Bavachinin selectively modulates PPAR γ and maintains bone homeostasis in Type 2 Diabetes.

Full peroxisome proliferator-activated receptor (PPAR) γ agonists, Thiazolidinediones (TZDs), effectively prevent the process of Type 2 Diabetes Mellitus (T2DM), but their side effects have curtailed use in the clinic, including weight gain and bone loss. Here, we identified that a selective PPAR γ modulator, Bavachinin (BVC), isolated from the seeds of Psoralea Corylifolia L., could potently regulate bone homeostasis. MC3T3-E1 pre-osteoblast cells and C3H10T1/2 mesenchymal stem cells were assessed for osteogenic differentiation activities, and receptor activator of NF-κB ligand (RANKL)-induced RAW 264.7 cells were assessed osteoclasts formation. Leptin receptor-deficient mice and diet-induced obesity mice were applied to evaluate the effect of BVC on bone homeostasis in vivo. Compared to full PPAR γ agonist rosiglitazone, BVC significantly increased the osteogenesis differentiation activities under normal and high glucose conditions in MC3T3-E1 cells. Moreover, BVC could alleviate osteoclast differentiation in RANKL-induced RAW 264.7 cells. In vivo, synthesized BVC prodrug (BN) has been applied to improve water solubility, increase the extent of oral absorption of BVC and prolong its residence time in blood circulation. BN could prevent weight gain, ameliorate lipid metabolism disorders, improve insulin sensitivity, and maintain bone mass and bone biomechanical properties. BVC, a unique PPAR γ selective modulator, could maintain bone homeostasis, and its prodrug (BN) exhibits insulin sensitizer activity while circumventing the side effects of the TZDs, including bone loss and undesirable weight gain.

Synthesis of Four Pentacyclic Triterpene-Sialylglycopeptide Conjugates and Their Affinity Assays with Hemagglutinin.

Influenza outbreaks pose a serious threat to human health. Hemagglutinin (HA) is an important target for influenza virus entry inhibitors. In this study, we synthesized four pentacyclic triterpene conjugates with a sialylglycopeptide scaffold through the Cu(I)-catalyzed alkyne-azide cycloaddition reaction (CuAAC) and prepared affinity assays of these conjugates with two HAs, namely H1N1 (A/WSN/1933) and H5N1 (A/Hong Kong/483/97), respectively. With a dissociation constant (KD) of 6.89 µM, SCT-Asn-betulinic acid exhibited the strongest affinity with the H1N1 protein. Furthermore, with a KD value of 9.10 µM, SCT-Asn-oleanolic acid exhibited the strongest affinity with the H5N1 protein. The conjugates considerably enhanced antiviral activity, which indicates that pentacyclic triterpenes can be used as a ligand to improve the anti-influenza ability of the sialylglycopeptide molecule by acting on the HA protein.

Ruthenium(II)-Catalyzed Regioselective Ortho C-H Allenylation of Electron-Rich Aniline and Phenol Derivatives.

Ortho C-H allenylation of electron-rich benzene derivatives with propargylic alcohol derivatives has been a challenge, due to their great innate tendency toward a para C-H allenylation via an SN2'-type substitution process. Here, we described a Ru(II)-catalyzed regioselective ortho C-H allenylation of electron-rich aniline and phenol derivatives, which allows the previously challenging synthesis of a broad range of ortho allenylated aniline and phenol derivatives. More significantly, highly optically active fully substituted allenes can also be prepared with high enantiomeric excess via a highly efficient chirality transfer. No para C-H allenylation product was observed in the current catalytic system, thus showing a complete reversibility of the regioselectivity.

Prenylated flavonoid-standardized extract from seeds of Psoralea corylifolia L. activated fat browning in high-fat diet-induced obese mice.

We investigated the effects of the prenylated flavonoid-standardized extract (PFE) from the seeds of Psoralea corylifolia L. on countering obesity, which increases energy expenditure and stimulates thermogenesis in subcutaneous white adipose tissue (sWAT) and brown adipose tissue (BAT). For 12 weeks, C57BL/6 mice were fed a controlled high-fat diet (HFD) or HFDs with 0.2% or 0.5% w/w PFE. In vitro, the differentiation of 3 T3-L1 cells was used to elicit thermogenesis in the presence of PFE. PFE obviously reduced body weight and fat mass in a dose-dependent manner, increased energy expenditure, improved insulin sensitivity, and prevented hepatic steatosis by increasing lipid oxidation and secretion in HFD-fed mice. Moreover, PFE induced clear browning in sWAT, significantly increased phosphorylation of AMPKα1/2 and p38, increased BAT activity and the differentiation of 3 T3-L1 by increasing the expression of uncoupling protein 1 and other thermogenic genes. Our study showed that PFE prevented obesity by increasing browning and activating thermogenic genes in sWAT and BAT, improving glucose homeostasis, and protecting hepatic steatosis.

Alkaloid Enantiomers from the Roots of Isatis indigotica.

Five pairs of alkaloid enantiomers (1a/1b-5a/5b) were obtained from Isatis indigotica (I. indigotica) roots. Among them, 1a/1b, 2a/2b and 3a/3b were determined as three pairs of new alkaloid enantiomers. Their structures were elucidated by physicochemical properties and spectroscopic methods. The absolute configurations were deduced by comparison of their experimental circular dichroism (CD) and calculated electronic circular dichroism (ECD) spectra, as well as by single-crystal X-ray crystallography using anomalous scattering of Cu Kα radiation. Alkaloids 1a and 1b possess an unpresented carbon skeleton and their putative biosynthetic pathways are discussed. Moreover, all of the alkaloids were tested for their nitric oxide (NO) inhibitory effects in RAW 264.7 cells, and 4a and 4b showed inhibitory effects with IC50 values of 76.97 µM and 65.88 µM, respectively.

Pharmacokinetic and metabolism studies of bavachinin through ultra-high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

Bavachinin (BVC), one of the main bioactive prenylated flavonoids derived from Psoralea corylifolia Linn, has a wide variety of pharmacological effects, such as antiangiogenic, antitumor, antiallergic, anti-inflammatory and antibacterial activities, especially as a pan-peroxisome proliferator-activated receptors agonist. A rapid and sensitive method for quantifying BVC in rat plasma was developed and validated through ultra-high-performance liquid chromatography coupled with electrospray-ionization tandem mass spectrometry. Furthermore, a complete metabolic investigation of BVC was performed through ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. In the pharmacokinetic analysis, BVC exhibited rapid oral absorption (Tmax = 0.68 ± 0.21 h), good elimination (T1/2 = 2.27 ± 1.63 h) following oral administration and poor absolute bioavailability (5.27%). Moreover, 11 metabolites of BVC in plasma, urine, bile and feces were characterized. The main metabolic pathways of BVC involved isomeriszation, glucuronidation, sulfonation, hydroxylation, methoxylation and reduction. In conclusion, the present study provides a sensitive quantitative method with a lower limit of quantification of 1 ng/mL and an improved comprehension of the physiological disposition of BVC.

Bavachinin, as a novel natural pan-PPAR agonist, exhibits unique synergistic effects with synthetic PPAR-γ and PPAR-α agonists on carbohydrate and lipid metabolism in db/db and diet-induced obese mice.

AIMS/HYPOTHESIS: Pan-peroxisome proliferator-activated receptor (PPAR) agonists have long been sought as therapeutics against the metabolic syndrome, but current PPAR agonists show limited efficacy and adverse effects. Natural herbs provide a structurally untapped resource to prevent and treat complicated metabolic syndrome. METHODS: Natural PPAR agonists were screened using reporter gene, competitive binding and 3T3-L1 pre-adipocyte differentiation assays in vitro. The effects on metabolic phenotypes were verified in db/db and diet-induced obese mice. In addition, potentially synergistic actions of bavachinin (BVC, a novel natural pan-PPAR agonist from the fruit of the traditional Chinese glucose-lowering herb malaytea scurfpea) and synthetic PPAR agonists were studied through nuclear magnetic resonance, molecular docking, reporter gene assays and mouse studies. RESULTS: BVC exhibited glucose-lowering properties without inducing weight gain and hepatotoxicity. Importantly, BVC synergised with thiazolidinediones, which are synthetic PPAR-γ agonists, and fibrates, which are PPAR-α agonists, to induce PPAR transcriptional activity, as well as to lower glucose and triacylglycerol levels in db/db mice. We further found that BVC occupies a novel alternative binding site in addition to the canonical site of synthetic agonists of PPAR, and that the synthetic PPAR-γ agonist rosiglitazone can block BVC binding to this canonical site but not to the alternative site. CONCLUSIONS/INTERPRETATION: This is the first report of a synergistic glucose- and lipid-lowering effect of BVC and synthetic agonists induced by unique binding with PPAR-γ or -α. This combination may improve the efficacy and decrease the toxicity of marketed drugs for use as adjunctive therapy to treat the metabolic syndrome.

Structural elucidation of in vitro metabolites of bavachinin in rat liver microsomes by LC-ESI-MSn and chemical synthesis.

1. Bavachinin isolated from Psoralea corylifolia has various activities, such as antimicrobial, antiallergic, antitumor and so on. Our previous study showed that natural bavachinin exhibits peroxisome proliferator-activated receptor γ-agonist activity. 2. In vitro studies on bavachinin metabolism were conducted using rat liver microsomes incubated at 37 °C for 60 min. 3. Structures of eight metabolites of the incubation mixtures were cautiously characterized using electrospray tandem mass spectra and three synthetic compounds. The results indicated that eight metabolites of bavachinin were biotransformed mainly through oxidation. 4. The metabolic pathways of bavachinin were elucidated in vitro. These results contribute to the understanding of bavachinin's in vivo metabolism.

Saponin-enriched sea cucumber extracts exhibit an antiobesity effect through inhibition of pancreatic lipase activity and upregulation of LXR-ß signaling.

CONTEXT: Sea cucumbers have been consumed as tonic, food, and nutrition supplements for many years. OBJECTIVE: The objective of this study is to investigate the antiobesity and lipid-lowering effects of sea cucumber extracts in in vitro and in vivo models and elucidate the mechanism of action of the extracts on obesity and dyslipidemia. MATERIALS AND METHODS: The 60% ethanol extracts from the body walls of 10 different sea cucumbers were investigated for the inhibition of pancreatic lipase (PL) activity in vitro. The optimal active extract (SC-3) was further chemically analyzed by LC-MS and UV. And 0.1% and 0.2% of SC-3 was mixed with a high-fat diet to treat C57/BL6 mice for 6 weeks or 2 weeks as preventive and therapeutic study. The body weight, serum, and liver lipid profile in the mice were investigated. RESULTS: The crude extract of Pearsonothuria graeffei Semper (Holothuriidae) inhibited the PL activity by 36.44% of control at 0.5 µg/mL. SC-3 and echinoside A inhibited PL with an IC50 value at 2.86 µg/mL and 0.76 µM. 0.1% of SC-3 reduced the body weight (23.0 ± 0.62 versus 26.3 ± 0.76 g), the serum TC (2.46 ± 0.04 versus 2.83 ± 0.12 mmol/L), TG (0.19 ± 0.08 versus 0.40 ± 0.03 mmo/L), and LDL-c (0.48 ± 0.02 versus 0.51 ± 0.02 mmol/L), and liver TC (1.19 ± 0.17 versus 1.85 ± 0.13 mmol/mg) and TG (6.18 ± 0.92 versus 10.87 ± 0.97 mmol/mg) contents of the obese C57BL/six mice on a high-fat diet. DISCUSSION AND CONCLUSION: Sea cucumber may be used for developing antiobesity and antihyperlipidemia drugs.

Separation and peroxisome proliferator-activated receptor-γ agonist activity evaluation of synthetic racemic bavachinin enantiomers.

Bavachinin, isolated from Psoralea corylifolia seeds, has been reported to demonstrate peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist activity. However, isolated bavachinin is actually a mixture of S and R configurations, with an enantiomeric excess value of approximately 24.3%. For further study on the structure-activity relationships of bavachinin, investigating the PPAR-γ agonist activity of the two enantiomers is crucial. Considering the limited availability, racemic bavachinin was prepared in this study using chemical synthesis. The enantiomers of racemic bavachinin were then separated using supercritical fluid chromatography. This concise strategy yielded (S)- and (R)-bavachinin in optical purity as high as ⩾97.5%. The PPAR-γ agonist activity of the two enantiomers was evaluated using a time-resolved fluorescence resonance energy transfer-based competitive binding assay method; IC50 values of (S)- and (R)-bavachinin were 616.7 and 471.2 nM, respectively. The interaction between the compounds and PPAR-γ was further explored using a molecular docking method. This study suggests that (S)- and (R)-bavachinin demonstrate similar PPAR-γ agonist activities.

Efficient Determination of the Enantiomeric Purity and Absolute Configuration of Flavanones by Using (S)-3,3'-Dibromo-1,1'-bi-2-naphthol as a Chiral Solvating Agent.

The enantiomeric purity and absolute configuration of flavanones were first determined using (S)-3,3'-dibromo-1,1'-bi-2-naphthol as a chiral solvating agent by means of (1)H NMR spectroscopy. The enantiomeric purity results closely matched those based on chiral HPLC analysis.

Meroterpenes from Psoralea corylifolia against Pyricularia oryzae.

Six new meroterpenes, namely, 13-methoxyisobakuchiol (1), 13-ethoxyisobakuchiol (2), 12,13-dihydro-13-hydroxybakuchiol (3), Δ(10)-12,13-dihydro-12-(R,S)-methoxyisobakuchiol (4 and 5), and 15-demetyl-12,13-dihydro-13-ketobakuchiol (6), together with four known ones, namely, Δ(3),2-hydroxybakuchiol (7), Δ(1),3-hydroxybakuchiol (8), bakuchiol (9), and Δ(1,3)-bakuchiol (10), were isolated from the seeds of Psoralea corylifolia. Their structures were identified based on spectral data, including those obtained via 1D and 2D NMR, and MS spectral analyses. Antifungal screening results indicated that all compounds showed moderate inhibitory activities against Pyricularia oryzae.

Two new sulfated sesquiterpenoids from Petasites tricholobus.

Two new sulfated sesquiterpenoids, megastigman-7-ene-3, 5, 6, 9-tetrol-3-O-ß-D-6'-sulfonated-glucopyranoside (1) and 3-O-ß-D-6'-sulfonated-glucopyranosyl-6-(3-oxo-2-butenylidenyl)-1, 1, 5-trimethylcyclohexan-5-ol (2), along with one known sesquitepenoid compound icariside B1 (3) were isolated from the whole herb of Petasites tricholobus Franch. Their structures were identified by their chemical and spectroscopic characters. All obtained compounds were tested for their cytotoxicity against four cancer cell lines.

[A new neolignan from fruit of Solanum torvum].

One new neolignan identified as 2, 3-( trans) -dihydro-2-(4-hydroxy-3-methoxyphenyl) -3-[(beta-D-glucopyranosyloxy) methyl]-7-methoxybenzofuran-5-propenoic acid (1) and five known steroidal glycosides namely torvoside A(2), torvoside C(3), torvoside H(4), solanolactoside A (5), (25S)-6alpha-hydroxy-5alpha-spirostan-3-one-6-0-[alpha-L-rhamnopyranosyl-(1-->3-beta3)-beta-D-D-quinovopyr-anoside] (6) were isolated from the fruits of Solanum torvum. Their structures were elucidated on the basis of 1D, 2D NMR and MS spectroscopic analysis.

Curcuma wenyujin rhizomes extract ameliorates lipid accumulation.

Curcuma wenyujin (C. wenyujin) is a medicinal plant that is traditionally used to treat blood stagnation, liver fibrosis, pain, and jaundice. In this study, we examined the effect of C. wenyujin rhizome extract on hepatic lipid accumulation both in vivo and in vitro. We found that the petroleum ether fraction of C. wenyujin rhizome extract (CWP) considerably reduced the accumulation of lipids in HepG2 cells treated with oleic and palmitic acid. Ultra-high-performance liquid chromatography coupled with LTQ-Orbitrap mass spectrometry was used to analyze the main chemical constituents of CWP, and 21 sesquiterpenes were identified. In vivo experiments revealed that the administration of CWP significantly reduced the body weight and serum total cholesterol (TC) level of low-density-lipoprotein receptor knockout mice treated with a high-fat diet without affecting their food intake. CWP also significantly reduced the levels of liver TC, liver triglycerides, aspartate transaminase, and alanine transaminase. Histological examination revealed that CWP dose-dependently reduced steatosis in liver tissue, significantly downregulated the expression of lipogenesis genes, and increased the ß-oxidation of fatty acids. CWP also significantly increased autophagy-related proteins. In conclusion, CWP rich in sesquiterpenes reduces the accumulation of lipids in vivo and in vitro by improving lipid metabolism and activating autophagy.

Germacrone, isolated from Curcuma wenyujin, inhibits melanin synthesis through the regulation of the MAPK signaling pathway.

Abnormal melanin synthesis causes hyperpigmentation disorders, such as chloasma, freckles, and melanoma, which are highly multiple and prevalent. There were few reports on the anti-melanogenic effect of Curcuma wenyujin Y.H. Chen et C. Ling, and the bioactive compound has not been elucidated as well. The study aims to investigate the anti-melanogenic effect of C. wenyujin, and identify the bioactive compound, and further explore its underlying mechanism. Our results showed that the Petroleum ether fraction extracted from C. wenyujin rhizome had a significant anti-melanogenic effect, and germacrone isolated from it was confirmed as the major bioactive compound. To our data, germacrone significantly inhibited tyrosinase (TYR) activity, reduced melanosome synthesis, reduced dendrites formation of B16F10 cells, and melanosome transport to keratinocytes. Moreover, germacrone effectively decreased the hyperpigmentation in zebrafish and the skin of guinea pigs in vivo. Western-blot analysis showed that germacrone down-regulated the expression of TYR, TRP-1, TRP-2, Rab27a, Cdc42, and MITF proteins via the activation of the MAPK signaling pathway. Taken together, germacrone is an effective bioactive compound for melanogenesis inhibition. Our studies suggest that germacrone may be considered a potential candidate for skin whitening.

Characterization of total phenolic constituents from the stems of Spatholobus suberectus using LC-DAD-MS(n) and their inhibitory effect on human neutrophil elastase activity.

Spatholobus suberectus Dunn, belonging to the legume family (Fabaceae), has been used as a Traditional Chinese Medicine for the treatment of anemia, menoxenia and rheumatism. A limited number of studies report that various types of flavonoids are the main characteristic constituents of this herb. We have now found that S. suberectus contains about 2% phenolic components and characterized the major phenolic components as homogeneous B-type procyanidin conjugates using a liquid chromatography with diode-array detection-ESI mass spectrometry (LC-DAD/ESI-MS) method. This is the first report on occurrence of most B-type procyanidins in this herb. Moreover, the total phenolics extract was assayed for inhibitory activity on human neutrophil elastase and its IC50 was found to be 1.33 µg/mL.

[Phenolic constituents from Lysimachia patungensis].

To study the chemical constituents of Lysimachia patungensis Hand.-Mazz., silica gel column chromatography, reverse phase ODS column chromatography, MCI and Sephadex LH-20, were used to separate the 95% EtOH extract of the whole plant of Lysimachia patungensis Hand.-Mazz.. The structures of the isolated compounds have been established on the basis of chemical and NMR spectroscopic evidence as well as ESI-MS in some cases. Twelve phenolic compounds were obtained and identified as quercetin-3, 3'-di- O-alpha-L-rhamnoside (1), myricetrin (2), quercitrin (3), rutin (4), 2-hydroxynaringenin-4'-O-glucopyranoside (5), naringenin 7-O-glucopyranoside (6), liquiritin apioside (7), licochalcone B (8), tetrahydroxymethoxy chalcone (9), methyl-p-coumarate (10), 2, 4, 6-trihydroxy acetophenone-2-O-glucopyranoside (11) and vaccihein A (12). Among them, compound 1 is a new compound, and compounds 5, 11 and 12 are isolated from the genus Lysimachia L. for the first time, and the others are isolated from the plant for the first time.

Structures, Sources, Identification/Quantification Methods, Health Benefits, Bioaccessibility, and Products of Isorhamnetin Glycosides as Phytonutrients.

In recent years, people have tended to consume phytonutrients and nutrients in their daily diets. Isorhamnetin glycosides (IGs) are an essential class of flavonoids derived from dietary and medicinal plants such as Opuntia ficus-indica, Hippophae rhamnoides, and Ginkgo biloba. This review summarizes the structures, sources, quantitative and qualitative analysis technologies, health benefits, bioaccessibility, and marketed products of IGs. Routine and innovative assay methods, such as IR, TLC, NMR, UV, MS, HPLC, UPLC, and HSCCC, have been widely used for the characterization and quantification of IGs. All of the therapeutic effects of IGs discovered to date are collected and discussed in this study, with an emphasis on the relevant mechanisms of their health-promoting effects. IGs exhibit diverse biological activities against cancer, diabetes, hepatic diseases, obesity, and thrombosis. They exert therapeutic effects through multiple networks of underlying molecular signaling pathways. Owing to these benefits, IGs could be utilized to make foods and functional foods. IGs exhibit higher bioaccessibility and plasma concentrations and longer average residence time in blood than aglycones. Overall, IGs as phytonutrients are very promising and have excellent application potential.

The structures of three metabolites of the algal hepatotoxin okadaic acid produced by oxidation with human cytochrome P450.

Four metabolites of okadaic acid were generated by incubation with human recombinant cytochrome P450 3A4. The structures of two of the four metabolites have been determined by MS/MS experiments and 1D and 2D NMR methods using 94 and 133 µg of each metabolite. The structure of a third metabolite was determined by oxidation to a metabolite of known structure. Like okadaic acid, the metabolites are inhibitors of protein phosphatase PP2A. Although one of the metabolites does have an α,ß unsaturated carbonyl with the potential to form adducts with an active site cysteine, all of the metabolites are reversible inhibitors of PP2A.