Serum albumin exposure enhances cell invasiveness and paclitaxel resistance in human neuroblastoma cells, with attenuation by valeriana-type iridoid glycosides

Neuroblastoma, a prevalent extracranial solid tumor in children, arises from undifferentiated nerve cells. While tumor vasculature, often characterized by increased permeability, influences metastasis and recurrence, the direct impact of blood-borne molecules on tumor progression remains unclear. In the present study, we focused on the effect of exposure to albumin, one of the most abundant proteins in the serum, on human neuroblastoma cells. Albumin exposure elevated oxidative stress and led to mitochondria dysfunction via the activation of TGFβ and PI3K pathways, accompanied by an increase in the metastatic and invasive properties of neuroblastoma cells. Proteins relevant to the induction of autophagy were upregulated in response to prolonged albumin exposure. Additionally, pre-exposure to albumin before treatment resulted in increased resistance to paclitaxel. Two valeriana-type iridoid glycosides, patrisophoroside and patrinalloside, recently isolated from Nardostachys jatamansi significantly mitigated the effect of albumin on oxidative stress, cell invasiveness, and chemoresistance. These findings illuminate the potential role of blood-borne molecules, such as albumin, in the progression and metastasis of neuroblastoma, as well as the possible therapeutic implications of valeriana-type iridoid glycosides in anti-cancer treatment.

Efficacy of hydroxyapatite and fibrin sealant as carriers for bone morphogenetic protein-2 in maxillary sinus floor augmentation: a retrospective study

The aim of this retrospective study was to assess the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) with hydroxyapatite (HA) granules and fibrin sealant (FS) in maxillary sinus floor augmentation (MSFA), with a focus on the volume change. Fifty-two of 137 patients who underwent MSFA with rhBMP-2/HA grafting between June 2016 and December 2022 met the study inclusion criteria; 25 had received rhBMP-2/HA without FS and 27 had received rhBMP-2/HA with FS. Computed tomography (CT) images were obtained preoperatively, immediately following the operation, and at 6 months postoperative. These images were three-dimensionally reconstructed to measure the volumetric and height changes following MSFA. The mean ± standard deviation percentage of volumetric change at 6 months was 48.75 ± 37.44% in the group with FS and 29.77 ± 13.42% in the group without FS (P = 0.019). The vertical height measured at a specific site of the grafted area showed a mean percentage change at 6 months of 4.05 ± 12.08% in the group with FS and 6.07 ± 10.15% in the group without FS (P = 0.518). The additional use of FS as a carrier for rhBMP-2/HA in MSFA was found to improve surgical convenience and bone regeneration ability.

Napyradiomycin B4 Suppresses RANKL-Induced Osteoclastogenesis and Prevents Alveolar Bone Destruction in Experimental Periodontitis

The unique structure and beneficial biological properties of marine natural products have drawn interest in drug development. Here, we examined the therapeutic potential of napyradiomycin B4 isolated from marine-derived Streptomyces species for osteoclast-related skeletal diseases. Bone marrow-derived macrophages were treated with napyradiomycin B4 in an osteoclast-inducing medium, and osteoclast formation, osteoclast-specific gene expression, and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) localization were evaluated using tartrate-resistant acid phosphatase staining, real-time PCR, and immunostaining, respectively. Phosphorylation levels of signaling proteins were assessed by immunoblot analysis to understand the molecular action of napyradiomycin B4. The in vivo efficacy of napyradiomycin B4 was examined under experimental periodontitis, and alveolar bone destruction was evaluated by microcomputed tomography (micro-CT) and histological analyses. Among the eight napyradiomycin derivatives screened, napyradiomycin B4 considerably inhibited osteoclastogenesis. Napyradiomycin B4 significantly suppressed the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation and disrupted the expression of NFATc1 and its target genes. Mitogen-activated extracellular signal-regulated kinase (MEK) and extracellular signal-regulated kinase (ERK) phosphorylation levels were reduced by napyradiomycin B4 in response to RANKL. Under in vivo experimental periodontitis, napyradiomycin B4 significantly attenuated osteoclast formation and decreased the distance between the cementoenamel junction and alveolar bone crest. Our findings demonstrate the antiosteoclastogenic activity of napyradiomycin B4 by inhibiting the RANKL-induced MEK-ERK signaling pathway and its protective effect on alveolar bone destruction.

Correction to "Diving into the Molecular Diversity of Aplysina cavernicola's Exometabolites: Contribution of Bromo-Spiroisoxazoline Alkaloids"

[This corrects the article DOI: 10.1021/acsomega.2c05415.].

Fabrication of stem cell heterospheroids with sustained-release chitosan and poly(lactic-co-glycolic acid) microspheres to guide cell fate toward chondrogenic differentiation

Mesenchymal stem cell (MSC)-based therapies show great potential in treating various diseases. However, control of the fate of injected cells needs to be improved. In this work, we developed an efficient methodology for modulating chondrogenic differentiation of MSCs. We fabricated heterospheroids with two sustained-release depots, a quaternized chitosan microsphere (QCS-MP) and a poly (lactic-co-glycolic acid) microsphere (PLGA-MP). The results show that heterospheroids composed of 1 × 104 to 5 × 104 MSCs formed rapidly during incubation in methylcellulose medium and maintained high cell viability in long-term culture. The MPs were uniformly distributed in the heterospheroids, as shown by confocal laser scanning microscopy. Incorporation of transforming growth factor beta 3 into QCS-MPs and of dexamethasone into PLGA-MPs significantly promoted the expression of chondrogenic genes and high accumulation of glycosaminoglycan in heterospheroids. Changes in crucial metabolites in the dual drug depot-engineered heterospheroids were also evaluated using 1H NMR-based metabolomics analysis to verify their successful chondrogenic differentiation. Our heterospheroid fabrication platform could be used in tissue engineering to study the effects of various therapeutic agents on stem cell fate.

Angular dihydropyranocoumarins from the flowers of Peucedanum japonicum and their aldo-keto reductase inhibitory activities

Twenty-one angular dihydropyranocoumarins and a linear furanocoumarin, including four previously undescribed compounds (1-4), were isolated from the flowers of Peucedanum japonicum (Umbelliferae). The structures of 1-4, along with their absolute stereochemistry, were determined to be (3'S,4'S)-3'-O-propanoyl-4'-O-(3‴-methyl-2‴-butenoyl)khellactone (1), (3'S,4'S)-3'-O-propanoyl-4'-O-(2‴-methyl-2‴Z-butenoyl)khellactone (2), (3'S,4'S)-3'-O-propanoyl-4'-O-(2‴-methylbutanoyl)khellactone (3), and (3'S,4'S)-3'-O-(2″-methylpropanoyl)-4'-O-(3‴-methyl-2‴-butenoyl)khellactone (4) using one- and two-dimensional nuclear magnetic resonance, high-resolution electrospray ionization mass spectroscopy, and electronic circular dichroism spectroscopy. In addition, the absolute configuration of the three angular dihydropyranocoumarins (5-7) was determined for the first time in this study. Among the previously reported compounds isolated in this study, 8 and 9 were isolated for the first time from the genus Peucedanum, whereas 10 and 11 were previously unreported and had not been isolated from P. japonicum to date. Furthermore, all isolated compounds were evaluated for their aldo-keto reductase 1C1 inhibitory activities on A549 human non-small-cell lung cancer cells. Compounds 10 and 12 exhibited substantial AKR1C1 inhibitory activities with IC50 values of 35.8 ± 0.9 and 44.2 ± 1.5 μM, respectively.

Phytochemical profile and anti-inflammatory activity of the hull of γ-irradiated wheat mutant lines (Triticum aestivum L.)

Wheat (Triticum aestivum Linn.; Poaceae) is the second most cultivated food crop among all global cereal crop production. The high carbohydrate content of its grains provides energy, multiple nutrients, and dietary fiber. After threshing, a substantial amount of wheat hull is produced, which serves as the non-food component of wheat. For the valorization of these by-products as a new resource from which functional components can be extracted, the hull from the seeds of cultivated wheat mutant lines bred after γ-irradiation were collected. Untargeted metabolite analysis of the hull of the original cultivar (a crossbreeding cultivar., Woori-mil × D-7) and its 983 mutant lines were conducted using ultra-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry technique. A total of 55 molecules were tentatively identified, including 21 compounds found in the Triticum species for the first time and 13 compounds not previously described. Among them, seven flavonolignans with a diastereomeric structure, isolated as a single compound from the hull of T. aestivum in our previous study, were used as the standards in the metabolite analysis. The differences in their collision cross-section values were shown to contribute to the clear distinction between tricine-lignan stereoisomers. To select functionally active agents with anti-inflammatory activity among the identified compounds, the wheat hull samples were evaluated for their inhibitory effect on nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells. As a result of multivariate analysis based on the results of chemical and biological profiles of the wheat hull samples, 10 metabolites were identified as key markers, contributing to the distinction between active and inactive mutant lines. Considering that one of the four key markers attributed to anti-inflammatory activity has been identified to be a flavonolignan, the wheat hull could be a valuable source of diverse tricin-lignan type compounds and used as a natural health-promoting product in food supplements.

Cuminaldehyde-3-hydroxy-2-napthoichydrazone: Synthesis, effect of solvents, nonlinear optical activity, antioxidant activity, antimicrobial activity, and DFT analysis

Hydrazones derived from essential oil components have attracted considerable interest because of their antimicrobial, antioxidant, and nonlinear optical applications. In the present work, a new essential oil component derivative (EOCD), cuminaldehyde-3-hydroxy-2-napthoichydrazone (CHNH), was synthesized. EOCD was characterized by Fourier transform infrared spectroscopy, mass spectrometry, nuclear magnetic resonance (1H and 13C) spectroscopy, elemental analysis, ultraviolet-visible absorption spectroscopy, and field-emission scanning electron microscopy. Thermogravimetric analysis and X-ray diffraction showed a higher stability, phase-pure, and non-existent isomorphic phase transition in EOCD. Solvent studies indicated that the normal emission band was caused by the locally excited state and the large Stokes shifted emission originated because of the twisted intramolecular charge transfer. The EOCD possessed higher direct and indirect band gap energies of 3.05 eV and 2.90 eV respectively, as determined by the Kubelka-Munk algorithm. The outcomes of frontier molecular orbitals, global reactivity descriptors, Mulliken, and molecular electrostatic potential surface by density functional theory calculations revealed high intramolecular charge transfer, good realistic stability, and high reactiveness of EOCD. The hydrazone EOCD exhibited higher hyperpolarizability (18.248 × 10-30 esu) in comparison to urea. Antioxidant test results indicated that EOCD showed significant antioxidant activity (p < 0.05), as determined by the DPPH radical scavenging assay. The newly synthesized EOCD showed no antifungal activity against Aspergillus flavus. Additionally, the EOCD showed good antibacterial activity against Escherichia coli and Bacillus subtilis.

Structure Confirmation of Dechlorotrichotoxin A through Stereoselective Total Synthesis

The stereoselective total synthesis of dechlorotrichotoxin A, alongside the synthesis of a 1:1 10E/Z mixture of trichotoxin A, was successfully achieved, commencing from the natural monoterpenoid (-)-citronellal. Key steps in the synthesis involved introducing three alkenes and establishing a stereogenic secondary alcohol center. These transformations were accomplished through olefin cross-metathesis, Tebbe olefination, and enantioselective allylation using a chiral phosphoric acid. A comparison of the spectroscopic data between the synthetic dechlorotrichotoxin A and the reported spectra confirmed that the polyketide isolated from a Smenospongia species corresponds to trichotoxin A rather than dechlorotrichotoxin A.

Antimetastatic activity of seongsanamide B in γ-irradiated human lung cancer

Lung cancer, which has a high incidence and mortality rates, often metastasizes and exhibits resistance to radiation therapy. Seongsanamide B has conformational features that suggest it has therapeutic potential; however, its antitumor activity has not yet been reported. We evaluated the possibility of seongsanamide B as a radiation therapy efficiency enhancer to suppress γ-irradiation-induced metastasis in non-small cell lung cancer. Seongsanamide B suppressed non-small cell lung cancer cell migration and invasion caused by γ-irradiation. Furthermore, it suppressed γ-irradiation-induced upregulation of Bcl-XL and its downstream signaling molecules, such as superoxide dismutase 2 (SOD2) and phosphorylated Src, by blocking the nuclear translocation of phosphorylated STAT3. Additionally, seongsanamide B markedly modulated the γ-irradiation-induced upregulation of E-cadherin and vimentin. Consistent with the results obtained in vitro, while seongsanamide B did not affect xenograft tumor growth, it significantly suppressed γ-irradiation-induced metastasis by inhibiting Bcl-XL/SOD2/phosphorylated-Src expression and modulating E-cadherin and vimentin expression in a mouse model. Thus, seongsanamide B may demonstrate potential applicability as a radiation therapy efficiency enhancer for lung cancer treatment.

Efficacy of Veronica incana for Treating Osteoarthritis Induced by Monosodium Iodoacetate in Rats

The aim of this study is to investigate the efficacy and the underlying mechanism of Veronica incana in osteoarthritis (OA) induced by intraarticular injection of monosodium iodoacetate (MIA). The selected major four compounds (A-D) of V. incana were found from fractions 3 and 4. Its structure elucidation was determined by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) data analysis and nuclear magnetic resonance (NMR) data comparison with literature. MIA (50 μL with 80 mg/mL) for the animal experiment was injected into the right knee joint. The V. incana was administered orally every day to rats for 14 days from 7 days after MIA treatment. Finally, we confirmed the four compounds: (A) verproside; (B) catalposide; (C) 6-vanilloylcatapol; and (D) 6-isovanilloylcatapol. When we evaluated the effect of V. incana on the MIA injection-induced knee OA model, there were a noticeable initial decreased in hind paw weight-bearing distribution compared to the Normal group (P < .001), but V. incana supplementation resulted in a significant increase in the weight-bearing distribution to the treated knee (P < .001). Moreover, the V. incana treatment led to a decrease in the levels of liver function enzymes and tissue malondialdehyde (P < .05 and .01). The V. incana significantly suppressed the inflammatory factors through the nuclear factor-kappa B signaling pathway and downregulated the expression of matrix metalloproteinases, which are involved in the degradation of the extracellular matrix (P < .01 and .001). In addition, we confirmed the alleviation of cartilage degeneration through tissue stains. In conclusion, this study confirmed the major four compounds of V. incana and suggested that V. incana could serve as an anti-inflammatory candidate agent for patients with OA.

Scalable and Uniform Fabrication of Dexamethasone-Eluting Depot-Engineered Stem Cell Spheroids as a Microtissue Construct to Target Bone Regeneration

Potentiation of stem cell potency is critical for successful tissue engineering, especially for bone regeneration. Three-dimensional cell culture and bioactive molecule co-delivery with cells have been proposed to achieve this effect. Here, we provide a uniform and scalable fabrication of osteogenic microtissue constructs of mesenchymal stem cell (MSC) spheroids surface-engineered with dexamethasone-releasing polydopamine-coated microparticles (PD-DEXA/MPs) to target bone regeneration. The microparticle conjugation process was rapid and cell-friendly and did not affect the cell viability or key functionalities. The incorporation of DEXA in the conjugated system significantly enhanced the osteogenic differentiation of MSC spheroids, as evidenced by upregulating osteogenic gene expression and intense alkaline phosphatase and alizarin red S staining. In addition, the migration of MSCs from spheroids was tested on a biocompatible macroporous fibrin scaffold (MFS). The result showed that PD-DEXA/MPs were stably anchored on MSCs during cell migration over time. Finally, the implantation of PD-DEXA/MP-conjugated spheroid-loaded MFS into a calvarial defect in a mouse model showed substantial bone regeneration. In conclusion, the uniform fabrication of microtissue constructs containing MSC spheroids with drug depots shows a potential to improve the performance of MSCs in tissue engineering.

Diterpene and biflavone derivatives from Thuja koraiensis and their cytotoxicities against A549 cells

During the screening of the cytotoxicity of rare Korean endemic plants, the extract of Thuja koraiensis Nakai displayed potent cytotoxicity against the adenocarcinomic human alveolar basal epithelial A549 cell line. Through a series of separations via column chromatography, three undescribed abietanes, an undescribed labdane along with a labdane, and a biflavonoid were purified from methylene chloride (CH₂Cl₂) fraction possessing a potent cytotoxic effect. Extensive 1D and 2D NMR spectroscopic data analyses, in combination with quantum chemical calculations were conducted to establish the planar and absolute configurations of thujakoraienes A-C. The chemical structure of thujakoraiene D was elucidated by spectroscopic data analysis and competing enantioselective acylation. Thujakoraienes A and C along with 7,7″-di-O-methylamentoflavone, showed cytotoxic effects on A549 cells, with IC₅₀ values of 64.86, 47.97, and 16.14 μM, respectively. Finally, thujakoraiene C and 7,7″-di-O-methylamentoflavone were identified as potent cytotoxic compounds in A549 cells, followed by an additional cytotoxicity test in the normal human lung fibroblast MRC-5 cell line. This is the first study on the non-volatile chemicals in the extract of T. koraiensis and comparison of chemical profiles of T. orientalis and T. koraiensis.

Methionine consumption by cancer cells drives a progressive upregulation of PD-1 expression in CD4 T cells

Programmed cell death protein 1 (PD-1), expressed on tumor-infiltrating T cells, is a T cell exhaustion marker. The mechanisms underlying PD-1 upregulation in CD4 T cells remain unknown. Here we develop nutrient-deprived media and a conditional knockout female mouse model to study the mechanism underlying PD-1 upregulation. Reduced methionine increases PD-1 expression on CD4 T cells. The genetic ablation of SLC43A2 in cancer cells restores methionine metabolism in CD4 T cells, increasing the intracellular levels of S-adenosylmethionine and yielding H3K79me2. Reduced H3K79me2 due to methionine deprivation downregulates AMPK, upregulates PD-1 expression and impairs antitumor immunity in CD4 T cells. Methionine supplementation restores H3K79 methylation and AMPK expression, lowering PD-1 levels. AMPK-deficient CD4 T cells exhibit increased endoplasmic reticulum stress and Xbp1s transcript levels. Our results demonstrate that AMPK is a methionine-dependent regulator of the epigenetic control of PD-1 expression in CD4 T cells, a metabolic checkpoint for CD4 T cell exhaustion.

Prokinetic Activity of Mulberry Fruit, Morus alba L

The fruit of Morus alba L. (MAF) has been consumed as a food worldwide. MAF has also been widely used in traditional medicine for thousands of years in East Asia, and its diverse bioactivities have been reported in numerous publications. However, no prokinetic activity has been reported for MAF or its components. In the present study, therefore, we investigated the effects of MAF on gastrointestinal motor function by measuring the intestinal transit rate (ITR) of Evans blue in mice in vivo. The ITR values accelerated by MAF were significantly higher than those accelerated by cisapride or metoclopramide, suggesting that MAF has potential as a new prokinetic agent to replace cisapride and metoclopramide. We also investigated the effects of MAF on myogenic and neurogenic contractions in human intestinal smooth muscles by measuring spontaneous contractions of smooth muscle strips, smooth muscle contractions induced by neural stimulation, and migrating motor complexes from intestinal segments in the human ileum and sigmoid colon in situ. MAF increased both myogenic and neurogenic contractions to enhance ileal and colonic motility in the human intestine. Taken together, these results indicate that MAF enhanced intestinal motility by increasing both myogenic and neurogenic contractions, thereby accelerating the ITR.

Diving into the Molecular Diversity of Aplysina cavernicola's Exometabolites: Contribution of Bromo-Spiroisoxazoline Alkaloids

Sponges are prolific producers of specialized metabolites with unique structural scaffolds. Their chemical diversity has always inspired natural product chemists working in drug discovery. As part of their metabolic filter-feeding activities, sponges are known to release molecules, possibly including their specialized metabolites. These released "Exo-Metabolites" (EMs) may be considered as new chemical reservoirs that could be collected from the water column while preserving marine biodiversity. The present work aims to determine the proportion and diversity of specialized EMs released by the sponge Aplysina cavernicola (Vacelet 1959). This Mediterranean sponge produces bromo-spiroisoxazoline alkaloids that are widely distributed in the Aplysinidae family. Aquarium experiments were designed to facilitate a continuous concentration of dissolved and diluted metabolites from the seawater around the sponges. Mass Spectrometry (MS)-based metabolomics combined with a dereplication pipeline were performed to investigate the proportion and identity of brominated alkaloids released as EMs. Chemometric analysis revealed that brominated features represented 12% of the total sponge's EM features. Consequently, a total of 13 bromotyrosine alkaloids were reproducibly detected as EMs. The most abundant ones were aerothionin, purealidin L, aerophobin 1, and a new structural congener, herein named aplysine 1. Their structural identity was confirmed by NMR analyses following their isolation. MS-based quantification indicated that these major brominated EMs represented up to 1.0 ± 0.3% w/w of the concentrated seawater extract. This analytical workflow and collected results will serve as a stepping stone to characterize the composition of A. cavernicola's EMs and those released by other sponges through in situ experiments, leading to further evaluate the biological properties of such EMs.

Quantum-Mechanical Driven 1H Iterative Full Spin Analysis Addresses Complex Peak Patterns of Choline Sulfate

Choline and choline esters are essential nutrients in biological systems for carrying out normal functions, such as the modulation of neurotransmission and the formation and maintenance of cell membranes. Choline sulfate is reportedly involved in the defense mechanism of accumulating sulfur resources against sulfur deficiency. Contrary to expectations, a full assignment of the ¹H NMR spectrum of choline sulfate has not been reported. The present study pioneered a full assignment by quantum-mechanical driven ¹H iterative full spin analysis. The complex peak patterns were analyzed in terms of heteronuclear and non-first-order coupling. The ¹H-¹⁴N coupling constants, including two-bond coupling, which can be neglected, were accurately determined by iterative optimization. Non-first-order splitting has been described to be due to the presence of magnetically non-equivalent geminal protons. Moreover, in the comparison of the methylene proton resonance patterns of choline sulfate with choline and choline phosphate, the differences in the geminal and vicinal coupling constants were further examined through spectral simulation excluding the heteronuclear coupling. The precise spectral interpretation provided in this study is expected to contribute to future ¹H NMR-based qualitative or quantitative studies of choline sulfate-containing sources.

Stability of valeriana-type iridoid glycosides from rhizomes of Nardostachys jatamansi and their protection against H2O2-induced oxidative stress in SH-SY5Y cells

Nardostachys jatamansi is close to Valerian in consideration of their same psychoactive effects, such as sedation and neuroprotection. Valeriana-type iridoids are major active components of Valerian, but few valeriana-type iridoids have been isolated from N. jatamansi. Iridoid-targeting chemical investigation of the rhizomes of N. jatamansi resulted in the isolation of seven valeriana-type iridoid glycosides, four of which are previously undescribed. Their structures were determined through NMR spectroscopy, high-resolution mass spectrometry, and optical rotation experiments. In addition, the inaccurate configurations of patrinalloside and 6″-acetylpatrinalloside from previous reports were corrected. These compounds, unstable due to alcoholic solvents, were more stable in the mixtures than in purified forms, as monitored by the qNMR method, supporting the use of natural products as mixtures. Furthermore, the isolates, as well as crude and solvent partition extracts, were found to have a protective effect against hydrogen-peroxide-induced toxicity in human neuroblastoma cells, as confirmed by assays for cell viability and antioxidation. These findings suggest the potential therapeutic application of the valeriana-type iridoid glycosides isolated herein with improved biochemical stability.

Comparative Analysis of Coumarin Profiles in Different Parts of Peucedanum japonicum and Their Aldo-Keto Reductase Inhibitory Activities

Peucedanum japonicum (Umbelliferae) is widely distributed throughout Southeast Asian countries. The root of this plant is used in traditional medicine to treat colds and pain, whereas the young leaves are considered an edible vegetable. In this study, the differences in coumarin profiles for different parts of P. japonicum including the flowers, roots, leaves, and stems were compared using ultra-performance liquid chromatography time-of-flight mass spectrometry. Twenty-eight compounds were tentatively identified, including three compounds found in the genus Peucedanum for the first time. Principal component analysis using the data set of the measured mass values and intensities of the compounds exhibited distinct clustering of the flower, leaf, stem, and root samples. In addition, their anticancer activities were screened using an Aldo-keto reductase (AKR)1C1 assay on A549 human non-small-cell lung cancer cells and the flower extract inhibited AKR1C1 activity. Based on these results, seven compounds were selected as potential markers to distinguish between the flower part versus the root, stem, and leaf parts using an orthogonal partial least-squares discriminant analysis. This study is the first to provide information on the comparison of coumarin profiles from different parts of P. japonicum as well as their AKR1C1 inhibitory activities. Taken together, the flowers of P. japonicum offer a new use related to the efficacy of overcoming anticancer drug resistance, and may be a promising source for the isolation of active lead compounds.

Content of Two Major Steroidal Glycoalkaloids in Tomato (Solanum lycopersicum cv. Micro-Tom) Mutant Lines at Different Ripening Stages

Esculeoside A and tomatine are two major steroidal alkaloids in tomato fruit (Solanum lycopersicum) that exhibit anti-inflammatory, anticancer, and anti-hyperlipidemia activities. Tomatine contained in immature tomato fruit is converted to esculeoside A as the fruit matures. To develop new tomato varieties based on the content analysis of functional secondary metabolites, 184 mutant lines were generated from the original cultivar (S. lycopersicum cv. Micro-Tom) by radiation breeding. Ultra-performance liquid chromatography coupled with evaporative light scattering detector was used to identify the mutant lines with good traits by analyzing tomatine and esculeoside A content. Compared with the original cultivar, candidates for highly functional cultivars with high esculeoside A content were identified in the mature fruit of the mutant lines. The mutant lines with low and high tomatine content at an immature stage were selected as edible cultivars due to toxicity reduction and as a source of tomatine with various pharmacological activities, respectively. During the process of ripening from green to red tomatoes, the rate of conversion of tomatine to esculeoside A was high in the green tomatoes with a low tomatine content, whereas green tomatoes with a high tomatine content exhibited a low conversion rate. Using methanol extracts prepared from unripe and ripe fruits of the original cultivar and its mutant lines and two major compounds, we examined their cytotoxicity against FaDu human hypopharynx squamous carcinoma cells. Only tomatine exhibited cytotoxicity with an IC₅₀ value of 5.589 μM, whereas the other samples did not exhibit cytotoxicity. Therefore, radiation breeding represents a useful tool for developing new cultivars with high quality, and metabolite analysis is applicable for the rapid and objective selection of potential mutant lines.

Combining NMR and MS to Describe Pyrrole-2-Carbaldehydes in Wheat Bran of Radiation

Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) are indispensable analytical tools to provide chemical fingerprints in metabolomics studies. The present study evaluated radiation breeding wheat lines for chemical changes by non-targeted NMR-based metabolomics analysis of bran extracts. Multivariate analysis following spectral binning suggested pyrrole-2-carbaldehydes as chemical markers of four mutant lines with distinct NMR fingerprints in a δ_H range of 9.28-9.40 ppm. Further NMR and MS data analysis, along with chromatographic fractionation and synthetic preparation, aimed at structure identification of marker metabolites and identified five pyrrole-2-carbaldehydes. Quantum-mechanical driven ¹H iterative full spin analysis (QM-HiFSA) on synthetic pyrrole-2-carbaldehydes provided a precise description of complex peak patterns. Biological evaluation of pyrrole-2-carbaldehydes was performed with nine synthetic products, and six compounds showed hepatoprotective effects via modulation of reactive oxygen species production. Given that three out of five identified in wheat bran of radiation were described for hepatoprotective activity, the value of radiation mutation to greatly enhance pyrrole-2-carbaldehyde production was supported.

Absolute Quantification of Isoflavones in the Flowers of Pueraria lobata by qHNMR

Pueraria lobata (Willd.) Ohwi. is a widely used medicinal plant in Korea, China, and Japan. The flower of P. lobata (Puerariae Flos) contains various bioactive substances such as triterpenoidal saponins and isoflavonoids. In this study, we developed a quantitative analysis of the isoflavones of Puerariae Flos by quantitative proton nuclear magnetic resonance (qHNMR) spectroscopy using the internal calibrant (IC). From the qHNMR results, the isoflavone content was found to be 7.99% and 10.57% for the MeOH sonication extract (PLs) and the MeOH reflux extract (PLr) of Puerariae Flos, respectively. The quantified isoflavone content was validated using the conventional analytical method, high-performance liquid chromatography with ultraviolet detection (HPLC-UV). The present study shows that validated qHNMR spectroscopy is a reliable method for quantifying and standardizing the isoflavone content in Puerariae Flos.

1H NMR-Based Chemometrics to Gain Insights Into the Bran of Radiation-Induced Colored Wheat Mutant

Recently, wheat has attracted attention as a functional food, rather than a simple dietary energy source. Accordingly, whole-grain intake increases with an understanding of bioactive phytochemicals in bran. The development of colored wheat has drawn more attention to the value of bran owing to its nutritional quality, as well as the antioxidant properties of the colorant. The present ¹H NMR-based chemometric study evaluated the compositional improvement of radiation-induced mutants in purple wheat by focusing on the predominant metabolites with high polarity. A total of 33 metabolites, including three choline derivatives, three sugar alcohols, four sugars, 13 amino acids, eight organic acids, and two nucleosides, were identified throughout the ¹H NMR spectra, and quantification data were obtained for the identified metabolites via peak shape-based quantification. Principal component and hierarchical cluster analyses were conducted for performing multivariate analyses. The colored original wheat was found to exhibit improvements compared to yellow wheat in terms of the contents of primary metabolites, thus highlighting the importance of conducting investigations of polar metabolites. The chemometrics studies further revealed mutant lines with a compositional enhancement for metabolites, including lysine, proline, acetate, and glycerol.

Gardeniae Fructus Attenuates Thioacetamide-Induced Liver Fibrosis in Mice via Both AMPK/SIRT1/NF-κB Pathway and Nrf2 Signaling

Liver fibrosis, which means a sort of the excessive accumulation of extracellular matrices (ECMs) components through the liver tissue, is considered as tissue repair or wound-healing status. This pathological stage potentially leads to cirrhosis, if not controlled, it progressively results in hepatocellular carcinoma. Herein, we investigated the pharmacological properties and underlying mechanisms of Gardeniae Fructus (GF) against thioacetamide (TAA)-induced liver fibrosis of mice model. GF not only attenuated hepatic tissue oxidation but also improved hepatic inflammation. We further confirmed that GF led to ameliorating liver fibrosis by ECMs degradations. Regarding the possible underlying mechanism of GF, we observed GF regulated epigenetic regulator, Sirtuin 1 (SIRT1), in TAA-injected liver tissue. These alterations were well supported by SIRT1 related signaling pathways through regulations of its downstream proteins including, AMP-activated protein kinase (AMPK), p47^phox, NADPH oxidase 2, nuclear factor erythroid 2–related factor 2 (Nrf2), and heme oxygenase-1, respectively. To validate the possible mechanism of GF, we used HepG2 cells with hydrogen peroxide treated oxidative stress and chronic exposure conditions via deteriorations of cellular SIRT1. Moreover, GF remarkably attenuated ECMs accumulations in transforming growth factor–β1-induced LX-2 cells relying on the SIRT1 existence. Taken together, GF attenuated liver fibrosis through AMPK/SIRT1 pathway as well as Nrf2 signaling cascades. Therefore, GF could be a clinical remedy for liver fibrosis patients in the future.

Compositional variation of atranorin-related components of lichen Myelochroa leucotyliza dependent on extraction solvent and their quantitative analysis by qHNMR

INTRODUCTION

Quantitative nuclear magnetic resonance (qNMR) is one of the effective and reliable quantification tools for natural product research. Myelochroa leucotyliza belongs to the genus Myelochroa, a common foliose lichen genus found in the Korean Peninsula, and has not been quantitatively analysed using NMR. Previous chemical studies on M. leucotyliza have been limited to the main components by traditional thin-layer chromatography (TLC) experiments.

OBJECTIVE

We explored the stability of atranorin, a major component of M. leucotyliza, in methanol and acetone using NMR and characterised the changes in the chemical profiles of the lichen extracts in methanol and acetone using qNMR.

METHODOLOGY

Atranorin transformation in the presence of methanol was analysed using time-dependent proton (¹ H)-NMR analysis (600 MHz NMR spectrometer). A ¹ H qNMR (qHNMR) method was established using dimethyl sulfone as the internal standard for quantifying the selected components isolated from M. leucotyliza. Homogenous mixtures of the samples were dissolved in deuterated chloroform.

RESULTS

Time-dependent ¹ H-NMR experiments revealed that atranorin (5) from lichen M. leucotyliza decomposed into atraric acid (1) and methyl haemmatommate (2) in methanol. Four components were identified from M. leucotyliza: 1, 2, usnic acid (4), and 5, and their respective contents were determined using qHNMR. The percentages (w/w) of 1, 2, and 4 in the methanol extract were calculated as 5.66%, 0.69%, and 0.90%, while those of 1, 4, and 5 in the acetone extract were 1.70%, 1.68%, and 19.11%, respectively.

CONCLUSION

We used qHNMR to effectively analyse quantitative compositional variations in two different M. leucotyliza extracts and reliably determined the chemical conversion of the unstable compound atranorin.

Allergic Inflammation Caused by Dimerized Translationally Controlled Tumor Protein is Attenuated by Cardamonin

We demonstrated in our previous reports that dimeric form of translationally controlled tumor protein (dTCTP) initiates a variety of allergic phenomena. In the present study, we examined whether and how dTCTP's role in allergic inflammation can be modulated or negated. The possible potential of cardamonin as an anti-allergic agent was assessed by ELISA using BEAS-2B cells and OVA-challenged allergic mouse model. The interaction between cardamonin and dTCTP was confirmed by SPR assay. Cardamonin was found to reduce the secretion of IL-8 caused by dTCTP in BEAS-2B cells by interacting with dTCTP. This interaction between dTCTP and cardamonin was confirmed through kinetic analysis (K_D = 4.72 ± 0.07 μM). Also, cardamonin reduced the migration of various inflammatory cells in the bronchoalveolar lavage fluid (BALF), inhibited OVA specific IgE secretion and bronchial remodeling. In addition, cardamonin was observed to have an anti-allergic response by inhibiting the activity of NF-κB. Cardamonin exerts anti-allergic anti-inflammatory effect by inhibiting dTCTP, suggesting that it may be useful in the therapy of allergic diseases.

The qNMR Summit 5.0: Proceedings and Status of qNMR Technology

The goal of the qNMR Summit is to take stock of the status quo and the recent developments in qNMR research and applications in a timely and accurate manner. It provides a platform for both advanced and novice qNMR practitioners to receive a well-rounded update and discuss potential qNMR-related applications and collaborations. For over a decade, scientists from academia, industry, nonprofit institutions, and governmental bodies have focused on the standardization of qNMR methodology, as well as its metrological and pharmacopeial utility. This paper reviews key content of qNMR Summits 1.0 to 4.0 and puts into perspective the outcomes and available transcripts of the October 2019 Summit 5.0, with attendees from the United States, Canada, Japan, Korea, and several European countries. Summit presentations focused on qNMR methodology in the pharmaceutical industry, advanced quantitation algorithms, and promising developments.

Metabolite Profiling and Dipeptidyl Peptidase IV Inhibitory Activity of Coreopsis Cultivars in Different Mutations

Coreopsis species have been developed to produce cultivars of various floral colors and sizes and are also used in traditional medicine. To identify and evaluate mutant cultivars of C. rosea and C. verticillata, their phytochemical profiles were systematically characterized using ultra-performance liquid chromatography time-of-flight mass spectrometry, and their anti-diabetic effects were evaluated using the dipeptidyl peptidase (DPP)-IV inhibitor screening assay. Forty compounds were tentatively identified. This study is the first to provide comprehensive chemical information on the anti-diabetic effect of C. rosea and C. verticillata. All 32 methanol extracts of Coreopsis cultivars inhibited DPP-IV activity in a concentration-dependent manner (IC₅₀ values: 34.01–158.83 μg/mL). Thirteen compounds presented as potential markers for distinction among the 32 Coreopsis cultivars via principal component analysis and orthogonal partial least squares discriminant analysis. Therefore, these bio-chemometric models can be useful in distinguishing cultivars as potential dietary supplements for functional plants.

Anticancer Activity of 2-O-caffeoyl Alphitolic Acid Extracted from the Lichen, Usnea barbata 2017-KL-10

Colorectal cancer is one of the life-threatening ailments causing high mortality and morbidity worldwide. Despite the innovation in medical genetics, the prognosis for metastatic colorectal cancer in patients remains unsatisfactory. Recently, lichens have attracted the attention of researchers in the search for targets to fight against cancer. Lichens are considered mines of thousands of metabolites. Researchers have reported that lichen-derived metabolites demonstrated biological effects, such as anticancer, antiviral, anti-inflammatory, antibacterial, analgesic, antipyretic, antiproliferative, and cytotoxic, on various cell lines. However, the exploration of the biological activities of lichens' metabolites is limited. Thus, the main objective of our study was to evaluate the anticancer effect of secondary metabolites isolated from lichen (Usnea barbata 2017-KL-10) on the human colorectal cancer cell line HCT116. In this study, 2OCAA exhibited concentration-dependent anticancer activities by suppressing antiapoptotic genes, such as MCL-1, and inducing apoptotic genes, such as BAX, TP53, and CDKN1A(p21). Moreover, 2OCAA inhibited the migration and invasion of colorectal cancer cells in a concentration-dependent manner. Taken together, these data suggest that 2OCAA is a better therapeutic candidate for colorectal cancer.

Estrogenic Effects of Extracts and Isolated Compounds from Belowground and Aerial Parts of Spartina anglica

Menopause, caused by decreases in estrogen production, results in symptoms such as facial flushing, vaginal atrophy, and osteoporosis. Although hormone replacement therapy is utilized to treat menopausal symptoms, it is associated with a risk of breast cancer development. We aimed to evaluate the estrogenic activities of Spartina anglica (SA) and its compounds and identify potential candidates for the treatment of estrogen reduction without the risk of breast cancer. We evaluated the estrogenic and anti-proliferative effects of extracts of SA and its compounds in MCF-7 breast cancer cells. We performed an uterotrophic assay using an immature female rat model. Among extracts of SA, belowground part (SA-bg-E50) had potent estrogenic activity. In the immature female rat model, the administration of SA-bg-E50 increased uterine weight compared with that in the normal group. Among the compounds isolated from SA, 1,3-di-O-trans-feruloyl-(-)-quinic acid (1) had significant estrogenic activity and induced phosphorylation at serine residues of estrogen receptor (ER)α. All extracts and compounds from SA did not increase MCF-7 cell proliferation. Compound 1 is expected to act as an ERα ligand and have estrogenic effects, without side effects, such as breast cancer development.

Changes in the aquatic ecotoxicological effects of Triton X-100 after UV photodegradation

Various spray adjuvants including surfactants are widely used in agricultural pesticide formulations, and some of them may remain in soils and waters and impose more adverse effects than active pesticide ingredients on organisms. However, previous studies are more focused on the active pesticide ingredients than the adjuvants. Thus, this study investigates the changes in toxic effects of surfactants during photodegradation, which is one way of naturally degrading contaminants in natural waters. Triton X-100, a water-soluble non-ionic surfactant, was degraded using different types of UV radiation (UVA, UVB, and UVC), and the changes in the toxic effects were determined using bioluminescent bacteria and water flea. The Triton X-100 removals were negligible with UVA within 24 h, while its removal was 81% with UVB and almost complete with UVC. The NMR spectra indicated possible molecule rearrangement after photolysis. On the other hand, the toxic effects based on the mortality of Daphnia magna and the bioluminescence of Aliivibrio fischeri increased (i.e., lower EC50 values) after photodegradation, suggesting the generation of photoproducts that are likely to have higher toxic effects or higher bioavailability. Furthermore, the sensitivities of D. magna and A. fischeri for Triton X-100 and the photodegraded Triton X-100 were different. This study suggests that the changes in the chemical composition of the Triton X-100 containing water with photodegradation can lead to changes in the relative toxic effects on different aquatic organisms. Therefore, not only the management of parent compound (i.e., Triton X-100) but also the photoproducts generated from the parent compound need to be considered when managing water environment subject to photodegradation.

Antioxidant, Pancreatic Lipase Inhibitory, and Tyrosinase Inhibitory Activities of Extracts of the Invasive Plant Spartina anglica (Cord-Grass)

Since 2016, the invasive halophyte Spartina anglica has been colonizing mudflats along the western coast of South Korea. In order to minimize costs on S. anglica expansion management and waste-treatment of collected biomass, the potential application of the collected biomass of S. anglica was investigated. Ethanolic extracts and subfractions thereof (hexanes, methylene chloride, ethyl acetate, 1-butanol, and water-soluble) of the aerial and belowground parts of S. anglica showed free radical-scavenging [2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)], tyrosinase inhibitory, and pancreatic lipase inhibitory activities. An ethyl acetate fraction derived from aerial parts (EA-a) showed the most potent radical-scavenging and pancreatic lipase inhibitory activities, whereas tyrosinase inhibition was mainly observed in the methylene chloride soluble fractions (MC-bg) and other lipophilic fractions (ethyl acetate and hexanes layers) obtained from belowground parts. The major EA-a compound isolated and identified was 1,3-di-O-trans-feruloyl quinic acid (1) based on spectroscopic analysis, whereas the two major MC-bg compounds were identified as p-hydroxybenzaldehyde (2) and N-trans-feruloyltyramine (3). Compounds 1 and 3 scavenged both DPPH and ABTS radicals, whereas 1 and 2 inhibited pancreatic lipase activity. These results indicate that extracts and fractions of S. anglica have antioxidant, anti-obesity, and whitening properties with potential pharmaceutical, cosmeceutical, and functional food applications.

9‑Hydroxy‑isoegomaketone inhibits LPS‑induced NO and inflammatory cytokine production in RAW264.7 cells

Isoegomaketone (IK) is a known component of Perilla frutescens that reportedly exhibits anti-inflammatory, anti-cancer and anti-allergic properties. A novel compound known as 9-HIK has been isolated from the extract of a radiation mutant P. frutescens var. crispa using supercritical carbon dioxide. In the present study, 9-HIK induced heme oxygenase-1 (HO-1) mRNA expression in RAW264.7 cells, with maximal levels observed 4 h after 9-HIK treatment. In addition, 9-HIK inhibited the mRNA and protein expression of pro-inflammatory mediators, such as IL-6 and interferon-β, as well as the production of nitric oxide (NO) in lipopolysaccharide-stimulated RAW264.7 cells. Furthermore, N-acetyl-L-cysteine, a reactive oxygen species scavenger, inhibited NO production and HO-1 mRNA expression levels through the nuclear factor erythroid 2-related factor 2 pathway. Overall, 9-HIK displayed anti-inflammatory properties in LPS-induced RAW264.7 cells via direct suppression of inflammatory mediators and HO-1 induction.

Targeting Trimeric and Tetrameric Proanthocyanidins of Cinnamomum verum Bark as Bioactives for Dental Therapies

The present study elucidated the structures of three A-type tri- and tetrameric proanthocyanidins (PACs) isolated from Cinnamomum verum bark to the level of absolute configuration and determined their dental bioactivity using two therapeutically relevant bioassays. After selecting a PAC oligomer fraction via a biologically diverse bioassay-guided process, in tandem with centrifugal partition chromatography, phytochemical studies led to the isolation of PAC oligomers that represent the main bioactive principles of C. verum: two A-type tetrameric PACs, epicatechin-(2β→O→7,4β→8)-epicatechin-(4β→6)-epicatechin-(2β→O→7,4β→8)-catechin (1) and parameritannin A1 (2), together with a trimer, cinnamtannin B1 (3). Structure determination of the underivatized proanthocyanidins utilized a combination of HRESIMS, ECD, 1D/2D NMR, and 1H iterative full spin analysis data and led to NMR-based evidence for the deduction of absolute configuration in constituent catechin and epicatechin monomeric units.

Proanthocyanidin Block Arrays (PACBAR) for Comprehensive Capture and Delineation of Proanthocyanidin Structures

Proanthocyanidins (PACs) are near-ubiquitous and chemically complex metabolites, prototypical of higher plants. Their roles in food/feed/nutrition and ethnomedicine are widely recognized but poorly understood. With the analysis of evidence that underlies this challenge, this perspective identifies shortcomings in capturing and delineating PAC structures as key factors. While several groups have forwarded new representations, a consensus method that captures PAC structures concisely and offers high integrity for electronic storage is required to reduce confusion in this expansive field. The PAC block arrays (PACBAR) system fills this gap by providing precise and human- and machine-readable structural descriptors that capture PAC metabolomic structural diversity. PACBAR enables communication of PAC structures for the development of precise structure-activity relationships and will assist in advancing PAC research to the next level.

Suntamide A, a neuroprotective cyclic peptide from Cicadidae Periostracum

Suntamide A (1), a new cyclic peptide, was isolated from Cicadidae Periostracum. The gross structure of 1 was elucidated by detailed analysis of HRMS and 1D/2D NMR spectra, and the absolute configuration was established by C3 Marfey's method. We extended our study to examine biological activity of 1, and found that 1 protected SH-SY5Y cells against rotenone-induced neurotoxicity. This effect of 1 seemed to be attributed to antioxidant induction and protection of mitochondria from rotenone-caused injury. Along with augmentation of the antioxidant system by 1, there was an evident activation of Nrf2, a transcription factor involved in the activation of the antioxidant system. These results indicate that 1 rescued the cells from rotenone-mediated neurotoxicity by enhancing antioxidant capacity via induction of Nrf2, suggesting that the compound could be used as a therapeutic intervention in neurodegenerative diseases such as Parkinson's disease.

A dynamic mechanical method to assess bulk viscoelastic behavior of the dentin extracellular matrix

OBJECTIVES

To develop a protocol for assessment of the bulk viscoelastic behavior of dentin extracellular matrix (ECM), and to assess relationships between induced collagen cross-linking and viscoelasticity of the dentin ECM.

METHODS

Dentin ECM was treated with agents to induce exogenous collagen cross-linking: proanthocyanidins (PACs) from Vitis vinifera - VVe, PACs from Pinus massoniana - PMe, glutaraldehyde - (GA), or kept untreated (control). A dynamic mechanical strain sweep method was carried out in a 3-point bending submersion clamp at treatment; after protein destabilization with 4 M urea and after 7-day, 6-month, and 12-month incubation in simulated body fluid. Tan δ, storage (E'), loss (E"), and complex moduli (E*) were calculated and data were statistically analyzed using two-way ANOVA and post-hoc tests (α = 0.05). Chemical analysis of dentin ECM before and after protein destabilization was assessed with ATR-FTIR spectroscopy.

RESULTS

Significant interactions between study factors (treatment vs. time points, p < 0.001) were found for all viscoelastic parameters. Despite a significant decrease in all moduli after destabilization, PAC-treated dentin remained statistically higher than control (p < 0.001), indicating permanent mechanical enhancement after biomodification. Covalently crosslinked, GA-treated dentin was unaffected by destabilization (p = 0.873) and showed the lowest damping capacity (tan δ) at all time points (p < 0.001). After 12 months, the damping capacity of PMe and VVe groups decreased significantly. Changes in all amide IR resonances revealed a partial chemical reversal of PAC-mediated biomodification.

SIGNIFICANCE

Viscoelastic measurements and IR spectroscopy aid in elucidating the role of inter-molecular collagen cross-linking in the mechanical behavior of dentin ECM.

N-Acetyldopamine derivatives from Periostracum Cicadae and their regulatory activities on Th1 and Th17 cell differentiation

Bioassay-guided fractionation of a 90% ethanol extract of Periostracum Cicadae led to the isolation of two new N-acetyldopamine dimers (1a/1b) along with six known dimers (2a/2b, 3a/3b, and 4a/4b) and two monomers (5a/5b); compounds 2a/2b, 4a/4b and 5a/5b were newly isolated from this material. All compounds were isolated as enantiomeric mixtures and each enantiomer was successfully separated by chiral-phase HPLC. The structures including absolute configurations were confirmed by high-resolution electrospray ionization mass spectrometry (HR-ESIMS), 1D/2D nuclear magnetic resonance (NMR) spectroscopy, ¹H iterative Full Spin Analysis (HiFSA), and electronic circular dichroism (ECD) spectroscopy. Subsequently, the bioactivities of these isolates were evaluated via CD4⁺ T cell differentiations, which are critical for immune responses and inflammation. The results revealed that compound 5b was observed to enhance the IFN-γ⁺ Th1 differentiation, which may have a potential for cancer immunotherapy.

Tri- and Tetrameric Proanthocyanidins with Dentin Bioactivities from Pinus massoniana

Guided by dentin biomechanical bioactivity, this phytochemical study led to the elucidation of an extended set of structurally demanding proanthocyanidins (PACs). Unambiguous structure determination involved detailed spectroscopic and chemical characterization of four A-type dimers (2 and 4-6), seven trimers (10-16), and six tetramers (17-22). New outcomes confirm the feasibility of determining the absolute configuration of the catechol monomers in oligomeric PACs by one-dimensional (1D) and two-dimensional (2D) NMR. Electronic circular dichroism as well as phloroglucinolysis followed by mass spectrometry and chiral phase high-performance liquid chromatography (HPLC) analysis generated the necessary chiral reference data. In the context of previously reported dentin-bioactive PACs, accurately and precisely assigned ¹³C NMR resonances enabled absolute stereochemical assignments of PAC monomers via (i) inclusion of the ¹³C NMR γ-gauche effect and (ii) determination of differential ¹³C chemical shift values (Δδ_C) in comparison with those of the terminal monomer (unit II) in the dimers 2 and 4-6. Among the 13 fully elucidated PACs, eight were identified as new, and one structure (11) was revised based on new knowledge gained regarding the subtle, stereospecific spectroscopic properties of PACs.

A stilbene dimer and flavonoids from the aerial parts of Chromolaena odorata with proprotein convertase subtilisin/kexin type 9 expression inhibitory activity

Investigation of components of the chloroform-soluble and ethyl acetate-soluble extracts of the aerial parts of Chromolaena odorata L. selected by PCSK9 mRNA expression monitoring assay in HepG2 cells led to the isolation of a new stilbene dimer, (+)-8b-epi-ampelopsin A (1), and 30 known compounds (2-31). The structures of the isolates were established by interpretation of NMR spectroscopic data and the stereochemistry of the new stilbene (1) was proposed based on ECD and NMR calculations. Among the isolates, 1, 5,6,7,4'-tetramethoxyflavanone (6), 5,6,7,3',4'-pentamethoxyflavanone (7), acacetin (18), and uridine (21) were found to inhibit PCSK9 mRNA expression with IC₅₀ values of 20.6, 21.4, 31.7, 15.0, and 13.7 µM, respectively. Furthermore, the most abundant isolate among the selected compounds, 6, suppressed PCSK9 and low-density lipoprotein receptor protein expression in addition to downregulating the mRNA expression of HNF-1α.

Purification of Phenylpropanoids from the Scaly Bulbs of Lilium Longiflorum by CPC and Determination of Their DPP-IV Inhibitory Potentials

The scaly bulbs of Lilium longiflorum (Liliaceae) are used as a food ingredient and a traditional medicine in East Asia. A preliminary study revealed that treatment with 100 μg/mL of the ethyl acetate fraction of this plant material inhibited dipeptidyl peptidase IV (DPP-IV) to 58.99%. Phytochemical studies were conducted to identify the active ingredient, and five compounds, namely, 1 (2.9 mg, 75.8% purity at 320 nm), 2 (12.2 mg, 97.9% purity at 320 nm), 3 (3.1 mg, 66.5% purity at 320 nm), 4 (6.8 mg, 96.9% purity at 320 nm), and 5 (6.2 mg, 90.2% purity at 320 nm) were purified from 200 mg of the ethyl acetate fraction of L. longiflorum via centrifugal partition chromatography (CPC) with a two-phase solvent system composed of chloroform/methanol/isopropanol/water (5:2:2:4, v/v/v/v) in an ascending mode. Their structures were identified as 1-O-p-coumaroyl-2-O-β-glucopyranosylglycerol (regaloside D, 1), 3,6'-O-diferuloylsucrose (2), 1-O-p-coumaroyl-2-O-β-glucopyranosyl-3-O-acetylglycerol (regaloside B, 3), 1-O-p-coumaroylglycerol (4), and 4-O-acetyl-3,6'-O-diferuloylsucrose (5), respectively, by ¹H and ¹³C NMR and MS analysis. Compounds 2 and 5 exhibited DPP-IV inhibitory activities with IC₅₀ values of 46.19 and 63.26 μM, respectively. Compounds 1, 3, and 4 did not show activities, indicating that biphenylpropanoids linked via the sugar moiety are more effective than phenylpropanoids with glycerol or glyceryl glucoside. This is the first report of simultaneous separation of five phenylpropanoids from L. longiflorum by CPC and evaluation of their DPP-IV inhibitory activities.

Proanthocyanidin Dimers and Trimers from Vitis vinifera Provide Diverse Structural Motifs for the Evaluation of Dentin Biomodification

Aimed at exploring the dentin biomodification potential of proanthocyanidins (PACs) for the development of dental biomaterials, this study reports the phytochemical and dental evaluation of nine B-type PACs from grape seed extract (GSE). Out of seven isolated dimers (1-7), four new compounds (2, 3, 5, and 6) involved relatively rare ent-catechin or ent-epicatechin monomeric flavan-3-ol units. Low-temperature NMR analyses conducted along with phloroglucinolysis and electronic circular dichroism enabled unequivocal structural characterization and stereochemical assignment. Additionally, one known (8) and one new (9) B-type trimer were characterized. Differential ¹³C NMR chemical shifts (Δδ) were used to determine the absolute configuration of 9, relative to the dimers 1 and 2 as the possible constituent subunits. Compared to the dimers, the trimers showed superior dentin biomodification properties. The dimers, 1-7, exhibited pronounced differences in their collagenase inhibitory activity, while enhancing dentin stiffness comparably. This suggests that PAC structural features such as the degree of polymerization, relative and absolute configuration have a differential influence on enhancement of dentin biomechanical and biostability. As mechanical enhancement to dentin and resistance to proteolytic biodegradation are both essential properties functional and stable dentin substrate, the structurally closely related PACs suggest a new metric, the dentin biomodification potential (DBMP) that may rationalize both properties.

Mycousfurans A and B, Antibacterial Usnic Acid Congeners from the Fungus Mycosphaerella sp., Isolated from a Marine Sediment

Mycousfurans (1 and 2), two new usnic acid congeners, along with (−)-mycousnine (3), (−)-placodiolic acid (4), and (+)-usnic acid (5), were isolated using high-performance liquid chromatography-ultraviolet (HPLC-UV)-guided fractionation of extracts of Mycosphaerella sp. isolated from a marine sediment. The planar structures of 1 and 2 were elucidated using 1D and 2D NMR spectra. The relative configurations of the stereogenic carbons of 1 and 2 were established via analysis of their nuclear Overhauser spectroscopy (NOESY) spectra, and their absolute configurations were determined using a comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1 and 2 were found to have antibacterial activity, showing moderate activity against Kocuria rhizophila and Staphylococcus aureus.

The value of universally available raw NMR data for transparency, reproducibility, and integrity in natural product research

Covering: up to 2018With contributions from the global natural product (NP) research community, and continuing the Raw Data Initiative, this review collects a comprehensive demonstration of the immense scientific value of disseminating raw nuclear magnetic resonance (NMR) data, independently of, and in parallel with, classical publishing outlets. A comprehensive compilation of historic to present-day cases as well as contemporary and future applications show that addressing the urgent need for a repository of publicly accessible raw NMR data has the potential to transform natural products (NPs) and associated fields of chemical and biomedical research. The call for advancing open sharing mechanisms for raw data is intended to enhance the transparency of experimental protocols, augment the reproducibility of reported outcomes, including biological studies, become a regular component of responsible research, and thereby enrich the integrity of NP research and related fields.

Evidence to the role of interflavan linkages and galloylation of proanthocyanidins at sustaining long-term dentin biomodification

OBJECTIVES

The interactivity of proanthocyanidins (PACs) with collagen modulates dentin matrix biomechanics and biostability. Herein, PAC extracts selected based on structural diversity were investigated to determine key PAC features driving sustained effects on dentin matrices over a period of 18months.

METHODS

The chemical profiles of PAC-rich plant sources, Pinus massoniana (PM), Cinnamomum verum (CV) and Hamamelis virginiana (HV) barks, as well as Vitis vinifera (VV) seeds, were obtained by diol HPLC analysis after partitioning of the extracts between methyl acetate and water. Dentin matrices (n=15) were prepared from human molars to determine the apparent modulus of elasticity over 18months of aging. Susceptibility of the dentin matrix to degradation by endogenous and exogenous proteases was determined by presence of solubilized collagen in supernatant, and resistance to degradation by bacterial collagenase, respectively. Data were analyzed using ANOVA and Games-Howell post hoc tests (α=0.05).

RESULTS

After 18months, dentin matrices modified by PM and CV extracts, containing only non-galloylated PACs, were highly stable mechanically (p<0.05). Dentin matrices treated with CV exhibited the lowest degradation by bacterial collagenase after 1h and 18months of aging (p<0.05), while dentin matrices treated with PM showed the least mass loss and collagen solubilization by endogenous enzymes over time (p<0.05).

SIGNIFICANCE

Resistance against long-term degradation was observed for all experimental groups; however, the most potent and long-lasting dentin biomodification resulted from non-galloylated PACs.