was used as the standard in this study. Structure-activity relationship was established by considering the parent skeleton and different substitutions on aryl ring. The compounds were also subjected for kinetic studies to study their mechanism of action and they showed competitive mode of inhibition against both enzymes. The molecular docking studies have supported the results and showed that these compounds have been involved in various binding interactions within the active site of enzyme.

Ursolic Acid-Based Derivatives as Potential Anti-Cancer Agents: An Update.

Ursolic acid is a pharmacologically active pentacyclic triterpenoid derived from medicinal plants, fruit, and vegetables. The pharmacological activities of ursolic acid have been extensively studied over the past few years and various reports have revealed that ursolic acid has multiple biological activities, which include anti-inflammatory, antioxidant, anti-cancer, etc. In terms of cancer treatment, ursolic acid interacts with a number of molecular targets that play an essential role in many cell signaling pathways. It suppresses transformation, inhibits proliferation, and induces apoptosis of tumor cells. Although ursolic acid has many benefits, its therapeutic applications in clinical medicine are limited by its poor bioavailability and absorption. To overcome such disadvantages, researchers around the globe have designed and developed synthetic ursolic acid derivatives with enhanced therapeutic effects by structurally modifying the parent skeleton of ursolic acid. These structurally modified compounds display enhanced therapeutic effects when compared to ursolic acid. This present review summarizes various synthesized derivatives of ursolic acid with anti-cancer activity which were reported from 2015 to date.