New Pimarane Diterpenoids Isolated from EtOAc-Extract of Apiospora arundinis Culture Medium Show Antibenign Prostatic Hyperplasia Potential.

Three new pimarane diterpenoids, libertellenones U-W (1-3), together with libertellenone C (4) and myrocin A (5) were isolated from an EtOAc-extract of Apiospora arundinis culture medium. The chemical structures of the new compounds were elucidated using MS, NMR, and CD spectroscopic data. Benign prostatic hyperplasia (BPH), the abnormal and pathological proliferation of epithelial and stromal cells in prostatic tissues, is a common disease in middle-aged and elderly men. In this study, the anti-BPH effects of myrocin A (5) were evaluated using BPH-1 and WPMY-1 cells. Treatment with myrocin A (5) exerted antiproliferative effects in BPH-1 and dihydrotestosterone (DHT)-stimulated WPMY-1 cells. In BPH, treatment with myrocin A (5) significantly suppressed the mRNA levels of androgen receptor (AR) and its downstream targets nuclear receptor coactivator 1 (NCOA1), proliferating cell nuclear antigen (PCNA) and kallikrein-related peptidase 3 (KLK3). Additionally, DHT-stimulated WPMY-1 cells demonstrated an upregulated mRNA levels of AR, NCOA1, PCNA, and KLK3. However, treatment with myrocin A (5) resulted in suppression of the mRNA levels. Moreover, myrocin A (5) docked computationally into the binding site of the androgen receptor (-5.5 kcal/mol).

Targeting phosphorylation circuits on CREB and CRTCs as the strategy to prevent acquired skin hyperpigmentation.

Background: The cAMP response element-binding protein (CREB) and CREB-regulated transcription coactivators (CRTCs) cooperate in the transcriptional activation of microphthalmia-associated transcription factor subtype M (MITF-M) that is a master regulator in the biogenesis, pigmentation and transfer of melanosomes at epidermal melanocytes. Here, we propose the targeting of phosphorylation circuits on CREB and CRTCs in the expression of MITF-M as the rationale to prevent skin hyperpigmentation by elucidating the inhibitory activity and mechanism of yakuchinone A (Yaku A) on facultative melanogenesis. Methods: We employed human epidermal melanocyte cell, mouse skin, and mouse melanoma cell, and applied Western blotting, reverse transcription-polymerase chain reaction, immunoprecipitation and confocal microscopy to conduct this study. Results: This study suggested that α-melanocyte stimulating hormone (α-MSH)-induced melanogenic programs could switch on the axis of protein kinase A-salt inducible kinases (PKA-SIKs) rather than that of PKA-AMP activated protein kinase (PKA-AMPK) during the dephosphorylation of CRTCs in the expression of MITF-M. SIK inhibitors rather than AMPK inhibitors stimulated melanin production in melanocyte cultures in the absence of extracellular melanogenic stimuli, wherein SIK inhibitors increased the dephosphorylation of CRTCs but bypassed the phosphorylation of CREB for the expression of MITF-M. Treatment with Yaku A prevented ultraviolet B (UV-B)-irradiated skin hyperpigmentation in mice and inhibited melanin production in α-MSH- or SIK inhibitor-activated melanocyte cultures. Mechanistically, Yaku A suppressed the expression of MITF-M via dually targeting the i) cAMP-dependent dissociation of PKA holoenzyme at the upstream from PKA-catalyzed phosphorylation of CREB coupled with PKA-SIKs axis-mediated dephosphorylation of CRTCs in α-MSH-induced melanogenic programs, and ii) nuclear import of CRTCs after SIK inhibitor-induced dephosphorylation of CRTCs. Conclusions: Taken together, the targeting phosphorylation circuits on CREB and CRTCs in the expression of MITF-M could be a suitable strategy to prevent pigmentary disorders in the skin.

Targeted Isolation of N-Acetylcysteine-Containing Angucycline Derivatives from Streptomyces sp. MC16 and Their Antiproliferative Effects.

Liquid chromatography-mass spectrometry (LC-MS/MS)-based molecular networking analysis was applied to Streptomyces sp. MC16. The automatic classification of the MolNetEnhancer module revealed that its major constituent was an angucycline derivative. By targeted isolation of unique clusters in the molecular network, which showed different patterns from typical angucycline compounds, two new N-acetylcysteine-attached angucycline derivatives (1 and 2) were isolated. The structures were elucidated based on intensive NMR analysis and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). All isolated compounds (1-4) were tested for their inhibitory effects on the proliferation of A431, A549, and HeLa cell lines. Antibiotics 100-1 (3) and vineomycinone B2 (4) showed moderate inhibitory effects on these three cell lines with IC50 values ranging from 18.5 to 59.0 µM, while compounds 1 and 2 with an additional N-acetylcysteine residue showed weak inhibitory effects only on the HeLa cell line with IC50 values of 54.7 and 65.2 µM, respectively.

Molecular networking-assisted isolation of chlorophenolic glycosides from the rhizomes of Curculigo orchioides and their inhibitory effect on α-glucosidase.

Molecular networking analysis and in silico tools, such as Network Annotation Propagation (NAP) and MolNetEnhancer, were applied to explore bioactive constituents present in the ethyl acetate-soluble fraction of the rhizomes of Curculigo orchioides. Among the molecular networks, the most abundant cluster was classified as a phenolic glycoside using the ClassyFire module of MolNetEnhancer. Further, the major node in this cluster was accurately predicted as curculigine A using the in silico fragment analysis tool, NAP. Six undescribed chlorophenolic glycosides (1-6) and 11 known phenolic glycosides were isolated, using molecular networking-assisted isolation methods, and their structures were elucidated using 1D, 2D-NMR and HRESIMS. In particular, the structures of the isolated chlorophenolic glycosides, which have non-protonated aromatic rings, were determined using various NMR experiments, such as 1D-selective NOE, ROESY, and LR-HMBC, and acid hydrolysis. All isolated compounds were examined to determine their inhibitory effects on α-glucosidase and compounds 3, 8, 10, 11, 13, 14, and 16 revealed the IC50 values ranging from 19.6 to 35.5 µM. Their structure-activity relationships were also evaluated based on the analysis of their inhibitory effects and performance of molecular docking simulations.

Targeted isolation of sesquiterpene lactone dimers from Aucklandia lappa guided by LC-HRMS/MS-based molecular networking.

An LC-HRMS/MS-based molecular networking strategy was applied to investigate the potential sesquiterpene dimers of Aucklandia lappa, leading to the isolation of three undescribed guaiane-guaiane dimers and one guaiane-eudesmane dimer together with six known sesquiterpenes. The structures were determined by analyzing their 1D, 2D NMR, and HRESIMS data as well as ECD calculations. The biogenetic pathway of the sesquiterpene dimers was postulated to involve the Diels-Alder cycloaddition as the key step. All compounds exhibited their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages with IC50 values ranging from 0.3 to 25.1 µM.

Molecular Networking-Guided Isolation of Cycloartane-type Triterpenoids from Curculigo orchioides and Their Inhibitory Effect on Nitric Oxide Production.

The MolNetEnhancer workflow was applied to molecular networking analysis of the CH2Cl2-soluble fraction of the rhizomes of Curculigo orchioides, which showed a potent inhibitory effect on the lipopolysaccharide (LPS)-induced nitric oxide production. Among the molecular network, clusters of cycloartane-type triterpenoids were classified using the ClassyFire module of MolNetEnhancer, and their structures were predicted by the in silico fragment analysis tool, Network Annotation Propagation (NAP). Using mass spectrometry (MS)-guided isolation methods, six cycloartane-type triterpenoids (1-6) were isolated, and their structures were elucidated based on the interpretation of NMR, HRESIMS, and single-crystal X-ray diffraction. Among the isolates, compounds 1 and 4, which have an α,ß-unsaturated carbonyl moiety on the A-ring, exhibited significant inhibitory effects on LPS-induced nitric oxide production in RAW264.7 cells with IC50 values of 12.4 and 11.8 µM, respectively.

Bioactive molecular network-guided discovery of dihydro-ß-agarofurans from the fruits of Celastrus orbiculatus.

A bioactive molecular networking strategy has been applied to discovery of bioactive constituents from the fruits of Celastrus orbiculatus Thunb., which showed significant inhibitory effects on the α-MSH-induced melanin production in B16F0 melanoma cells. In the obtained molecular network, the nodes with relatively high bioactive scores were prioritized for isolation; as a result, 12 undescribed dihydro-ß-agarofuran sesquiterpenes together with 15 known compounds were isolated from MeOH extracts of the fruits of C. orbiculatus. Their structures were elucidated based on the interpretation of NMR, HRESIMS, ECD data, and single crystal X-ray diffraction. Among the obtained isolates, celastorbin A and (1R,2S,4R,5S,7S,8S,9R,10S)-1,2,8-triacetoxy-9-cinnamoyloxydihydro-ß-agarofuran, which possessed high bioactive scores in the molecular network, exhibited potent inhibitory effects on the α-MSH-induced melanin production in B16F0 cells with IC50 values of 4.1 and 2.0 µM, respectively.

Polyacetylenes from the roots of Cirsium japonicum var. ussuriense.

Eight previously undescribed polyacetylenes, cirussurynes A-H, were isolated from the methanolic extract of the roots of Cirsium japonicum var. ussuriense. Their structures were elucidated by interpretation of extensive 1D and 2D NMR spectroscopy and HRESIMS spectrometry data. The configuration of triols in cirussurynes A, B, and E-G was deduced by the J-value based configuration analysis together with specific rotation values. All compounds were evaluated for their inhibitory effects on nitric oxide production against LPS-induced RAW 264.7 macrophages, and exhibited IC50 values ranging from 5.5 to 68.7 µM.

Chemical constituents from Pterocarpus santalinus and their inhibitory effects on nitric oxide production.

A tropolone (2) and an acorane sesquiterpene (3), along with twenty previously known compounds were isolated from the heartwood of Pterocarpus santalinus. The structure of the isolated compounds was elucidated via 1D and 2D NMR spectroscopy and HRESIMS analysis. The absolute configuration of 3 was determined by comparison of the experimental and calculated ECD data. All compounds were evaluated for their inhibitory effects against nitric oxide production in LPS-stimulated RAW 264.7 macrophages.

Dianthiamides A-E, Proline-Containing Orbitides from Dianthus chinensis.

Orbitides are plant-derived small cyclic peptides with a wide range of biological activities. Phytochemical investigation of the whole plants of Dianthus chinensis was performed with the aim to discover new bioactive orbitides. Five undescribed proline-containing orbitides, dianthiamides A-E (1-5), were isolated from a methanolic extract of Dianthus chinensis. Their structures were elucidated by extensive analysis of 1D and 2D NMR and HRESI-TOF-MS as well as ESI-MS/MS fragmentation data. The absolute configuration of the amino acid residues of compounds 1-5 was determined by Marfey's method. All compounds were tested for their cytotoxic activity, and dianthiamide A (1) exhibited weak activity against A549 cell line with IC50 value of 47.9 µM.

Comparative Study of Bioactivity and Safety Evaluation of Ethanolic Extracts of Zanthoxylum schinifolium Fruit and Pericarp.

The fruit and pericarp of Zanthoxylum schinifolium (ZS) have been used in traditional medicine; however, few studies have characterized ZS fruit and pericarp. Therefore, in the present study, we evaluated the safety of ZS fruit (ZSF) and pericarp (ZSP) extracts and compared their bioactivity. To evaluate the safety of ZSF and ZSP, mutagenicity, cytotoxicity, and oxidative stress assays were performed and nontoxic concentration ranges were obtained. ZSP was found to be superior to ZSF in terms of its antimutagenic, antioxidant, and anti-inflammatory activities. In the S9 mix, the mutation inhibition rate of ZSP was close to 100% at concentrations exceeding 625 µg·plate-1 for both the TA98 and TA100 strains. ZSP exhibited efficient DPPH (IC50 = 75.6 ± 6.1 µg·mL-1) and ABTS (IC50 = 57.4 ± 6 µg·mL-1) scavenging activities. ZSP inhibited the release of cytokines, involved in IL-1ß (IC50 = 134.4 ± 7.8), IL-6 (IC50 = 262.8 ± 11.2), and TNF-α (IC50 = 223.8 ± 5.8). These results indicate that ZSP contains a higher amount of biochemicals than ZSF, or that ZSP contains unique biochemicals. In conclusion, for certain physiological activities, the use of ZSP alone may be more beneficial than the combined use of ZSF and ZSP.

Sesquiterpenoids from Chrysanthemum indicum with Inhibitory Effects on NO Production.

Three new guaianolide lactones (1-3) and four new 9-oxonerolidol glucosides (5-8) together with 20 known compounds were isolated from the MeOH extract of the flowers of Chrysanthemum indicum. Their structures were elucidated based on the interpretation of NMR, HRESIMS, and electronic circular dichroism (ECD) data along with acid hydrolysis. Of the isolates, sesquiterpenoids 1-4 and 15 and flavones 17 and 18 exhibited inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide production in RAW 264.7 cells with IC50 values in the range 0.2-27.0 µM.

Pentacyclic triterpenes with nitric oxide inhibitory activity from Potentilla chinensis.

Three new ursane-type triterpenes (1-3) and twenty-one known triterpenoids (4-24) were isolated from the methanolic extract of the whole plants of Potentilla chinensis. Their structures were elucidated by extensive spectroscopic analysis of 1D and 2D NMR (HSQC, HMBC, COSY and ROESY) and HRESIMS data. The bioassay screening revealed the inhibitory effects on nitric oxide production of compounds 2, 5, 7, 9, 10, and 13-24 in LPS-induced RAW264.7 macrophages.

UPLC-ESI-Q-TOF-MS-Based Metabolite Profiling, Antioxidant and Anti-Inflammatory Properties of Different Organ Extracts of Abeliophyllum distichum.

Plant extracts have gained more attention as natural therapeutic agents against inflammation characterized by an overproduction of several inflammatory mediators such as reactive oxygen species and pro-inflammatory cytokines. Although Abeliophyllum distichum Nakai is generally known for its ornamental value, recent pharmacological research has demonstrated its potential therapeutic properties. Thus, to further evaluate the applicability of A. distichum in the food, cosmetic, and medical industries, we identified the phytochemicals in three organ extracts (fruits: AF, branches: AB, leaves: AL) of A. distichum and determined their antioxidant and anti-inflammatory activities. Using UPLC-ESI-Q-TOF-MS, a total of 19 compounds, including dendromoniliside D, forsythoside B, isoacteoside, isomucronulatol 7-O-Glucoside, plantamajoside, and wighteone were identified in the A. distichum organ extracts. AB exhibited a strong reducing power, an oxygen radical antioxidant capacity, and radical scavenging values compared with other samples, whereas AL exhibited the best anti-inflammatory properties. Gene expression, western blot, and molecular docking analyses suggested that the anti-inflammatory effect of AL was mediated by its ability to suppress lipopolysaccharide (LPS)-induced production of reactive oxygen species and/or inhibit LPS-stimulated activation of extracellular signal-regulated protein kinases (ERK1/2) in RAW264.7 cells. Collectively, these results indicate that AL is a potential source of phytochemicals that could be used to treat inflammation-associated diseases.

Diterpenoids and Diacetylenes from the Roots of Aralia cordata with Inhibitory Effects on Nitric Oxide Production.

Bioactivity-guided isolation of a MeOH extract of Aralia cordata led to the isolation of four new ent-pimarane diterpenoids (1-4) and a diacetylene (5) together with 21 known compounds (6-26). Their structures were established based on the interpretation of one- and two-dimensional NMR and HRESIMS data. The absolute configurations of the new isolates were determined by electronic circular dichroism data analysis, single crystal X-ray diffraction, and Mosher's esterification method. All compounds exhibited inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages with IC50 values ranging from 1.1 to 69.4 µM.

Quinic acid esters from Erycibe obtusifolia with antioxidant and tyrosinase inhibitory activities.

AbstractA new quinic acid derivative, 3-O-syringoylquinic acid methyl ester (1), along with eight known quinic acid derivatives (2-9), three coumarins (10-12), one phenylpropanoid (13), three feruloyltyramine derivatives (14-16), one lignan (17) and two isoflavones (18-19) were isolated from an ethyl acetate-soluble fraction of the roots and stems of Erycibe obtusifolia. The structure was elucidated on the basis of spectroscopic methods such as 1D and 2D-NMR, including HR-ESI-MS spectrometry. All of these compounds were investigated for their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and inhibitory effects on mushroom tyrosinase. Compounds 2-9, quinic acid derivatives with caffeoyl moiety, showed significant DPPH radical scavenging activity. Moreover, compounds 2 and 5-10 showed weak mushroom tyrosinase inhibitory effects.

Organic acid conjugated phenolic compounds of hardy kiwifruit (Actinidia arguta) and their NF-κB inhibitory activity.

Nine new compounds, argutinosides A-I (1-9) together with 20 known compounds (10-29), were isolated from the fruits of Actinidia arguta. Using spectral analysis, the structures of the isolated compounds were identified as 10 succinic acid derivatives, 11 quinic acid derivatives, two shikimic acid derivatives and six citric acid derivatives. The NF-κB transcriptional inhibitory activity of the compounds was evaluated using RAW 264.7 macrophages cells induced by lipopolysaccharide. Among four groups of different organic acid derivatives, the quinic acid derivatives inhibited NF-κB transcriptional activity with an IC50 value of 4.0 µM. Fruit is rich in organic acid and secondary metabolites, which differ depending on the type of fruit. Our present study showed the presence of various organic acids conjugates including nine new 2-methylsuccinic acid phenolic conjugates in kiwiberry and compared their biological activities. This will contribute to application of kiwiberry and also the diversity of different fruits.

Lignans from Saururus chinensis with Inhibitory Effects on Nitric Oxide Production.

Three biogenetically related ent-sauchinone-type lignans (1-3), four 8-O-4'-type neolignans (4-7), a diaryldimethylbutane lignan (8), and a cyclic carbonate (9), along with 12 known compounds, have been isolated from a methanol extract of the aerial parts of Saururus chinensis. The structures of the new compounds (1-9) were determined by analysis of their 1D and 2D NMR spectra, HRESIMS, and ECD data. A putative biosynthetic pathway for the three ent-sauchinone-type lignans (1-3) was postulated. Compounds 1, 7, and 10 showed inhibitory effects on LPS-induced NO production in RAW 264.7 cells with IC50 values of 5.6, 8.6, and 9.2 µM, respectively.

Pyranoflavanones and Pyranochalcones from the Fruits of Amomum tsao-ko.

Eight new geranylated and farnesylated pyranoflavanones (1-8) and two new farnesylated pyranochalcones (9 and 10) were isolated from the methanolic extract of the fruits of Amomum tsao-ko. Their structures were elucidated by extensive analysis of the 1D and 2D NMR spectra and from the HRESIMS, combined with experimental ECD data. All compounds were evaluated for their inhibitory effects on the nitric oxide production against lipopolysaccharide-induced RAW 264.7 macrophages and exhibited IC50 values ranging from 10.6 to 41.5 µM.

Dimeric- and trimeric sesquiterpenes from the flower of Inula japonica.

An undescribed unusual sesquiterpene trimer and three sesquiterpene dimers were isolated from the flowers of Inula japonica. Their structures were elucidated by extensive analysis of 1D and 2D NMR spectroscopic data as well as HRESIMS data. Inulajaponicolide A has an undescribed carbon skeleton comprising of one xanthanolide and two guaianolide units with the linkage mode of C-11/C-3' and C-11'/C-1'' via a Diels-Alder cycloaddition reaction. Inulajaponicolides C and D exhibited moderate cytotoxic activity against A 549 and NCI-H460 human cancer cell lines with IC50 values ranging from 8.5 to 17.8 µM. Inulajaponicolides A-D and lineariifolianoid A possessed significant inhibitory potency against nitric oxide production in LPS-induced RAW264.7 cells with IC50 values ranging from 1.0 to 4.1 µM.