Phytoalexins from the crucifer rutabaga: structures, syntheses, biosyntheses, and antifungal activity

Phytoalexins are inducible chemical defenses produced de novo by plants in response to diverse forms of stress, including microbial attack. Our search for phytoalexins from economically important crucifers lead us to examine rutabaga tubers (Brassica napus L. ssp. rapifera). Three new phytoalexins, named isalexin (9), brassicanate A (10), and rutalexin (11), were isolated together with five known phytoalexins, brassinin (4), 1-methoxybrassinin (5), spirobrassinin (13), brassicanal A (14), and brassilexin (15). The chemical structures of the new phytoalexins were proven by syntheses, and their biological activity against four plant pathogens were determined. Biosynthetic studies using tetra- and pentadeuterated precursors established that indolyl-3-acetaldoxime (22) and brassinin (4) are precursors of brassicanate A (10) and rutalexin (11) and that cyclobrassinin (23) is a biosynthetic precursor of rutalexin (11), whereas tryptamine (24) is not a precursor of rutabaga phytoalexins.     

Stability studies of arsenic, selenium, antimony and tellurium species in water, urine, fish and soil extracts using HPLC/ICP-MS

The stability of arsenic, selenium, antimony and tellurium species in water and urine (NIST SRM 2670n) as well as in extracts of fish and soil certified reference materials (DORM-2 and NIST SRM 2710) has been investigated. Stability studies were carried out with As(III), As(V), arsenobetaine, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), phenylarsonic acid (PAA), Se(IV), Se(VI), selenomethionine, Sb(III), Sb(V) and Te(VI). Speciation analysis was performed by on-line coupling of anion exchange high-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS). Best storage of aqueous mixtures of the examined species was achieved at 3 degrees C whereas at -20 degrees C species transformation especially of selenomethionine and Sb(V) took place and a new selenium species appeared within a period of 30 days. Losses and species transformations during extraction processes were investigated. Extraction of the spiked fish material with methanol/water led to partial conversion of Sb(III), Sb(V) and selenomethionine to two new antimony and one new selenium species. The other arsenic, selenium and tellurium species were almost quantitatively extracted. For soil spiked with MMA, PAA, Se(IV) and Sb(III), recoveries after extraction with water and sulfuric acid (0.01 mol/L) were below 20%.     

Syntheses,structure, reactivity,and thermal properties of new cyclic phosphine oxide epoxy resins cured by diamines

A new type of epoxy resin which contained cyclic phosphine oxide group in the main chain was synthesized. The structure of the new type of epoxy resin was confirmed by elemental analyses (EA), infrared spectroscopy (IR), and ¹H-NMR and ¹³C-NMR spectroscopies. In addition, compositions of the new synthesized cyclic phosphine oxide epoxy resin (EPCAO) with three curing agents, e.g., bis(3-aminophenyl)methylphosphine oxide (BAMP), 4,4′-diamino-diphenylmethane (DDM), and 4,4′-diaminodiphenylsulfone (DDS), were used for making a comparison of its curing reactivity, heat, and flame retardancy with that of Epon828 and DEN438. The reactivities were measured by differential scanning calorimetry (DSC). Through the evaluation of thermal gravimetric analysis (TGA), those polymers which were obtained through the curing reactions between the new epoxy resin and three curing agents (BAMP, DDM, DDS) also demonstrated excellent thermal properties as well as a high char yield. © 1996 John Wiley & Sons, Inc.     

Structures of new flavonoids, erycibenins D, E, and F, and NO production inhibitors from Erycibe expansa originating in Thailand

A new flavanol, erycibenin D, and two new flavans, erycibenins E and F, were isolated from the stems of Erycibe expansa originating in Thailand. The structures of new flavonoids were elucidated on the basis of chemical and physicochemical evidence. In addition, the inhibitory activities of the isolated constituents from E. expansa on lipopolysaccharide-activated nitric oxide production in mouse peritoneal macrophages were examined. Among the principal constituents, two isoflavones, clycosin (IC50 = 13 microM) and erythrinin B (18 microM), and two rotenoids, deguelin (26 microM) and rotenone (27 microM), were found to show potent inhibitory activity.     

Medicinal flowers. XXI. Structures of perennisaponins A, B, C, D, E, and F, acylated oleanane-type triterpene oligoglycosides, from the flowers of Bellis perennis

Six new acylated oleanane-type triterpene oligoglycosides, perennisaponins A (1), B (2), C (3), D (4), E (5), and F (6), were isolated from the flowers of Bellis perennis (Daisy flower) together with 14 saponins, nine flavonoids, and two glycosides. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence.     

地耳苯抗疟有效成份的研究—地耳苯系A、B、C、D的分离和结构

从地耳草中分离到四个间苯三酚衍生物, 定名为地耳草素A、B、C、D. 通过紫外、红外、核磁和质谱分析以及化学反应, 推定其结构分别为4、8、12和14. 4和8对鼠疟原虫有显著抑制作用.     

Steroidal glycosides from Veronica chamaedrys L. Part I. The structures of chamaedrosides C, C1, C2, E, E1 and E2

Two new spirostane glycosides, chamaedrosides C (1) and C1 (2), two new furostane glycosides, chamaedrosides E (4) and E1 (5), and two new furospirostane glycosides, chamaedrosides C2 (3) and E2 (6), have been isolated from Veronica chamaedrys L. plants. Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods, including 1D- and 2D-NMR experiments, as well as MS analysis. The given compounds have been found for the first time.     

Two new alkylanacardic acids, ozorcardic A and B, from Ozoroa pulcherrima

Two new alkylanacardic acids, ozorcardic A (1) and B (2), along with the known and related metabolite anacardic acid (3), were isolated from Ozoroa pulcherrima. The structures of the new compounds were elucidated by detailed spectroscopic and spectrometric analysis.     

Three new quassinoids,ailantinol E,F, and G,from Ailanthus altissima

Three new quassinoids, ailantinol E (1), ailantinol F (2), and ailantinol G (3), and related compounds were isolated from Ailanthus altissima grown in Taiwan. Their structures were elucidated from spectral evidence. Each new quassinoid was evaluated for its antitumor promoting effects against Epstein-Barr virus early antigen activation introduced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. The new quassinoids were found to show potent activity without showing any cytotoxicity. The screening for inhibitors against nitric oxide donor action was also conducted using the new quassinoids and some standard samples.     

Chlorodifluoroacetyl Azide, ClF(2)CC(O)N(3): Preparation, Properties, and Decomposition

Chlorodifluoroacetyl azide, ClF(2)CC(O)N(3), was prepared and characterized by IR (gas, Ar matrix), Raman (liquid), UV-vis (gas), and (19)F, (13)C NMR spectroscopy. The vibrational spectra were analyzed in terms of a single conformer, gauche-syn, where the Cl-C and the N(α)═N(β) bonds are gauche and syn to the C═O bond, respectively. The photo and thermal decomposition reactions of the azide were studied with the aid of matrix isolation. In both cases, a new isocyanate species ClF(2)CNCO was produced and characterized by matrix IR spectroscopy. The conformational properties and the Curtius rearrangement pathways of this new carbonyl azide were theoretically explored, which suggest the preference of a concerted over stepwise decomposition for the global minimum gauche-syn conformer.     

Absolute structures of new megastigmane glycosides, foliasalaciosides E(1), E(2), E(3), F, G, H, and I from the leaves of Salacia chinensis

Following the investigation of foliasalaciosides A(1), A(2), B(1), B(2), C, and D, seven new megastigmane glycosides named foliasalaciosides E(1)-I (1-7), together with four known constituents, were isolated from the leaves of Salacia chinensis LINN. collected in Thailand. The absolute stereostructures of the new compounds were characterized on the basis of chemical and physicochemical evidence, including the application of the modified Mosher's method.     

Stoloniferone-a, -b, -c,and -d,four new cytotoxic steroids from the okinawan soft coral clavularia viridis

Four new cytotoxic steroids named stoloniferone-a (7a), -b (7b), -c (7c), and -d (7d) were isolated from the stoloniferan Okinawan soft coral Clavularia viridis and their absolute stereostructures were elucidated.     

Alkali metal atom-aromatic ring: a novel interaction mode realizes large first hyperpolarizabilities of M@AR (M=Li, Na, and K, AR=pyrrole, indole, thiophene, and benzene)

Several new electride compounds M@pyrrole (M = Li, Na, and K), Li@AR (AR = indole, thiophene, and benzene), Li@tryptophan and Li@serotonin were designed and investigated, which exhibit considerably large first hyperpolarizabilities (β(0)) (6705, 1116, 11399, 5781, 4808, 1536, 8106, and 9389 au, respectively) by comparison with their corresponding sole molecules pyrrole (β(0) = 30 au), indole (104 au), thiophene (6 au), benzene (0 au), tryptophan (159 au) and serotonin (151 au), respectively. The computational results revealed that the interaction of the alkali metal atom with π-conjugated aromatic ring (AR) is one effectively new approach to produce diffuse excess electron to get a large β(0) value, which is advantageous for the design of the novel high-performance NLO materials with π-conjugated AR: alkali metal atoms doped nanomaterials and biomolecules.     

Synthesis of certain pyridinyl and diazinyl hydrazones containing one or more ferroin groups, and their chromogenic reactions with iron, copper, cobalt and nickel

Fifteen new hydrazones with one or more ferroin groups were prepared, and their chelation and chromogenic properties with iron(II), copper(I), cobalt(II) and nickel(II) were investigated. Improved sensitivity in the spectrophotometric determination of cobalt, copper, and nickel is provided by several of the new compounds. Several others are capable of forming unusually stable and interesting binuclear iron(II) complexes.     

Structures of euglobal-G1, -G2, and -G3 from Eucalyptus grandis, three new inhibitors of Epstein-Barr virus activation

Three new euglobals with acylphloroglucinol-monoterpene structures, named euglobal -G1 (1), -G2 (2), and -G3 (3) were isolated from the chloroform extract of the juvenile leaves of Eucalyptus grandis (Myrtaceae). The structures of these new compounds were determined on the basis of their spectral data. The compounds strongly inhibited the Epstein-Barr virus activation.     

Six immunosuppressive features from an ascomycete, Zopfiella longicaudata, found in a screening study monitored by immunomodulatory activity

In a screening study on immunomodulatory fungal metabolites, three known anthraquinones, carviolin (roseo-purpurin) (1), 1-O-methylemodin (2), omega-hydroxyemodin (citreorosein) (4), and a new anthraquinone, omega-acetylcarviolin (3), together with a known steroid, ergosta-4,6,8(14),22-tetraen-3-one (5) and a new steroid, 25-hydroxyergosta-4,6,8(14),22-tetraen-3-one (6) were isolated from an Ascomycete, Zopfiella longicaudata, and found to have moderate immunosuppressive activities. The structure-activity relationships of these metabolites are discussed.     

Three new types of indoloditerpenes, emindole PA-PC, from Emericella purpurea. Revision of the structure of emindole PA

Three new type indoloditerpenes, emindoles PA (1), PB (2), and PC (3), were isolated from the mycelium of Emericella purpurea along with the sesterterpenes variecolol and variecolactone, and the dicyanide derivatives epurpurins A to C. The structures of 1-3 were confirmed by the spectroscopic investigation. The structure of emindoles PA (1) was revised from our preliminary report. Emindoles PA (1), PB (2), and PC (3) are the indoloditerpenes having a new type of carbon skeleton.     

Bioactive aromatic derivatives from endophytic fungus, Cytospora sp

Two new benzyl gamma-butyrolactone analogues, (R)-5-((S)-hydroxy(phenyl)-methyl)dihydrofuran-2(3H)-one (1) and its 6-acetate (2), and a new naphthalenone derivative (8), together with eight additional known aromatic derivatives, (S)-5-((S)-hydroxy(phenyl)-methyl)dihydrofuran-2(3H)-one (3), (S)-5-benzyl-dihydrofuran-2(3H)-one (4), 5-phenyl-4-oxopentanoic acid (5), gamma-oxo-benzenepentanoic acid methyl ester (6), 3-(2,5-dihydro-4-hydroxy-5-oxo-3-phenyl-2-furyl)propionic acid (7), (3R)-5-methylmellein (9), integracins A (10) and B (11) were isolated from Cytospora sp., an endophytic fungus isolated from Ilex canariensis from Gomera. The structures of these compounds were elucidated by detailed spectroscopic analysis, comparison with reported data, and chemical interconversion. The absolute configurations of the new compounds (1, 2, 8) were established on the basis of optical rotation or CD spectra analysis. Preliminary studies showed antimicrobial activity of these compounds against the fungi Microbotryum violaceum, Botrytis cinerea and Septoria tritici, the alga Chlorella fusca, and the bacterium Bacillus megaterium.     

Sesquiterpenes, nortriterpenes and other constituents from Ligularia tongolensis

Two new eremophilane-type sesquiterpenes, 3beta-(2'-methylbutanoyloxy)-8betaH-eremophil-7(11)-ene-12,8alpha-(14,6alpha)-diolide (1) and 8betaH-eremophil-3,7(11)-diene-12,8alpha(14,6alpha)-diolide (2), and two new norursane-type triterpenes, 2alpha,3beta,19alpha-trihydroxy-28-norurs-12-ene (7) and 2alpha,3alpha,19alpha-trihydroxy-28-norurs-12-ene (8), were isolated from the roots of Ligularia tongolensis, together with nine known compounds. The structures of the new compounds were elucidated by spectroscopic methods.     

DFT Investigations(Geometry Optimization,UV/Vis,FT-IR,NMR, HOMO-LUMO,FMO, MEP,NBO, Excited States) and the Syntheses of New Pyrimidine Dyes

In the present work, the molecular structures of two new synthesized dyes:(4,6-dimethylpyrimidin-2-ylamino)(5-p-tolylisoxazol-3-yl)methanol(PS-1) and N-(4,6-dimethylpyrimidin-2-yl)-5-phenylisoxazole-3-carboxamide(PS-2), have been investigated using density functional theory(DFT) in dimethylformamide(DMF) for the first time. The electronic spectra of new dyes in a DMF solvent were carried out by time dependent density functional theory(TD-DFT) method. After quantum-chemical calculations two new dyes for the optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. NucleusIndependent Chemical Shifts(NICS) calculations have also been carried out for the title compounds. The computed absorption spectral data of the title compounds are in good agreement with the experimental data, thus allowing an assignment of the UV spectra. The HOMO and LUMO molecular orbitals, excitation energies and oscillator strengths for the dyes have also been calculated and presented.