Synthesis and Biological Activity of (±)2′,3′-Dihydroabscisic Acid

An enzyme which catalyzes the oxidation of poly(vinyl alcohol) (PVA) has been purified from a fraction adsorbed to DEAE-Sephadex at pH 7.0 from PVA-degrading enzyme activities produced by a bacterial symbiotic mixed culture in a culture broth when the culture was grown in a minimal medium where PVA served as a sole source of carbon and energy. The enzyme was separated from a coexisting oxidized PVA hydrolase by dye-ligand chromatography on Matrex Gel Blue A. The purified enzyme was homogeneous as judged by polyacrylamide gel electrophoreses in the absence and presence of SDS.

The enzyme is a single polypeptide with a molecular weight of about 40,000 and has an isoelectric point of 4.5. The amino acid composition of the enzyme has been determined and found to have no histidine. The N- and C-terminal amino acid residues are both alanine. The enzyme solution is pink and shows absorption maxima at 276, 364, and 469 nm. One atom of non-heme iron has been detected per molecule in the enzyme.

The enzyme catalyzes the oxidation of PVA and also of various low molecular weight secondary alcohols to the corresponding ketones with the production of H₂0₂ and the consumption of 0₂. The molar ratio of these ketones, H₂0₂ and 0₂ is 1:1:1. The most effective electron acceptor is 0₂, while 2,6-dichlorophenolindophenol and nitro blue tetrazolium also serve as the acceptor with efficiencies to 0₂ of about 31 and 16%, respectively. The enzyme is, therefore, considered to be a secondary alcohol oxidase.

The enzyme is most active at pH 7.0 and at 45°C and is stable between pH 5.0 and 9.0 and at temperatures below 45°C. The activity is inhibited by Hg²⁺ and is restored by the addition of reduced glutathione, although p-chloromercuribenzoate has no effect.

The enzyme shows a common antigenicity in immunodiffusion and neutralization reactions with antisera to a secondary alcohol oxidase previously isolated from another fraction adsorbed on SP-Sephadex at pH 7.0 of the PVA-degrading enzyme activities [Agric. Biol. Chem., 43, 1225 (1979)]. The relations between these two secondary alcohol oxidases are discussed.     

Synthesis of (±)-Tubaic Acid

An alternative synthesis of (±)-tubaic acid (I), a key intermediate compound of rotenone synthesis, has been accomplished by the Wittig reaction.     

Optical Resolution and Biological Activities of α-Ionylideneacetic Acid.

Nuclease activity associated with cells and protoplasts was analyzed by agarose gel electrophoresis. Datura innoxia protoplasts were found to possess a high exonuclease activity. On the other hand, Datura innoxia cells had an endonuclease activity, but no apparent exonuclease. The exonucleases from the protoplasts were active at pH 5 and 6, but not at pH 9. Endonuclease activity from the cells was also inhibited at pH 9. Cultured cells of Daucus carota, Glycine max, Pisum sativum and Vicia hajastana had endonuclease activity, but did not exhibit exonuclease activity. Nicotiana suaveolens cells had both types of nuclease activity. On the other hand, cells from cereals such as Triticum monococcum, Oryza sativa, and Zea mays had active exonuclease activity.     

Synthesis of (±)-Homosarkomycin and (±)-Rosaprostol

(±)-Homosarkomycin (2) and (±)-rosaprostol (3) were synthesized from (±)-methyl 2-oxo-bicyclo[3.1.0]hexane-1-carboxylate (1) by using the nucleophilic ring opening reaction on the double-activated cyclopropane ring as the key step.     

Synthesis of (±)-Lamprolobine and (±)-Epilamprolobine

(±)-Lamprolobine, the (+)-enatiomer of which was isolated from the leaves of Lamprolobium fruticosum, and (±)-epilamprolobine were synthesized from δ-valerolactam.     

The Synthesis of (±)-Azetidine-2-carboxylic Acid and 2-Pyrrolidinone Derivatives

(±)-Azetidine-2-carboxylic acid and 3-substituted-2-pyrrolidinones were synthesized from 2-pyrrolidinone via 3-bromo-2-methoxy-1-pyrroline (IIIa). The bromide (IIIa) was obtained by the bromination of 2-methoxy-l-pyrroline using NBS.     

Synthesis of ( ± )-Methyl Epijasmonate and ( ± )-Methyl Cucurbate

A novel synthesis of ( ± )-methyl epijasomonate (2) and the first synthesis of ( ± )-methyl cucurbate (4) were achieved starting from 2-allylcyclohexane-1,3-dione (8). The synthetic epimer 2 had a stronger jasmin flavor than the trans-isomer 1 with 95% purity.     

Synthesis of (±)-licarin-B

The synthesis of (±)-licarin-B, a neolignan of Licaria aritu Ducke (Lauraceae), was achieved by pyrolysis of 3-hydroxy-3-piperonyl-1-propyl-2-methoxy-4-(E)-propenylphenyl ethers.     

Synthesis of (±)-Hydroxytremetone

(±)Hydroxytremetone (III) has been synthesized from 2-(α-hydoxyisopropyl)-6-hydroxycoumaran (V b) via its O-acetate V c by dehydration with phosphorus tribromide in pyridine solution, followed by acylation with a mixture of trifluoroacetic anhydride and acetic acid. Isohydroxytremetone (IX b) was also synthesized.     

Synthesis of (±)-Xanthoxins

The enzymatic properties of P2-2 enzyme were determined by using cells of M. radiodurans. The enzyme was: most active at 60°C incubation temperature, stable at 40°C in neutral buffer, and inactivated by heating at 80°C for 15min. Maximal lytic activity occurred at pH 8.5 in Tris-HCl buffer. The range of enzyme stability was between pH 5.5 and 8. Bivalent metal ions, p-chloromercuribenzoate and monoiodo acetate inhibited lytic activity. The molecular weight was estimated to be 16,000 daltons by gel filtration on Sephadex G-75. The enzymatic digestion of peptidoglycans from the cell walls of M. radiodurans and M. lysodeikticus liberated free amino groups, but neither reducing groups nor N-acetylhexosamine, indicating that the enzyme was an endopeptidase. From analysis of the N-terminal amino acids of the digests, it is suggested that the P2-2 enzyme cleaves the peptide bond at the carboxyl group of D-alanine in peptidoglycan.     

Synthesis and Biological Activities of New Carbaacyclonucleosides and 1′-Oxaacyclonucleosides Related to Clitocine

Abstract

We describe the synthesis of two series of acyclonucleosides: carbaacyclonucleosides and 1′-oxaacyclonucleosides which possess the same aglycone as clitocine 3 which is a natural nucleoside exhibiting interesting biological properties. These compounds have been obtained by condensation of 4-aminobutanol or 3-silyloxypropoxyamine with 4,6-dichloro-5-nitropyrimidine. Structural modifications have been made on the heterocyclic base and the side chain to enhance their potential activity.     

Synthesis of (±)-Epoxydon and Related Natural Compounds

Synthesis of (±)-phyllostine, (±)-epoxydon, (±)-epiepoxydon, (±)-epoformin and (±)-epiepoformin by the retro-Diels—Alder reaction was described.     

Synthesis and Biological Activities of Some New 5′-Substituted S-Adenosylhomocysteine Analogues∗

Abstract

The synthesis of new S-adenosyl-homocysteine (SAH) analogues substituted at the 5′-position is described. Their activity on cell transformation induced by Rous sarcoma virus (RSV) as well as their effect on cell growth and on replication of polyoma virus were also studied. The best results were obtained with compounds having a phenyl group at the 5′-position of adenosine. These molecules inhibit very strongly uridine uptake by cells.     

A Total Synthesis of (±)-Pachyrrhizone

We examined whether developing cotyledons of soybean seed had photosynthetic activities. The cotyledons evolved oxygen under illumination and the activity was inhibited by 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea. The rate of oxygen evolution decreased during the development of seeds; about 30μ miol O₂ · mg chlorophyll^-1 · hr^-1 at the early developing stage and about 10μ miol O₂-mg chlorophyll^-1 · hr^-1 at the late developing stage. The rate of oxygen uptake remained at an almost constant level of 40^mol 0₂-mg chlorophyll^-1 · hr^-1 throughout the development. Photosynthetic ¹⁴CO₂-fixation by the cotyledon was observed. Ribulose bisphosphate carboxylase was immunochemically detected in the developing cotyledons. These results show that functional photosynthetic apparatus is present in the developing cotyledons of soybean seeds.     

Synthesis and Herbicidal Activities of α-Isocyanocycloalkylideneacetamides

Various α-isocyanocycloalkylideneacetamides were synthesized by the reaction of isocyanoacetamides with ketones and following by dehydration. These compounds were examined for their inhibitory activity against the germination of rice, cucumber and radish seeds, and for their herbicidal effects on rice, tomato and weed seedlings. Among them, α-isocyanocyclohexylidene-acetylpiperidine showed selective herbicidal activity against the broad-leaf plants.     

Synthesis of Isochroman-1,3-diones A New Synthesis of (±)Sclerin

(±)Sclerin (4,5,6,7-tetramethyl-8-hydroxyisochroman-1,3-dione), a mycerial extracts of Sclerotinia libertiana, and related compounds were synthesized. Alkylated-7-hydroxyindanones were obtained from alkylated phenols and α-bromobutyrylbromide, and these indanone derivatives were treated with benzaldehyde to give 2-benzylidene-7-hydroxyindanone derivatives. By ozonolysis of these benzylidene-indanones were obtained 8-hydroxyisochroman-1,3-diones.     

An Efficient Synthesis of Deuterated (±)-Dihydrozeatin-d5 and Its Riboside

The antifungal activity of 22 derivatives of 1-(3,5-dichlorophenyl)-2,5-pyrrolidinedione and 6 derivatives of 3-(3,5-dichlorophenyl)-2,4-oxazolidinedione, having various substituents on the imido rings, against Botrytis cinerea was determined by the agar medium dilution method. The structure-activity relationships were analyzed using the physicochemical parameters of the molecules: such as the hydrophobic log P, the electronic σ*, and the steric E_s^c values with the multiple regression technique. Only the hydrophobic effect is significant in determining the activity variations of both series of compounds. Furthermore, the structure-activity relationships of these two series of compounds are represented by an identical equation, having only the hydrophobic term as a variable.     

Synthesis and characterization of (±)-13-hydroxy-3,11-diaza steroids

An efficient strategy for introducing a nitrogen atom in positions 3 and 11 of the steroidal skeleton, which are key positions for biological purposes, is described. This procedure involves an intramolecular Diels-Alder cycloaddition of o-quinodimethanes which are generated from a 3-azabicyclo[4.2.0]octa-1,3,5-trien-7-one. The characteristic (1)H and (13)C NMR spectroscopic features of the synthesized compounds are reported.     

Systematic Synthesis and Biological Evaluation of α - and β-D-Xylo- and Lyxofuranonucleosides of the Five Naturally Occurring Nucleic Acid Bases

Abstract

The α-and β-D-Xylofuranosyl and -lyxofuranosyl analogues of the five naturally occurring nucleic acid bases have been the subject of a systematic synthesis and examination of some of their biological properties, i.e. antiviral, antimetabolic and cytostatic activities.