Metabolite profiling reveals comprehensive effects of Chaetomium globosum on citrus preservation.

The huge economic loss of citrus fruit after harvest called for safe and efficient preservatives, as chemically synthesized agents threatened the environment and human health. Herein a biocontrol fungus Chaetomium globosum QY-1 near the orchard in riparian area was identified to have antimicrobial, antioxidant and tyrosinase inhibition activity, which meets the requirements of an ideal preservative. Metabolite profiling based on bioassay-guided fractionation was carried out, and eight polyketones were determined by MS and NMR. The most abundant CheA exhibited strong inhibition to Penicillium digitatum, the main pathogen caused citrus fruit rot. Among these metabolites, Epicoccone and Epicoccolide B showed higher antioxidant activity, while Epicoccone and CheA had higher tyrosinase inhibitory activity. All the activities were close to or even better than the positive control (Vc; glutathione; Vc and arbutin; Bellkute), implying that the metabolites of C. globosum had comprehensive effects as natural preservatives.

Sanxiapeptin, a linear pentapeptide from Penicillium oxalicum, inhibited the growth of citrus green mold.

Penicillium oxalicum has been used as a biocontrol fungus in agriculture for many years, but the antimicrobial substances are still uncertain. Herein, we isolated a linear peptide named Sanxiapeptin in the culture broth of Penicillium oxalicum SG-4 collecting from the Three Gorges riparian zone. Sanxiapeptin exhibited potent inhibitory effect on citrus green mold Penicillium digitatum, the main fungi responsible for postharvest decay. Sanxiapeptin was elucidated as composing of five amino acids, which were ß-amino-α-methoxybutyric acid (Amoba), N-Me-l-Thr, d-Thr, N-Me-l-Val and l-Ser. By analyzing three chemically synthesized oligopeptides with similar structures, we found that the first amino acid of Amoba was crucial to the antifungal activity, as was the methylation of peptide bond. Sanxiapeptin may act as an antimicrobial agent by affecting the function of cell membranes or walls. The antimicrobial spectrum, safety and stability analysis supported that Sanxiapeptin was a promising antifungal agent for citrus preservation.

Mild synthesis of isoxazoline derivatives via an efficient [4 + 1] annulation reaction of transient nitrosoalkenes and sulfur ylides.

An efficient [4 + 1] annulation between α-bromooximes and sulfur ylides via in situ generation of nitrosoalkenes under mild basic reaction conditions has been developed, providing an expeditious and scalable approach to synthesize biologically interesting isoxazoline derivatives with good to excellent yields.

Isolation, structure identification and hepatoprotective activity of a polysaccharide from Sabia parviflora.

The extraction, purification, structure and hepatoprotective activity of a homogenous polysaccharide (SPS60) from Sabia parviflora were investigated. SPS60 was screened after purification with Sephadex G-100 and showed the excellent hepatoprotective activity. Its structural characteristics were investigated by Time of flight mass spectrometry (TOF-MS), PMP Pre-column derivatization-HPLC (PMP-HPLC), nuclear magnetic resonance (NMR) spectroscopy and Atomic Force Microscopy (AFM). The results showed that SPS60 possessed the molecular weight of 16900 Da and the monosaccharide component was glucose, as well as a 1 â†’ 6 glycosidic bond. The results of atomic force microscopy (AFM) show that SPS60 is a blocky sphere in solution. Furthermore, the SPS60 could significantly improve the survival rate of LO2 hepatocytes which were damaged by CCl4. Therefore, SPS60 may be an active substance of S. parviflora as a local functional tea.

Seven new chemical constituents from the underground parts of Eupatorium chinense.

Three new sesquiterpenoids (1-3) and four new benzofuran dimers (+)-4 and (-)-4, (+)-5 and (-)-5, and four known benzofuran dimers (+)-6 and (-)-6, (+)-7 and (-)-7 were isolated from the underground parts of Eupatorium chinense. The enantiomers of racemates (±)-4 ~ (±)-7 were separated by chiral HPLC columns, and their absolute configurations were determined by circular dichroism experiments. The structures of all new compounds were elucidated on the basis of their NMR, and MS data as well as by comparison with literature values. The all of the isolated compounds were tested in vitro for their cytotoxic activities against the Caski, MDA-MB-231 and HepG2 cancer cell lines.

Aspergoterpenins A⁻D: Four New Antimicrobial Bisabolane Sesquiterpenoid Derivatives from an Endophytic Fungus Aspergillus versicolor.

Aspergoterpenins A⁻D (1⁻4), four new bisabolane sesquiterpenoid derivatives, were obtained from the endophytic fungus, Aspergillus versicolor, together with eight known compounds (5⁻12), and their structures were elucidated by a comprehensive analysis of their NMR (Nuclear Magnetic Resonance), MS (Mass Spectrum) and CD (Circular Dichroism) spectra. Aspergoterpenin A (1) was the first example with a characteristic ketal bridged-ring part in the degraded natural bisabolane-type sesquiterpene structures. The compounds 1⁻12 displayed no significant activities against four cancer cell lines (A549, Caski, HepG2 and MCF-7). Further, the antimicrobial activities to Erwinia carotovora sub sp. Carotovora were evaluated, and the results showed that compounds 1⁻12 displayed antimicrobial activities with MIC values ranging from 15.2 to 85.2 µg/mL.

Caroguaianolide A-E, five new cytotoxic sesquiterpene lactones from Carpesium abrotanoides L.

Five new guaiane-type sesquiterpene lactones, caroguaianolide A-E (1-5), along with nine known sesquiterpene lactones (6-14) were isolated from the whole plant of Carpesium abrotanoides L. Their structures were elucidated on the basis of spectroscopic date, HRESIMS analysis, and comparison of experimental and calculated ECD data. All isolated compounds (1-14) were tested in vitro for their cytotoxic activities against the MDA-MB-231, HGC-27 cancer cell lines, of which compounds 1-3, 6, 7, 11 and 12 showed significant cytotoxic activities with IC50 values ranging from 2.67 to 12.34 µM.

Penicitroamide, an Antimicrobial Metabolite with High Carbonylization from the Endophytic Fungus Penicillium sp. (NO. 24).

Penicitroamide (1), a new metabolite with a new framework, was isolated from the ethyl acetate extract of the PDB (Potato Dextrose Broth) medium of Penicillium sp. (NO. 24). The endophytic fungus Penicillium sp. (NO. 24) was obtained from the healthy leaves of Tapiscia sinensis Oliv. The structure of penicitroamide (1) features a bicyclo[3.2.1]octane core unit with a high degree of carbonylization (four carbonyl groups and one enol group). The chemical structure of penicitroamide (1) was elucidated by analysis of 1D-, 2D-NMR and MS data. In bioassays, penicitroamide (1) displayed antibacterial potency against two plant pathogens, Erwinia carotovora subsp. Carotovora (Jones) Bersey, et al. and Sclerotium rolfsii Sacc. with MIC50 at 45 and 50 µg/mL. Compound 1 also showed 60% lethality against brine shrimp at 10 µg/mL. Penicitroamide (1) exhibited no significant activity against A549, Caski, HepG2 and MCF-7 cells with IC50 > 50 µg/mL. Finally, the possible biosynthetic pathway of penicitroamide (1) was discussed.

Two new steroidal glycosides with unique structural feature of 14α-hydroxy-5ß-steroids from Reineckia carnea.

Two new steroidal glycosides (1-2) were isolated from the roots of Reineckia carnea, together with three known compounds (3-5). Their structures were determined on the basis of chemical methods and spectral data. Compounds 1-2 were the unique steroidal glycosides possessing structural feature of 14α-hydroxy-5ß-steroids, and compounds 4-5 were isolated from R. carnea for the first time. The isolated compounds (1-5) were tested in vitro for their cytotoxic activities against the A549, HepG 2 and Caski cancer cell lines. Among them, the compounds 2 and 3 showed cytotoxicity against Caski cancer cell line with IC50 values of 34.4 and 3.7µM, respectively.

[Research on Chemical Constituents and Anti-tumor Activity of Eupatorium chinense].

Objective: To study the chemical constituents and their anti-tumor activity of Eupatorium chinense. Methods: The chemical constituents were separated and purified by the normal phase silica gel column chromatography,preparative thin-layer chromatography,and preparative HPLC. Their structures were determined by various spectral data,their antitumor activity in vitro was determined by MTT assay. Results: Six compounds were isolated from the ethyl acetate extract of Eupatorium chinense,and the structures were identified as eupalinilide G( 1),8ß-( 4'-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin( 2),3-( hydroxymethyl)-1,13,14,15-tetrahydroxy-7,11,15-trimethyl-2,6,10-hexadecatriene( 3),3-( hydroxymethyl)-1,13,15-trihydroxy-7,11,15-trimethyl-2,6,10-hexadecatrien-14-yl acetate( 4),eupafolin( 5) and hiyodorilactone B( 6). Compound 2 showed cytotoxicity against HGC-27 and B16 cancer cell lines with IC50 values of 4. 29 µg/m L and 5. 53 µg/m L,respectively. Methods: The chemical constituents were separated and purified by the normal phase silica gel column chromatography,preparative thin-layer chromatography,and preparative HPLC. Their structures were determined by various spectral data,their antitumor activity in vitro was determined by MTT assay. Results: Six compounds were isolated from the ethyl acetate extract of Eupatorium chinense,and the structures were identified as eupalinilide G( 1),8ß-( 4'-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin( 2),3-( hydroxymethyl)-1,13,14,15-tetrahydroxy-7,11,15-trimethyl-2,6,10-hexadecatriene( 3),3-( hydroxymethyl)-1,13,15-trihydroxy-7,11,15-trimethyl-2,6,10-hexadecatrien-14-yl acetate( 4),eupafolin( 5) and hiyodorilactone B( 6). Compound 2 showed cytotoxicity against HGC-27 and B16 cancer cell lines with IC50 values of 4. 29 µg/m L and 5. 53 µg/m L,respectively. Conclusion: Compounds 2 ~ 5 are isolated from the Eupatorium chinense for the first time,and compound 2 has significant cytotoxic activity against HGC-27 cell line.

Tupisteroide A-C, three new polyhydroxylated steroidal constituents from the roots of Tupistra chinensis.

Three new steroidal compounds with polyhydroxy groups, tupisteroide A-C (1-3), were obtained from the roots of Tupistra chinensis, together with one known compound (4) that was isolated from this plant for the first time. The structures of tupisteroide A-C were determined on the basis of one- and two-dimensional NMR spectroscopy, including (1) H-(1) H Correlation Spectroscopy, Heteronuclear Multiple Bond Correlation, and Heteronuclear Single Quantum Coherence experiments. The isolated compounds were evaluated for their cytotoxic activities against A549, HepG2, and CaSki cancer cell lines in vitro. Among them, compounds 1, 2, and 4 did not show significant inhibitory activity, but compound 3 showed cytotoxicity against A549 cancer cell lines with IC(50) values of 25.0 µM.

Five new furostanol saponins from the rhizomes of Tupistra chinensis.

Five new furostanol saponins (1-5), together with three known compounds (6-8) were obtained from the n-butanol soluble fraction of ethanol extract from Tupistra chinensis. Their structures were determined on the basis of chemical methods and spectral data. The isolated compounds were tested in vitro for their cytotoxic activities against the A549, HepG 2 and Caski cancer cell lines. Among them, compounds 6, 7, and 8 showed cytotoxicity against A549 cancer cell lines with IC(50) values of 6.6, 6.7 and 29.1 µM, respectively.