Experimental and computational approaches to reveal the potential of Ficus deltoidea leaves extract as α-amylase inhibitor

Ficus deltoidea leaves extract are known to have good therapeutic properties such as antioxidant, anti-inflammatory and anti-diabetic. We showed that 50% ethanol-water extract of F. deltoidea leaves and its pungent compounds vitexin and isovitexin exhibited significant (p < 0.05) α-amylase inhibition with IC₅₀ (vitexin: 4.6 μM [0.02 μg/mL]; isovitexin: 0.06 μg/mL [13.8 μM] and DPPH scavenging with IC₅₀ (vitexin: 92.5 μM [0.4 μg/mL]; isovitexin: 0.5 μg/mL [115.4 μM]). Additionally, molecular docking analysis confirmed that vitexin has a higher binding affinity (-7.54 kcal/mol) towards α-amylase compared to isovitexin (?5.61 kcal/mol). On the other hand, the molecular dynamics findings showed that vitexin-α-amylase complex is more stable during the simulation of 20 ns when compared to the isovitexin-α-amylase complex. Our results suggest that vitexin is more potent and stable against α-amylase enzyme, thus it could develop as a therapeutic drug for the treatment of diabetes.     

Flavonoid Glycosides from Terminalia catappa L.

Under the inhibition of Cu⁺²‐induced LDL oxidation‐guided fractionation, two new flavone glycosides with galloyl substitution were isolated from the dried fallen leaves of Terminalia catappa L. Their structures were established as apigenin 6‐C‐(2″‐O‐galloyl)‐β‐D‐glucopyranoside ( 1 ) and apigenin 8‐C‐(2″‐O‐galloyl)‐β‐D‐glucopyranoside ( 2 ), together with four known flavone glycosides, isovitexin, vitexin, isoorientin, and rutin, on the basis of spectroscopic method. Compounds 1 and 2 showed significant antioxidative effects. Their IC₅₀ were 2.1 and 4.5 μM, respectively.     

Coprinus comatus filtrate extract,a novel neuroprotective agent of natural origin

Abstract

In vitro acetylholinesterase (AChE) inhibitory activity of an autochthonous sample of the mushroom Coprinus comatus (encompassing fruiting body FB, mycelia M and filtrate F from the submerged cultivation) was the subject of this study. C. comatus F extract exhibited rather potent anti-AChE activity (73.0?±?1.5%) at in liquid conditions, comparable to those of the conventional drug donepezil (80.6?±?1.4%). Also, the same extract exhibited high anti-AChE activity (1?µg) in solid. While its FTIR spectrum indicated the presence of phenolic compounds, quercetin (28.1?µg g^?1 d.w.) was found to affect the observed bioactivity (59.8?±?0.9%). This is the first report of profound anti-AChE activity of any C. comatus extract, a medicinal mushroom that has been successfully cultivated in P.R. China, due to the demanding needs of food industry.     

Characterization ofC-glycosylflavones fromDissotis rotundifolia by liquid chromatography — UV diode array detection — tandem mass spectrometry

Summary By high-performance liquid chromatography (HPLC) coupled with UV diode-array detection (DAD) and thermospray mass spectrometry (TSP-MS), four main constituents of a polar, whole plant extract fromDissotis rotundifolia T. were characterized. The fourC-glycosylflavones, isoorientin, orientin, vitexin and isovitexin were detected in the methanolic and hydroalcoholic extract of the plant as well as in the commercial drug preparation ‘Sirop de Dissotis’. Although the UV data and TSP mass spectra allowed rapid characterisation of all fourC-glycosylflavones, exact attribution of the peaks to their structures could not be achieved as neither the UV spectra nor the TSP mass spectra enabled differentiation of one position isomer from the other. Therefore a successful attempt was made to distinguish the 6-C from the 8-C-glycosylflavones by thermospray tandem mass spectrometry (TSP-MS-MS). The collision induced dissociation (CID) spectra of the particular ion [M+H-120]⁺ gave fragments which permitted differentiation of position isomers. To confirm the accuracy of on-line results, reference compounds were included in the HPLC study.     

A new benzopyrans derivatives from a mangrove-derived fungus Penicillium citrinum from the South China Sea

One new benzopyran derivative (2R^*,4R^*)-3,4-dihydro-5-methoxy-2-methyl-2H-1-benzopyran-4-ol (1), together with five known compounds (2?6), were obtained from the EtOAc extract of the endophytic fungus Penicillium citrinum HL-5126 isolated from the mangrove Brguiera sexangula var. rhynchopetala collected in the South China Sea. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. All compounds were evaluated for their antibacterial activities. Compound 6 exhibited potent inhibitory activity against Bacillus subtilis, Bacillus cereus and Micrococcus tetragenus with the same MIC values of 6.94 μM.     

Isolation and structure elucidation of two new compounds from artemisia Ordosica Krasch

Abstract

Two new compounds, namely arteordoyn A (1) and arteordoyn B (2), together with four known compounds, were isolated from the petroleum ether extract of Artemisia ordosica Krasch. The structures elucidation of 1 and 2 were carried out by 1D-NMR (¹H and ¹³C NMR), 2D-NMR (COSY, HSQC, HMBC and NOESY) and HR-ESI-MS spectral analysis.     

Zur Kenntnis des Faktors F430 aus methanogenen Bakterien: Struktur des porphinoiden Ligandsystems

Factor F430 from Methanogenic Bacteria: Structure of the Porphninoid Ligand System A structure is proposed for F430M, a non-cristalline methanolysis product of isolates of the nickel-containing, porphinoid factor F430 from Methanobacterium thermoautotrophicum. Crucial to the structure determination are five incorporation experiments with M. thermoautotrophicum (strain Marburg) in which the specifically mono-¹³C-labeled biosynthetic precursors (2-¹³C), (3-¹³C), (4-¹³C)-, (5-¹³C) ALA (ALA = δ-amino-levulinic acid) and L-(methyl-¹³C)methionine were incorporated into F430 with high efficiency. The ¹³C-NMR,-spectra of the specifically labeled F430M samples derived therefrom, together with the UV./VIS. spectral data of F430M, contain all the information necessary for the deduction of the constitution of the F430M chromophore, assuming the established pattern of porphinoid biosynthesis to be operative in F430 biosynthesis. ¹H-NMR. spectroscopy and, in particular, ¹H-NMR.-NOE-difference spectroscopy corroborates and completes the constitutional assignments and, furthermore, makes possible an almost complete derivation of the molecule's relative configuration. Schemes 3 and 4 summarize the results of ¹H-NMR. spectroscopy, presenting them within the context of the proposed structure for F430M. The assignment of absolute configuration implied in the formula is given preference because of F430M's very close structural and (assumed) biosynthetic relationship to sirohydrochlorin and vitamin B₁₂ (with respect to ring C, the assignment is based on degradative evidence). According to the proposed structure, the nickel complex F430M possesses an uroporphinoid (Type III) ligand skeleton with an additional carbocyclic ring and a chromophore system not previously encountered among natural porphinoids. It can be considered to be a (tetrahydro) derivative of the corphin system, combining structural elements of both porphyrins and corrins.     

A new indole-alkaloid and a new phenolic-glycoside with cytotoxic activity from Strychnos fendleri

A new indole alkaloid strychnosinol (1) and a new phenolic-glycoside (2) were isolated from the bark and leaves of Strychnos fendleri Sprague & Sandwith, together with six known compounds reported for the first time in this species. The structures of these compounds were determined on the basis of spectroscopic data; mainly those obtained by using ¹H and ¹³C NMR (1D and 2D) and mass spectrometry. Strychnosinol (1) and the phenolic glycoside (2) together with compounds 3–8 were evaluated for cytotoxicity against a panel of five tumour cell lines; IC₅₀ values between 0.090 and 0.227 μM for the human tumour cell lines were observed for compound 2.     

Identification of Iridoids,Flavonoids and Triterpenes from the Methanolic Extract of Melampyrum bihariense A. Kern. and the Antioxidant Activity of the Extract

Melampyrum bihariense A. Kern. (Scrophulariaceae), a plant species used in traditional medicine for the treatment of rheumatic disorders and skin infections, was investigated with regard to its antioxidant activity and identification of its bioactive chemical constituents. The crude methanolic extract of the aerial parts of M. bihariense was examined by the spectrophotometric DPPH (1,1-diphenyl-2-picrylhydrazyl) and ferric reducing antioxidant power methods. The free radical scavenging capacity (SC₅₀) of the extract was found by the DPPH method to be 27.10 mg mL⁻¹, and the ferric reducing ability equivalent to ascorbic acid at 50 mg mL⁻¹ was 0.709 μg mL⁻¹. The chemical composition of this highly effective in the methanolic extract was analysed, and the main compounds were isolated through solvent–solvent partition, and multiple chromatographic separations, including column chromatography, vacuum liquid chromatography, centrifugal planar chromatography and preparative thin-layer chromatography. The structures were established by one- and two-dimensional NMR and liquid chromatography-mass spectrometry. The iridoids aucubin (1), 8-epi-loganin (2) and mussaenoside (3), the flavones apigenin and luteolin and the triterpene acids ursolic acid and oleanolic acid were identified; components 2, 3, ursolic acid and oleanolic acid for the first time in this species. The present study reveals that M. bihariense exerts antioxidant activity, and the iridoids, flavonoids and triterpene acids may be the main bioactive constituents of its methanolic extract.

     

A new flavane acid from the fruits of Illicium verum

A new compound, illiciumflavane acid (1), along with 13 known compounds (2–14), were isolated from the fruits of Illicium verum Hook. F. Their structures were elucidated through various spectroscopic methods, including 1D NMR (¹H NMR, ¹³C NMR), 2D NMR (HMQC, HMBC and NOESY) and HRMS. The stereochemistry at the chiral centres was determined using CD spectrum as well as analyses of coupling constants and optical rotation data. Cytotoxicity evaluation of four compounds showed that illiciumflavane acid and (E)-1,2-bis(4-methoxyphenyl)ethene exhibited potential against A549 activities with IC₅₀ values of 4.63 μM and 9.17 μM, respectively.     

PRECURSORS OF HEXA-AZAMACROCYCLES. SYNTHESIS AND X-RAY STRUCTURE OF 2,9-DIAMINOPHENANTHROLINEBISACETATE-Co(II) AND 6,6′-DIAMINOBIPYRIDINE-BISACETATE-M(II) (M = Ni,Cu)

Abstract

The synthesis, conventional characterisations and x-ray structures of the following monomeric complexes are given for 2,9-diaminophenanthroline-bisacetate-cobalt(II) ( A ) and 6,6′-diaminobipyridine-bisacetate-M(II) (M = nickel( C ) and copper( B )). Complex A crystalizes in the monoclinic, C2/c space group with a=12.813(6), b = 10.218(3), c= 13.811(5), Å; β= 118.17(2)°; Z=4; V=1549(2) ų. A total of 1787 unique reflections with F > 6σ(F) were refined to values of R and R_w 0.0461 and 0.0774, respectively. Complex B crystallizes in the triclinic, P-1 space group with a=10.099(5), b=10.257(5), c=8.015(11), Å; α=112.98(2), β=93.13(2), γ=92.960(2),°; Z=2; V = 761(1), ų. A total of 2603 unique reflections with F > 3.00σ(F) were refined to values of R and R_w 0.0764 and 0.1022, respectively. Complex C crystallizes in the monoclinic, P2₁/n space group with a=8.124(5), b=10.343(6), c=18.724(11), β=98.36(2),°; Z=4; V=1556(1), ų. A total of 2537 unique reflections with F > 3.00σ(F) were refined to values of R and R_w 0.0689 and 0.0975, respectively. The structures consist of six-coordinate [M(CH₃COO)₂(L)] (L=2,9-diaminophenanthroline or 6,6′-diaminobipyridine) discrete monomeric neutral species, although in the Cu(II) compound the elongation of two long Cu—O bonds, due to the Jahn-Teller effect, makes the metal essentially four-coordinate. In the Ni and Co compounds the acetate acts as a bidentate ligand. The diamino ligands are coordinated by the pyridine nitrogen atoms. The IR spectra of the complexes have been recorded and are discussed in relation to the crystal structure and the acetate coordination mode.     

A new cytotoxic diterpenoid glycoside from the leaves of Blumea lacera and its effects on apoptosis and cell cycle

A new diterpenoid glycoside, 6E,10E,14Z-(3S)-17-hydroxygeranyllinalool-17-O-β-d-glucopyranosyl-(1?→?2)-[α-l-rhamnopyranosyl-(1?→?6)]-β-d-glucopyranoside (1) together with the known diterpenoid glycoside (2) and two known flavonoid glycosides (3, 4) were isolated from the methanol extract of Blumea lacera leaves. The structures were determined by the interpretation of their spectroscopic data and comparison with the literature. All compounds were isolated for the first time from B. lacera and evaluated for their cytotoxic activity. Only the new compound (1) showed strong cytotoxic activity with the lowest IC₅₀ value (8.3 μM) being displayed against MCF-7 breast cancer cells. In apoptosis and cell cycle analysis, 1 revealed strong apoptotic activity against MCF-7 cells (45.5% AV⁺/PI^?) after 24 h, but showed no arresting of any of the cell cycle phases in MCF-7.     

Two new polyketides from the fungus Penicillium oxalicum MHZ153

Two new polyketides, penicilloxalones A (1) and B (2), together with 13 known compounds (3–15), were isolated from the ethyl acetate extract of the solid substrate fermentation cultures of the fungus Penicillium oxalicum MHZ153. The structures of the isolates were determined by spectroscopic analysis and comparison of their spectroscopic and physicochemical data with the literature values. Compounds 7 and 11 showed inhibition of nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells with IC₅₀ values of 0.9 ± 0.2 μM and 87.9 ± 0.7 μM, respectively.     

New sesquiterpenoid derivatives from Solanum septemlobum with cytotoxicities

Two new sesquiterpenoid derivatives, attributable to eudesmane-type (1–2, named septemlobin D and 11,12-O-isopropylidenesolajiangxin F), were isolated from the whole plant of Solanum septemlobum. Their structures were elucidated on the basis of integrated spectroscopic techniques, mainly HR-FAB-MS, 1D and 2D-NMR (¹H–¹H COSY, HMQC, HMBC and ROESY). In vitro, two sesquiterpenoid derivatives were found to show significant cytotoxicity against three cancer cell lines (P-388, HONE-1 and HT-29), and gave IC₅₀ values in the range of 3.0–7.3 μM.     

Antifungal activity of compounds isolated from Aspergillus niger and their molecular docking studies with tomatinase

Abstract

Using a dual culture antagonism assay, Aspergillus niger exhibited 51.5?±?1.1% growth inhibition against Fusarium oxysporum f.sp. lycopersici, the wilt pathogen of tomato. For enhanced production of antifungal metabolites, nutrient optimization was performed and in vitro well-diffusion antifungal assays demonstrated that crude extract obtained from GPYB culture showed a maximum zone of inhibition (8.8?±?0.4?mm) against the wilt pathogen, which is corroborated by the comparative LCMS profiles of the extracts from all three media i.e. GPYB, YEB and PDB. Two known compounds, Asperazine (m/z 665 [M?+?H]⁺) and Nigerone (m/z 571 [M?+?H]⁺), were isolated from A. niger and their antifungal activity is reported here for the first time. In MIC experiments, Asperazine and Nigerone inhibited the pathogen at 60 and 80?µg·mL^?1 respectively. Molecular docking studies of Nigerone and Asperazine with F. oxysporum tomatinase showed five and six binding interactions respectively.     

Three new phenanthrenone constituents from Trigonostemonlii

Three new phenanthrenone constituents, trigoxyphins U–W (1, 7 and 9), together with eight known ones, trigoxyphin M (2), 6,9-O-dimethyltrigonostemone (3), trigonstemone (4), thrigonosomone B (5), trigonochinene E (6), actephiiol A (8), epiactephilol A (10) and neoboutomannin (11), were obtained from the methanol extract of the leaves and stems of Trigonostemonlii. The structures of the new metabolites were elucidated by analysing the spectroscopic data (1D NMR, 2D NMR, HR-ESI-MS and IR). Compounds 1–6 were evaluated for their cytotoxic activities on five human tumour cell lines by using the MTT method, and compound 1 exhibited inhibitory activity against HL-60, SMMC-7721, A-549, MCF-7 and SW480 with IC₅₀ values ranging from 3.77 to 14.51 μM.     

Contribution à la phytochimie du genre Gentiana I. Etude des composés flavoniques et xanthoniques dans les feuilles de Gentiana lutea L. (1re communication)

Six polyphenolheterosides have been isolated from the leaves of G. lutea L. by means of thin layer and column chromatography on polyamide. The xanthones mangiferin (III) and gentioside (IV), the flavones isoorientin (V) isovitexin (VI) and two new heterosides (E and F) have been isolated. E gave isoorientin and glucose on hydrolysis and F isovitexin, glucose and gentiobiose. Structure identification has been achieved by UV., IR. and NMR. spectroscopy as well as by synthesis of the corresponding aglycones.     

Autoradiolysis of the 2-deoxy-2-[<Superscript>18</Superscript>F]fluoro-D-glucose radiopharmaceutical

Summary To control virtually the toxic compounds and to improve quality control of the solution of 2-deoxy-2-[¹⁸F]fluoro-d-glucose (2-[¹⁸F]FDG), the products of its autoradiolysis were analyzed by high-performance liquid chromatography with electrospray mass spectrometric and radiometric detectors (HPLC/MS/RAD), thin layer chromatography on TLC silica plate and HPTLC on amino modified silica plate. Except Kryptofix^™ 2.2.2, glucose and fluoride anion, no by-products and impurities were observed by LC/MS analysis of fresh 2-[¹⁸F]FDG samples. The analysis performed in the time interval of 6 to 48 hours after the end of 2-[¹⁸F]FDG synthesis indicated that the activity of the autoradiolysis products separated by HPLC did not exceed 1.3%. As the main autoradiolysis products of 3.3 ^. 10^-5 to 4.4 ^. 10^-5M 2-[¹⁸F]FDG solution of original specific activity 0.5-1.5 GBq ^. cm^-3 were established: arabinose - 2.8 μM (G= 0.07/100 eV), gluconic and glucuronic acids 1.8-0.5 μM (G =0.01-0.05/100 eV), arabinose and araburonic acids occurred under 0.5 μM concentration at residual glucose contents about 0.14 mM. Radiation chemical yields of active products were calculated from molar activity of 2-[¹⁸F]FDG and the percentage of their activity: 0.5% radiochemical yield of 2-[¹⁸F]fluoroglucuronic acid corresponds to the G = 0.004/100 eV and 0.3% yield of 2-[¹⁸F]fluorogluconic acid issues G = 0.003/100 eV.     

Two new ionone glycosides from the roots of Rehmannia glutinosa Libosch.

Two new ionone glycosides, named frehmaglutoside G (1) and frehmaglutoside H (2), together with six known compounds, rehmapicroside (3), sec-hydroxyaeginetic acid (4), dihydroxy-β-ionone (5), trihydroxy-β-ionone (6), rehmaionoside A (7) and rehmaionoside C (8), were isolated from the 95% EtOH extract of the dried roots of Rehmannia glutinosa Libosch. Their structures were determined on the basis of extensive spectroscopic analyses, including HR-ESI-MS, UV, IR, 1D and 2D NMR (¹H–¹H COSY, HSQC, HMBC and NOESY) methods. The absolute configurations were confirmed via the circular dichroism spectra.     

A new benzofuran from Artemisia halodendron Turcz. ex Bess.

A new benzofuran, methyl (2S,2″S,3′E)-[2-(1″-acetoxypropan-2-yl)-2,3-dihydrobenzofuran-5-yl]acrylate (1), and 13 known compounds (2–14) were isolated from an ethanol extract of Artemisia halodendron Turcz. ex Bess. The chemical structures of these compounds were determined by 1D and 2D NMR (¹H-¹H COSY, HMBC, HMQC and NOESY) and HR-ESI-MS spectra, and results were compared with data from the literature. The effects of compounds 1–14 were measured on NF-κB activation, with compounds 2 and 3 exhibiting inhibitory activities against TNF-α-induced NF-κB reporter gene expression in HeLa cells from 10 to 100 μM.