The adsorption of water on Pt(111) surface has been studied with ab initio molecular dynamics simulation. Both the energetics and vibrational indicate existence a well-ordered bilayer this surface. This conclusion is in contrast to recent result Ru(0001) surface, but agrees available experiments. In addition, our calculation identifies two different hydrogen bonds bilayer. can be directly recognized from spectra OH stretch modes.

Six new β-resorcylic acid lactones (1−6), named paecilomycins A−F, and five known compounds, aigilomycin B (7), zeaenol (8), aigialomycin D (9), F (10), aigialospirol, were isolated from the mycelial solid culture of Paecilomyces sp. SC0924. Their structures elucidated by extensive NMR analysis, single-crystal X-ray study, chemical correlations. Compounds 5 10 exhibited antiplasmodial activity against Plasmodium falciparum line 3D7 with IC50 values 20.0 10.9 nM, respectively, compounds 5−7...

Two new polycyclic tetramate macrolactams, lysobacteramides A (1) and B (2), together with HSAF (heat-stable antifungal factor, 3), 3-dehydroxy (4), alteramide (5) were isolated from a culture of Lysobacter enzymogenes C3 in nutrient yeast glycerol medium. Their structures determined by MS extensive NMR analysis. The absolute configurations 1–5 assigned theoretical calculations their ECD spectra. Although analogues reported several microorganisms, had not been established. isolation the...

The adsorption of water on a fully hydroxylated silica surface is studied by using density-functional total-energy and molecular dynamics calculations. (100) $\ensuremath{\beta}(\ensuremath{\alpha})$-cristobalite covered geminal hydroxyls has been taken as the substrate. A well-ordered stable two-dimensional ice with quadrangular octagonal patterns hydrogen bond (H-bond) networks---an tessellation---is found for first time. With vibrational recognition, four molecules in quadrangle are to be...

Various studies have documented the beneficial effects of black soybean extract against diabetes. However, specific active compounds responsible for these remain elusive. Here, we aimed to identify α-glucosidase inhibitors present in soybeans using affinity ultrafiltration. Seven isoflavones with inhibitory activity were identified, among which daidzein and genistein demonstrated remarkably superior compared that acarbose (IC50 = 632.5 ± 70.0 μmol/L), exhibiting IC50 values 15.7 0.3 3.2 1.2...

A rearranged sterol with an unusual tetracycle core skeleton, penicillitone (1), and a new sterol, penicillisterol (2), were obtained from the culture of fungus Penicillium purpurogenum SC0070. Their structures characterized by spectroscopic analysis, DFT/TDDFT compuations, X-ray diffraction. Compound 1 demonstrated potent inhibitory effects on tumor cell growth key pro-inflammatory cytokine production in macrophages. biogenetic pathway oxidative cleavage vinylogous aldol addition as...

2, 4-Diacetylphloroglucinol (2,4-DAPG), a natural phenolic compound, has been investigated in light of its biological activities against plant pathogens. To improve potential application, fourteen 2,4-DAPG analogous were synthesized through the Friedel-Crafts reaction using acyl chlorides and phloroglucinol. Of derivatives, MP4 exhibited much higher antifungal activity Penicillium digitatum P. italicum, major pathogenic fungi citrus fruit, than 4-DAPG vitro, significantly inhibited...

Thirteen new pentacyclic triterpenoids, cleistocalyxic acids A-K (1, 2, 4, 5, and 7-13) cleistocalyxolides A (3) B (6), 15 known analogues (14-28), based on taraxastane, oleanane, ursane, multiflorane, lupane skeletons, were isolated from the leaves of Cleistocalyx operculatus. The structures 1-13 elucidated by analysis their spectroscopic data ECD/TDDFT computations. Cleistocalyxolide (3), presumed to be derived taraxastane-type compound 14, has a rare rearranged triterpenoid backbone....

Eight new β-resorcylic acid lactones (RALs), including the hypothemycin-type compounds paecilomycins N–P (1–3) and radicicol-type metabolites dechloropochonin I (4), monocillins VI (5) VII (6), 4′-hydroxymonocillin IV (7), 4′-methoxymonocillin (8), along with nine known RALs (9–17), were isolated from cultures of Paecilomyces sp. SC0924. Compounds 1 2 feature a novel 6/11/5 ring system, 3 is first 5′-keto RAL. The structures 1–8 elucidated on basis extensive spectroscopic analysis, X-ray...

Three new isochroman derivatives, 1-acetonyl-7-carboxyl-6,8-dihydroxy-3,4,5-trimethylisochroman (1), 7-carboxyl-6,8-dihydroxy-1,1,3,4,5-pentamethylisochroman (2), and 6,8-dihydroxy-3,4,5-trimethylisochroman (3), together with decarboxydihydrocitrinone (4), were isolated from mycelial solid culture of a Cylindrocarpon fungus.Their structures established by spectroscopic methods.In the course our continual search for antibacterial antifungal natural products produced filamentous fungi...

The antifungal activity of a natural resorcylic acid lactone, hypothemycin (HPM), against Peronophythora litchii in vitro and vivo was investigated. HPM treatment substantially suppressed spore germination P. litchi, with the inhibition rate 100% when 0.78 μg/mL applied. Similarly, mycelial growth efficiently inhibited. Furthermore, caused ultrastructural modifications litchii, including disruption cell wall endomembrane system, especially plasma membrane, mitochondria, vacuoles, which led...

Four new cyclodepsipeptides, dinghupeptins A-D (1-4), possessing a rare N5-(2-hydroxylethyl)glutamine moiety, were isolated from cultures of the soil-derived Streptomyces sp. SC0581. Their structures elucidated by spectroscopic and advanced Marfey's amino acid analysis, their 3D established theoretical conformational analysis. Compounds 1 2, containing 3-amino-6-hydroxypiperidone unit, displayed selective inhibition chymotrypsin with IC50 values 2.1 1.1 μM, respectively. Enzyme kinetic...

Aspergillus niger is one of the major pathogenic fungi causing postharvest grape decay. The development antifungal agents beneficial to reduce loss grapes during storage. aim this study was investigate mechanism cyclosporin A (CsA). It indicated that rot on caused by A. almost completely inhibited with CsA in vivo at a concentration 200 mg/L. transcriptomic analysis revealed expression levels genes involved rRNA processing and ribosome biogenesis were down-regulated, whereas those related...

Four novel prenylflavonols, macaranones A—D (1—4), were isolated from the leaves of Macaranga sampsonii. Their structures elucidated on basis spectroscopic data. Macaranones C (3) and D (4) represent first two examples flavonols having an unusual peltogynoid skeleton which is formed a 2′-geranylflavonol by cyclization between 3-OH C-1″ 2′-geranyl substituent flavonol. Compounds 1—4 evaluated for cytotoxicity against several human cancer cell lines.

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 elucidated by spectroscopic analysis, X-ray diffraction, and ECD/TDDFT computations. Compound 3 exhibited inhibitory effects on production TNF-α, IL-6, NO in LPS-stimulated macrophages. A biogenetic pathway a [4 + 2] cycloaddition as key reaction is proposed for 1–3.

Four dimeric acremines, bisacremines A–D (1–4), with a novel carbon skeleton and new monomer, acremine T (5), were obtained from cultures of the soil-derived fungus Acremonium persicinum SC0105. Their structures characterized by analysis spectroscopic data, ECD/TDDFT computations, X-ray diffraction. Compounds 1 2 exhibited weak cytotoxicity against HeLa cells, also showed modest activity A549 HepG2 cells.

Four new dammarane-type saponins, operculinosides A-D (1-4), were isolated from the aerial parts of Operculina turpethum, which 1 and 2 are first two triterpenoids having an oxymethyl group at C-24. Their structures determined by spectroscopic analysis acid hydrolysis. The absolute configuration operculinoside A (1) was confirmed X-ray crystallography. Compounds 3 showed significant protective activities against d-galactosamine-induced toxicity in L-02 human hepatic cells.

Seven structurally related new polyoxygenated methyl cyclohexanoids, ampelomins A−G (1−7), were isolated from the mycelial solid culture of a soil-derived Ampelomyces fungus. Their structures determined by spectroscopic and chemical means. Ampelomins A (1), C (3), E (5), G (7) exhibited weak activity against α-glucosidase with IC50 values 1.74−5.93 mM, ampelomin (1) showed moderate antibacterial MIC90 ranging 202.4 to 1015.9 μM. plausible polyketide biogenetic pathway is postulated for these...