Phaeosphaones: Tyrosinase Inhibitory Thiodiketopiperazines from an Endophytic Phaeosphaeria fuckelii.

Phaeosphaeria fuckelii, an endophytic fungus associated with the herbal medicine Phlomis umbrosa, produced four new thiodiketopiperazine alkaloids, phaeosphaones A-D (1-4), featuring an unusual ß-(oxy)thiotryptophan motif, along with four known analogues, phaeosphaone E (5), chetoseminudin B (6), polanrazine B (7), and leptosin D (8). Their structures were elucidated by extensive spectroscopic data analysis, and their absolute configurations were determined by single-crystal X-ray diffraction and ECD calculations. Compounds 4, 6, and 8 were found to display mushroom tyrosinase inhibitory activity with IC50 values of 33.2 ± 0.2, 31.7 ± 0.2, and 28.4 ± 0.2 µM, respectively, more potent than that of the positive control, kojic acid (IC50 = 40.4 ± 0.1 µM). A molecular-docking study disclosed the π-π stacking interaction between the indole moiety of 8 and the His243 residue of tyrosinase.

Identification of insecticidal constituents of the essential oils of Dahlia pinnata Cav. against Sitophilus zeamais and Sitophilus oryzae.

The aim of this research was to determine the chemical composition of the essential oils of Dahlia pinnata, their insecticidal activity against Sitophilus zeamais and Sitophilusoryzae and to isolate insecticidal constituents. Based on bioactivity-guided fractionation, active constituents were isolated and identified as D-limonene, 4-terpineol and α-terpineol. Essential oils and active compounds tested exhibited contact toxicity, with LD50 values ranging from 132.48 to 828.79 µg/cm(2) against S. zeamais and S. oryzae. Essential oils possessed fumigant toxicity against S. zeamais and S. oryzae with LC50 from 14.10 to 73.46 mg/L. d-Limonene (LC50 = 4.55 and 7.92 mg/L) showed stronger fumigant toxicity against target insects. 4-Terpineol (88 ± 8%) and d-limonene (87 ± 5%) showed the strongest repellency against S. zeamais and S. oryzae, respectively. The results indicate that essential oils and insecticidal constituents have potential for development into natural fumigants, insecticides or repellents for control of the stored-product insect pests.

Phillyrin attenuates LPS-induced pulmonary inflammation via suppression of MAPK and NF-κB activation in acute lung injury mice.

Phillyrin (Phil) is one of the main chemical constituents of Forsythia suspensa (Thunb.), which has shown to be an important traditional Chinese medicine. We tested the hypothesis that Phil modulates pulmonary inflammation in an ALI model induced by LPS. Male BALB/c mice were pretreated with or without Phil before respiratory administration with LPS, and pretreated with dexamethasone as a control. Cytokine release (TNF-α, IL-1ß, and IL-6) and amounts of inflammatory cell in bronchoalveolar lavage fluid (BALF) were detected by ELISA and cell counting separately. Pathologic changes, including neutrophil infiltration, interstitial edema, hemorrhage, hyaline membrane formation, necrosis, and congestion during acute lung injury in mice were evaluated via pathological section with HE staining. To further investigate the mechanism of Phil anti-inflammatory effects, activation of MAPK and NF-κB pathways was tested by western blot assay. Phil pretreatment significantly attenuated LPS-induced pulmonary histopathologic changes, alveolar hemorrhage, and neutrophil infiltration. The lung wet-to-dry weight ratios, as the index of pulmonary edema, were markedly decreased by Phil pretreatment. In addition, Phil decreased the production of the proinflammatory cytokines including (TNF-α, IL-1ß, and IL-6) and the concentration of myeloperoxidase (MPO) in lung tissues. Phil pretreatment also significantly suppressed LPS-induced activation of MAPK and NF-κB pathways in lung tissues. Taken together, the results suggest that Phil may have a protective effect on LPS-induced ALI, and it potentially contributes to the suppression of the activation of MAPK and NF-κB pathways. Phil may be a new preventive agent of ALI in the clinical setting.

Protective effect of esculentoside A on lipopolysaccharide-induced acute lung injury in mice.

BACKGROUND: Esculentoside A (EsA) is a saponin isolated from the Chinese herb Phytolacca esculenta. In our study, we sought to investigate the protective effects of EsA on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. MATERIALS AND METHODS: To determine the effects of EsA on the reduction of histopathologic changes in mice with ALI, inflammatory cell count in bronchoalveolar lavage fluid (BALF) and lung wet-to-dry weight ratio were measured in LPS-challenged mice, and lung histopathologic changes observed via paraffin section were assessed. Next, cytokine production induced by LPS in BALF was measured by enzyme-linked immunosorbent assay. To further study the mechanism of EsA protective effects on ALI, IκBa, p38, and extracellular signal receptor-activated kinase pathways were investigated in lung tissue of mice with ALI. RESULTS: In the present investigation, EsA showed marked effects by reducing inflammatory infiltration, thickening of the alveolar wall, and pulmonary congestion. Levels of tumor necrosis factor α and interleukin 6 elevated by LPS were significantly decreased in BALF in EsA-pretreated ALI model. Furthermore, EsA significantly suppressed phosphorylation of IκBa, p38, and extracellular signal receptor-activated kinase. CONCLUSIONS: Taken together, our results suggest that EsA suppressed inflammatory responses in LPS-induced ALI through inhibition of the nuclear factor kappa B and mitogen activated protein kinase signaling pathways. EsA may be a promising potential preventive agent for ALI treatment.

Sulfated derivatives of 20(S)-ginsenoside Rh2 and their inhibitory effects on LPS-induced inflammatory cytokines and mediators.

Ginsenoside Rh2 is one of the most important ginsenosides in ginseng with antitumor, antidiabetic, antiallergic, and anti-inflammatory effects. However, the extremely poor oral bioavailability induced by its low water solubility greatly limits the potency of Rh2 in clinical use. Therefore, in this study we sulfated 20(S)-ginsenoside Rh2 with chlorosulfonic acid and pyridine method, and got two new sulfated derivatives, Rh2-B1 and Rh2-B2, with higher water solubility. Their chemical structures were characterized by spectroscopic methods (IR, MS and NMR). Additionally, Rh2-B1 and Rh2-B2 had the greater anti-inflammatory effects than Rh2 through inhibiting inflammatory cytokines and mediators in LPS-induced mouse RAW264.7 macrophages cells. These results suggested that the sulfated modification of Rh2 improved its water solubility and the sulfated derivatives could be more potential candidates for developing as anti-inflammatory agents.

[Chemical constituents from the fruits of Kadsura marmorata].

OBJECTIVE: To study the chemical constituents from the fruits of Kadsura marmorata. METHODS: The chemical constituents were isolated and purified by chromatography on silica gel, Sephadex LH-20 column and HPLC. RESULTS: 9 compounds were isolated and identified as 4,5-dihydroxy-3-methoxybiphenyl (I), eriobofuran (II), 3beta, 16beta-dihydroxy urs-2-ene (III), 2alpha, 3beta, 6beta, 23-tetrahydroxy urs-12,18-dien-28-oic acid (IV), 2alpha,3beta,23-trihydroxy urs-12-en-28-oic acid (V), rutin (VI), 2-ethylhexanoic acid (VII), 2-monolaurin (VIII), glyceryl monoricinoleate (IX) on the basis of NMR and EI-MS spectroscopic analysis. CONCLUSION: All these compounds are isolated from this genus for the first time.

[Studies on chemical constituents of Syringa veutina].

OBJECTIVE: To study the chemical constituents of Syringa veutina Kom. METHODS: The constituents were isolated and repeatedly purified on silica and Sephadex LH-20 column chromatography. They were dentified and structurally elucidated by spectral analysis. RESULTS: Seven compounds were obtained. They were identified as Syningin(1), Liriodendrin(2), (+) -Medioresinol di-O-beta-D-glucopyranosied (3), Rutin(4), Quercetin 3-O-beta-D-glucopyranoside (5), Kaempferol-3-O-beta-D-glucopyranosied (6), D-mannitol (7). CONCLUSION: Compound 2 and 3 were isolated from this genus for the first time. Compound 4, 5, 6 and 7 were isolated from this plant for the first time.

New secoiridoid glycosides from the roots of Picrorhiza scrophulariiflora.

Three new secoiridoid glycosides, named picrogentiosides A (1), B (2) and C (3), have been isolated from the underground parts of Picrorhiza Scrophulariiflora, together with the two known compounds plantamajoside (4) and plantainoside D (5). Their structures were established by spectroscopic analyses and comparisons with data from related compounds. A pilot pharmacological study showed that picrogentiosides A (1) and B (2) have an immunomodulatory effect in vitro.

[Determination of the cucurbitacins from Cucubita pepo cv dayangua by HPLC].

OBJECTIVE: To establish an HPLC method for the simultaneous determination of four bioactive cucurbitacins in Cucubita pepo cv Dayangua. METHODS: The HPLC chromatography was carried out with a lineal gradient programming and detection wavelength at 215 nm. Kromasil C8 column (150 mm x 4.6 mm ID, 5 microm)was used. The mobile phase was acetonitrile-water (containing 2.0% HAc) and the flow rate was 1.0 ml/min. RESULTS: The linear range of 23, 24-dihydrocucurbitacin F was 0.28-5.6 microg/ml (r = 0.9978), 23, 24-dihydrocucurbitacin D 0.39-7.8 microg/ml (r = 0.9986), cucurbitacin B 0.304-6.08 microg/ml (r = 0.9983), cucurbitacin E 2. 52 -50. 4 microg/ml (r = 0.9998). The method was accurate with variation less than 5% and recovery more than 95%. CONCLUSION: The method is successfully applied to determination of the four cucurbitacins from Cucubita pepo cv dayangua.

Primary structural determination of N-terminally blocked peptides from the bark of Eucommia ulmoides Oliv by mass spectrometric analysis.

Sequencing of N-terminally blocked proteins/peptides is a challenge since these molecules inhibit processing by Edman degradation. By using high accuracy Fourier transform ion cyclotron resonance (FTICR) tandem mass spectrometry and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), the primary structures of two novel N-terminally blocked antifungal peptides (EAFP1 and EAFP2), purified from the bark of Eucommia ulmoides Oliv, have been determined. The results show that the high mass accuracy provided by FTICR mass spectrometry is effective to determine the N-terminally blocking group, and can simplify the task of spectral interpretation and improve the precision of sequence determination. The combination of MALDI-TOFMS with carboxyl peptidase Y digestion was used to determine the C-terminal 36- and 27-residue sequences of EAFP1 and EAFP2, respectively, to provide the sequence linkage information for tryptic fragments. Compared with traditional peptide chemistry the advantage of mass spectrometric techniques is their simplicity, speed and sensitivity.

cDNA cloning, high-level expression, purification, and characterization of an avian Cu,Zn superoxide dismutase from Peking duck.

As a special species of avian, Peking duck is often used as a model for exploring effective factors against cardio-cerebrovascular diseases, and therefore investigations of antioxidant enzymes including superoxide dismutase are intriguing. By using 3(')-RACE with a gene-specific primer, a cDNA encoding duck Cu,Zn SOD was amplified from the total RNA extracted from Peking duck liver. Three free cysteine residues are found in the deduced amino acid sequence of duck SOD, among which Cys153 at the carbonyl-terminal is a distinctive feature. Production with a high yield of recombinant duck Cu,Zn SOD was achieved in Escherichia coli after the reconstituted expression vector pET-3a-dSOD was transformed into the bacterial strain BL21(DE3)pLysS. After two steps of anion exchange chromatography, a great quantity of the purified enzyme (100mg/L fermented culture) with an enzymatic activity comparable to that of native duck and bovine SOD was finally obtained. Duck SOD is a homodimer with 153 residues for each subunit. The molecular mass of the recombinant enzyme is 15,540.0Da measured by mass spectrum, which well coincides with the estimated size of the sequence but significantly differs from that of the native counterpart. Five charge isomers were observed on isoelectricfocusing (IEF). The most interesting observation is that the thermal stability of duck SOD is much lower than that of the bovine enzyme as revealed by irreversible heat inactivation at 70 degrees C. These properties are discussed in relation to the distinctive free Cys residues in duck Cu,Zn SOD.

Two novel antifungal peptides distinct with a five-disulfide motif from the bark of Eucommia ulmoides Oliv.

Two antifungal peptides, named EAFP1 and EAFP2, have been purified from the bark of Eucommia ulmoides Oliv. Each of the sequences consists of 41 residues with a N-terminal blockage by pyroglutamic acid determined by automated Edman degradation in combination with the tandem mass spectroscopy and the C-terminal ladder sequencing analysis. The primary structurs all contain 10 cysteines, which are cross-linked to form five disulfide bridges with a pairing pattern (C1-C5, C2-C9, C3-C6, C4-C7, C8-C10). This is the first finding of a plant antifungal peptide with a five-disulfide motif. EAFP1 and EAFP2 show characteristics of hevein domain and exhibit chitin-binding properties similar to the previously identified hevein-like peptides. They exhibit relatively broad spectra of antifungal activities against eight pathogenic fungi from cotton, wheat, potato, tomato and tobacco. The inhibition activity of EAFP1 and EAFP2 can be effective on both chitin-containing and chitin-free fungi. The values of IC(50) range from 35 to 155 microg/ml for EAFP1 and 18 to 109 microg/ml for EAFP2. Their antifungal effects are strongly antagonized by calcium ions.