Antifeedants against Locusta migratoria from the Japanese Cedar,Cryptomeria japonica

(1S,6R)-2,7(14),10-bisabolatrien-1-ol-4-one and (+)-7(14),10-bisaboladien-1-ol-4-one were isolated and identified from Cryptomeria japonica as antifeedants against Locusta migratoria L. which is well known as a serious pest to cereals throughout the world. These compounds strongly inhibited the feeding of L. migratoria only when they were combined, but each compound alone did not show any activity.     

Repellents in the Japanese Cedar,Cryptomeria japonica,against the Pill-bug,Armadillidium vulgare

Sandaracopimarinol and (1S,6R)-2,7(14),10-bisabolatrien-1-ol-4-one were isolated and identified from Cryptomeria japonica as repellents against Armadillidium vulgare which is well known as an unpleasant pest in the house and as vegetable pest in Japan. These compounds strongly repelled A. vulgare when they were combined, although each compound alone did not show any activity.     

Cell-Bound Serine Proteinase of Sporulating Cells of Bacillus subtilis

2-Deuterio-2-cyclohexen-l-one, 3-deuterio-2-cyclohexen-l-one and 2-methyl-2-cyclohexen-1-one were reduced by Clostridium La 1 giving a single bioconversion product resulting from reduction of the carbon-carbon double bond. Stereochemistry of the reaction was studied.     

Antifeedants against Acusta despesta from the Japanese cedar, Cryptomeria japonica II

Cryptomeria japonica against Acusta despesta. This hexane soluble-fraction was used to isolate and identify two sesquiterpenols, (-)-cubebol and (+)-2,7(14),10-bisabolatrien-1-ol-4-one, as the active compounds. Both compounds strongly inhibited the feeding behavior of A. despesta at 120 microg/cm2 and 80 microg/cm2 concentrations, respectively.     

Antifeedants against Acusta despesta from the Japanese cedar, Cryptomeria japonica

During our studies on the components in Japanese cedar, Cryptomeria japonica, we found that the crude methanol extract of C. japonica showed intense antifeeding activity against one snail species, Acusta despesta, which is well-known as a pest of many vegetables and crops. The active components in the extract were separated into the hexane and ethyl acetate soluble fractions. From the active ethyl acetate soluble fraction, two norlignans, sequirin-C and agatharesinol, were isolated and identified as the active compounds. Both compounds inhibited feeding behavior of A. despesta at 30 microg/cm2 and 40 microg/cm2 concentrations, respectively, when applied by an eggplant leaf or filter paper containing 20 microl of 5% sucrose solution.     

Antifeedants against Locusta migratoria from the Japanese Cedar, Cryptomeria japonica II

A methanol extract of Cryptomeria japonica completely inhibited feeding by Locusta migratoria. Based on bioassay-guided fractionation, two active terpenols, (+)-ferruginol and (-)-cubebol, were isolated and identified as antifeedants against this insect species. Each compound separately showed weak activity, but they showed intense activity against this insect species when they were combined.     

Antifeedants against Locusta migratoria from the Japanese Cedar, Cryptomeria japonica

(1S,6R)-2,7(14),10-bisabolatrien-1-ol-4-one and (+)-7(14),10-bisaboladien-1-ol-4-one were isolated and identified from Cryptomeria japonica as antifeedants against Locusta migratoria L. which is well known as a serious pest to cereals throughout the world. These compounds strongly inhibited the feeding of L. migratoria only when they were combined, but each compound alone did not show any activity.     

A sesquiterpene hydrocarbon from the bogwoods of Cryptomeria japonica D. Don, presumably formed by diagenetic hydrogenation

Structure of an hitherto unknown component of the essential oils from two bogwoods of Cryptomeria japonica D. Don was determined by mass spectrometry and NMR analyses. It was identified as cadina-1(10)-ene, a new cadinane-type sesquiterpene hydrocarbon with a single double bond.     

Synthesis, spectroscopic characterization and biological activity on newly synthesized copper(II) and nickel(II) complexes incorporating bidentate oxygen-nitrogen hydrazone ligands

We report the synthesis of the hydrazone ligands, 1-(phenyl-hydrazono)-propan-2-one (PHP), 1-(p-tolyl-hydrazono)-propan-2-one (THP), 1-[(4-chloro-hydrazono)]-propan-2-one (CHP), and their Ni(II) and Cu(II) metal complexes. The structure of the ligands and their complexes were investigated using elemental analysis, magnetic susceptibility, molar conductance and spectral (IR, UV, and EPR) measurements. IR spectra indicate that the free ligands exist in the hydrazo-ketone rather than azo-enol form in the solid state. Also, the hydrazo-NH exists as hydrogen bonded to the keto-oxygen either as intra or as intermolecular hydrogen bonding. In all the studied complexes, all ligands behave as a neutral bidentate ligands with coordination involving the hydrazone-nitrogen and the keto-oxygen atoms. The magnetic and spectral data indicate a square planar geometry for Cu²⁺ complexes and an octahedral geometry for Ni²⁺ complexes. The ligands and their metal chelates have been screened for their antimicrobial activities using the disc diffusion method against the selected bacteria and fungi. They were found to be more active against Gram-positive than Gram-negative bacteria. It may be concluded that the antimicrobial activity of the compounds is related to cell wall structure of bacteria.Protonation constant of (PHP) ligand and stability constants of its Cu²⁺ and Ni²⁺ complexes were determined by potentiometric titration method in aqueous solution at ionic strength of 0.1 M sodium nitrate. It has been observed that the hydrazone ligand (PHP) titrated here has one protonation constant. The divalent metal ions Cu²⁺ and Ni²⁺ form with (PHP) 1:1 and 1:2 complexes. The insolubility of (THP) and (CHP) ligands in aqueous medium does not permit the determination of their protonation constants and formation constants of the corresponding complexes in aqueous solution.     

Germacrane and eudesmane derivatives from Calea reticulata

Calea reticulata afforded in addition to known compounds two new sesquiterpenes. These were germacrane and eudesmane derivatives, identified as germacra-4(15),5,10(14)-trien-1-one and 6-epi-β-verbesinol coumarate, respectively.     

Protective effect of hydroxychavicol, a phenolic component of betel leaf, against the tobacco-specific carcinogens

The phenolic compound, hydroxychavicol (HC), present in betel leaf, was synthesized and tested for its antimutagenic effect against the mutagenicity of the 2 tobacco-specific N-nitrosamines (TSNA), N′-nitrosonornicotine (NNN) and 4-(nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK), in 2 different test systems, viz. the Ames Salmonella/microsome assay and the micronucleus test using Swiss male mice. We are reporting the synthesis of HC of a high degree of purity. We observed that HC suppressed the mutagenic effects of NNN and NNK in both test systems used. These results indicate that HC may have a role to play in reducing the risk of oral cancer in betel quid with tobacco chewers.     

Neolignans from Virola elongata

The bark of Virola elongata contains the new 8.8′-neolignan, 1-(3,4-dimethoxyphenyl)2,3-dimethyl-4-piperonylbutan-1-one besides the known 8.8′, 2.7′-neolignans, 4-hydroxy-2,3-dimethyl-6,7-dimethoxy-4-piperonyl-1-tetralone and 4-hydroxy-2,3-dimethyl-5,6-methylenedioxy-4-piperonyl-1-tetralone.     

Production of antisera against contraceptive steroids

A four step synthesis of 6-(O-carboxymethyl)oximinoethynylestradiol is reported. This compound, 6-(O-carboxymethyl)oximinomestranol, the 3-(O-carboxymethyl)oximes of norethindrone and norgestrel and the 3-hemisuccinate of ethynylestradiol were synthesized and conjugated with bovine serum albumin. Rabbits were immunized at 3 dose levels of haptene (20, 66 and 200 nmoles) and eight weeks later with a booster containing 66 nmoles of haptene. The antibody titer and association constant of responding rabbits was nearly independent of dose although most antibody production occurred after the booster injection. Antibodies to mestranol crossreacted more than 100% with ethynylestradiol and to a small extent with norethindrone and norgestrel.     

Immunosuppressive diacetylenes, ceramides and cerebrosides from Hydrocotyle leucocephala

Three C-17 diacetylenic compounds (1-3), one monoterpenoid (4), seven ceramides (leucoceramides A-G, 5a-g), six cerebrosides (leucocerebrosides A-F, 6a-f) and nine known compounds were isolated from the methanolic extract of Hydrocotyle leucocephala. Their structures were established by spectroscopic methods. The isolated compounds 1-3, 5a-g, 6a-f and 7 were shown to be active in the lipopolysaccharide (LPS) induced cytokine production assay for IL-10, IL-12, and TNF-alpha.     

Dihydroisocoumarin from Xyris pterygoblephara active against dermatophyte fungi

The ethanol extract from Xyris pteygoblephara aerial parts was evaluated against five microorganism strains, by the microdilution and agar diffusion methods. Extract fractionation led to the isolation of three compounds, whose structures were assigned by spectrometric data (1D and 2D NMR, IR, MS and UV) as (3R,4R)-(-)-6-methoxy-3,4-dihydro-3-n-pentil-4-acethoxy-1H-2-benzopyran-1-one (1), moronic acid and quercetin. The absolute configuration of 1 was defined by circular dichroism spectroscopy and comparison with data reported for other dihydroisocoumarins. Assay of 1 (100 microg/disc) by the agar diffusion method against clinical isolates of the dermatophytes Epidermophyton floccosum (inhibition zone, mm+/-s.d.: 4.5+/-0.8), Trichophyton mentagrophytes (4.8+/-0.4) and Trichophyton rubrum (10.2+/-0.8) revealed similar inhibition zones to the positive control amphotericin B (32 microg/disc; 5.0+/-0.2; 5.0+/-0.6 and 8.8+/-1.2, respectively). The result corroborates the ethnomedical use of Xyris species to treat dermatitis.     

Activity of chalcones derived from 2,4,5-trimethoxybenzaldehyde against Meloidogyne exigua and in silico interaction of one chalcone with a putative caffeic acid 3-O-methyltransferase from Meloidogyne incognita

Meloidogyne exigua is a parasitic nematode of plants that causes great losses to coffee farmers. In an effort to develop parasitic controls, 154 chalcones were synthesized and screened for activity against this nematode. The best results were obtained with (2E)-1-(4′-nitrophenyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (6) with a 50% lethal concentration (LC₅₀) of 171 μg/ml against M. exigua second-stage juveniles, in comparison to the commercially-available nematicide carbofuran which had an LC₅₀ of 260 μg/ml under the same conditions. When coffee plants were used, 6 reduced the nematode population to ∼50% of that observed in control plants. To investigate the mechanism of action of 6, an in silico study was carried out, which indicated that 6 may act against M. exigua through inhibition of a putative caffeic acid 3-O-methyltransferase homodimer, the amino acid sequence of which was determined by examining the genome of Meloidogyne incognita.     

H2 metabolism in photosynthetic organisms. II. Light-dependent H2 evolution by preparations from Chlamydomonas, Scenedesmus and spinach.

Light-dependent H₂ evolution from dithiothreitol as electron donor was observed with cell-free preparations of anaerobically adapted $\text{Chlamydomonas reinhardii, Scenedesmus obliquus}$ and from spinach chloroplasts mixed with $\text{Chlamydomonas}$ hydrogenase. NADH substituted for dithiothreitol as electron donor only in the $\text{Chlarmydomonas}$ preparation. Dibromothymoquinone, an antagonist of plastoquinone, selectively inhibited H₂ photoevolution from NADH. These results are interpreted as indicating that 3-(3,4-dichlorophenyl)-1,1-dimethyl urea insensitive H₂ photoevolution by algae containing hydrogenase is due to the capability of NADH to reduce plastoquinone in the electron transport chain, and to evolve H₂ by a low redox potential carrier of photosystem I.     

Studies on the mechanism of action of the aromatase inhibitor, 4-hydroxyandrostenedione

[1 beta-3H], [1 alpha,2 alpha-3H] and [1 beta,2 beta-3H] 4-Hydroxyandrostenedione (4-OH-A) were synthesized to study the mechanism of inhibition of aromatase by 4-OH-A. Incubations of [1 beta-3H] and [1 beta,2 beta-3H] 4-OH-A with placental microsomes in the presence of NADPH showed very little loss of tritium, with aromatization of 4-OH-A ranging from 0.3 to 0.6 percent. No loss of tritium was observed in the absence of NADPH. The extent of covalent binding of 4-OH-A to microsomal proteins was higher with incubations in the absence of NADPH than with those in the presence of NADPH. These results are discussed in light of what has been proposed for the mechanism of androgen aromatization.     

The structures of garcinones a,b and c: Three new xanthones from Garcinia mangostana

Three new tetraoxygenated xanthones (garcinones A, B and C), each disubstituted with C₅-units, have been isolated from the chloroform extract of the fruit-hulls of Garcinia mangostana. Their structures were established by a combination of spectral interpretation and chemical correlation.