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An acetylene derivative monomer with a pyrimidine – type sidechain with three rings was synthesized by Steglich esterification. Polymerization of the acetylene derivative was then carried out with a rhodium complex. The acetylene monomer and mono-substituted polyacetylene derivative showed liquid crystals (LCs) because their tricyclic parts worked as a mesogenic core. The monomer as an acetylene derivative showed smectic with a tilted structure in the LC aggregation form. The mono-substituted polyacetylene bearing mesogen via short alkyl spacer showed lyotropic and thermotropic LCs of the smectic phase, although generally flexible long alkyl spacer from the main chain connected to sidechain mesogen is required for exhibiting liquid crystal in sidechain type polymer liquid crystals. In the present study, rigid mainchain aligns the sidechain mesogen array to form non-tilted LC. Properties of LCs were evaluated by various analytical techniques, including polarizing optical microscopy. Structural properties were evaluated by nuclear magnetic resonance spectroscopy, gel permeation chromatography, infrared spectroscopy, and ultraviolet – visible absorption spectroscopy. [ABSTRACT FROM AUTHOR]

Dendropanax morbifera Leveille is a traditional medicine used to treat migraine headache and dysmenorrhea. In this study, three polyacetylenes, methyl (10E,9R,16R)-16-acetoxy-9-hydroxyoctadeca-10,17-dien-12,14-diynoate (1), methyl (10E,9R,16S)-9,16-dihydroxyoctadeca-10-en-12,14-diynoate (2), and methyl (10Z,9R,16S)-9,16-dihydroxyoctadeca-10,17-dien-12,14-diynoate (3), were isolated from the aerial parts of D. morbifera, together with seven known compounds (4–10). Importantly, the isolates (6 and 8) were found in the family Araliaceae for the first time in this study. Compounds 1−10 were evaluated for their binding affinity to AMPK and CTSS receptors using in silico docking simulations. Only compound 7 increased the protein expression levels of PPAR-α, Sirt1, and AMPK when administered to HepG2 cells as a PPAR-α agonist. On the other hand, 7 did not produce any significant reduction in CTSS activity. This study could pave the way for the discovery of novel treatments from D. morbifera targeting PPAR-α and AMPK. [ABSTRACT FROM AUTHOR]

Background: Scalp hair plays a crucial role in social communication by expressing personal appearance and self-identity. Consequently, hair loss often leads to a perception of unattractiveness, negatively impacting an individual's life and mental health. Currently, the use of Food and Drug Administration (FDA)-approved drugs for hair loss is associated with several side effects, highlighting the need for identifying new drug candidates, such as plant-derived phytochemicals, to overcome these issues. Objective: This study investigated the hair growth-promoting effects of araliadiol, a polyacetylene compound found in plants such as Centella asiatica. Methods: We employed an in vitro model comprising human hair follicle stem cells (HHFSCs) and human dermal papilla cells (HDPCs) to evaluate the hair growth-promoting effects of araliadiol. The proliferation-stimulating effects of araliadiol were assessed using water-soluble tetrazolium salt assay, adenosine triphosphate content assay, and crystal violet staining assay. In addition, we performed luciferase reporter assay, polymerase chain reaction analysis, cell fractionation, Western blot analysis, and enzyme-linked immunosorbent assay (ELISA) to elucidate the mechanism underlying the hair growth-inductive effects of araliadiol. Results: Araliadiol exhibited both proliferation- and hair growth-promoting effects in HHFSCs and HDPCs. Specifically, it increased the protein expression of cyclin B1 and Ki67. In HHFSCs, it elevated the expression of hair growth-promoting factors, including CD34, vascular endothelial growth factor (VEGF), and angiopoietin-like 4. Similarly, araliadiol increased the expression of hair growth-inductive proteins such as fibroblast growth factor 7, VEGF, noggin, and insulin-like growth factor 1 in HDPCs. Subsequent Western blot analysis and ELISA using inhibitors such as GW9662 and SB202190 confirmed that these hair growth-promoting effects were dependent on the p38/PPAR-γ signaling in both HHFSCs and HDPCs. Conclusion: Araliadiol promotes hair growth through the p38/PPAR-γ signaling pathway in human hair follicle cells. Therefore, araliadiol can be considered a novel drug candidate for the treatment of alopecia. [ABSTRACT FROM AUTHOR]

AbstractIn this work, we investigate high-harmonic generation (HHG) spectra in polyacetylene with two relevant bands by numerically solving the time-dependent Schrödinger equation. Using the Su-Schrieffer-Heeger (SSH) model, the problem reduces to a 2 × 2 tight-binding Bloch Hamiltonian. Additionally, coupling to the laser field requires solving the time-dependent Schrödinger equation numerically in reciprocal space. The HHG spectra are obtained by performing a Fourier transform in two consecutive steps: first on the lattice momentum and then on time. The k-integration of velocity is carried out to ensure the coherent addition of the momentum contributions of all electrons within the Brillouin zone. The time integration of the acceleration yields the HHG spectra. Our findings reveal the well-known signatures of high harmonics from solids. [ABSTRACT FROM AUTHOR]

Polyacetylene (PA) compounds, as natural products, exhibit remarkable properties and distinctive chemical activities. Three structurally similar C14-PA compounds—Echinophorin D, Echinophorin B, and Echinophorin A—extracted from plants demonstrate varying biological activities on the Transient Receptor Potential Channel A1 (TRPA1) protein, which belongs to the TRP (Transient Receptor Potential) family. In the current study, we investigated the binding modes of these three PA compounds with TRPA1 using molecular dynamics (MD), molecular docking, binding free energy calculations, and quantum mechanics/molecular mechanics (QM/MM) methods. Initially, a putative binding site (site-II) in TRPA1 was identified for these compounds; Echinophorin B was found to stabilize the upward A-loop of TRPA1, which is critical for its activation. Furthermore, the binding affinity calculations of PA compounds through molecular fragment decomposition indicate that the arrangement of two triple bonds and one double bond in C14-PA compounds is vital for regulating TRPA1 bioactivity. Additionally, the lipophilic and electronic properties of the three molecules were analyzed in relation to binding affinity, establishing a correlation between TRPA1 activity and these molecular properties. [ABSTRACT FROM AUTHOR]

Recently, polyacetylene (PA) has been receiving renewed scientific attention due to its electrical properties, potentially useful for energy applications (e.g., fabrication of electrodes for rechargeable batteries and supercapacitors), and unique functional characteristics (e.g., gas trap, oxygen scavenger, EMI shielding, etc.). This chemical compound can be obtained in the form of polyacetylene–PVOH copolymers simply through the chemical dehydration of poly(vinyl alcohol) (PVOH), which is a very common type of polymer, widely used in packaging and other technological areas. This very inexpensive chemical reaction for the large-scale synthesis of PA/polyvinylenes is investigated by reacting PVOH with sulfuric acid at room temperature. In this process, PVOH, shaped in the form of a film, is dipped in sulfuric acid (i.e., H2SO4 at 95%–97%) and, after complete chemical dehydration, it is mechanically removed from the liquid phase by using a nylon sieve. The reduction process leads to a substantial PVOH film conversion into PA, as demonstrated by infrared spectroscopy (ATR mode). Indeed, the ATR spectrum of the reaction product includes all the characteristic absorption bands of PA. The reaction product is also characterized through the use of UV–Vis spectroscopy in order to evidence the presence in the structure of conjugated carbon–carbon double bonds of various lengths. Differential scanning calorimetry (DSC) and thermogravimetric analysis are used to investigate the PA solid-state cis–trans isomerization and thermal stability in air and nitrogen, respectively. XRD is used to verify the polymer amorphous nature. [ABSTRACT FROM AUTHOR]