Discrimination of four Cinnamomum species by proximate, antioxidant, and chemical profiling: towards quality assessment and authenticity.

Cinnamon (genus Cinnamomum) is a worldwide used spice. The highly valued, non-hepatotoxic C. verum (CV) is frequently adulterated with the cheaper hepatotoxic substitutes (C. burmannii (CB), C. cassia (CC), and C. loureiroi (CL)). Therefore, this study evaluated four major Cinnamomum species by proximate composition, antioxidant properties, and chemical analysis. The results showed that CB contained more ash and crude protein content. CC exhibited more moisture, crude fat, and nutritive value, while CV had more crude fiber and total carbohydrate content. The 80% methanol extracts of four Cinnamomum species exhibited the highest total phenolic contents (42.16 to 182.85 mg GAE/g), total flavonoid contents (0.80 to 1.07 mg QE/g), DPPH radical scavenging activities (EC50, 0.94 to 3.98 mg/mL), and ABTS radical scavenging activities (EC50, 0.09 to 0.33 mg/mL). The GC-MS based chemical profiling of CV was markedly different to those of CB, CC, and CL. Compared to the other three species, CV presented the highest eugenol content (5.77%) and the lowest coumarin content (1.90%). Principal component analysis (PCA) accounted for 94.91% of the variability, completely separating CV in quadrant I. Overall, nutritional and chemical profiles in combination with PCA could be effectively applied for monitoring Cinnamomum species, thereby ensuring food safety. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05788-y.

Identification of G-quadruplex structures in MALAT1 lncRNA that interact with nucleolin and nucleophosmin.

Nuclear-retained long non-coding RNAs (lncRNAs) including MALAT1 have emerged as critical regulators of many molecular processes including transcription, alternative splicing and chromatin organization. Here, we report the presence of three conserved and thermodynamically stable RNA G-quadruplexes (rG4s) located in the 3' region of MALAT1. Using rG4 domain-specific RNA pull-down followed by mass spectrometry and RNA immunoprecipitation, we demonstrated that the MALAT1 rG4 structures are specifically bound by two nucleolar proteins, Nucleolin (NCL) and Nucleophosmin (NPM). Using imaging, we found that the MALAT1 rG4s facilitate the localization of both NCL and NPM to nuclear speckles, and specific G-to-A mutations that disrupt the rG4 structures compromised the localization of both NCL and NPM in speckles. In vitro biophysical studies established that a truncated version of NCL (ΔNCL) binds tightly to all three rG4s. Overall, our study revealed new rG4s within MALAT1, established that they are specifically recognized by NCL and NPM, and showed that disrupting the rG4s abolished localization of these proteins to nuclear speckles.

Polarity-Induced Morphological Transformation with Tunable Optical Output of Terpyridine-Phenanthro[9,10-d]imidazole-Based Ligand and Its Zn(II) Complexes with I-V Characteristics.

Self-assembled nanostructures obtained from various functional π-conjugated organic molecules have been able to draw substantial interest due to their inherent optical properties, which are imperative for developing optoelectronic devices, multiple-color-emitting devices with color-tunable displays, and optical sensors. These π-conjugated molecules have proven their potential employment in various organic electronic applications. Therefore, the stimuli-responsive fabrication of these π-conjugated systems into a well-ordered assembly is extremely crucial to tuning their inherent optical properties for improved performance in organic electronic applications. To this end, herein, we have designed and synthesized a functional π-conjugated molecule (TP) having phenanthro[9,10-d]imidazole with terpyridine substitution at the 2 position and its corresponding metal complexes (TPZn and (TP)2Zn). By varying the polarity of the self-assembly medium, TP, TPZn, and (TP)2Zn are fabricated into well-ordered superstructures with morphological individualities. However, this medium polarity-induced self-assembly can tune the inherent optical properties of TP, TPZn, and (TP)2Zn and generate multiple fluorescence colors. Particularly, this property makes them useful for organic electronic applications, which require adjustable luminescence output. More importantly, in 10% aqueous-THF medium, TPZn exhibited H-type aggregation-induced white light emission and behaved as a single-component white light emitter. The experimentally obtained results of the solvent polarity-induced variation in optical properties as well as self-assembly patterns were further confirmed by theoretical investigation using density functional theory calculations. Furthermore, we investigated the I-V characteristics, both vertical and horizontal, using ITO and glass surfaces coated with TP, TPZn, and (TP)2Zn, respectively, and displayed maximum current density for the TPZn-coated surface with the order of measured current density TPZn > TP > (TP)2Zn. This observed order of current density measurements was also supported by a direct band gap calculation associated with the frontier molecular orbitals using the Tauc plot. Hence, solvent polarity-induced self-assembly behavior with adjustable luminescence output and superior I-V characteristics of TPZn make it an exceptional candidate for organic electronic applications and electronic device fabrication.

Discrimination of Four Cinnamomum Species with Physico-Functional Properties and Chemometric Techniques: Application of PCA and MDA Models.

Discrimination of highly valued and non-hepatotoxic Cinnamomum species (C. verum) from hepatotoxic (C. burmannii, C. loureiroi, and C. cassia) is essential for preventing food adulteration and safety problems. In this study, we developed a new method for the discrimination of four Cinnamomum species using physico-functional properties and chemometric techniques. The data were analyzed through principal component analysis (PCA) and multiclass discriminant analysis (MDA). The results showed that the cumulative variability of the first three principal components was 81.70%. The PCA score plot indicated a clear separation of the different Cinnamomum species. The training set was used to build the discriminant MDA model. The testing set was verified by this model. The prediction rate of 100% proved that the model was valid and reliable. Therefore, physico-functional properties coupled with chemometric techniques constitute a practical approach for discrimination of Cinnamomum species to prevent food fraud.

Fabrication of self-assembled nanostructures for intracellular drug delivery from diphenylalanine analogues with rigid or flexible chemical linkers.

Self-assembly of molecular building blocks is a simple and useful approach to generate supramolecular structures with varied morphologies and functions. By studying the chemical properties of the building blocks and tuning the parameters of their self-assembly process, the resultant supramolecular assemblies can be optimized for the required downstream applications. To this end, in the present study we have designed and synthesized three different molecular building blocks composed of two diphenylalanine (FF) units connected to each other through three different linkers: ethylenediamine, succinic acid, or terephthalaldehyde. Under identical conditions, all the three building blocks self-assemble into supramolecular architectures with distinct morphologies. However, by varying the polarity of the self-assembly medium, the nature of the non-covalent interactions changes in such a way as to generate additional self-assembled structures unique to each building block. Utilizing microscopic and spectroscopic techniques, we characterized the morphological variety generated by each building block/linker combination. These data represent the first report analysing the diversity of nanostructures that can be generated from identical dipeptide-based molecular backbones simply by varying the chemical linker. We also demonstrate that the spherical assemblies and nanorod structures fabricated from these dipeptide/linker pairs can act as drug delivery systems. More specifically, the spherical assembly generated by two FF dipeptides linked via ethylenediamine and nanorods fabricated from terephthalaldehyde linked FF dipeptides were able to encapsulate the cancer chemotherapeutic agent doxorubicin (DOX) and chaperone the drug into cells. Thus, these supramolecular assemblies represent a new platform for the development of efficient and effective intracellular drug delivery systems.

Supramolecular Structures Generated via Self-Assembly of a Cell Penetrating Tetrapeptide Facilitate Intracellular Delivery of a Pro-apoptotic Chemotherapeutic Drug.

Development of drug carriers, which can chaperone xenobiotics directly to their site of action, is an essential step for the advancement of precision medicine. Cationic nanoparticles can be used as a drug delivery platform for various agents including chemotherapeutics, oligonucleotides, and antibodies. Self-assembly of short peptides facilitates the formation of well-defined nanostructures suitable for drug delivery, and varying the polarity of the self-assembly medium changes the nature of noncovalent interactions in such a way as to generate numerous unique nanostructures. Here, we have synthesized an ultrashort cell-penetrating tetrapeptide (sequence Lys-Val-Ala-Val), with Lys as a cationic amino acid, and studied the self-assembly property of the BOC-protected (L1) and -deprotected (L2) analogues. Spherical assemblies obtained from L1/L2 in a 1:1 aqueous ethanol system have the ability to encapsulate small molecules and successfully enter into cells, thus representing them as potential candidates for intracellular drug delivery. To verify the efficacy of these peptides in the facilitation of drug efficacy, we generated encapsulated versions of the chemotherapeutic drug doxorubicin (Dox). L1- and L2-encapsulated Dox (Dox-L1 and Dox-L2), similar to the unencapsulated drug, induced upregulation of regulator of G protein signaling 6 (RGS6) and Gß5, the critical mediators of ATM/p53-dependent apoptosis in Dox-treated cancer cells. Further, Dox-L1/L2 damaged DNA, triggered oxidative stress and mitochondrial dysfunction, compromised cell viability, and induced apoptosis. The ability of Dox-L1 to mediate cell death could be ameliorated via knockdown of either RGS6 or Gß5, comparable to the results obtained with the unencapsulated drug. These data provide an important proof of principle, identifying L1/L2 as drug delivery matrices.

Glucose effects on polyglutamine-induced proteotoxic stress in Caenorhabditis elegans.

Alterations in protein folding may lead to aggregation of misfolded proteins, which is strongly correlated with neurotoxicity and cell death. Protein aggregation has been shown as a normal consequence of aging, but it is largely associated with age-related disease, particularly neurodegenerative diseases like Huntington disease (HD). HD is caused by a CAG repeat expansion in the huntingtin gene and serves as a useful model for neurodegeneration due to its strictly genetic origin. Research in the model organism Caenorhabditis elegans suggests that glucose protects against cell stress, including proteotoxicity related to aggregation, despite the well-known, lifespan-shortening effects of glucose. We hypothesized that glucose could be beneficial by alleviating energy deficiency, a well-characterized phenomenon in HD. We used C. elegans expressing polyglutamine repeats to quantify lifespan, motility, reproduction, learning, and activity of succinate dehydrogenase (SDH), with and without glucose, to identify the role of glucose in proteotoxicity and neuroprotection. Our data show poly-Q worms on glucose plates exhibited shorter lifespans, no change in motility, learning, or SDH product formation, but had altered reproductive phenotypes. Notably, worms expressing toxic polyglutamine repeats were unable to learn association of food with a neutral odorant, even early in life.