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OSMAC approach was performed on the soft coral-derived fungus Trichoderma harzianum (XS-20090075) leading to the significant changes of its secondary metabolites by using two different cultures. A new naphthalene derivative, trichoharzin B (1) and a new natural product, methyl-trichoharzin (2) were isolated by using rice medium. Whereas, a new natural product, ethyl 2-bromo-4-chloroquinoline-3-carboxylate (9) was obtained by using Czapek's medium. Their structures were established by extensive spectroscopic investigation. The absolute configuration of 5 was determined by single-crystal X-ray diffraction. Compound 9 was the first halogenate quinoline derivative isolated from the genus of Trichoderma.

A series of five bis(salicylaldehydes), including four isomeric compounds based on a benzene scaffold and a closely related naphthalene derivative, were investigated in order to elucidate the impact of resonance effects and intramolecular hydrogen bonds (HBs) on the macroscopic properties of these systems. Density functional theory (DFT) computations revealed important differences between isomers on the molecular level, which was reflected in different charge distributions, aromatic C-C bond orders, and aromaticity characters. The consequences of these features were evidenced by the UV-vis absorption spectra: for 1,3-diformyl-4,6-dihydroxybenzene (

A synthesis of decaarylanthracene with nine different substituents has been accomplished by a coupling/ring-transformation strategy. The oxidation of tetraarylthiophenes with four different substituents to the corresponding thiophene S-oxides, and a [4+2] cycloaddition with a double benzyne precursor afforded a multiply arylated naphthalene derivative. Subsequently, the naphthalene derivative was converted into a naphthalyne, and then a [4+2] cycloaddition of another thiophene S-oxide provided decaarylanthracenes with nine different aryl groups.

In this work, we developed a novel fluorescent probe 1 for quantitative detection of nitroxyl (HNO). Probe 1 consisted of a naphthalene backbone and 2-(diphenylphosphino)benzoate which was used as a nitroxyl recognition unit. The probe exhibited an intense fluorescence turn-on response to nitroxyl via aza-ylide formation and its subsequent Staudinger ligation to release compound 2. The probe can be applied to the quantification of nitroxyl with a linear range from 5.0 × 10−8 to 9.0 × 10−6 mol L−1. The detection limit of probe 1 toward nitroxyl was estimated to be 43 nM. Furthermore, probe 1 displayed a much higher selectivity for nitroxyl than other biologically relevant species. Importantly, owing to the high cell permeability and low cytotoxicity of probe 1, it was successfully applied to cell imaging of nitroxyl in living cells. The probe is expected to be a useful chemical tool for investigating the detailed functions and mechanisms of HNO in living systems.

Synthetic strategies are described to prepare acyclic cucurbituril derivatives with two different types of appended functional groups, one that mediates water solubility and another one that allows further functionalisation. The syntheses started with the coupling of a 1,4-disubstituted naphthalene derivative containing one 2-chloroethoxy and one 3-sulfonatopropoxy group to a suitable tetrameric glycoluril-derived precursor. This reaction afforded two regioisomers, differing in the relative orientation of the peripheral substituents, which could be separated in a straightforward fashion and structurally characterised. Both isomers were then converted into the corresponding diazides and diamines that served to append further residues by, respectively, copper(I)-catalysed azide–alkyne cycloaddition or amide formation. Binding studies showed that the functionalised dianionic acyclic cucurbiturils thus obtained possess a notable cation affinity in water, albeit a lower one than an analogue with four peripheral negatively charged substituents. This work constitutes the basis for the development of water-soluble acyclic cucurbiturils whose applications could potentially go beyond the use as receptors.

The title naphthalene derivative, C24H20O2, features 4-methyoxy-substituted benzene rings in the 1 and 4 positions of the naphthalene ring system. There are two crystallographically independent molecules (A and B) in asymmetric unit. The independent molecules have very similar conformations in which the naphthalene ring systems are only slightly bent, exhibiting dihedral angles between the constituent benzene rings of 3.76 (15) and 3.39 (15)° for A and B, respectively. The pendent 4-methyoxybenzene rings are splayed out of the plane through the naphthalene ring system to which they are connected [range of dihedral angles = 59.63 (13) to 67.09 (13)°]. In the crystal, the molecular packing is consolidated by intermolecular C—H...π interactions, leading to supramolecular chains along the b axis. The chains assemble without directional interactions between them.

We designed and synthesized a simple and readily available fluorescent probe 3 for cysteine (Cys) based on naphthalene derivative. The probe is composed of a new class of aggregation-induced emission enhancement (AIEE) active dye 2 based on excited-state intramolecular proton transfer (ESIPT) and an acrylate group as the Cys recognition unit as well as the ESIPT blocking agent, which can be cut off by Cys from the probe in aqueous solution with mild conditions. The probe had great sensitivity and selectivity for the detection of Cys over homocysteine (Hcy) and glutathione (GSH) with a detection limit of 0.05 µM. In addition, we have successfully applied the probe for bioimaging studies of Cys in living cells, indicating that the probe holds great potential for biological applications.

Different types of starting materials have been designed and their ability to undergo cascade reactions has been investigated. New polycycles containing five-, six-, and seven-membered rings are described via original cascade reactions. The process works via a twofold cyclocarbopalladation followed by C(sp2)-H or C(sp3)-H activation. During these cascades, the palladium is moving several times along the carbon structure forming three new C C bonds and three new cycles.

A Schiff base compound derived from naphthalene has been synthesized and characterized as an Al3+-selective fluorescent probe. The chemosensor (L) exhibits high selectively for Al3+ in aqueous solution, even in the presence of biologically relevant cations such as Na+, K+, Ca2+, Mg2+, Pb2+ and several transition metal ions. There was no observed interference from anions like Br−, Cl−, HSO3−, SO32−, S2O32−, NO2−, CO32− and AC−. The lowest detection limit for the chemosensor L was found to be 1.89 × 10−8 M with a linear response towards Al3+ over a concentration range of 5 × 10−6 to 4 × 10−5 M. Furthermore, the proposed chemosensor has been used for imaging of Al3+ in two different types of cells with satisfying results, which further demonstrates its value for practical application in biological systems.

Generation of a σ,σ,π-triradical was attempted by collision-activated dissociation (CAD) of two iodine atoms and an NO● radical from 2,4-diiodo-5-nitroquinolinium cation in an ion trap mass spectrometer. However, the reactivity of the product was consistent with a monoradical rather than a triradical. The mechanism of its formation was explored. In the first CAD step, an iodine atom is lost to generate the 2-iodo-5-nitro-4-dehydroquinolinium cation. Quantum chemical calculations suggest that in the second CAD step, the radical site at C-4 adds to the adjacent NO2 group followed by loss of NO● to generate the 2-iodo-4-oxyl-5-dehydroquinolinium cation. Calculations also suggest that in the third CAD step, this cation cyclizes to form an oxygen-peribridged 2-iodoquinolinium cation that then loses the remaining iodine atom to generate a distonic 4,5-oxygen-peribridged 2-dehydroquinolinium cation. For the analogous 4-oxyl-5-dehydroquinolinium cation, the cyclization is calculated to be exoergic by 8.7 kcal mol-1 with a free energy barrier of 14.0 kcal mol-1. The cyclized product is the first experimentally observed oxygen-peribridged naphthalene derivative. It displays low reactivity. However, it's monoradical counterpart is highly reactive and undergoes typical radical reactions.

Cassia grandis is used for the treatment of skin disorders, back pain, aches, etc. in Vietnamese traditional medicine. In this paper, phytochemicals of the leaves were investigated. A new naphthalene derivative (1, cassgranon D) and, seven known compounds rutin (2), afzelin (3), quercitrin (4), epicatechin (5), (-)-epiafzelechin (6), isoquercitrin (7) and aloe emodin (8) were isolated from the ethyl acetate and methanol extracts. Their structures were elucidated by spectral evidences (UV, IR, MS, 1H, 13C, DEPT, HSQC and HMBC NMR), as well as by comparing with published data.

[EN] Mesoporous silica nanoparticles loaded with fluorescein and capped by a pseudorotaxane, formed between a naphthalene derivative and cyclobis(paraquat-p-phenylene) (CBPQT(4+)), were used for the selective and sensitive fluorogenic detection of 3,4-methylenedioxy-methamphetamine (MDMA)., The authors acknowledge the financial support from the Spanish Government (projects MAT2015-64139-C4-1-R and AGL2015-70235-C2-2-R) and the Generalitat Valenciana (project GVA/2014/13). B. L-T. is grateful to the Ministerio de Economia y Competitividad for her PhD grant. A. B. thanks the Spanish Government for the financial support "Juan de la CiervaIncorporacion'' (IJCI-2014-21534). J. O. J. thanks The Danish Natural Science Research Council (FNU, project no. 11-106744) and the Villum Foundation for financial support.

Benzonorbornadiene and 7-oxabenzonorbornadiene were reacted with Meldrum's acid and dimethyl malonate in the presence of Mn(OAc)3 and Cu(OAc)2 in acetic acid. The reaction of benzonorbornadiene with Meldrum's acid gave a naphthalene derivative whereas the reaction with dimethyl malonate formed rearranged products derived from a carbocation intermediate. However, the reaction of 7-oxabenzonorbornadiene with Meldrum's acid gave two nonrearranged products. On the other hand, the reaction with dimethyl malonate unexpectedly formed a dihydronapthalene derivative with an unusual structure. The mechanism for the formation of the products is discussed.

Interstrand cross-linking of DNA or RNA inhibits the double strands from dissociating into single strands. This article contains detailed procedures for the synthesis of a novel interstrand cross-linker that comprises a bis-aminooxy naphthalene derivative and a description of its use in the preparation of sequence-specific interstrand cross-linked oligonucleotide duplexes. The interstrand cross-linker covalently connects a pair of apurinic/apyrimidinic sites in DNA/RNA duplexes with bis(aminooxy) groups. The resulting oxime linkages are stable under physiological conditions and greatly improve the thermal stability of the duplex. In addition, we construct a novel anti-miRNA oligonucleotide (AMO) flanked by interstrand cross-linked 2'-O-methylated RNA duplexes (CLs). AMO flanked by CLs at the 5'- and 3'-termini exhibited high inhibition activity toward miRNA function in cells. The novel interstrand cross-linker indicates potent activity and is applicable in biophysical studies, oligonucleotide therapeutics, and materials science. © 2018 by John Wiley & Sons, Inc.

As a part of our continuing search for anti-HCV agents from a medicinal plant, Flueggea virosa, we identified fourteen new ingredients, including 13-methyl-3,4-seco-ent-podocarpanes (1–13) and a new naphthalene derivative (14). Their structures were determined by analysis of 2D NMR spectroscopic data, while their absolute configurations were determined by comparison of specific optical rotations with related analogues in the literature. The therapeutic potential against hepatitis C virus (HCV) infection was evaluated for the isolates. Compound 8 showed the most potent anti-HCV activity with a therapeutic index (TI = IC50/EC50) of 100.5.

The synthesis of an octa-alkoxy substituted isotopically labeled naphthalene derivative, shown to have excellent properties in singlet NMR experiments, is described. This highly substituted naphthalene system, which incorporates an adjacent (13)C spin pair, is readily accessed from a commercially available (13)C2-labeled building block via sequential thermal alkynyl- and arylcyclobutenone rearrangements. The synthetic route incorporates a simple desymmetrization approach leading to a small difference in the chemical shifts of the (13)C spin pair, a design constraint crucial for accessing nuclear singlet order.

Periplocain A (2), a new naphthalene derivative together with four known compounds: 2-ethylhexyl benzoate (1), quercetin-3-O-α-l-rhamnopyranoside (3), quercetin-3-O-β-d-glucopyranoside (4), and quercetin-3-(6-O-α-l-rhamnopyranosyl-β-d-glucopyranoside) (5) were isolated from the AcOEt fraction of the aerial parts of Periploca aphylla (Asclepiadaceae). Their structures were established by multiple spectroscopic methods in addition to HR-ESI-MS and by comparison with literature data.

Two new (1-2) and eight known (3-10) secondary metabolites were isolated from the rhizomes of Kniphofia reflexa Hutchinson ex Codd. Among them, an indane derivative kniphofiarindane (1), and naphthalene derivative kniphofiarexine (2), were identified as new natural products. 1D- and 2D-NMR spectroscopic studies together with single-crystal X-ray diffraction techniques were employed in the structural elucidation of the new compounds, 1 and 2. These compounds were evaluated for their cytotoxic effect against kidney epithelial cell line (LLC-MK2). Compound 3 was found to be highly cytotoxic, while compounds 1, and 10 showed moderate cytotoxicity with CC50 values of 4.44 +/- 0.79, 16.35 +/- 1.54, and 11.24 +/- 1.22 mu g/mL, respectively against the tested standard Gleevec (Imatinib), (CC (50) = 18.50 +/- 1.21 mu g/mL). Compounds 8, and 9 also showed moderate anti-inflammatory activity (CC (50 )= 38.7 +/- 4.90, and 20.00 +/- 4.40 mu g/mL, respectively) against ROS production.

Reactions of benzyne with ester derivatives of spiro[2.4]hepta-4,6-dien-1-ylmethanol were performed. By rearrangement reaction of cyclopropyl methanol units of ((1s*,1'R*,2R*,4'S*)-1',4'-dihydrospiro [cyclopropane-1,9'-[1,4]methanonaphthalen]-2-yl) methyl 3,5-dinitrobenzoate (13) and its isomer (14), corresponding allyl chlorides were obtained. Two rearrangement products were obtained from bromination of compound 13 with an equivalent amount of Br-2. A naphthalene derivative including allyl and CHO moiety was formed for reactions from compounds with epoxide of 13 and 14 with NaN3 by sequential rearrangements. Formations of products are discussed. (C) 2018 Elsevier Ltd. All rights reserved., TUBITAK - The Scientific and Technological Research Council of Turkey [109T403]; Ataturk University, Faculty of Science, Department of Chemistry, This study was financed by TUBITAK - The Scientific and Technological Research Council of Turkey (Project No: 109T403) and realized in Ataturk University, Faculty of Science, Department of Chemistry. We are grateful to both institutes for their supports.

The genus Atraphaxis comprises about 18 species spread throughout Asia, northern Africa, and southern Europe. The aerial parts of Atraphaxis laetevirens were the subject of a natural compound investigation. Recently, anthraquinones and a naphthalene derivative have been isolated from A. laetevirens as antibacterial compounds, whereas their chemotaxonomic properties were not discussed. In addition, there are no other phytochemical studies on A. laetevirens and no distinguishing chemotaxonomic markers in the genus Atraphaxis. This is the first report on the presence of 8-O-acetyl-7-O-methylgossypetin in a natural source and its detailed NMR chemical shift data is reported here. 8-O-acetyl-7-O-methylgossypetin may be a more useful and distinguishing compound for chemotaxonomic studies of the genus Atraphaxis than other flavanoids.

Novel poly(aryl ether) dendron-based low-molecular-weight organogelaters (LMWG) containing naphthalene units at the core have been synthesized, and the self-Assembly of the system has been examined in a variety of solvents and solvent mixtures. The compounds readily form gels with attractive critical gel concentration values associated with gelation-induced enhanced emission (GIEE). In addition to the remarkable properties of the previously reported anthracene and pyrene analogues (Rajamalli, P.; Prasad, E. Org. Lett.2011, 13, 3714 and Rajamalli, P.; Prasad, E. Soft Matter2012, 8, 8896), the self-Assembled systems exhibit distinctly different structure-property relationships. Unlike the reported ones, the present system forms sheetlike morphology in nonpolar solvent mixtures, giant vesicles in polar solvent mixtures, and lamellar or hexagonal columnar phases in single solvents. The unique properties of the self-Assembled systems, which were analyzed through electron microscopic (SEM, TEM, AFM) and spectroscopic techniques (POM, fluorescence), are attributed to the replacement of anthracene/pyrene units by naphthalene units. The present work unravels the subtle role of minute structural change in altering the properties of LMWGs based on poly(aryl ether) dendrons. � 2013 American Chemical Society.

Periplocain A (2), a new naphthalene derivative together with four known compounds: 2-ethylhexyl benzoate (1), quercetin-3-O-α-l-rhamnopyranoside (3), quercetin-3-O-β-d-glucopyranoside (4), and quercetin-3-(6-O-α-l-rhamnopyranosyl-β-d-glucopyranoside) (5) were isolated from the AcOEt fraction of the aerial parts of Periploca aphylla (Asclepiadaceae). Their structures were established by multiple spectroscopic methods in addition to HR-ESI-MS and by comparison with literature data.

Substituted phosphathiahelicenes have been prepared via a straightforward two-step procedure involving the regioselective bromination of a preformed helical scaffold, followed by palladium catalyzed coupling reactions. The new helicenes have been used as ligands in gold(I)-catalyzed [4+2] cyclizations of 1,6-enynes. The resulting dihydro-cyclopenta[b]naphthalene derivative was obtained in excellent yields and with up to 91% ee.

As a part of our continuing search for anti-HCV agents from a medicinal plant, Flueggea virosa, we identified fourteen new ingredients, including 13-methyl-3,4-seco-ent-podocarpanes (1–13) and a new naphthalene derivative (14). Their structures were determined by analysis of 2D NMR spectroscopic data, while their absolute configurations were determined by comparison of specific optical rotations with related analogues in the literature. The therapeutic potential against hepatitis C virus (HCV) infection was evaluated for the isolates. Compound 8 showed the most potent anti-HCV activity with a therapeutic index (TI = IC50/EC50) of 100.5.

Five new compounds, named ancistronaphtosides A and B (1 and 2), anciscochine (3), anciscochine 6-O-β-d-glucopyranoside (4), and 4'-methoxy-5-epi-ancistecrorine A1 (5), together with tortoside A (6) and 4-hydroxy-2-methoxyphenyl-6-O-syringoyl-β-d-glucopyranoside (7) were isolated from the methanolic extract of Ancistrocladus cochinchinensis. Their chemical structures were established using HR-ESI-MS, NMR spectroscopic, and chiroptical methods. Compound 5 significantly exhibited anti-proliferation against HL-60, LU-1, and SK-MEL-2 cells with IC50 values of 5.0±1.2, 6.5±1.6, and 6.8±2.0μg/mL, respectively.

Claire L. Gordon, Sarah Whiting, Greg Haran, Ann Ward, Mark Coleman, Robert Baird, Cameron J. Jeremiah, Marina Mileva, Joshua S. Davis, Lachlan J. Warren, David H. Ellis, Bart J. Currie

Synthesis of meso-Substituted Tetraarylalkynylporphyrins Al Samarat,a Yoichiro Kuninobu,*b Kazuhiko Takai*b a University of Carthage, Faculty of Sciences of Bizerte, Jarzouna 7021, Bizerte, Tunisia b Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Kita-ku, Okayama 700-8530, Japan Fax +81(86)2518094; E-mail: kuninobu@cc.okayama-u.ac.jp; E-mail: ktakai@cc.okayama-u.ac.jp Received 11 July 2011

A new triglucosylated naphthalene derivative, named aloveroside A (1), together with two known anthraquinone dimers and two 6-phenyl-2-pyrone derivatives, was isolated from the Aloe vera ethanolic extracts. The structure of 1 was established as 1-(((4-(1-O-beta-D-glucopyranosyl -(1-->4)-beta-D-xylopyranoside)-hydroxymethyl)-1-hydroxy-8-O-alpha-L-rhamnopyranoside)naphthalene-2-yl)-ethanone by means of spectroscopic evidences and chemical methods. All these compounds were tested for their BACE inhibitory activity but no significant activities were found.

Chiral and achiral pincer type palladium complexes bearing abnormal N-heterocyclic carbene ligands derived from 1,2,3-triazole are reported. Both complexes are effective as catalysts for non-asymmetric Suzuki coupling reaction for the synthesis of biphenyl derivatives. However, both the complexes failed to catalyze the formation of binaphthyl derivatives, by the asymmetric Suzuki coupling in case of the chiral complex and the non-asymmetric version in case of the achiral pincer complex. Instead deboronation of arylboronic acid occurred very efficiently leaving the aryl bromide intact. � 2009 Elsevier Ltd. All rights reserved.

A new naphthalene derivative, 1-methyl-2,3-methylenedioxy-6-naphthalenecarboxylic acid methyl ester (1), and a new alkaloid, ( +/- )-1-phenyl-2-imido-1-propanol (2), together with the four known compounds, ephedrine, pseudoephedrine, N-methylephedrine, and 6-methoxykynurenic acid, have been isolated from the stems of Ephedra sinica, a famous traditional Chinese herbal medicine. The structures of 1 and 2 were determined by spectroscopic methods, including 1D- and 2D-NMR experiments as well as HR-EI-MS analysis.

We report here the photophysical properties of a naphthalene derivative of a specially designed cryptand system (L). The system exhibits the unusual phenomenon of emission from T2 and T1 states of naphthalene which has been attributed to the inherent rigidity of the system. The results obtained have been analysed by comparison with two other model systems where the flexibility of the fluorophore unit with respect to the receptor moiety have been varied.

A novel thioureido naphthalene derivative was synthesized and characterized. The compound proved itself as an effective fluoride sensor with respect to selectivity and sensitivity. In acetonitrile, the fluorescence intensity increased by 40-fold with the addition of 5 equiv. of fluoride. Fluorescence intensity did not substantially change with other halides, suggesting that the thioureido protons interact strongly with fluoride but not with other halides. The enhanced fluorescence is due to increased quantum efficiency of the fluoride complex.Key words: fluoride sensing, thioureido compound, fluorescence.

In the present paper, we report the synthesis, characterization, and biological evaluation as antifungal, antibacterial, antioxidant, and cytotoxic/anticancer agents of N-, S-, O-substituted-1,4-naphtho- and 2,5-bis(amino-substituted)-1,4-benzoquinone derivatives. In the synthesized compounds, antimicrobial activity at low concentrations against Escherichia coli B-906, Staphylococcus aureus 209-P, and Mycobacterium luteum B-917 bacteria and Candida tennis VKM Y-70 and Aspergillus niger F-1119 fungi in comparison with controls was identified. 2-(N-Diphenylmethylpiperazin-1-yl)-3-chloro-1,4-naphthoquinone 9a was the most potent, with a minimum inhibitory concentration value of 3.9, mu g/mL against test culture M. luteum. The synthesized compounds were screened for their antioxidant capacity using the cupric-reducing antioxidant capacity (CUPRAC) method. 2,2'-[1-(2-Aminoethyl)piperazin-1-yl]-3,3'-dichloro-bis(1,4-naphthoquinone) 10 showed the highest antioxidant capacity, with a 0.455 CUPRAC-trolox equivalent antioxidant capacity (TEAC) coefficient. Other parameters of antioxidant activity (scavenging effects on OH center dot, O-2(center dot-), and H2O2) of these compounds were also determined. The cytotoxic activity of the compounds was investigated by employing the sulforhodamine B cell viability assay against A549 (lung), MCF-7 (breast), DU145 (prostate), and HT-29 (colon) cancer cell lines. Compound 10 exhibited the most powerful cytotoxic activity at a concentration of 20 mu m against all cell lines. In addition to the strongest antioxidant activity of compound 10, it also had lowest IC50 values (

Benzo[g]indole derivatives [(IV), (V), (VI), and (IX)] are synthesized starting from bis(dimethylamino)naphthalene derivative (I) through base-promoted transformation via pyrrole ring closure.

A new Naphthalene derivative with two urea groups, 1,8-bis[ N -( o -methoxyphenyl)ureido]naphthalene ( BMPUN ), was synthesized for detecting Cu(II) ratiometrically. Complexation between urea groups of BMPUN and Cu(II) with high selectivity gives rise to a great red-shift from 380 to 440 nm in the emission spectra. The introduction of electron donating groups is helpful to increase the electron density of the nitrogen atom of urea groups and then enhance the ability of complexation for Cu(II).

[reaction: see text] The mechanisms of perphenylbutenyne reactivity are examined through B3LYP and multireference ab initio calculations on model systems. Calculations for the formation of a naphthalene derivative suggest a process similar to that seen previously in the literature. A new mechanism for perphenylbutenyne dimerization to form a semibullvalene derivative is proposed and supported by calculations.

Dimerization of the trimethyl ether of resveratrol catalyzed by phosphotungstic acid gave two tetralins and a naphthalene derivative. The structure of the tetralins was obtained by X-ray crystallography and confirms the reported stereochemical configuration of resformicol A and B.

In situ infrared spectra of 1-methylnaphthalene (1-MeNapht) hydrogenation, over sulfided NiMo/Al2O3-TiO2 catalysts, were compared with theoretically derived properties of methylnaphthalene and its bicyclic products: MeDilin, MeTetralin, MeOctalin and MeDecalin, and with conversion data from literature. Comparisons were also made between the un-substituted and methyl-substituted two-rings, and between the 1- and 5-methyl isomers of 1,4-dihydronaphthalene (dilin) and 1,2,3,4-tetrahydronaphthalene (tetralin). IR spectra of MeNapht adsorption, on the sulfided catalyst, were matched with data for adsorption on the catalyst without sulfidation and the empty support. Surface bound MeNapht is observed below 250 °C on all catalysts. MeNapht adsorption suppresses OH groups non-discriminatory on the empty support and the metal loaded catalyst. We relate the results to previous data on the interaction between the supported metal sulfides and titanium modified aluminas. Calculated total energies, and experimentally derived heats of formation, pointed at decahydronaphthalene (decalin) as the dominant product of naphthalene hydrogenation, with tetralin as an abundant intermediate, and dilin and 1,2,3,4,5,6,7,8-octahydronaphthalene (octalin) as short lived transient stages. The spectroscopic modeling showed that the orbital fingerprints of the five bicyclic compounds were not distinctly different, nor more than marginally modified by methyl substitution or isomerization. The only significant difference came at the highest occupied orbital, where a high naphthalene density of states (DoS) overlapped with the valence bands of metal or metal sulfide catalysts. The vibrational bands for naphthalene, dilin, tetralin and octalin were well separated. Octalin and decalin, alone, have similar vibrational spectra. Upheaval of ring degeneracy for methyl-substituted two-ring structures broadened all infrared bands in a characteristic way.

1,8-Naphthalenediol, 5, and its 4-methoxy derivative, 6, were found to be potent H-atom transfer (HAT) compounds on the basis of their rate constants for H-atom transfer to the 2,2-di(4-t-octylphenyl)-1-picrylhydrazyl radical (DOPPH*), k(ArOH/DOPPH)*, or as antioxidants during inhibited styrene autoxidation, k(ArOH/ROO)*, initiated with AIBN. The rate constants showed that 5 and 6 are more active HAT compounds than the ortho-diols, catechol, 1, 2,3-naphthalenediol, 2, and 3,5-di-tert-butylcatechol, 3. Compound 6 has almost twice the antioxidant activity, k(ArOH/ROO)* = 6.0 x 10(6) M(-)(1) s(-1), of that of the vitamin E model compound, 2,2,5,7,8-pentamethyl-6-chromanol, 4. Calculations of the O-H bond dissociation enthalpies compared to those of phenols, (deltaBDEs), of 1-6 predict a HAT order of reactivity of 213 approximately 456 in general agreement with kinetic results. Calculations on the diols show that intramolecular H-bonding stabilizes the radicals formed on H-atom transfer more than it does the parent diols, and this effect contributes to the increased HAT activity of 5 and 6 compared to the activities of the catechols. For example, the increased stabilization due to the intramolecular H-bond of 5 radical over 5 parent of 8.6 kcal/mol was about double that of 2 radical over 2 parent of 4.6 kcal/mol. Linear free energy plots of log k(ArOH/DOPPH)* and log k(ArOH/ROO)* versus deltaBDEs for compounds 1-6 along with available literature values for nonsterically hindered monophenols placed the compounds on common scales. The derived Evans-Polanyi constants from the plots for the two reactions, alpha(DOPPH)* = 0.48alpha(ROO)* = 0.32, gave the expected order, since the ROO* reaction is more exothermic than the DOPPH* reaction. Compound 6 is sufficiently reactive to react directly with oxygen, and it lies off the log k(ArOH/ROO)* versus deltaBDE plot.

The aim of this study is to determine the chemical composition, and evaluate the genotoxic, and anti-growth potency of the methanol extracts of lichen species Hypogymnia physodes (L.) Nyl. (HPE). Anti-growth effect was tested in two different human breast cancer cell lines (MCF-7 and MDA-MB-231) by the MTT and ATP viability assays and apoptosis was assayed by the caspase-cleaved cytokeratin 18 (M30-antigen). Genotoxic activity of HPE was studied using chromosome aberration and micronuclei tests in human lymphocytes culture in vitro. The chemical composition of H. physodes was analyzed by using direct thermal desorption method coupled with comprehensive gas chromatography-time of flight mass spectrometry (GCXGC-TOF/MS). Our results indicate that HPE has an anti-growth effect at relatively lower concentrations, while relatively higher concentrations are required for genotoxic activity. HPE, therefore, seems to represent a therapeutic potential and poses new challenges for medicinal chemistry.

Steady state, pre-steady state kinetic experiments, and site-directed mutagenesis have been used to dissect the catalytic mechanism of human glutathione transferase T2-2 with 1-menaphthyl sulfate as co-substrate. This enzyme is close to the ancestral precursor of the more recently evolved glutathione transferases belonging to Alpha, Pi, and Mu classes. The enzyme displays a random kinetic mechanism with very low k(cat) and k(cat)/K(m)((GSH)) values and with a rate-limiting step identified as the product release. The chemical step, which is fast and causes product accumulation before the steady state catalysis, strictly depends on the deprotonation of the bound GSH. Replacement of Arg-107 with Ala dramatically affects the fast phase, indicating that this residue is crucial both in the activation and orientation of GSH in the ternary complex. All pre-steady state and steady state kinetic data were convincingly fit to a kinetic mechanism that reflects a quite primordial catalytic efficiency of this enzyme. It involves two slowly interconverting or not interconverting enzyme populations (or active sites of the dimeric enzyme) both able to bind and activate GSH and strongly inhibited by the product. Only one population or subunit is catalytically competent. The proposed mechanism accounts for the apparent half-site behavior of this enzyme and for the apparent negative cooperativity observed under steady state conditions. These findings also suggest some evolutionary strategies in the glutathione transferase family that have been adopted for the optimization of the catalytic activity, which are mainly based on an increased flexibility of critical protein segments and on an optimal orientation of the substrate.

Transformation of 4-(methylthio)-1-phenyl-2-(p-tolylsulfonyl)-1,3-butadiene 1a was found to give 2-(p-tolylsulfonyl)naphthalene 3a either by the action of I2 in refluxing acetonitrile or by irradiation with a high-pressure Hg lamp. An electron-withdrawing group (p-F or p-CO2Me) on the phenyl ring retarded the thermal reaction, but the corresponding naphthalene derivative was efficiently produced by the photolysis in the presence of I2. The substituent effect of an electron-donating methoxyl group is also reported. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:385–391, 2001

Pd(OAc)2-catalyzed decomposition of ethyl 2-diazo-4-(4-indolyl)-3-oxobutanoate leads to a tricyclic tetrahydrobenzindole compound formed by a formal C–H insertion reaction. This tricyclic indole rearranges to a novel and thermodynamically more stable naphthalene derivative. Treatment of N-tosyl-protected ethyl 2-diazo-4-(4-indolyl)-3-oxobutanoate with a base induces facile pyrazole formation.

Two clerodane diterpenoids, blepharolides A and B, have been isolated from Salvia blepharophylla Brandegee ex Epling. Their structures were determined using a combination of one- and two-dimensional NMR techniques. The relative stereochemistry for blepharolide A was determined by X-ray diffraction. To our knowledge this is the first crystal structure determination of a 5,6-unsaturated octahydro-1H-cyclopropa[a]naphthalene derivative.

The asymmetric unit of the title compound, C11H9NO3, contains two molecules,AandB. In moleculeA, the dihedral angle between the planes of the naphthalene ring system (r.m.s. deviation = 0.003 Å) and the nitro group is 89.9 (2)°, and the C atom of the methoxy group deviates from the naphthyl plane by 0.022 (2) Å. Equivalent data for moleculeBare 0.008 Å, 65.9 (2)° and −0.198 (2) Å, respectively. In the crystal, molecules are linked by weak C—H...O interactions, forming [100] chains of alternatingAandBmolecules. Weak aromatic π–π stacking contacts, with a range of centroid–centroid distances from 3.5863 (9) to 3.8048 (9) Å, are also observed.