A highly sensitive and selective rhodamine-semicarbazide based fluorescent sensor for Cu detection in real water samples and fluorescence bioimaging in HepG2 cells.

A colorimetric and fluorescent sensor, selective for Cu ions, was synthesized in two steps using a rhodamine-based compound attached to the semicarbazide-picolylamine moiety (RBP). Spectroscopic measurements, including UV-Vis absorption and fluorescence emission, were conducted in the semi-aqueous medium containing acetonitrile/4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, denoted as MeCN/HEPES buffer (2:8, v/v, pH 7.0).

Structural and mutational analysis of glycoside hydrolase family 1 Br2 -glucosidase derived from bovine rumen metagenome.

Ruminant animals rely on the activities of -glucosidases from residential microbes to convert feed fibers into glucose for further metabolic uses. In this report, we determined the structures of Br2, which is a glycoside hydrolase family 1 -glucosidase from the bovine rumen metagenome. Br2 folds into a classical (/)-TIM barrel domain but displays unique structural features at loop 5→5 and -helix 5, resulting in different positive subsites from those of other GH1 enzymes.

A Rhodamine-coumarin Triazole Conjugate as a Fluorescent Chemodosimeter for Cu(II) Detection and its Application in Live Cell Bioimaging.

A rhodamine-triazole fluorescent probe bearing a coumarin moiety RTC was synthesized using the Cu(I)-catalyzed click reaction. The rhodamine-triazole conjugate was highly selective to Cu among other metal ions, including Ca, Co, Cu, Cd, Mg, Fe, Fe, Hg, Zn, Ni, Pd and Pb in physiological conditions. Upon the addition of Cu, the colorless RTC solution turned pink and exhibited a significant fluorescence emission centered at 578 nm.

A novel highly selective FRET sensor for Fe(III) and DFT mechanistic evaluation.

A novel FRET-based sensor has been designed and developed through the conjugation of naphthyl and rhodamine via propylamine spacer, Naph-Rh. The naphthyl moiety serves as a FRET donor due to its emission spectrum overlapping with the rhodamine B absorption band. Naph-Rh exhibited a selectivity for sensing Fe over other metal ions with a visual color change and fluorescent enhancement.

A Rhodamine-based Fluorescent Chemodosimeter for Au in Aqueous Solution and Living Cells.

A highly selective rhodamine hydrazide-based fluorescent chemosensor for Au detection was developed. The aqueous solution of rhodamine N-hydroxysemicarbazide (RHS), in the presence of Au, exhibited a significant 55-fold turn-on fluorescence response at 591 nm and a colorimetric change from colorless to pink. Other interested ions including Li, Na, K, Cs, Mg, Ca, Ba, Pb, Mn, Co, Ni, Ag, Cd, Cu, Hg, Zn, Sn, Fe, Fe, Cr, Ce did not induce any distinct color/spectral changes.

Pyranonaphthoquinone and anthraquinone derivatives from Ventilago harmandiana and their potent anti-inflammatory activity.

The chemical study on the heartwoods extract of Ventilago harmandiana (Rhamnaceae) resulted in the isolation of ten previously undescribed pyranonaphthoquinones (ventilanones A-J), an undescribed anthraquinone (ventilanone K), together with eight known anthraquinone derivatives. Their structures were elucidated by extensive analysis of their spectroscopic data. The absolute configuration of ventilanone A was established from single crystal X-ray crystallographic analysis of its p-bromobenzenesulfonate ester derivative using Cu Kα radiation.

Cytotoxic polyoxygenated cyclohexene derivatives from the aerial parts of Uvaria cherrevensis.

Three previously undescribed polyoxygenated cyclohexene derivatives named cherrevenol M (1), cherrevenol N (2), and cherrevenone (3), together with nine related known analogues 4-12 were isolated from the ethyl acetate fraction partitioned from the methanol extract of the aerial parts of Uvaria cherrevensis (Annonaceae). The determination of the structures and their relative configurations of the isolated compounds were established by spectroscopic techniques, electronic circular dichroism (ECD) analysis as well as comparison with the literature data. For cherrevenone (3), the relative and absolute configurations were also confirmed by using X-ray diffraction and ECD techniques, respectively.

New bioactive cyclopeptide alkaloids with rare terminal unit from the root bark of .

Six new 14-membered ring cyclopeptide alkaloids, cambodines A-F (1-6), and two known compounds, frangufoline (7) and lotusanine B (8), were isolated from the root bark extract of Pierre. Their structures and configurations were established based on 1D and 2D NMR, HRMS, ECD, and X-ray crystallographic data. Compounds 1 and 3 are rare 5(14)-type cyclopeptide alkaloids that possess an imidazolidin-4-one ring in the terminal unit.

A chromogenic and fluorogenic rhodol-based chemosensor for hydrazine detection and its application in live cell bioimaging.

A rhodol-based fluorescent probe has been developed as a selective hydrazine chemosensor using levulinate as a recognition site. The rhodol levulinate probe (RL) demonstrated high selectivity and sensitivity toward hydrazine among other molecules. The chromogenic response of RL solution to hydrazine from colorless to pink could be readily observed by the naked eye, while strong fluorescence emission could be monitored upon excitation at 525 nm.

A rhodamine-triazole fluorescent chemodosimeter for Cu detection and its application in bioimaging.

A rhodamine-based fluorescent chemodosimeter rhodamine hydrazide-triazole (RHT) tethered with a triazole moiety was developed for Cu detection. In aqueous medium, the RHT probe exhibited high selectivity and sensitivity toward Cu among other metal ions. The addition of Cu triggered a fluorescence emission of RHT by 384-fold (Φ = 0.

Anti-HIV and cytotoxic biphenyls, benzophenones and xanthones from stems, leaves and twigs of Garcinia speciosa.

Eleven previously undescribed compounds, including four benzophenones (garciosones A-D), four xanthones (garciosones E-H) and three biphenyls (garciosines A-C), along with eighteen known compounds were isolated from the stems, leaves and twigs of Garcinia speciosa Wall. (Clusiaceae). Their structures were established by extensive spectroscopic analysis.

Polycyclic polyprenylated acylphloroglucinols and biphenyl derivatives from the roots of Garcinia nuntasaenii Ngerns. & Suddee.

Seven previously undescribed compounds, including three polycyclic polyprenylated acylphloroglucinols (garcinuntins A-C), three biphenyl derivatives (garcinuntabiphenyls A-C) and a lanostane triterpene (garcinuntine), along with thirteen known compounds were isolated from the root of Garcinia nuntasaenii Ngerns. & Suddee. Their structures were elucidated on the basis of spectroscopic techniques.

A thiourea-appended rhodamine chemodosimeter for mercury(II) and its bioimaging application.

A rhodamine-thiourea conjugate RTP with an o-phenylenediamine linker was developed as a fluorogenic chemodosimeter for Hg detection. In the presence of Hg, a colorless solution of RTP turned pink with a maximum absorption band at 555nm and with a 62-fold fluorescence enhancement at 578nm (Φ=0.34).

A rhodol-based fluorescent chemosensor for hydrazine and its application in live cell bioimaging.

A rhodol cinnamate fluorescent chemosensor (RC) has been developed for selective detection of hydrazine (NH). In aqueous medium, the rhodol-based probe exhibited high selectivity for hydrazine among other molecules. The addition of hydrazine triggered a fluorescence emission with 48-fold enhancement based on hydrazinolysis and a subsequent ring-opening process.

Anti-inflammatory 12,20-Epoxypregnane and 11,12-seco-Pregnane Glycosides from the Stems of Hoya kerrii.

Five 12,20-epoxypregnane glycosides (1-3, 5, and 6) and two 11,12-seco-pregnane glycosides (4 and 7) with spirodilactone motifs, as well as spirodilactone cleavage products 8 and 9, were isolated from the stems of Hoya kerrii. The relative configurations of the three related skeletons were supported by ROESY experiments and X-ray crystallographic analyses. The isolates were evaluated for their anti-inflammatory activity based on the inhibition of NO production in RAW264.

Terphenyl derivatives and drimane - Phathalide/isoindolinones from Hypoxylon fendleri BCC32408.

The genus Hypoxylon, a member of the family Xylariaceae, has been known to produce significant secondary metabolites in terms of chemical diversity. Moreover, the compounds isolated can also be used as chemotaxonomic characters for differentiation among the two sections, which are sect. Annulata and sect.

Characterization of the selective alkylation site in hemoglobin A by dihydroartemisinin with tandem mass spectrometry.

The reaction between the antimalarial drug dihydroartemisinin (DHA) and hemoglobin A (HbA) was investigated in vitro. A fluorescein-tagged artemisinin analog reacted with HbA and fluorescent HbA-drug adducts could be visualized on SDS-PAGE to confirm stable covalent reaction adducts and necessity of the endoperoxide moiety and Fe(II). Mass spectrometric analyses revealed that DHA favourably alkylated protein part rather than heme and the modification site was identified to be at Tyr35 of the beta globin chain.

F-THENA: a chiral derivatizing agent for the determination of the absolute configuration of secondary aromatic alcohols with a self-validating system.

F-THENA is designed as an alternative fluorine-containing chiral derivatizing agent (CDA). The fluorine atom functions exclusively as a reporter which can directly sense an anisotropic effect from an aromatic substituent of a chiral alcohol. In combination with chemical shift differences from both F NMR and H NMR, the F-THENA method can successfully be used for determining the absolute configuration of chiral secondary aromatic alcohols with a self-validating system.

Cytotoxic lanostanes from fruits of Garcinia wallichii Choisy (Guttiferae).

Five new lanostanes, wallichinanes A-E (1-5) together with a known lanostane derivative 6 were isolated from the cytotoxic hexanes extract of fruits of Garcinia wallichii Choisy (Guttiferae). The structures of the isolated compounds were established by analysis of spectroscopic data, X-ray diffraction technique as well as comparison with the literature data. The cytotoxicity of all isolated compounds against a panel of cultured cancer cell lines was evaluated.

Benzimidazole-triazole ligands with pendent triazole functionality: unexpected formation and effects on copper-catalyzed aerobic alcohol oxidation.

A series of benzimidazole-triazole ligands (NN') having a pendent triazole arm with different triazole substituents including CHPh (3a), cyclo-CH (3b), and CHSiMe (3c) were obtained in moderate yields from Cu-catalyzed oxidative C-N cyclization of the respective amine-triazole compounds N,N'-bis((1-R-1,2,3-triazol-4-yl)methyl)benzene-1,2-diamine (2a-2c). Treatment of CuCl with one equiv. of the benzimidazole-triazole ligands afforded the corresponding Cu complexes with the empirical formula of Cu(NN')Cl (4a-4c).

Phenalenone derivatives and the unusual tricyclic sesterterpene acid from the marine fungus Lophiostoma bipolare BCC25910.

Ten compounds including nine phenalenone derivatives (five bipolarides and four bipolarols) and a sesterterpene acid (bipolarenic acid), were isolated from a marine isolated of the fungus Lophiostoma bipolare (BCC25910), along with the known compounds, (-)-scleroderolide, (-)-sclerodin, and oxasetin. Chemical structures were elucidated based on NMR spectroscopic data and HRESIMS analysis. In addition, the absolute configurations of the phenalenones were resolved using specific rotations and chemical means, while the relative configuration of bipolarenic acid was confirmed by X-ray crystallographic analysis.

Crystal structure of 1-(2,4-dihy-droxy-6-methyl-phen-yl)ethanone.

The title compound, C9H10O3, is a bioactive secondary metabolite, isolated from the endophytic fungus Nodulisporium sp. The compound exhibits an intra-molecular O-H⋯O hydrogen bond between the phenolic H atom and the carbonyl O atom of the adjacent acetyl group. In the crystal, mol-ecules are linked by hydrogen bonds involving the 4-phenolic H atom and a symmetry-related carbonyl O atom of a neighboring mol-ecule, resulting in extended supra-molecular chains along the a-axis direction.

Crystal structure of 4,6-di-amino-2,2-dimethyl-3-[3-(2,4,5-tri-chloro-phen-oxy)prop-oxy]-2,3-di-hydro-1,3,5-triazin-1-ium chloride methanol monosolvate.

In the title methanol-solvated salt, C14H19Cl3N5O2 (+)·Cl(-)·CH3OH, the triazine mol-ecule is protonated at one of the triazine N atoms. In the crystal, the triazine cations are linked through a pair of N-H⋯N hydrogen bonds, with graph-set R 2 (2)(8), forming an inversion dimer. The protonated N atom and the 2- and 4-amino groups of the triazine cation inter-act with the chloride anion through N-H⋯Cl hydrogen bonds, leading to the formation of a tape structure running along the b-axis direction.

Polyoxygenated cyclohexene derivatives isolated from Dasymaschalon sootepense and their biological activities.

Six new naturally occurring polyoxygenated cyclohexene derivatives together with eight related known derivatives, two known alkaloids, and two known flavonoid derivatives were isolated from bioassay-guided fractionation of the ethyl acetate extract of the leaves and twigs of Dasymaschalon sootepense. The structure elucidation and determination of absolute configurations were established by various spectroscopic methods, X-ray diffraction techniques as well as comparison with the literature data. Several isolated compounds were evaluated for their cytotoxic, anti-HIV-1 RT and anti-inflammatory activities.