New cyclopeptide alkaloid of Condalia buxifolia and the absolute stereochemistry of Condaline A.

During the course of a study of Condalia buxifolia (Rhamnaceae), one new cyclopeptide alkaloid condaline B (1), together with six known cyclopeptide alkaloids, condaline A (2), and the scutianines B (3), - D (4) and -E (5), frangulanine (6), and 3,4,28-tris-epi-scutianene N (7), were isolated from the rind bark of Condalia buxifolia. Their structures have been confirmed through spectroscopic analyses such as 1D and 2D NMR experiments. The absolute stereochemistry of condaline A (2), was elucidated by X-ray crystal structure determination of its HI salt.

Synthesis of unprotected glyco-alkynones molybdenum-catalyzed carbonylative Sonogashira cross-coupling reaction.

Herein we report a novel Mo-catalyzed carbonylative Sonogashira cross-coupling between 2-iodoglycals and terminal alkynes. The reaction displays major improvements compared to a related Pd-catalyzed procedure previously published by our group, such as utilizing unprotected sugar derivatives as starting materials and tolerance to substrates bearing chelating groups. In this work we also demonstrate the utility of the glyco-alkynone products as platform for further functionalization by synthesizing glyco-flavones Au-catalyzed 6--dig cyclization.

Alkaloids from the stem barks of Scutia buxifolia Reissek (Rhamnaceae): Structures and antimicrobial evaluation.

A reinvestigation of the chemical constituents of the stem barks of Scutia buxifolia, a member of the Rhamnaceae, resulted, along with the known alkaloids scutianine C and scutianene L, in the isolation of three undescribed diastereoisomeric alkaloids - scutianine N, 27-epi-scutianine N and 3, 4, 7-tri-epi-scutianine N -, one undescribed non macrocyclic alkaloid - scutianine Q - and a neutral compound -scutianene M. Their structures were determined using extensive NMR techniques and HRMS. The absolute configurations of the stereogenic centers of the three diastereoisomeric alkaloids have been assigned by gas chromatography employing modified cyclodextrins as chiral stationary phases.

Organic composition of epilithic biofilms from agricultural and urban watershed in South Brazil.

Active functional groups in biofilms determine the adsorption and desorption of contaminants and nutrients. Epilithic biofilms were characterized in order to understand the association between the chemistry alteration patterns and the surrounding anthropic activities of the Guaporé River watershed. The instrumental analyses included pyrolysis coupled to gas chromatography and mass spectroscopy, spectroscopy in the IR region with attenuated total reflectance, and two-dimensional nuclear magnetic resonance.

Physicochemical characterization, released profile, and antinociceptive activity of diphenhydraminium ibuprofenate supported on mesoporous silica.

The thermal, physical, and morphological properties of diphenhydraminium ibuprofenate ([DIP][IBU]) adsorbed onto mesoporous silica (SiO-60 Å and SiO-90 Å) from solution were determined. The thermal, physical, and morphological properties of [DIP][IBU] supported on silica were determined. The adsorption of [DIP][IBU] on the pores and surface of silica was proven by N adsorption/desorption isotherms.

Maxwell-Wagner Effect Applied to Microwave-Induced Self-Ignition: A Novel Approach for Carbon-Based Materials.

A new method for analytical applications based on the Maxwell-Wagner effect is proposed. Considering the interaction of carbonaceous materials with an electromagnetic field in the microwave frequency range, a very fast heating is observed due to interfacial polarization that results in localized microplasma formation. Such effect was evaluated in this work using a monomode microwave system, and temperature was recorded using an infrared camera.

Lanostane-type triterpenes from the fungal endophyte Scleroderma UFSMSc1 (Persoon) Fries.

Two lanostane triterpenoids (sclerodols A and B) were isolated from the culture of the Eucalyptus grandis derived from the endophyte Scleroderma UFSM Sc1(Persoon) Fries together with three known compounds: one related triterpenoid lanosta-8,23-dien-3β,25-diol, the disaccharide α,β-trehalose, and the sugar alcohol mannitol. Their structures were elucidated on the basis of 2D NMR, HRME, and single-crystal X-ray diffraction data. The methanol crude extract and the isolated lanostane triterpenoids showed promising anticandidal activities.

Crystal structure of 4-formyl-pyridine semicarbazone hemihydrate.

The mol-ecule of the title compound C7H8N4O·0.5H2O, alternatively called (E)-1-(pyridin-4-yl-methyl-ene)semi-carb-azide hemihydrate, is in the E conformation and is almost planar; the r.m.

A new sesquiterpene lactone and other constituents of Moquiniastrum polymorphum subsp. floccosum (Asteraceae).

A new guaianolide, 1S, 3S, 5R, 6S, 7S, 11R-l-hydroxy-11α,13-dihydrozaluzanin C (1), was isolated from Moquiniastrum polymorphum subsp. floccosum trunk bark, together with fifteen known compounds, which were identified as 11α,13-dihydroglucozaluzanin C (2), 8α-hydroxy-11α,13-dihydrozaluzanin C (3), zaluzanin C (4), gochnatiolide B (5), ethyl caffeate (6), methyl chlorogenate (7), ethyl chlorogenate (8), methyl 3,5-dicaffeoyl quinate (9), ethyl 3,5-dicaffeoyl quinate (10), methyl 4,5-dicaffeoyl quinate (11), ethyl 4,5-dicaffeoyl quinate (12), ethyl 3,4-dicaffeoyl quinate (13), 3,5-dicaffeoyl quinic acid (14), 4,5-dicaffeoyl quinic acid (15), and 3,4-dicaffeoyl quinic acid (16). With the exception of 5, all known compounds are being reported for the first time in M.

Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO4.

Chiral nonracemic aminated nitroso acetals were synthesized via diastereoselective multicomponent [4 + 2]/[3 + 2] cycloadditions employing new (S,E)-γ-nitrogenated nitroalkenes 5a-c as heterodienes, ethyl vinyl ether (EVE) as a dienophile, and selected electron-deficient alkenes as 1,3-dipolarophiles. The employment of different organic solutions of LiClO4 or LiCl as promoter systems provided the respective nitroso acetals with yields from 34-72% and good levels of diastereoselectivity. In addition, the nitroso acetal 9c was transformed to the pyrrolizidin-3-one derivative 14c, proving the usefulness of the route in the synthesis of an interesting chiral compound.

(9H-Fluoren-9-yl)(phen-yl)phosphinic acid.

The crystal structure of the title compound, C19H15O2P, features pairs of mol-ecules joined by O-H⋯O hydrogen bonds across crystallographic inversion centers. In addition, π-π inter-actions, with a centroid-centroid distance of 3.6273 (9) Å between the fluorene ring systems, connect the dimers into chains along [01-1].

Redetermination of cis-bis-(ethyl-ene-diamine-κ(2) N,N')bis-(nitrito-κN)cobalt(III) (ethyl-enediamine-κ(2) N,N')tetra-kis-(nitrito-κN)cobaltate(III) monohydrate.

The structure of the title compound, [Co(NO2)2(NH2CH2CH2NH2)2][Co(NO2)4(NH2CH2CH2NH2)]·H2O, was redetermined with a modern CCD-equipped diffractometer. In comparison with the original determination based on photographic data [Kushi et al. (1976 ▶).

rac-Eth-yl(phen-yl)phosphinic acid.

The crystal structure of the title compound, C8H11O2P, features O-H⋯O hydrogen bonds, which link mol-ecules related by the b-glide plane into chains along [010].

Nickel(II) complexes with methyl(2-pyridyl)ketone oxime: synthesis, crystal structures and DFT calculations.

The synthesis and structural characterization of the three novel nickel(II) complexes [Ni(OOCPh)(2)(mpkoH)(2)] (1), [Ni(NO(3))(2)(mpkoH)(2)] (2) and [Ni(mpkoH)(3)](NO(3))(2)·½H(2)O (3·½H(2)O), with mpkoH=methyl(2-pyridyl)ketone oxime is reported. Geometry optimization and population analyses were performed by means of DFT calculations for the previously mentioned compounds as well as for [NiCl(2)(mpkoH)(2)] (4). Electronic UV-vis spectra were also simulated in the TD-DFT framework to assign the origin of the absorption bands and in doing so, to have a clear picture of the absorptive features of the coordination compounds under investigation.

Absolute configuration of franganine.

The absolute configuration of franganine (1), a cyclopeptide alkaloid isolated from the methanol root bark extract of Discaria americana, was established on the basis of detailed NMR spectroscopic data and X-ray diffraction analysis of its salt (2).

Meth-yl(phen-yl)phosphinic acid.

The crystal structure of the title compound, C(7)H(9)O(2)P, displays O-H⋯O hydrogen bonding , which links individual mol-ecules related via the c-glide plane and translational symmetry along the crystallographic b-axis direction into continuous chains.

Benz-yl(phen-yl)phosphinic acid.

The title compound, C(13)H(13)O(2)P, crystallized as enanti-omerically pure crystals; for the crystal measured, the P atom has R stereochemistry. The crystal structure displays O-H⋯O hydrogen bonding, which links individual mol-ecules related by a 2(1) screw axis parallel to the crystallographic a-axis direction into continuous chains.

Cyclopeptide alkaloids from Scutia buxifolia Reiss.

Scutianene E (1), 3,4,28-tris-epi-scutiaene E (2), 28-epi-scutianene E (3) and scutianene L (4), four neutral cyclopeptide alkaloids, were isolated from Scutia buxifolia Reiss, together with four known cyclopeptide alkaloids, scutianines B, C, D and E. Scutianenes 1-3 are diastereoisomeric compounds, with 3-hydroxyleucine as a β-hydroxy amino acid unit, which is connected to the styryl fragment via an ether bridge, β-phenylserine, as a common ring-bonded amino acid residue. Attached to the amino group of β-hydroxyamino acid is a side chain [trans-CH=CH-Ph].

A centrosymmetric polymorph of chloridotris(triphenylphosphine-kappaP)copper(I) at 150 K.

This study characterizes a new polymorph of the title compound, [CuCl(C18H15P)3], and analyses the influence of the extensive network of weak hydrogen-bonding interactions in the generation of this different crystal structure. The compound crystallizes in the centrosymmetric space group C2/c with two crystallographically independent molecules per asymmetric unit, in contrast with the previously determined polymorph which crystallizes in the noncentrosymmetric space group P3 with three crystallographically independent molecules in the asymmetric unit, each with crystallographically imposed C3 symmetry [Gill, Mayerle, Welcker, Lewis, Ucko, Barton, Stowens & Lippard (1976). Inorg.

Quinolone alkaloids from Waltheria douradinha.

A phytochemical investigation of the stems of Waltheria douradinha resulted in isolation of two 4-quinolone alkaloids, waltherione B and vanessine, along with three known alkaloids, waltherione A, antidesmone and O-methyltembamide. Their structures were elucidated on the basis of their 2D NMR spectroscopic analyses, and from X-ray crystallographic analysis of waltherione A and the O-methyl derivative of waltherione B. Additionally, waltherione B and vanessine, and the O- and N-methyl derivatives of waltherione A and waltherione B, were evaluated for their antimicrobial activities; only vanessine displayed any (weak) antimicrobial activity.

Design and microwave-assisted synthesis of 5-trifluoromethyl-4,5-dihydro-1H-pyrazoles: novel agents with analgesic and anti-inflammatory properties.

In this work, we reported the synthesis and evaluation of the analgesic and anti-inflammatory properties of novel 3- or 4-substituted 5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-1-carboxyamidepyrazoles (where 3-/4-substituent=H/H, Me/H, Et/H, Pr/H, i-Pr/H, Bu/H, t-Bu/H, Ph/H, 4-Br-Ph/H and H/Me) designed in the exploration of the bioisosteric replacement of benzene present in salicylamide with a 5-trifluoromethyl-4,5-dihydro-1H-pyrazole scaffold. Target compounds were synthesized from the cyclocondensation of 4-alkoxy-1,1,1-trifluoromethyl-3-alken-2-ones with semicarbazide hydrochloride through a rapid one-pot reaction via microwave irradiation. In addition to spectroscopic data, the structure of the compounds was supported by X-ray diffraction.

Poly[(mu3-1,1-dioxo-1,2-benzoisothiazole-3-thiolato-kappa3N:S3:S3)silver(I)].

The centrosymmetric title compound, [Ag(C(7)H(4)NO(2)S(2))]n, consists of dinuclear units in which two thiosaccharinate anions each bridge two Ag atoms via an endocyclic N atom and an exocyclic S atom across a crystallographic centre of inversion midway between the Ag atoms. The dimeric units are connected via Ag-S(exo) interactions to create two-dimensional networks. The thiosaccharinate anions bridge in a mu3-S:S:N manner.

Alkaloids from Melochia chamaedrys.

Investigation of the chemical constituents from the roots of Melochia chamaedrys (Sterculiaceae) resulted in the isolation of two quinolinone alkaloids: a new alkaloid, named chamaedrone (1), and a known alkaloid, antidesmone (2). Their structures and stereochemistry were elucidated on the basis of 2D NMR and X-ray crystallographic analysis. Furthermore, alkaloids 1 and 2, and the synthetic analogues 3-6 obtained from 2, were screened for antimicrobial activities.

catena-Poly[[(N,N-dimethylformamide-kappaO)(nitrato-kappaO)silver(I)]-mu-1,2-bis(diphenylphosphino)ethane-kappa(2)P:P'] at 100 and 293 K: temperature effects on the volume of the solvent pocket.

In the title chain compound, [Ag(NO(3))(C(3)H(7)NO)(C(26)H(24)P(2))](n), the bis(diphenylphosphino)ethane (dppe) components lie across centres of inversion. The dppe units link the Ag(+) ions into chains along [100]. A nitrate anion is coordinated to the Ag atom, together with one molecule of N,N-dimethylformamide (DMF) solvent.

Mercury bis(phenyltellurolate) as a precursor for the synthesis of binary and ternary nanoclusters.

The reaction of Hg(TePh)2 with AgX (X = Cl, NO3) in the presence of PPh3 and PMePh2 in dimethylformamide (DMF) affords the cluster [Hg6Ag4(TePh)16] (1) at room temperature or [Hg6Ag4Te(TePh)14]2 (2) with heating. When Hg(TePh)2 is reacted with [Co(PPh3)2Cl2] or [Ni(PPh3)2Cl2], the clusters [Hg8Te(PhTe)12Cl4]Q [3; Q = [Co(DMF)6]2+ (3a), [Ni(DMF)6]2+ (3b)] are formed. The syntheses of 1 and 2 occur with the incorporation of AgI into the cluster, and the single-crystal analyses show that the two ternary clusters consist of Hg, Ag, and Te centers occupying well-defined positions.