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Two new dimers of ambuic acid, pestaloversicoloric acids A (1) and B (2), and a known derivative, 13(S)-hydroxyambuic acid (3), were isolated from the static fermentation product of Pestalotiopsis versicolor. The structural identification was accomplished via analyses on the data of HR-MS, 1 D and 2 D NMR, and ECD. Different from the well-known exo-type dimer, torreyanic acid, compounds 1 and 2 represent the first example of endo-type product derived from the intermolecular Diels-Alder reaction of two molecules of ambuic acid derivative with the identical absolute stereochemistry. [ABSTRACT FROM AUTHOR]

Abstract: Two new 7,6?-coupled naphthylisoquinolines, namely ancistrotectorines A (1) and B (2), two new 5,3?-coupled naphthylisoquinolines, namely ancistrotectorines C (3) and D (4), and one new 7,8-coupled naphthylisoquinoline, namely ancistrotectorine E (5), together with 9 known naphthylisoquinoline alkaloids, hamatine (6), ancistrobertsonine B (7), ancistrocladinine (8), hamatinine (9), ancistrotanzanine A (10), ancistrotanzanine B (11), ancistrotectoriline B (12), 7-epi-ancistrobrevine D (13), and ancistrotectorine (14), were isolated from the 70% EtOH extract of Ancistrocladus tectorius. Their structures were elucidated based on the extensive analysis of spectroscopic data (1D, 2D NMR and MS). Compound 5 exhibited inhibitory activities against HL-60, K562 and U937 cell lines with IC50 values of 1.70, 4.18 and 2.56?M respectively. [Copyright &y& Elsevier]

Two new triterpenoids, 3-oxotirucalla-7,9(11),24-trien-21-oic acid (1) and 18Hα,3β,20β-ursanediol (2), along with 15 known triterpenes, α-amyrin, α-boswellic acid, β-boswellic acid, acetyl α-boswellic acid, acetyl β-boswellic acid, 9,11-dehydro-β-boswellic acid, 9,11-dehydro-α-boswellic acid, acetyl 11α-methoxy-β-boswellic acid, 11-keto-β-boswellic acid, acetyl 11-keto-β-boswellic acid, acetyl α-elemolic acid, 3β-hydroxytirucalla-8,24-dien-21-oic acid, elemonic acid, 3α-hydroxytirucalla-7,24-dien-21-oic acid, and 3α-hydroxytirucall-24-en-21-oic acid, were isolated from the resin of Boswellia carterii Birdw. [ABSTRACT FROM AUTHOR]

A new friedelane-type triterpene (1), along with seven known triterpenoids, was isolated from the stems and leaves of Calophyllum inophyllum Linn. Their structures were established as 3β, 23-epoxy-friedelan-28-oic acid (1), friedelin (2), epifriedelanol (3), canophyllal (4), canophyllol (5), canophyllic acid (6), 3-oxo-friedelan-28-oic acid (7), and oleanolic acid (8) by spectroscopic methods (NMR, EI-MS). The growth inhibitory effects of these triterpenoids on human leukemia HL-60 cells were determined. [Copyright &y& Elsevier]

A new compound, 3β,18,19β-trihydroxylupane, was isolated from Garcinia tetralata, along with five known compounds, garcinexanthone B, morolic acid acetate, toxyloxanthone A, 6,11-dihydroxy-2,2-dimethylpyrano[3,2-c]xanthen-7(2H)-one, and 1,4-dihydroxy-5,6-dimethoxy-xanthone. The structure of the new compound was established by extensive spectroscopic techniques. [ABSTRACT FROM AUTHOR]

Inspired by arylamide-based oligomeric foldermers that are stabilized by intramolecular hydrogen bonding, a series of polyamides with intramolecular hydrogen-bonding motifs were synthesized viapolycondensation reactions. These polymers can fold into helical conformation different from their linear control. The chirality of helical conformation can further be tuned viaacid–base complexation using chiral residues. [ABSTRACT FROM AUTHOR]

The structures of pestalrones A-B were revised via reinterpretation of the NMR data and a brief chemical transformation from the co-occurring polyketides, in our investigation on the secondary metabolites of Pestalotiopsis zonata, which also afforded a new α-pyrone derivative, pestazonatic acid, and four known analogs. [ABSTRACT FROM AUTHOR]

Rigid linear compounds G1 and G2, which contained two 4-phenylpyridinium (PhPy+) units, have been prepared to investigate their binding with cucurbit[8]uril (CB[8]). X-ray crystallographic structures revealed that in the solid state both compounds were included by CB[8], through antiparallel stacking, to form 2:2 quaternary complexes (G1)2@(CB[8])2 and (G2)2@(CB[8])2. For the former complex, CB[8] entrapped G1 by holding two heterodimers of its Py + and benzyl units, which were at opposite ends of the backbone. In contrast, for the first time, the second complex disclosed parallel stacking of two cationic Py + units of G2 in the cavity of CB[8] in the solid state, despite the generation of important electrostatic repulsion. Isothermal titrations in water afforded high apparent association constants of 4.36x 106 and 6.43 x 106 M-1 for 1:1 complexes G1@CB[8] and G2@CB[8], respectively, and 1H NMR spectroscopy experiments in D2O confirmed a similar stacking pattern to that observed in the solid state. A previous study and crystal structures of the 2:1 complexes formed between three new controls, G3-5, and CB[8] did not display such unusual stacking of the cationic Py+ unit; this may be attributed to the multivalency of the two CB[8] encapsulation interactions. [ABSTRACT FROM AUTHOR]

Two water-soluble para-xylylene-connected 4,4′-bipyridinium (BIPY2+) polymers have been prepared. UV-Vis absorption, 1H NMR spectroscopy, and cyclic voltammetry experiments support that in water the BIPY2+ units in the polymers form stable 1:1 charge-transfer complexes with tetrathiafulvalene (TTF) guests that bear two or four carboxylate groups. These charge-transfer complexes are stabilized by the donor-acceptor interaction between electron-rich TTF and electron-deficient BIPY2+ units and electrostatic attraction between the dicationic BIPY2+ units and the anionic carboxylate groups attached to the TTF core. On the basis of UV-Vis experiments, a lower limit to the apparent association constant of the TTF⋅BIPY2+ complexes of the mixtures, 1.8×106 m−1, has been estimated in water. Control experiments reveal substantially reduced binding ability of the neutral TTF di- and tetracarboxylic acids to the BIPY2+ molecules and polymers. Moreover, the stability of the charge-transfer complexes formed by the BIPY2+ units of the polymers are considerably higher than that of the complexes formed between two monomeric BIPY2+ controls and the dicarboxylate-TTF donor; this has been attributed to the mutually strengthened electron-deficient nature of the BIPY2+ units of the polymers due to the electron-withdrawing effect of the BIPY2+ units. [ABSTRACT FROM AUTHOR]

A series of trans-Pt(ii)(salicylaldimine)(4-picoline)Cl complexes were synthesized in 78–87% yield using a one-pot procedure from commercially available precursors. The structures of these complexes were characterized by 1H, 19F and 13C NMR spectroscopy, HRMS (ESI) as well as single crystal X-ray analysis. Bioactivity investigations including bio-assay, time- and dose-dependent, cell cycle progression study, caspase 3 and 9 apoptosis marker assay and DNA interaction using pBR322 plasmid DNA by gel electrophoresis were performed. The results indicated that the complexes showed promising in vitro cytotoxicity in MCF-7 and A549 cancer cell lines. Moreover these complexes enhanced the expression of p53 tumor suppressor gene family members such as p63 and p73. [ABSTRACT FROM AUTHOR]

A new 1-aryl-isochroman, trolliusol A (1), was isolated from the flowers of Trollius chinensis, along with seven known phenolic compounds in an antimicrobial activity-directed phytochemical investigation. The structures of these compounds were elucidated by spectroscopic methods, and their inhibitory activities against one fungus and four bacterial strains were measured. [ABSTRACT FROM AUTHOR]

Folding-induced folding for the construction of artificial hybrid helices from two different kinds of aromatic sequences is described. Linear compounds 1a, 1b, and 2, containing one aromatic amide trimer or pentamer and one or two aromatic 1,2,3-triazole tetramers, have been designed and synthesized. The trimeric and pentameric amide segments are driven by intramolecluar N—H···F hydrogen bonding to adopt a folded or helical conformation, whereas the triazole segment is intrinsically disordered. In organic solvents of low polarity, the amide foldamer segment induces the attached triazole segment(s) to fold through intramolecular stacking, leading to the formation of hybrid helices. The helical conformation of these hybrid sequences has been confirmed by 1H and 19F NMR spectroscopy, UV/Vis spectroscopy, circular dichroism (CD) experiments, and theoretical calculations. It was found that the amide pentamer exhibits a stronger ability to induce the folding of the attached triazole segment(s) compared with that of the shorter trimer. Enantiomers (R)-3 and (S)-3, which contain an R- or S-(1-naphthyl)ethylamino group at the end of a tetraamide segment, have also been synthesized. CD experiments showed that introduction of a chiral group caused the whole framework to produce a strong helicity bias. Densityfunctional- theory calculations on (S)-3 suggested that this compound exists as a right-handed (P) helix. [ABSTRACT FROM AUTHOR]

Investigation of the constituents from the stem barks ofGarcinia multiflorahas yielded two new compounds, multiflorabiphenyl A (1) and 24-p-E-coumaroyl-tetracosanyl (E)-ferulate (2), along with 10 known compounds, friedelin (3), friedelan-3β-ol (4), α,β-amyrin (5), rheediachromenoxanthone (6), 1,7-dihydroxyxanthone (7), 9-hydroxycalabaxanthone (8), oblongifoliagarcinine B (9), 1,24-tetracosandiol diferulate (10), 30-epi-cambogin (11), and guttiferone F (12). The structures of these compounds were determined by detailed spectroscopic methods including HR-ESI-MS and 1D and 2D NMR. [ABSTRACT FROM PUBLISHER]

Myricitrin is a strong antioxidant agent and abundantly present in bayberry tree bark. The separation and purification of myricitrin from the crude extract of bayberry tree bark was achieved by high-speed counter-current chromatography (HSCCC) in the present study. An analytical HSCCC was used to screen the solvent system, and a two-phase solvent system composed ofn-hexane–ethyl acetate–methanol–water (3:4:4:3, v/v) was selected for preparative purification. Using HSCCC followed by Sephadex LH-20 chromatography, 195 mg of myricitrin was obtained from 500 mg of crude extract with the purity of 98.5% as determined by high-performance liquid chromatography (HPLC). The chemical structure of myricitrin was identified by UV, IR, ESI-MS,1H NMR, and13C NMR spectra data. The results showed that HSCCC was an efficient technique to separate and purify myricitrin from bayberry tree bark extract. [ABSTRACT FROM AUTHOR]

Our current marine natural product program investigated the second metabolites of an actinomyceteStreptomyces cavourensisYY01-17 originating from the Antarctic ecological niche to discover potential antitumor chemical entities. Two new compounds, along with a known compound, were isolated from the ethyl acetate extract of the fermentation broth of the marine-derived actinomycete, and their structures were elucidated, respectively, as 2(S)-3′-hydroxybutan-2′-yl 2-hydroxypropanoate (1), (E)-3-hydroxy-2,4-dimethylhept-4-enamide (2), and 2-hydroxy-3-methylbutanoic acid (3) on the basis of spectroscopic data interpretation. [ABSTRACT FROM PUBLISHER]

Abstract: The intramolecular six-membered C–H⋯X (X=F, Cl, Br) hydrogen bonding motif of halogen-substituted 1,4-diphenyl-1,2,3-triazole compounds has been assessed. Twelve triazole derivatives have been designed and prepared, which bear fluorine, chlorine or bromine atoms on the ortho- and/or para-positions of the benzene rings. 1H NMR, X-ray crystallography, and DFT calculation investigations revealed that the ortho-fluorine, chlorine, and bromine atoms of the benzene ring on the C-4 of the triazole unit all can form six-membered C–H⋯X hydrogen bonding. In contrast, only fluorine forms similar, relatively stable intramolecular hydrogen bonding on the N-1 side of the triazole unit. [Copyright &y& Elsevier]

Three new compounds, 4′-(4,5-dimethyl-1,3-dioxolan-2-yl)methyl-phenol (1), (3′-hydroxybutan-2′-yl)5-oxopyrrolidine-2-carboxylate (2), and atroviridetide (3), have been isolated from the marine-derived fungus Trichoderma atroviride G 20-12. Their structures were determined on the basis of chemical and spectroscopic methods. [ABSTRACT FROM PUBLISHER]

Abstract: Hydrogen bonded arylamide foldamers have been introduced in switchable pseudo[2]rotaxanes and [2]rotaxanes, which also include a cyclobisparaquat(p-phenylene) (CBPQT4+) ring and a ‘dumbbell’ containing tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP, for rotaxanes). The foldamer size changes through folding and unfolding serve as a steric handle to modulate the mechanical movement of the CBPQT4+ ring along the dumbbell of the pseudo[2]rotaxanes and [2]rotaxanes. By varying the number of the repeating units in the foldamer, the kinetics of the solvent-dependent slippage/deslippage of pseudo[2]rotaxanes and the switching of the ring between TTF and DNP of the [2]rotoxanes can be tuned remarkably, with the time scope ranging from several minutes to several days, in twelve solvents of varying polarity, which have been confirmed by the 1H NMR, UV–vis spectroscopy, and cyclic voltammogram experiments. [Copyright &y& Elsevier]

Two series of novel benzoimidazole sulfonamides as combretastatin A-4 analogs were synthesized. The cytotoxicities of the title compounds were evaluated against five different cancer cell lines. Among the tested compounds, four compounds displayed cytotoxicities against the HCT8 cell line. Compound 6a has shown the strongest potency against the tested human tumor cell lines with an IC50 value ranging from submicromolar to micromolar level. [ABSTRACT FROM AUTHOR]