Syntheses of Thiadiazolopyrimidine and Related Compounds

A homologous transformation system was developed using the endogenous ATP-sulfurylase gene, AasC, as a selectable marker in Aspergillus aculeatus. Spontaneous mutation was proved to be beneficial in isolating AasC-deficient mutants. Molecular analysis of sC ⁺ transformants revealed that the frequency of single copy integration at ATP-sulfurylase locus was more than 40%.     

Syntheses of Naturally Occurring Terphenyls and Related Compounds

Naturally occurring terphenyls and related compounds such as terferol and its corresponding quinone and phlebiarubrone were synthesized from 2,5-diphenyl-1,4-benzoquinone. According to the proposed biosynthetic pathway, chemical conversion of phlebiarubrone to ustalic acid, a toxic compound isolated from the poisonous mushroom, Tricholoma ustale, was examined to find a low-yield conversion to the ustalic acid dimethyl ester.     

Syntheses of Several Compounds Related to Helminthosporol and their Plant Growth-regulating Activities

Several compounds related to helminthosporol (I), a natural plant-growth promoter, were prepared from I and their plant-growth regulating activities were examined together with those of the derivatives reported in the previous paper, using rice and lettuce seedlings. Among the compounds tested, helminthosporic acid (III) exhibited marked elongation effect to the shoot growth of rice and lettuce seedlings, whereas the effect of I was specific to the former. Results of the biological test are reported in details.     

Syntheses and PMR Studies of 1,2,3,4,5-Pentachlorocyclohexane Isomers,Tetrachloromonomethoxycyclohexane Isomers and Related Compounds

Two diastereomers of 1,2,3,4,5-pentachlorocyclohexane and two diastereomers of tetrachloromonomethoxycyclohexane were synthesized stepwise from diastereomers of 3,4,5-trichlorocyclohexene, which had been derived from the dl-(36/45)-, dl-(34/56)- and (346/5)-isomers of 3,4,5,6-tetrachlorocyclohexenen (α-, β- and γ-BTC, respectively) by selective reduction with LiAlH₄. The configurations of all the products and intermediary trichlorocyclohexene isomers were determined by PMR studies.     

Syntheses of Jasmonic Acid Related Compounds and Their Structure-Activity Relationships on the Growth of Rice Seedings

Jasmonic acid (JA)-related compounds were synthesized, and their inhibitory activities on rice seedling growth were investigated. Three functions (C-1 CH₂COOH or CH₂COOCH₃, C-2 (Z)-2′-pentenyl or n-pentyl and C-3 ketone or hydroxyl) were essential for exhibiting inhibitory activity in this series of compounds. A dihydro-JA-related compound, 4-acetyl-nonanoic acid, also showed inhibitory activity similar to JA.     

Syntheses of Compounds Possessing Chicken-Flavor

2,4-Decadien-1-ol and 2,4-dodecadien-1-ol were synthesized from n-caproaldehyde and caprylaldehyde, respectively and their flavors were shown to be similar to those of chicken meat and chicken fat.     

The Synthesis of Cyclotene and Its Related Compounds by the Acyloin Condensation

A mutant which required glutamate for growth as the sole nitrogen source was derived from alkalophilic Bacillus No. 8–1 by UV irradiation. The relationship was examined between cell growth and glutamate transport into cells.

Cell growth and glutamate transport into cells were dependent on extracellular pH in the presence of Na⁺, and both were maximum between pH 9 and 10. The quantitative relation between specific growth rate and glutamate uptake rate indicated that the amount of glutamate required for growth at pH 7 and 9 was consistent with that of glutamate transported at pH 7 and 9, respectively. But the amount of glutamate transported at pH 7 was not sufficient to support growth at pH 9. The glutamate transport system of this mutant strain evidently had an effect on growth.     

Cyclohexenyl Nucleosides and Related Compounds

Abstract

Cis and trans-1-(4-hydroxy-2-cyclohexenyl)- and 1-(2-hydroxy-5-cyclohexenyl) thymines were obtained by stereospecific routes. Oxidation of the 1, 4-products afforded 1-(4-oxo-2-cyclohexenyl)thymine, the carbocyclic analog of a reportedly antiviral ketopyranosyl nucleoside. Exclusive 1, 6-conjugate addition occurred with heterocyclic bases and methyl 1, 3-cyclohexadiene-1-carboxylate. Reduction of the thymine adduct gave 1-(4-hydroxymethyl1-3-cyclohexenyl)thymine. Michael-type addition provided a direct route to 3-oxocycloalkyl nucleosides, and lactone nucleosides resulted from addition of bases to α-methylene-γ-butyrolactone. Anti-HIV screening revealed no activity for the new compounds.     

Facile Syntheses of C-Glycosides of Aromatic Compounds

Aspartokinase (ATP: l-aspartate 4-phosphotransferase) was extracted and partially purified 11-fold from an extreme thermophile, Thermus flavus AT–62. The enzyme has a temperature optimum near 75°C and a pH optimum of 7 to 8. The enzyme activity was feedback inhibited 80% by l-threonine at the concentration of 0.1 mm at 60°C. No concerted effect of l-threonine with any other aspartate family amino acids was observed. The aspartokinase and homoserine dehydrogenase activities were eluted at different concentrations of KCl from DEAE-cellulose column. The aspartokinase was not inactivated after 30 min at 70°C, but 30% of the original activity was lost after 30 min at 80°C and rapid inactivation occurred above 85°C. The allosteric sensitivity of the enzyirie was maintained even at 60~80°C but was reduced with the increase of temperature, accompanying desensitization above 80°C. The heat stability of the enzyme activity and of the allosteric sensitivity was discussed in comparison with other allosteric enzymes of thermophiles.     

Peroxyl Radical Scavenging Activity of Caffeic Acid and Its Related Phenolic Compounds in Solution

The esterase gene (est) of Pseudomonas putida MR-2068 was cloned into Escherichia coli JM109. An 8-kb inserted DNA directed synthesis of an esterase in E. coli. The esterase gene was in a 1.1-kb PstI-ClaI fragment within the insert DNA. The complete nucleotides of the DNA fragment containing the esterase gene were sequenced and found to include a single open reading frame of 828 bp coding for a protein of 276 amino acid residues. The open reading frame was confirmed by N-terminal amino acid sequence analysis of the purified esterase. A potential Shine-Dalgarno sequence is followed by the open reading frame. The esterase activity of the recombinant E. coli was more than 200 times higher than that of parental strain, P. putida MR-2068.     

Convenient Syntheses of 6-Methylpurine and Related Nucleosides

Abstract

Efficient methods for the synthesis of 6-methylpurine (3), 9-(2-deoxy-β-D-erythro-pentofuranosyl)-6-methylpurine (8), and 6-methyl-9-β-D-ribofuranosylpurine (5) are described. Methodology involving the (Ph₃P)₄Pd catalyzed cross-coupling reaction of CH₃ZnBr with several different 6-chloropurine derivatives is described in high yield. This methodology now provides a facile and high-yielding synthesis of 8, which is needed in significant amounts for studies in cancer gene therapy.     

Acyclic Nucleotide Analogues and Related Compounds

Abstract

Acyclic nucleotide analogues bearing amino- and N-substituted amino groups in the side chain were prepared by alkylation of the bases with corresponding oxiranes and subsequent introduction of phosphonomethyl ether function. Novel enantiomeric synthons for the preparation of HPMP-compounds were prepared from a common intermediate and applied to syntheses of novel compounds (e.g. 8-azaguanine derivatives).     

Fungicidal Activity of N-Benzoylanthranilates and Related Compounds

Methyl N-(substituted benzoyl)anthranilates were found to possess inhibitory activity against the powdery mildew of cucumber caused by Sphaerotheca fuliginea. Both the anthranilate and the N-benzoyl moieties were essential for this type of fungicidal activity. Substitution at the 2- and 4-positions of the N-benzoyl group was unfavorable to the activity except for the 4-methoxy group. Substitution at the 3-position varied the fungicidal activity to various extents. The variation in the activity of 3-substituted derivatives was analyzed quantitatively with substituent parameters and regression analysis indicating that the variation in the steric dimension of substituents was most responsible for the activity.     

Biocidal Activities of Glutaraldehyde and Related Compounds

S ummary . Glutaraldehyde in 2% aqueous alkaline solution is rapidly bactericidal and sporicidal, killing 99.99% of the spores of Bacillus anthracis and Clostridium tetani in 15 and 30 min, respectively. It exhibits some degree of tuberculocidal activity, but it appears to be inferior to several other disinfectants when challenged with a large inoculum. Fungicidal action has been demonstrated but not assessed quantitatively. Evidence is presented to show that biocidal activity depends on the availability of two free aldehyde groups in the molecule.     

Structure-activity Relationships of Podolactones and Related Compounds

The plant-growth inhibitory activities of a number of compounds related to the podolactones were determined using a pea-stem growth system. Some conclusions regarding the effects of structure on activity are presented.     

Oxidation of Bisphenol A and Related Compounds

Bisphenol A was oxidized to monoquinone and bisquinone derivatives by Fremy’s salt, a radical oxidant, though salcomine and alkali did not catalyze the oxidation by molecular oxygen. Bisphenol A, bisphenol B, and 3,4'-(1-methylethylidene)bisphenol were converted to their monoquinone derivatives in the presence of tyrosinase at 25°C at pH 6.5, but not to the bisquinone derivatives under these conditions.     

Ent-kaurenic Acid and Its Related Compounds from Glandular Trichome Exudate and Leaf Extracts of Polymnia sonchifolia

Yacon (Polymnia sonchifolia) leaves possess glandular trichomes on the surface. The exudate from the glandular trichome and the leaf are itself rich in ent-kaurenic acid (ent-kaur-16-en-19-oic acid). A kaurene derivative, 15-α-angeloyloxy-ent-kauren-19-oic acid 16-epoxide, was isolated from the leaves, together with two known angeloyloxykaurenic acids. The high content of ent-kaurenic acid in the leaf suggests that these diterpenes play a certain physiological role, since the glandular trichome exudates of other species function in their defensive mechanism.     

Synthesis of Prostaglandin-F1 Related Compounds

Synthesis of several prostaglandin-F₁ related compounds utilizing bicyclo(2,2,1) heptene derivatives as key intermediates were investigated.     

Jasmonates and Related Compounds in Plant-Insect Interactions

Herbivore attack elicits defense responses in host plants by a complex chain of events that starts with the introduction of herbivore-specific elicitors into the wounds at the feeding or oviposition site, their recognition by the plant, and activation of several signaling cascades that trigger defense responses that finally increase resistance. Oxylipin signaling plays a central role in the activation of these herbivore-induced responses. Wounding activates some but not all of these defense responses, but herbivore attack frequently amplifies the oxylipin responses well beyond that elicited by wounding alone, suggesting recognition of herbivore attack. In addition to their signaling role within the plant, oxylipins can also directly influence the performance of herbivores or attract natural enemies to feeding herbivores. Here we review the literature on the regulation and function of herbivore-specific oxylipin signaling and the direct effects of oxylipins on herbivore performance. Online publication: 13 January 2005