Search

Five new pentacyclic triterpenoids, 6α-hydroxyursolic acid (1), 6α-hydroxycorosolic acid (2), 6-oxo-maslinic acid (3), 6-oxo-δ-maslinic acid (4), and 6-oxo-alphitolic acid (5), along with 15 known analogues were isolated from the leaves of Cleistocalyx conspersipunctatus. Their structures were elucidated by spectroscopic analysis. Compound 1 displayed better α-glucosidase inhibitory activity (IC50: 2.6 μM) than the known inhibitor corosolic acid (IC50: 15.5 μM). Structure–activity relationships in the activity were discussed for this group of isolates.

Six previously undescribed cytochalasans, ueckerchalasins A-E and 4'-hydroxycytochalasin J

Eight new diarylheptanoids, coriandralpinins A–H (1–8), were isolated from the rhizomes of Alpinia coriandriodora, an edible plant of the ginger family. Their structures, including the absolute configurations, were established by extensive spectroscopic analysis and ECD calculations. Compounds 1–8 have a 1,5-O-bridged diarylheptanoid structure featuring polyoxygenated aryl units. When evaluated for intracellular antioxidant activity using t-BHP stressed RAW264.7 macrophages, all these compounds scavenged reactive oxygen species (ROS) in a concentration-dependent manner. Compounds 3 and 5 also showed inhibitory activity against NO release in LPS-induced RAW 264.7 cells. Six known flavonols, 7,4′-di-O-methylkaempferol, 7-O-methylquercetin, 7,4′-di-O-methylquercetin, 7,3′,4′-tri-O- methylquercetin, kaempferol 3-O-β-d-(6-O-α-l-rhamnopyranosyl)glucopyranoside, and 3-O-β-d-glucopyranuronosylquercetin were also isolated and characterized from the rhizomes.

Two new 2H-pyranones (1 and 2), two new isocoumarins (4 and 5), and two known compounds (3 and 6) were obtained from solid cultures of the endophytic fungus Pestalotiopsis microspora SC3082. Their ...

Two new bisabolane-type sesquiterpenoids, (3R,4S,5R,7S)-3,4,5-trihydroxybisabola-10-ene-9-one (1), (1R,2S,5R,7R,8S)-2,8-epoxy-5-hydroxybisabola-3,10-diene-9-one (2), together with seven known anologues (3–9), were isolated from the cooking liquid of Curcuma longa rhizomes. Their structures were elucidated by a combination of 1D and 2D NMR spectroscopic and HRESIMS data. The absolute configurations of compounds 1 and 2 were assigned by electronic circular dichroism (ECD) calculations. Compound 2 exhibited in vitro anti-inflammatory activity with an IC50 value of 25.5 ± 3.1 μM comparable to that of the positive control.

Two new diketopiperazines, cyclo( l -Phe- l -NMe-DOPA) (2) and cyclo[ l -Phe- l -(NMe-3-(NMe-3-O-α- l -rhamnopyranosyl)-DOPA] (3), along with a known diketopiperazine (1), were isolated from the cultures of Streptomyces sp. SC0581. Their structures were elucidated by extensive spectroscopic analysis, single-crystal X-ray crystallographic analysis, and chemical correlation. Compounds 1 − 3 exhibited more potent ABTS radical cation scavenging activity (IC50 values: 3.7 − 14.6 μM) than l -ascorbic acid (IC50: 17.7 μM). Compounds 2 and 3 also showed remarkable DPPH radical scavenging activity.

Dealing with nitrogen-rich saline wastewater produced by industries remains challenging because of the inhibition of functional microorganisms by high salinity. The underlying mechanisms of anaerobic ammonium-oxidizing bacteria (AnAOB) exposed to salinity stress should be studied to investigate the potential of anaerobic ammonium oxidation (ANAMMOX) for applications in such wastewater. In this study, the total DNA from granular sludge was extracted from an expanded granular sludge bed (EGSB) reactor operated at 0, 15 and 30 g/L salinity and subjected to high-throughput sequencing. The nitrogen removal performance in the reactor could be maintained from 86.2 to 88.0% at less than 30 g/L salinity level. The microbial diversity in the reactor under saline conditions was lower than that under the salt-free condition. Three genera of AnAOB were detected in the reactor, and Candidatus Kuenenia was the most abundant. The predictive functional profiling based on the Clusters of Orthologous Groups of proteins (COGs) database showed that the inhibition of AnAOB under saline conditions was mainly characterised by the weakening of energy metabolism and intracellular repair. AnAOB might adapt to salinity stress by increasing their rigidity and intracellular osmotic pressure. The predictive functional profiling based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database revealed that the inhibition of AnAOB was mainly manifested by the weakening of intracellular carbohydrate and lipid metabolism, the blockage of intracellular energy supply and the reduction of membrane transport capacity. AnAOB might adapt to salinity stress by strengthening wall/membrane synthesis, essential cofactors (porphyrins) and energy productivity, enhancing intracellular material transformation and gene repair and changing its structure and group behaviour. The stability of the nitrogen removal performance could be maintained via the adaptation of AnAOB to salinity and their increased abundance.

Three new β-resorcylic acid derivatives, compounds 1–3 , along with six known analogues ( 4 – 9 ) were isolated from an endophytic fungus Lasiodiplodia sp. ZJ-HQ 1 derived from medicinal plant Acanthus ilicifolius. Their structures were elucidated by 1D and 2D NMR spectroscopic analysis, high resolution mass spectrometric (HREIMS) data, and X-ray crystallography. The absolute configurations of compounds 1 and 2 were determined by the modified Mosher’s method. Compounds 1–7 showed more potent inhibitory effects against α-glucosidase activity than the clinical α-glucosidase inhibitor acarbose.

Two new γ-pyrones, xylaropyrones B (1) and C (2), together with three known compounds, xylaropyrone (3), annularin A (4) and annularin C (5), were isolated from solid cultures of the endophytic fungus Xylaria sp. SC1440. The structures of these compounds were determined mainly by analysis of their NMR spectroscopic data. The relative configurations of 1 and 2 were assigned on the basis of J-based configurational analysis, and the absolute configurations were established by experimental and TDDFT calculated ECD spectra. The isolated compounds were evaluated for cytotoxic and tyrosinase inhibitory activity.

A novel Cephalotaxus alkaloid with an N-alkyl-3-benzazepine skeleton, cephalofortunone (1), and known congeners, cephalotaxine, drupacine, and demethylcephalotaxinone, were isolated from the stems of Cephalotaxus fortune Hook. f. Their structures were elucidated on the basis of spectroscopic data. The absolute configuration of 1 was assigned by the comparison of its experimental solution CD spectrum with the TDDFT-calculated one on DFT-optimized geometries. This is the first cephalotaxine derivative with an N-alkyl chain rather than 1-azaspiro[4.4]nonane moiety from Cephalotaxus spp.

Xylanthraquinone (1), a new anthraquinone, along with three known compounds, altersolanol A (2), deoxybostrycin (3) and bostrycin (4) was isolated from the fungus Xylaria sp. 2508 from the South China Sea. The structures of these compounds were identified by NMR experiments, and the absolute configuration of compound 1 was further confirmed by single-crystal X-ray diffraction with Cu Kα radiation. Compounds 1–4 did not show inhibitory activities against Mycobacterium tuberculosis protein tyrosine phosphatase B (IC50 values more than 100 μM).

Ergosterol,(1→3)-α-D-glucan and chitosan are important biomaterials. In this research, a process has been developed to integratively extract ergosterol, (1→3)-α-D-glucan, and chitosan from Penicillium chrysongenum mycelium. First, the mycelia are pretreated with 0.1mol · L−1 of NaOH. After recovery by centrifugation, the solid portion is made to undergo saponification and deacetylation reactions by addition of 2mol · L−1 NaOH and ethanol. After reaction, extraction is carried out by addition of petroleum ether, which separates the reaction mixture into two phases. The upper layer of petroleum ether contains extracted ergosterol, and the bottom layer of NaOH solution contains (1→3)-α-D-glucan; the chitosan is on the mycelia residuum. After isolation, the recovery yield of ergosterol is 0.52% of dry mycelium. That of (1→3)-α-D-glucan is about 8.2%; and chitosan is 5.7% with 86% deacetylation. The compositions have been characterized by IR, HPLC analyses.

Three dimeric acremines, bisacremines E-G (1-3), with an unusual carbon skeleton were isolated from cultures of the soil-derived fungus Acremonium persicinum SC0105. Their structures were elucidated by spectroscopic analysis, X-ray diffraction, and ECD/TDDFT computations. Compound 3 exhibited inhibitory effects on the production of TNF-α, IL-6, and NO in LPS-stimulated macrophages. A biogenetic pathway with a [4 + 2] cycloaddition as the key reaction is proposed for 1-3.

A new lovastatin analogue versicorin (1), together with three related compounds, decumbenones A (2) and B (3) and versiol (4), were isolated from mycelial solid cultures of Aspergillus versicolor SC0156. Their structures were elucidated on the basis of MS data and NMR spectroscopic analysis. The new compound versicorin (1) possesses a hexahydro-2H-naphtho[1,8-bc]furan moiety, which is a rare type of the lovastatin-analogous compounds. A hypothetical biosynthetic pathway for compounds 1–4 was proposed.

A water-insoluble linear (1--3)-alpha-D-glucan was isolated from Penicillium mycelia. Three kinds of epoxy-activated microspheres of this glucan were prepared as supports for Candida sp. lipase (EC3.1.1.3) immobilization. The highest immobilization yield was 36.4%. The specific activity was 26.85 U/mg, and only 4.1% of activity was lost in comparison with the free enzyme used for immobilization. The higher thermal stability, storage stability, and reusability of the immobilized lipase make it a potential candidate for wide application.

Asperterpenoid A (I) exhibits strong inhibitory activity against the title phosphatase (mPTPB) with an IC50 value of 2.2 μM.

Asperterpenoid A (1), a novel sesterterpenoid with a new carbon skeleton, has been isolated from a mangrove endophytic fungus Aspergillus sp. 16-5c. Its structure was characterized by extensive spectroscopic methods, and the absolute configuration was determined by single crystal X-ray diffraction analysis. Asperterpenoid A (1) exhibited strong inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (mPTPB) with an IC(50) value of 2.2 μM.