Biosynthesis of Fukinolic Acid Isolated from Petasites japonicus

The biosynthesis of fukinolic acid, which had been isolated from the Japanese fuki vegetable, Petasites japonicus, was investigated by feeding selected ¹³C-labeled compounds to axenic cultures of P. japonicus. [1,2-¹³C₂] sodium acetate and [1-¹³C] L-tyrosine were incorporated into the fukiic acid sub group, while [3-¹³C] L-phenylalanine was incorporated into the caffeic acid moiety.     

Fukiic Acid Isolated from the Hydrolysate of a Polyphenol in Petasites japonicus

d-Glucose-isomerizing enzyme was purified in a crystalline form with a good yield from the cells of Bacillus coagulans, strain HN-68, and some phsicochemical properties were investigated.

The purified enzyme was homogeneous on both ultracentrifugal and disc-electrophoretical analyses. The molecular weight of the enzyme was determined to be 175,000 and 160,000 from the sedimentation-viscosity method and the gel filtration method, respectively.

The sedimentation coefficient , partial specific volume, at 280 mμ, and the nitrogen content of the enzyme were determined to be 10.2×10^?13 sec, 0.705 cm³g^?1, 10.6 and 16.2%, respectively. The integral numbers of amino acid residues per molecule calculated on the basis of 160,000 were as follows; Lys₁₂₀, His₄₉, Arg₆₁, Asp₁₈₂, Thr₈₇, Ser₇₀, Glu₁₃₆, Pro₄₄, Gly₁₀₆, Ala₁₄₀, Half-Cys₀, Val₅₃, Met₂₇, Ileu₅₁, Leu₁₃₄, Tyr₅₈, Phe₉₆, Try₁₃, and amide-ammonia₈₀.

Purified enzyme preparation obtained from Bacillus coagulans, strain HN-68 requires Co²⁺ for d-glucose- and d-ribose-isomerizing activities and Mn²⁺ for d-xylose-isomerizing activity. The values of Km for d-glucose, d-xylose and d-ribose were 9×10^?2, 1.1×10^?3, 7.7×1O^?m and of the relative V_max were 0.52, 1.1 and 0.25 mg/min at 40°C, respectively. d-Glucose-isomerizing activity was inhibited by d-xylose and d-ribose. However, there was not a difference among three activities of the enzyme with respect to following properties: Activation energy was 14,600 cal per mol. The enzyme was inhibited in a competitive manner by tris(hydroxymethyl)aminomethane, d-xylitol, d-sorbitol and d-mannitol, and the Ki values for these inhibitor were 3×10^?4, 2.5×10^?3, 2.9×10^?2 and 7×10^?2m, respectively. The ratio of three activities did not change by heat- and pH-treatments. Mn²⁺, Co²⁺ and Ni²⁺ protected strongly the enzyme from heat denaturation. The enzyme can isomerize d-glucose, d-xylose and d-ribose to their corresponding ketose, but the kinetic constants and induction studies indicated that ^d-xylose is the natural substrate for the enzyme.     

Biosynthesis of fukinolic acid isolated from Petasites japonicus

The biosynthesis of fukinolic acid, which had been isolated from the Japanese fuki vegetable, Petasites japonicus, was investigated by feeding selected (13)C-labeled compounds to axenic cultures of P. japonicus. [1,2-(13)C(2)] sodium acetate and [1-(13)C] L-tyrosine were incorporated into the fukiic acid sub group, while [3-(13)C] L-phenylalanine was incorporated into the caffeic acid moiety.     

Allelopathic sesquiterpenoids from rhizomes of Petasites japonicus ssp. giganteus Kitam

Four sesquiterpenoids were isolated from Petasites japonicus (Siebold and Zucc.) Maxim. ssp. giganteus (F. Schmidt ex Trautv.) Kitam. (Compositae, Japanese name: Akitabuki) as allelochemicals. Their structures were elucidated on the basis of spectroscopic methods and their allelopathic effects were assessed.     

Petasites japonicus Stimulates the Proliferation of Mouse Spermatogonial Stem Cells

Oriental natural plants have been used as medical herbs for the treatment of various diseases for over 2,000 years. In this study, we evaluated the effect of several natural plants on the preservation of male fertility by assessing the ability of plant extracts to stimulate spermatogonial stem cell (SSC) proliferation by using a serum-free culture method. In vitro assays showed that Petasites japonicus extracts, especially the butanol fraction, have a significant effect on germ cells proliferation including SSCs. The activity of SSCs cultured in the presence of the Petasites japonicus butanol fraction was confirmed by normal colony formation and spermatogenesis following germ cell transplantation of the treated SSCs. Our findings could lead to the discovery of novel factors that activate SSCs and could be useful for the development of technologies for the prevention of male infertility.     

竹节参化学成分研究

从竹节参的乙醇提取物分离得到了12个化合物,通过MS和NMR等方法鉴定为:竹节参皂苷Ⅳa(1),楤木皂苷A(2),竹节参皂苷Ⅰb(3),竹节参皂苷Ⅴ(4),尿嘧啶(5),胸嘧啶(6),尿苷(7),鸟苷(8),胸苷(9),腺苷(10),肌苷(11),胞苷(12),其中5 ～ 12为首次从该植物中分离.     

Fukinolic acid and cimicifugic acids: a review

During the last decades, the research on the biological activities of extracts from Cimicifuga/Actaea species and Petasites japonicus as well as their active ingredients has been intensified. Besides terpenoids as dominant natural product group, hydroxycinnamic acid esters such as fukinolic acid and several cimicifugic acids have been isolated from Actaea and Petasites species and their chemical structures have been elucidated. Investigations on the biological properties of these hydroxycinnamic acid esters are currently undertaken and some compounds might be promising therapeutic tools. In this review, we have gathered information on the genera Actaea and Petasites, the occurrence of cimicifugic and fukinolic acids and some aspects of their biosynthesis. Furthermore, we have summarized the medicinal aspects of fukinolic acid and cimicifugic acids. In connection with the biological activities of these compounds, structural features of the hydroxycinnamic acid derivatives move into the focus. The position of the hydroxyl group at the aromatic rings and the introduction of an electron-donating moiety may be important for anti-inflammatory, antiviral, cytotoxic and vasoactive effects of these compounds.

     

麦冬块根化学成分的研究

从麦冬(Ophiopogon japornicus)块根中分得两个环二肽类化合物,一个酰胺类化合物和一个多羟基脂肪酸类化合物。通过光谱数据分析,分别鉴定为eyclo-(Phe-Tyr)(1),cyclo-(Leu-ILe)(2),N-(2．(4-hydroxyphenyl)ethyl)-4-hydroxycinnamide(3)和天师酸(4)。这四个化合物均为首次从沿阶草属植物分得。环二肽类化合物为首次从沿阶草属植物中分得的化合物类型。     

Isolation and measurement of quercetin glucosides in flower buds of Japanese butterbur (Petasites japonicus subsp. gigantea Kitam.)

Three quercetin glucosides were isolated from flower buds of Japanese butterbur (Petasites japonicus subsp. gigantea Kitam.) together with caffeic acid as the ingredients that had DPPH radical scavenging activity, using the DPPH-HPLC method for measuring the radical scavenging activity. These quercetin glucosides were identified as quercetin 3-O-beta-D-glucoside, quercetin 3-O-beta-D-6'-O-acetylglucoside, and rutin, and the amounts of the glucosides in flower buds were also examined by HPLC. The flower buds were harvested from four different sites, the total amount of quercetin glucosides in each site was 100-170 mg/100 g fr. wt., and there were no great differences of the amounts between growing fields.     

Structures of Hexadecenoic Acid and Octadecenoic Acid in Lipomyces starkeyi

Taxonomic and some other properties of a yeast strain, Candida sp. 36, which characteristically assimilates n-alkanes, were described. Identification of coenzyme Q, NMR spectroscopy of cell wall polysaccharides, determination of G+C content of DNA and some DNA-DNA hybridization experiments were carried out, in addition to the morphological and physiological observations. All the data were consistent with the suggestion that Candida cloacae Komagata, Nakase and Katsuya and Candida subtropicalis Nakase, Fukazawa and Tsuchiya are the synonyms of Candida maltosa Komagata, Nakase and Katsuya. Candida sp. 36 was identified as C. maltosa, too. The yeast was found to grow most abundantly on n-hexadecane and on n-octadecane in the presence of biotin.     

The Robustness of Naturally and Artificially Selected Nucleic Acid Secondary Structures

Thermodynamic stability and mutational robustness of secondary structure are critical to the function and evolutionary longevity of RNA molecules. We hypothesize that natural and artificial selection for functional molecules favors the formation of structures that are stable to both thermal and mutational perturbation. There is little direct evidence, however, that functional RNA molecules have been selected for their stability. Here we use thermodynamic secondary structure prediction algorithms to compare the thermal and mutational robustness of over 1000 naturally and artificially evolved molecules. Although we find evidence for the evolution of both types of stability in both sets of molecules, the naturally evolved functional RNA molecules were significantly more stable than those selected in vitro, and artificially evolved catalysts (ribozymes) were more stable than artificially evolved binding species (aptamers). The thermostability of RNA molecules bred in the laboratory is probably not constrained by a lack of suitable variation in the sequence pool but, rather, by intrinsic biases in the selection process.     

Purification and Properties of Hydroxycinnamic Acid Ester Hydrolase from Aspergillus japonicus

Hydroxycinnamic acid ester hydrolase from the wheat bran culture medium of Aspergillus japonicus was purified 255-fold by ammonium sulfate fractionation, DEAE-Sephadex treatment and column chromatographies on DEAE-Sephadex, CM-Sephadex and various other Sephadexes. The purified enzyme was free from tannase and found to be homogeneous on polyacrylamide disc gel electrophoresis. Its molecular weight was estimated to be 150,000 by gel filtration and 142,000 by SDS-gel electrophoresis. The isoelectric point of the enzyme was pH 4.80. As to its amino acid composition, aspartic acid and glycine were abundant. The optimum pH and temperature for the enzyme reaction were, respectively, 6.5 and 55°C when chlorogenic acid was used as a substrate. The enzyme was stable between pH 3.0 to 7.5 and inactivated completely by heat treatment at 70°C for 10 min.

All metal ions examined did not activate the enzyme, while Hg⁺⁺ reduced its activity. The enzyme was markedly inhibited by diisopropylfluorophosphate and an oxidizing reagent, iodine, although it was not affected so much by metal chelating or reducing reagents. The purified enzyme hydrolyzed not only esters of hydroxycinnamic acids such as chlorogenic acid, caffeoyl tartaric acid and p-coumaroyl tartaric acid, but also ethyl and benzyl esters of cinnamic acid. However, the enzyme did not act on ethyl esters of crotonic acid and acrylic acid or esters of hydroxybenzoic acids.     

Structures of Novel Sesquiterpene Alcohols from Chloranthus japonicus (Chloranthaceae)

Three novel sesquiterpene alcohols, shizuka-acoradienol (2), shizukafuranol (3) and shizukol-idol (4), were isolated from Chloranthus japonicus Sieb. (Japanese name: Hitori-shizuka, Chloranthaceae). Their structures were elucidated on the basis of their physicochemical properties and some chemical reactions. Furanodienone (5), scopoletin (6a) and isoscopoletin (6b) were also isolated from this plant.     

Aqueous Hydration of Nucleic Acid Constituents: Monte Carlo Computer Simulation Studies

Abstract

Monte Carlo computer simulations were performed on dilute aqueous solutions of thymine, cytosine, uracil, adenine, guanine, the dimethyl phosphate anion in the gauche-gauche conformation and a ribose and deoxyribose derivative. The aqueous hydration of each molecule was analysed in terms of quasi-component distribution functions based on the Proximity Criterion, and partitioned into hydrophobic, hydrophilic and ionic contributions. Color stereo views of selected hydration complexes are also presented. A preliminary discussion of the transferability of functional group coordination numbers is given. The results enable to comment on two current problems related to the hydration of nucleic acids: a) the theory of Dickerson and coworkers on the role of water in the relative stability of the A and B forms of DNA and b) the idea of water bridges and filaments emerging from the computer simulation results on the hydration of DNA fragments by Clementi.     

Degradation of Nucleic Acid Constituents by Free Radical Systems

Degradation of three nucleic acid bases, uracil, thymine and cytosine, by free radical systems containing ascorbic acid and/or hydrogen peroxide was found to occur when these two reagents were used in combination. Any significant differences in the mode of degradation were not observed among these pyrimidine bases. Ferrous ion added in this system intensified the degree of degradation.

Phosphate bond cleavage of mononucleotides by ascorbic acid—hydrogen peroxide was also demonstrated to occur in a lesser degree than other phosphate esters.

Special device of spectrometric determination of pyrimidine bases in the reaction system was worked out.     

Comparative Analysis of Nucleic Acid and Protein Primary Structures

The review considers the original works on the primary structure of biopolymers carried out from 1983 to 2003. Most works were supported by the Russian program Human Genome and earlier similar Russian programs. Little-known publications of 1983–1993 and recent unpublished results are described in detail. In the field of genome comparisons, these concern the OWEN hierarchic algorithm aligning syntenic regions of two genome sequences. The resulting global alignment is obtained as an ordered chain of local similarities. Alignment of megabase sequences takes several minutes. The concept of local similarity conflicts is generalized to multiple comparisons. New algorithms aligning protein sequences are described and compared with the Smith–Waterman algorithm, which is now most accurate. The ANCHOR hierarchic algorithm generates alignments of much the same accuracy and is twice as rapid as the Smith–Waterman one. The STRSWer algorithm takes into account the secondary structures of proteins under study. With the secondary structures predicted using the PSI-PRED software for pairs of proteins having 10–30% similarity, the average accuracy of alignments generated by STRSWer is 15% higher than that achieved with the Smith–Waterman algorithm.     

The impact of altitude and simulated herbivory on the growth and carbohydrate storage of Petasites albus

We tested the hypothesis that higher respiratory losses caused by higher temperatures in the lowlands, compared to montane sites, prevent growth of the montane hemicryptophyte Petasites albus (Asteraceae). In addition, we tested whether increased levels of herbivory enhanced carbon losses at lower elevations. Rhizomes of Petasites albus were transplanted to a montane and a lowland site. In the subsequent three growing seasons the plants were artificially defoliated to simulate mollusc herbivory. Whereas there were no altitudinal differences in the leaf number per plant, the leaf area was higher at the montane site. At the montane site, the leaf number and leaf area decreased with increasing damage, and the rhizome dry weight in the third year was much higher in the undamaged plants. In contrast, fructan concentrations in the rhizomes that were harvested at the end and at the beginning of the growing seasons were generally higher at the lowland site. No clear defoliation effects were observed on most harvest dates. The results indicate that the lower altitudinal limit of Petasites albus cannot be explained by the negative effects of higher temperatures or more leaf damage by herbivores in the lowlands, either alone or in combination. An explanation will require consideration of other site factors such as competition and possibly interactions with herbivory and carbohydrate storage.