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111.
112.
Five different types of pollen tetrads were detected from the short and long stamens of the male and hermaphrodite flowers of the androdioecious species, Mimosa pigra L. Light (LM) and scanning electron microscopes (SEM) were used in this study to redescribe the pollen forms and to identify the various pollen types encountered. An identification key and relative percentages of these pollen types were also presented. The study showed that the long stamens of the male flowers and those of the hermaphrodite ones have five (I, II, III, IV and V) and two (I and V) pollen types respectively, whereas the short stamens of both male and hermaphrodite flowers have only one pollen type (type I). We report here the first incidence of intra‐specific pollen polymorphism in androdioecious species. 相似文献
113.
Eriko Kudo Manabu Taura Kouki Matsuda Masako Shimamoto Ryusho Kariya Hiroki Goto Shinichiro Hattori Shinya Kimura Seiji Okada 《Bioorganic & medicinal chemistry letters》2013,23(3):606-609
The anti-HIV-1 activity of GUT-70, a natural product derived from the stem bark of Chlophyllum brasiliense, was evaluated. GUT-70 inhibited HIV-1 replication in both acutely and chronically infected cells through suppression of NF-κB. Our results strengthen the idea that NF-κB pathway is one of the potential targets to control HIV-1 replication and that GUT-70 could serve as a lead compound to develop novel therapeutic agents against HIV-1 infection. 相似文献
114.
Shinsaku Hayashida Kazuyoshi Ohta Perfecto Q. Flor Nobuya Nanri Ichiro Miyahara 《Bioscience, biotechnology, and biochemistry》2013,77(7):1947-1950
1-Pyrroline-5-carboxylate dehydrogenase was purified and crystallized from Bacillus sphaericus. The crystalline preparation gave a single band on polyacrylamide slab gel electrophoresis. The molecular weight of the enzyme was determined to be about 100,000 by gel filtration. The enzyme consists of two subunits which are identical in molecular weight (50,000), as judged on SDS slab gel electrophoresis. The enzyme shows an optimum pH of 6.5 to 7.0. Its activity was 8.1 times higher with NADP+ than with NAD +, and the enzyme was stabilized by NADP+. The apparent Km values for l-l-pyrroline-5-carboxylate, NADP+ and NAD+ are 4.2 × 10–5m (with NADP+), 9.5 × 10~6m and 2.5 × IO-3 m, respectively. The enzyme reaction is irreversible. A simple method for the determination of l-ornithine involving ornithine ¿-aminotransferase and 1- pyrroline-5-carboxylate dehydrogenase from B. sphaericus was developed. A linear relationship was found between the absorbance at 340 nm and the amount of l-ornithine (50 ~ 400 nmol), and between the fluorescence and the amount of l-ornithine (0.2 ~ 10 nmol). 相似文献
115.
Ichiro Tomida Hiroshi Kayahara Ryozo Iriye 《Bioscience, biotechnology, and biochemistry》2013,77(11):2549-2555
The degree of racemization in the several activated ester methods of the peptide synthesis was measured in using the critical racemization test, Pro-Val+Pro, with help of gas chromatography. The results were compared with that in the coupling reaction, Leu-Phe+Val, in which no racemization had been reported in the corresponding reaction conditions by F. Weygand et al., when the activated dipeptide esters had been prepared from Z-Leu+Phe-activated esters. The significantly higher racemization was observed in the methods of N-hydroxypiperidine ester and thiophenyl ester, even when the activated dipeptide esters were prepared from Z-Pro+Val-activated esters. On the other hand, almost no racemization was observed in the N-hydroxysuccinimide ester and p-nitrophenyl ester methods. A great extent of the racemization was detected when the activated dipeptide esters were prepared directly from Z-Pro-Val-OH. 相似文献
116.
We review the use of stable carbon isotope ratios (δ13C) and radiocarbon natural abundances (Δ14C) for stream food web studies. The δ13C value of primary producers (e.g., periphytic algae, hereafter periphyton) in streams is controlled by isotopic fractionation during photosynthesis and variable δ13C of dissolved CO2. When periphyton δ13C differs from that of terrestrial primary producers, the relative contribution of autochthony and allochthony to stream food webs can be calculated. Moreover, the variation in periphyton δ13C can reveal how much stream consumers rely on local resources because each stream habitat (e.g., riffle vs. pool, open vs. shaded) usually has a distinctive δ13C. However, periphyton δ13C often overlaps with that of terrestrial organic matter. On the other hand, periphyton Δ14C is less variable than δ13C among habitats, and reflects the Δ14C of dissolved CO2, which could be a mixture of “aged” (Δ14C < 0 ‰) and “modern” (Δ14C > 0 ‰) carbon. This is because the Δ14C is corrected by its δ13C value for the isotopic fractionation during photosynthesis. Recent studies and our data indicate that many stream food webs are supported by “aged” carbon derived from the watershed via autochthonous production. The combined use of δ13C and Δ14C allows robust estimation of the carbon transfer pathway in a stream food web at multiple spatial scales ranging from the stream habitat level (e.g., riffle and pool) to watershed level (autochthony and allochthony). Furthermore, the Δ14C of stream food webs will expand our understanding about the time frame of carbon cycles in the watersheds. 相似文献
117.
Takayuki Oritani Sachio Kudo Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(3):757-760
Asymmetric hydrolysis of acetate (10) of (±)-t-2,t-4-dimethyl-r-l-cyclohexanol with Bacillus subtilis var. niger gave (?)-(lS,2S,4S)-2,4-dimethyl-l-cyclohexanol (6a) and (+)-(1R,2R,4R)-acetate (10b) with high optical purities. Optically pure (?) and (+)-alcohols (6a and 6b) were prepared via corresponding 3,5-dinitrobenzoates. Oxidation of alcohols (6a and 6b) with chromic acid gave optically pure (?)-(2S,4S) and (+)-(2R,4R)-2,4-dimethyl-l-cyclohexanones (2a and 2b), respectively. 相似文献
118.
Tsutomu Ishikawa Tetsuya Tosa Ichiro Chibata 《Bioscience, biotechnology, and biochemistry》2013,77(3):193-198
Since Achromobacter pestifer EA isolated from soils shows markedly high ?-Iysine acylase activity compared with those of the other microorganisms ever tested, cultural conditions for the production of this enzyme were investigated.As a result, it was confirmed that simple medium containing 1% peptone, 5% glucose and some inorganic salts is most suitable for the enzyme production and that much more ?-Iysine acylase is produced by shaken culture or submerged culture in jar fermentor than by stationary culture. α-Amino acylase activity in this organism was also studied. 相似文献
119.
Tsutomu Ishikawa Tetsuya Tosa Ichiro Chibata 《Bioscience, biotechnology, and biochemistry》2013,77(7):412-416
?-Lysine acylase of Achromobacter pestifer EA was purified by fractionations with ammonium sulfate and acetone, and by vertical zone electrophoresis. As a result, this bacterial ?-lysine acylase was obtained as an electrophoretically homogeneous protein, specific activity of which is the highest among ?-lysine acylases ever reported. 相似文献
120.
Atsushi Tokida Ichiro Atobe Kazuo Maeda 《Bioscience, biotechnology, and biochemistry》2013,77(11):3109-3113
Using vented charcoal filters, the adsorption efficiencies of acetaldehyde, isoprene and acetone, the major components in the vapor phase of cigarette smoke, were studied. Filter ventilation was found to raise the adsorption efficiency of the adsorbent. The effect of increasing the ventilation rate through the filter was greatest for the adsorption of acetaldehyde. In order to clarify the effects of decreases of the flow rate and the concentration caused by ventilation, the adsorption by unvented charcoal filters under varied conditions was also measured. Although both raised the adsorptions of the three components, the lowered concentration was contributed to mainly by an increase of adsorption by the vented charcoal filters. Regardless of whether the filter was perforated or not, the adsorptions of the three components depended on the volume of the air drawn in at the top of the lighted end of the cigarette. 相似文献