Inhibiting NF-κB-S100A11 signaling and targeting S100A11 for anticancer effects of demethylzeylasteral in human colon cancer.

Colon cancer is a common and deadly malignancy of the gastrointestinal tract. Targeting proteins that inhibit tumor proliferation could lead to innovative treatment strategies for this disease. Demethylzeylasteral, extracted naturally from Tripterygium wilfordii Hook. f., demonstrates incredible anti-colon cancer activity. However, the molecular mechanism behind this requires further investigation. This study aims to identify crucial targets and mechanisms of demethylzeylasteral in treating colon cancer, making it a promising candidate for anti-tumor therapy. Through gene knockout, overexpression techniques, and double Luciferase experiments, we confirmed that demethylzeylasteral reduces S100A11 expression in HT29 cells and in vivo tumor models to anti-colon cancer. By conducting Surface Plasmon Resonance, immunofluorescence staining, and confocal laser microscopy observations, we verified the direct interaction between demethylzeylasteral and S100A11, and explored the impact of S100A11's subcellular localization on cell proliferation. Demethylzeylasteral inhibited S100A11 expression and exhibited anti-cancer activity in both in vitro and in vivo colon cancer models. Conversely, overexpression of S100A11 hindered apoptosis induced by demethylzeylasteral. Additionally, we found that knockdown or overexpression of NF-κB respectively decreased or increased S100A11 expression, subsequently affecting cell proliferation. The dual Luciferase reporting experiment revealed that NF-κB is an upstream transcription factor regulating S100A11 expression. And Surface plasmon resonance confirmed that S100A11 can directly interact with demethylzeylasteral, this interaction limited the transport of S100A11 from the cytoplasm to nucleus, attenuation S100A11 mediated cell proliferation effect.

Microbial Transformation of Yakuchinone A and Cytotoxicity Evaluation of Its Metabolites.

Yakuchinone A (1) is a bioactive diarylheptanoid isolated from the dried fruits of Alpinia oxyphylla. Microbial transformation has been recognized as an efficient method to produce new biologically active derivatives from natural products. In the present study, microbial transformation of yakuchinone A was performed with the fungus Mucor hiemalis KCTC 26779, which led to the isolation of nine new metabolites (2, 3a, 3b, and 4-9). Their structures were elucidated as (3S)-oxyphyllacinol (2), (3S,7R)- and (3S,7S)-7-hydroxyoxyphyllacinol (3a and 3b), (3S)-oxyphyllacinol-4'-O-ß-d-glucopyranoside (4), (3S)-4″-hydroxyoxyphyllacinol (5), (3S)-3″-hydroxyoxyphyllacinol (6), (3S)-2″-hydroxyoxyphyllacinol (7), (3S)-2″-hydroxyoxyphyllacinol-2″-O-ß-d-glucopyranoside (8), and (3S)-oxyphyllacinol-3-O-ß-d-glucopyranoside (9) based on the comprehensive spectroscopic analyses and the application of modified Mosher's method. All compounds were evaluated for their cytotoxic activities against melanoma, as well as breast, lung, and colorectal cancer cell lines. Compound 9, which was O-glucosylated on the diarylheptanoid alkyl chain, exhibited the most selective cytotoxic activities against melanoma cell lines with the IC50 values ranging from 6.09 to 9.74 µM, indicating that it might be considered as a possible anti-cancer lead compound.

Microbial Transformation and Biological Activities of the Prenylated Aromatic Compounds from Broussonetia kazinoki.

Broussonetia kazinoki has been used as a traditional medicine for the treatment of burns and acne, and its extracts have been found to show tyrosinase inhibitory and anticancer activities. In this study, the tyrosinase inhibitory and cytotoxic activities of B. kazinoki were explored, leading to the isolation of kazinol C (1), kazinol E (2), kazinol F (3), broussonol N (4), and kazinol X (5), of which the compounds 4 and 5 have not been previously reported. Microbial transformation has been recognized as an efficient tool to generate more active metabolites. Microbial transformation of the major compounds 1 and 3 was conducted with Mucor hiemalis, where four glucosylated metabolites (6-9) were produced from 1, while one hydroxylated (10) and one glucosylated (11) metabolites were obtained from 3. Structures of the isolated metabolites were determined by extensive spectroscopic analyses. All compounds were evaluated for their tyrosinase inhibitory and cytotoxic activities. Compound 3 and its metabolites, kazinol Y (10) and kazinol F-4″-O-ß-d-glucopyranoside (11), exhibited the most potent tyrosinase inhibitory activities with the IC50 values ranging from 0.71 to 3.36 µM. Meanwhile, none of the metabolites, except for kazinol C-2',3″-di-O-ß-d-glucopyranoside (7), showed moderate cytotoxic activities (IC50 17.80 to 24.22 µM) against A375P, B16F10 and B16F1 cell lines.

Effects of Microbial Transformation on the Biological Activities of Prenylated Chalcones from Angelica keiskei.

Microbial transformation is an alternative method for structural modification. The current study aimed at application of microbial transformation for discovering new derivatives and investigating the structure-activity relationship of isobavachalcone (1), 4-hydroxyderricin (2), and xanthoangelol (3) isolated from the herb Angelica keiskei. In the initial screening process, 1-3 were incubated with microbes using a two-stage fermentation method and analyzed through TLC monitoring. The screening results showed that Rhizopus oryzae and Mucor hiemalis were able to transform 1 and 2, respectively. Additionally, M. hiemalis and Mortierella ramanniana var. angulispora were able to transform 3. Following scale-up fermentation, four new (4, 5, 7, and 10) and five known (6, 8, 9, 11, and 12) metabolites were produced. Cytotoxicity of all the compounds (1-12) was investigated using three human cancer cell lines including A375P, HT-29, and MCF-7 by MTT method. Meanwhile, the tyrosinase inhibitory activity of 1-12 was evaluated using l-tyrosine as a substrate. Overall, 1 and 3 displayed the highest cytotoxicity, and 5 and 7 exhibited the most potent tyrosinase inhibitory activity with relatively low cytotoxicity. This allowed us to postulate that the introduction of 4'-O-glucopyranosyl group led to the reduction in cytotoxicity and improvement in tyrosinase inhibitory activity.

Biotransformation of (-)-α-Bisabolol by Absidia coerulea.

(-)-α-Bisabolol, a bioactive monocyclic sesquiterpene alcohol, has been used in pharmaceutical and cosmetic products with anti-inflammatory, antibacterial and skin-caring properties. However, the poor water solubility of (-)-α-bisabolol limits its pharmaceutical applications. It has been recognized that microbial transformation is a very useful approach to generate more polar metabolites. Fifteen microorganisms were screened for their ability to metabolize (-)-α-bisabolol in order to obtain its more polar derivatives, and the filamentous fungus Absidia coerulea was selected for scale-up fermentation. Seven new and four known metabolites were obtained from biotransformation of (-)-α-bisabolol (1), and all the metabolites exhibited higher aqueous solubility than that of the parent compound 1. The structures of newly formed metabolites were established as (1R,5R,7S)- and (1R,5S,7S)-5-hydroxy-α-bisabolol (2 and 3), (1R,5R,7S,10S)-5-hydroxybisabolol oxide B (4), (1R,7S,10S)-1-hydroxybisabolol oxide B (5), 12-hydroxy-α-bisabolol (7), (1S,3R,4S,7S)- and (1S,3S,4S,7S)-3,4-dihydroxy-α-bisabolol (8 and 10) on the basis of spectroscopic analyses. These compounds could also be used as reference standards for the detection and identification of the metabolic products of 1 in the mammalian system.

Microbial transformation of icariin and its derivatives.

Microbial transformation is an important tool to perform selective conversion of compounds to derivatives which are difficult to produce synthetically. In order to obtain icariside II and icaritin, the active components in Herba Epimedii in vivo, biotransformation studies using microbes as biocatalysts were carried out. Icariside II (2) and icaritin (3) were produced through biotransformation of icariin (1) using the fungi Hormoconis resinae and Mortierella ramanniana var. angulispora in 98% and 92% yields, respectively. In the subsequent transformation studies, 2 was deglycosylated to form 3 by Gliocladium deliquescens, whereas 3 was further converted to a novel compound icaritin-3-O-ß-d-glucopyranoside (4) and previously known icaritin-3,7-O-ß-d-diglucopyranoside (5) by Mucor hiemalis. Biological evaluation of these compounds using MTT assay exhibited potent cytotoxic activities against human cancer cell lines A549, A375P, and MCF-7, with icariin being the most active, indicating that glycosylation plays a role in the cytotoxic activity.

Biotransformation of the Phenolic Constituents from Licorice and Cytotoxicity Evaluation of Their Metabolites.

Biotransformation of four bioactive phenolic constituents from licorice, namely licoisoflavanone (1), glycyrrhisoflavone (2), echinatin (3), and isobavachalcone (4), was performed by the selected fungal strain Aspergillus niger KCCM 60332, leading to the isolation of seventeen metabolites (5-21). Structures of the isolated compounds were determined on the basis of extensive spectroscopic methods, twelve of which (5-7, 10-17 and 19) have been previously undescribed. A series of reactions including hydroxylation, hydrogenation, epoxidation, hydrolysis, reduction, cyclization, and alkylation was observed in the biotransformation process. All compounds were tested for their cytotoxic activities against three different human cancer cell lines including A375P, MCF-7, and HT-29. Compounds 1 and 12 exhibited most considerable cytotoxic activities against all the cell lines investigated, while compounds 2 and 4 were moderately cytotoxic. These findings will contribute to expanding the chemical diversity of phenolic compounds, and compounds 1 and 12 may serve as leads for the development of potential cancer chemopreventive agents.

Microbial Conjugation Studies of Licochalcones and Xanthohumol.

Microbial conjugation studies of licochalcones (1-4) and xanthohumol (5) were performed by using the fungi Mucor hiemalis and Absidia coerulea. As a result, one new glucosylated metabolite was produced by M. hiemalis whereas four new and three known sulfated metabolites were obtained by transformation with A. coerulea. Chemical structures of all the metabolites were elucidated on the basis of 1D-, 2D-NMR and mass spectroscopic data analyses. These results could contribute to a better understanding of the metabolic fates of licochalcones and xanthohumol in mammalian systems. Although licochalcone A 4'-sulfate (7) showed less cytotoxic activity against human cancer cell lines compared to its substrate licochalcone A, its activity was fairly retained with the IC50 values in the range of 27.35-43.07 µM.

Microbial Transformation of Broussochalcones A and B by Aspergillus niger.

Broussochalcones A (BCA, 1) and B (BCB, 2) are major bioactive constituents isolated from Broussonetia papyrifera, a polyphenol-rich plant belonging to the family Moraceae. Due to their low yields from natural sources, BCA (1) and BCB (2) were prepared synthetically by employing Claisen-Schmidt condensation, and these were used as substrates for microbial transformation to obtain novel derivatives. Microbial transformation of BCA (1) and BCB (2) with the endophytic fungus Aspergillus niger KCCM 60332 yielded 10 previously undescribed chalcones (1a-1e and 2a-2e). Their structures were established based on the spectroscopic methods. The cytotoxicity of BCA (1), BCB (2), and their metabolites (1a-1e and 2a-2e) was determined by human cancer cell lines A375P, A549, HT-29, MCF-7, and HepG2, with 1e shown to be most cytotoxic.

Prevention of Fine Dust-Induced Vascular Senescence by Humulus lupulus Extract and Its Major Bioactive Compounds.

Both short- and long-term exposure to fine dust (FD) from air pollution has been linked to various cardiovascular diseases (CVDs). Endothelial cell (EC) senescence is an important risk factor for CVDs, and recent evidence suggests that FD-induced premature EC senescence increases oxidative stress levels. Hop plant (Humulus lupulus) is a very rich source of polyphenols known to have nutritional and therapeutic properties, including antioxidant behavior. The aims of this study were to evaluate whether Humulus lupulus extract prevents FD-induced vascular senescence and dysfunction and, if so, to characterize the underlying mechanisms and active components. Porcine coronary arteries and endothelial cells were treated with FD in the presence or absence of hop extract (HOP), and the senescence-associated-beta galactosidase (SA-ß-gal) activity, cell-cycle progression, expression of senescence markers, oxidative stress level, and vascular function were evaluated. Results indicated that HOP inhibited FD-induced SA-ß-gal activity, cell-cycle arrest, and oxidative stress, suggesting that HOP prevents premature induction of senescence by FD. HOP also ameliorated FD-induced vascular dysfunction. Additionally, xanthohumol (XN) and isoxanthohumol (IX) were found to produce the protective effects of HOP. Treatment with HOP and its primary active components XN and IX downregulated the expression of p22phox, p53, and angiotensin type 1 receptor, which all are known FD-induced redox-sensitive EC senescence inducers. Taken together, HOP and its active components protect against FD-induced endothelial senescence most likely via antioxidant activity and may be a potential therapeutic agent for preventing and/or treating air-pollution-associated CVDs.

Constituents of Coreopsis lanceolata Flower and Their Dipeptidyl Peptidase IV Inhibitory Effects.

A new polyacetylene glycoside, (5R)-6E-tetradecene-8,10,12-triyne-1-ol-5-O-ß-glucoside (1), was isolated from the flower of Coreopsis lanceolata (Compositae), together with two known compounds, bidenoside C (10) and (3S,4S)-5E-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-ß-glucopyranoside (11), which were found in Coreopsis species for the first time. The other known compounds, lanceoletin (2), 3,2'-dihydroxy-4-3'-dimethoxychalcone-4'-glucoside (3), 4-methoxylanceoletin (4), lanceolin (5), leptosidin (6), (2R)-8-methoxybutin (7), luteolin (8) and quercetin (9), were isolated in this study and reported previously from this plant. The structure of 1 was elucidated by analyzing one-dimensional and two-dimensional nuclear magnetic resonance and high resolution-electrospray ionization-mass spectrometry data. All compounds were tested for their dipeptidyl peptidase IV (DPP-IV) inhibitory activity and compounds 2-4, 6 and 7 inhibited DPP-IV activity in a concentration-dependent manner, with IC50 values from 9.6 to 64.9 µM. These results suggest that C. lanceolata flower and its active constituents show potential as therapeutic agents for diseases associated with type 2 diabetes mellitus.

Composition and Antioxidant Activities of Volatile Organic Compounds in Radiation-Bred Coreopsis Cultivars.

Coreopsis is a flowering plant belonging to the Asteraceae family. It is an ornamental plant native to the Americas, Asia and Oceania and its flower is used as a raw material for tea and food manufacture in China. In this study, new cultivars of C. rosea ("golden ring") were developed via radiation-induced mutation of the original cultivar, "pumpkin pie". The chemical composition and antioxidant activities of flowers belonging to three different Coreopsis cultivars were evaluated: "golden ring", "pumpkin pie" and "snow chrysanthemum" (coreopsis tea; C. tinctoria). The volatile compounds were characterized via gas chromatography-mass spectrometry (GC-MS) and 50-59 oils representing 95.3-96.8% of the total volatile compounds in these flower materials were identified. "Golden ring" contained a high amount of fatty acids (38.13%), while "pumpkin pie" and "snow chrysanthemum" teas were rich in aliphatic amides (43.01%) and esters (67.22%), respectively. The antioxidant activities of the volatile oils of these cultivars were evaluated using 1,1-diphenyl-2-picrylhydraxyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays. The volatile extract of "golden ring" showed higher antioxidant activities compared with the extracts of the other cultivars. Therefore, "golden ring" can be used for further development as a raw material for tea manufacture or as a dietary supplement.

2α-Hydroxyeudesma-4,11(13)-Dien-8ß,12-Olide Isolated from Inula britannica Induces Apoptosis in Diffuse Large B-cell Lymphoma Cells.

2α-Hydroxyeudesma-4,11(13)-dien-8ß,12-olide (HEDO), a eudesmane-type sesquiterpene lactone belonging to large group of plant terpenoids isolated from Inula britannica, displays cytotoxic activity against diffuse large B cell lymphoma cells in vitro. However, the molecular mechanism of the anticancer effect remains unclear. In this study, we showed that HEDO inhibits cell growth by inducing apoptosis in lymphoma cell lines through its antiproliferative activity. HEDO increases the depolarization of mitochondrial membrane potential and upregulated intracellular reactive oxygen species (ROS). Furthermore, we examined the cell cycle effect, and our results provided evidence that the arrest of the cell cycle at the SubG0/G1 phase plays an important role in the ability of HEDO to inhibit cell growth in Ontario Cancer Institute (OCI)-LY3 lymphoma cells by preventing nuclear factor-kappa B (NF-κB) signaling. In addition, HEDO induced apoptosis by instigating the activation of Bcl-2-associated X (BAX) and cleaved caspase-3, decreasing B-cell lymphoma 2 (BCL2), B-cell lymphoma-extra large (BCL-XL), and procaspase 3 expression levels. Based on these findings, we suggest that HEDO has potential as an anticancer drug of lymphoma by inducing ROS-dependent accumulation of SubG0/G1 arrest and apoptosis in OCI-LY3 cells.

Microbial Transformation of Prenylquercetins by Mucor hiemalis.

Quercetin, one of the most widely distributed flavonoids, has been found to show various biological activities including antioxidant, anticancer, and anti-inflammatory effects. It has been reported that bioactivity enhancement of flavonoids has often been closely associated with nuclear prenylation, as shown in 8-prenylquercetin and 5'-prenylquercetin. It has also been revealed in many studies that the biological activities of flavonoids could be improved after glucosylation. Three prenylated quercetins were prepared in this study, and microbial transformation was carried out in order to identify derivatives of prenylquercetins with increased water solubility and improved bioavailability. The fungus M. hiemalis was proved to be capable of converting prenylquercetins into more polar metabolites and was selected for preparative fermentation. Six novel glucosylated metabolites were obtained and their chemical structures were elucidated by NMR and mass spectrometric analyses. All the microbial metabolites showed improvement in water solubility.

Microbial Transformation of Licochalcones.

Microbial transformation of licochalcones B (1), C (2), D (3), and H (4) using the filamentous fungi Aspergillus niger and Mucor hiemalis was investigated. Fungal transformation of the licochalcones followed by chromatographic separations led to the isolation of ten new compounds 5-14, including one hydrogenated, three dihydroxylated, three expoxidized, and three glucosylated metabolites. Their structures were elucidated by combined analyses of UV, IR, MS, NMR, and CD spectroscopic data. Absolute configurations of the 2″,3″-diols in the three dihydroxylated metabolites were determined by ECD experiments according to the Snatzke's method. The trans-cis isomerization was observed for the metabolites 7, 11, 13, and 14 as evidenced by the analysis of their 1H-NMR spectra and HPLC chromatograms. This could be useful in better understanding of the trans-cis isomerization mechanism of retrochalcones. The fungal transformation described herein also provides an effective method to expand the structural diversity of retrochalcones for further biological studies.

Identification of Two New Phenanthrenes from Dendrobii Herba and Their Cytotoxicity towards Human Hypopharynx Squamous Carcinoma Cell (FaDu).

Two new phenanthrenes, (1R,2R)-1,7-hydroxy-2,8-methoxy-2,3-dihydrophenanthrene-4(1H)-one (1) and 2,7-dihydroxy-phenanthrene-1,4-dione (2), were isolated from the ethyl acetate-soluble fraction of Dendrobii Herba, together with seven known phenanthrenes (3-9), two bibenzyls (10-12), and a lignan (13). Structures of 1 and 2 were elucidated by analyzing one-dimensional (1D) and two-dimensional (2D)-NMR and High-resolution electrospray ionization mass spectra (HR-ESI-MS) data. The absolute configuration of compound 1 was confirmed by the circular dichroism (CD) spectroscopic method. In cytotoxicity assay using FaDu human hypopharynx squamous carcinoma cell line, compounds 3-6, 8, 10, and 12 showed activities, with IC50 values that ranged from 2.55 to 17.70 µM.

Biotransformed Metabolites of the Hop Prenylflavanone Isoxanthohumol.

A metabolic conversion study on microbes is known as one of the most useful tools to predict the xenobiotic metabolism of organic compounds in mammalian systems. The microbial biotransformation of isoxanthohumol (1), a major hop prenylflavanone in beer, has resulted in the production of three diastereomeric pairs of oxygenated metabolites (2⁻7). The microbial metabolites of 1 were formed by epoxidation or hydroxylation of the prenyl group, and HPLC, NMR, and CD analyses revealed that all of the products were diastereomeric pairs composed of (2S)- and (2R)- isomers. The structures of these metabolic compounds were elucidated to be (2S,2"S)- and (2R,2"S)-4'-hydroxy-5-methoxy-7,8-(2,2-dimethyl-3-hydroxy-2,3-dihydro-4H-pyrano)-flavanones (2 and 3), (2S)- and (2R)-7,4'-dihydroxy-5-methoxy-8-(2,3-dihydroxy-3-methylbutyl)-flavanones (4 and 5) which were new oxygenated derivatives, along with (2R)- and (2S)-4'-hydroxy-5-methoxy-2"-(1-hydroxy-1-methylethyl)dihydrofuro[2,3-h]flavanones (6 and 7) on the basis of spectroscopic data. These results could contribute to understanding the metabolic fates of the major beer prenylflavanone isoxanthohumol that occur in mammalian system.

Inhibition of Human Neutrophil Elastase by Sesquiterpene Lactone Dimers from the Flowers of Inula britannica.

A new sesquiterpene lactone dimer [1], together with five known compounds (2-6), was isolated from the flowers of Inula britannica. The structures of these compounds were established by extensive spectroscopic studies and chemical evidence. The inhibitory activities of these isolated compounds (1-6) against human neutrophil elastase (HNE) were also evaluated in vitro; compounds 1 and 6 exhibited significant inhibitory effects against HNE activity, with IC50 values of 8.2 and 10.4 µM, respectively, comparable to that of epigallocatechin gallate (EGCG; IC50 = 10.9 µM). In addition, compounds 3 and 5 exhibited moderate HNE inhibitory effects, with IC50 values of 21.9 and 42.5 µM, respectively. In contrast, compounds 2 and 4 exhibited no such activity (IC50 ＞ 100 µM). The mechanism by which 1 and 3 inhibited HNE was noncompetitive inhibition, with inhibition constant (Ki) values of 8.0 and 22.8 µM, respectively.

Polyphenols from Euphorbia pekinensis Inhibit AGEs Formation In Vitro and Vessel Dilation in Larval Zebrafish In Vivo.

To identify active compounds in the roots of Euphorbia pekinensis for treatment of diabetic complications, an active column fraction from a 70% EtOH extract of E. pekinensis root was purified by preparative reversed-phase high-performance liquid chromatography, leading to the isolation of a new ellagic acid derivative, 3,3'-di-O-methylellagic acid 4-O-(6"-O-galloyl)-ß-D-galactopyranoside (1: ), along with three known compounds, geraniin (2: ), 3,3'-di-O-methylellagic acid 4-O-ß-D-xylopyranoside (3: ), and ellagic acid 3,3'-dimethyl ether (4: ). The structure of the new compound was established by extensive spectroscopic studies and chemical evidence. The inhibitory effects of isolated compounds 1: -4: on advanced glycation end-products (AGEs) formation were examined. All compounds exhibited considerable inhibition of AGEs formation and IC50 values of 0.41 - 12.33 µM, compared with those of the positive controls aminoguanidine (IC50 = 1122.34 µM) and quercetin (IC50 = 27.80 µM). In addition, the effects of 2: and 4: on the dilation of hyaloid-retinal vessels induced by high glucose (HG) in larval zebrafish were investigated; both compounds significantly reduced the HG-induced dilation of hyaloid-retinal vessels relative to the HG-treated control group.

Microbial transformation of quercetin and its prenylated derivatives.

The microbial transformation studies of 7-O-prenylquercetin (1), 4'-O-prenylquercetin (2) and quercetin (3) were investigated with 20 different microbial strains to discover new metabolites. It was revealed that the fungus Mucor hiemalis was the most appropriate micro-organism which was capable of transforming these flavonoids. Structures of the three new (4-6) and one known (7) metabolites were elucidated as 7-O-prenylquercetin 3-O-ß-D-glucopyranoside (4), 4'-O-prenylquercetin 3-O-ß-D-glucopyranoside (5), 4'-O-prenylquercetin 3'-O-ß-D-glucopyranoside (6) and quercetin 5-O-ß-D-glucopyranoside (7) by the spectroscopic methods.