共查询到20条相似文献,搜索用时 15 毫秒
1.
Xiaoguang Zhao Wenguo Wang Yaodong Li Jie Xing Fang Chen Shenghua Wang 《Plant Cell, Tissue and Organ Culture》2007,91(1):53-60
Microspores cultured in vitro can be regarded as a system to study gene regulation, cell fate determination and cell differentiation
during pollen development as well as an alternative method of genetic transformation in plants. In our study, pollen development
and viability in Orychophragmus violaceus in vivo were determined and then pollen from the late unicellular stage was cultured in vitro. MS liquid medium + White vitamins + 2%
(V/V) coconut milk + 0.5 M maltose, pH = 7.0 was the most appropriate for in vitro culture of Orychophragmus violaceus microspores. With this medium, the rates of in maturation and germination were 19.3% and 4.7%, respectively. Liquid medium
with 0.6 M maltose + 1.6 mM boric acid + 2.9 mM Ca(NO3)2 + 29.6 μM vitamin B1, pH = 7.0 was optimal for germination of pollen matured in vivo. The rate of germination was 70.7%.
Pollen matured in vitro cultured in similar medium exhibited a rate of germination of 62.7%. Hence, the experimental study
showed that in vitro maturation of microspores is feasible and this experimental system can be applied to further theoretical
and practical research. 相似文献
2.
Rutkowski M Grzegorczyk K Greger J 《Zeitschrift für Naturforschung. C, Journal of biosciences》2004,59(9-10):762-767
The phosphotungstate reagent (PTR) was used for quantitative spectrophotometric determination of physiological forms of vitamin C in blood plasma. An immediate action of PTR on the first half of the tested samples allowed to determine reduced vitamin C concentrations (I) at 700 nm. 10 mM dithiothreitol added to the second half of the samples reduced oxidized vitamin C in it--hence the total amount of this vitamin was reduced with a concentration (II) determined as above (remains of dithiothreitol were removed with N-ethylmaleimide). The difference of results (II) and (I) gave the concentration of oxidized vitamin C. The method is characterised by fault-less analytical parameters: correlation coefficients of analytical curves > 0.99, recovery factor 100.5%, variation coefficients intra- and inter-serial < 3% and < 5%, respectively, detection limit 0.05 microM. The simplicity of the method enables an easy control of the ratio of oxidized and reduced vitamin C concentrations in blood plasma--the biomarker of the level of oxidative damage to cells. 相似文献
3.
Rocío Elizabeth Escobar-Guzmán Fernando Hernández-Godínez Octavio Martínez de la Vega Neftalí Ochoa-Alejo 《Plant Cell, Tissue and Organ Culture》2009,96(2):181-189
Eight cultivars and two accessions of Physalis ixocarpa Brot. were tested for their capacity to regenerate embryos and plants from anther cultures. Anthers were pretreated at 4°C
for 2 days and then at 35°C for 8 days in the dark while cultured on MS medium supplemented with 0.045 μM 2,4-D + 0.03 mg l−1 vitamin B12 (MS1) or with 2.26 μM 2,4-D + 0.1 mg l−1 vitamin B12 (MS3). Anther incubation proceeded under a 16 h photoperiod at 25 ± 2°C. Embryo formation occurred after 6 weeks of incubation
in these conditions. Androgenetic responses were cultivar- and culture medium-dependent, with the greatest embryo yields recorded
for cv. Chapingo (36.3%) on MS1 medium, and with wild-type 2 (21.8%) on MS3. Further development of regenerated embryos was
promoted on MS medium supplemented with 0.54 μM NAA, 8.88 μM BA and 50 mg l−1 casein hydrolysate. The regenerated plants were cultured on half-strength mineral salts MS medium with 2.85 μM IAA to enhance
root formation. Rooted plantlets were transferred to pots and acclimatized to the greenhouse. Ploidy analysis of regenerated
plants using flow cytometry revealed 72% diploids, 15% haploids and 7% triploids. AFLP analysis of regenerated plants from
anthers of a single parental plant showed different polymorphic patterns indicating their gametophytic origin. 相似文献
4.
Chitta Ranjan Deb Aolemla Pongener 《Journal of plant biochemistry and biotechnology.》2012,21(2):235-241
In the present study aerial roots were successfully used as explants source for in vitro propagation of Cymbidium aloifolium and Cymbidium iridioides. Aerial roots of ~5?C6?week old from axenic cultures were cultured on MS medium adjuncts with different additives. In C. aloifolium within 20?days of culture ~60% of explants responded positively on MS medium containing sucrose (3%, w/v) and Kn (3???M) and formed PLBs. While in C. iridioides ~50% root explants responded positively on medium enriched with sucrose (3%), AC (0.1%) and IAA (3???M) after 40?days of culture. The shoot buds/PLBs converted into plantlets when maintained on regeneration medium. Of the three basal media tested, MS medium supported optimum regeneration and culture proliferation in both the species. In C. aloifolium ~12 shoot buds developed on medium nourished with sucrose (3%) and BA (3???M) but in C. iridioides optimum regeneration was achieved when medium supplemented with sucrose (3%), CW (15%), CH (100?mg?L?1) and ~20 shoot buds formed per subculture. The well rooted plantlets were acclimatized for 3?C4?week in 1/10th MS salt solution containing sucrose (1%), charcoal pieces, brick pieces and chopped mosses as support under normal laboratory conditions. The hardened plants were transferred to potting mix where 80 and 75% of transplants survived in C. aloifolium and C. iridioides respectively after 2?months of transfer. 相似文献
5.
Culture of in vitro-produced bovine embryos with vitamin E improves development in vitro and after transfer to recipients 总被引:5,自引:0,他引:5
Detrimental effects of oxygen-derived free radicals on embryos during culture have been demonstrated in several species. Vitamin E occurs naturally in cell membranes and protects cells from oxidative stress. Under some conditions, vitamin C acts synergistically to enhance the antioxidant effects of vitamin E, a benefit that may be further enhanced by EDTA. The present experiments concerned culture of bovine embryos derived from in vitro-matured, fertilized oocytes with vitamin E, vitamin C, and EDTA in a chemically defined culture medium + 0.2% BSA at 5% O(2), 5% CO(2), and 90% N(2). In the first experiment, more zygotes developed to expanded blastocysts (17%, n = 224, P < 0.05) when culture medium contained 100 microM vitamin E than in control medium (11%, n = 234). Development to early, expanded, and hatched blastocysts was lower with vitamins E and C combined than with vitamin E alone (15%, 9%, and 2% vs. 24%, 17%, and 5%, respectively; P < 0.05), as was the mean number of cells per blastocyst (56 vs. 84, P < 0.05). Addition of EDTA (3 microM) failed to improve development over that in culture with vitamin E + vitamin C. In experiment 2, in vitro-produced embryos cultured 5.5 days in medium with or without 100 microM vitamin E were transferred nonsurgically to recipient cows and heifers and then collected nonsurgically 7 days later. Embryos cultured with vitamin E (n = 37) were approximately 63% larger in surface area than controls (1.16 mm(2) vs. 0.71 mm(2) surface area; n = 27, P < 0.04). 相似文献
6.
The effects of vitamin K on the morphology and the growth of mouse neuroblastoma (P2), mouse melanoma (B-16) and rat glioma (C-6) cells in culture were studied. Vitamin K3 inhibited the growth (due to cell death and partial or complete inhibition of cell division) of all three cell types without causing any morphological differentiation. Vitamin K3 was more effective than vitamin K1. Neuroblastoma cells were more sensitive to vitamin K3 than were melanoma or glioma cells. Glioma cells did not grow in hormone-supplemented serum-free medium; however, both neuroblastoma and melanoma cells grew to a level 70–80% of that found in serum-supplemented medium. Neuroblastoma cells and melanoma cells cultured in serum-free medium exhibited a 2–3 fold higher sensitivity to vitamin K3 than those cultured in serum-supplemented medium. This suggests that serum factors attenuate the growth inhibitory effect of vitamin K3 on tumor cells in culture, probably by reducing the availability of this vitamin to the cells. Neuroblastoma cells were more sensitive to vitamin K3 than were melanoma cells even when they were treated in serum-free medium. The fact that micromolar concentrations of vitamin K3 inhibit the growth of tumor cells in culture suggests that this vitamin may be a potentially useful anticancer agent. 相似文献
7.
Elizabeth A. Offord Jean-Charles Gautier Ornella Avanti Corinne Scaletta Frank Runge Klaus Krmer Lee Ann Applegate 《Free radical biology & medicine》2002,32(12):483-1303
The photoprotective potential of the dietary antioxidants vitamin C, vitamin E, lycopene, β-carotene, and the rosemary polyphenol, carnosic acid, was tested in human dermal fibroblasts exposed to ultraviolet-A (UVA) light. The carotenoids were prepared in special nanoparticle formulations together with vitamin C and/or vitamin E. Nanoparticle formulations, in contrast to dimethylsulphoxide, stablized lycopene in the cell culture medium and allowed efficient cellular uptake. The presence of vitamin E in the formulation further increased the stability and cellular uptake of lycopene. UVA irradiation of the human skin fibroblasts led to a 10–15-fold rise in metalloproteinase 1 (MMP-1) mRNA. This rise was suppressed in the presence of low μM concentrations of vitamin E, vitamin C, or carnosic acid but not with β-carotene or lycopene. Indeed, in the presence of 0.5–1.0 μM β-carotene or lycopene, the UVA-induced MMP-1 mRNA was further increased by 1.5–2-fold. This increase was totally suppressed when vitamin E was included in the nanoparticle formulation. Heme-oxygenase 1 (HO-1) mRNA expression was strongly induced by UVA irradiation but none of the antioxidants inhibited this effect at the concentrations used in this study. Indeed, β-carotene or lycopene (0.5–1.0 μM) led to a further 1.5-fold rise in the UVA-induced HO-1 mRNA levels. In conclusion, vitamin C, vitamin E, and carnosic acid showed photoprotective potential. Lycopene and β-carotene did not protect on their own but in the presence of vitamin E, their stability in culture was improved and the rise in MMP-1 mRNA expression was suppressed, suggesting a requirement for antioxidant protection of the carotenoids against formation of oxidative derivatives that can influence the cellular and molecular responses. 相似文献
8.
Beatriz C. S. Boa Carlos M. M. R. Barros Maria das Gra?as C. Souza Raquel C. Castiglione Fátima Z. G. A. Cyrino Eliete Bouskela 《PloS one》2015,10(8)
Fructose, an everyday component of western diet associated to chronic hyperglycemia and enhanced free radical production, impairs endothelial function and supplementation with antioxidants might improve it. In this study we investigated if vitamin E could reverse the microvascular damage elicited by fructose. Male Syrian golden hamsters drank either 10% fructose solution (F) or filtered water (C), combined with three concentrations of vitamin E in their chows [zero, normal (VE) or 5X (5XVE)] during 60 days. Microvascular reactivity in response to topical application of acetylcholine (Ach; endothelium-dependent vasodilator) or sodium nitroprusside (SNP; endothelium-independent vasodilator) and macromolecular permeability increase induced by either 30 min ischemia followed by reperfusion (I/R) or topical application of histamine (5 μM) were assessed using the cheek pouch preparation. Compared to controls (drinking filtered water), fructose-drinking animals showed decreased vasodilatation to acetylcholine in all concentrations tested (-56.2% for 10-9M, -53.9% for 10-7M and -43.7% for 10-5M). On the other hand, vitamin E supplementation resulted in increased responses for both water and fructose drinking groups (177.4% for F vs. F/5XVE and 241.6% for C vs. C/5XVE for 10-5M Ach). Endothelial-independent vasodilatation explored by topical application of SNP was restored and even enhanced with the supplementation of 5X vitamin E in both groups (80.1% for F vs. F/5XVE; 144.2% for C vs. C/5XVE; 3.4% of difference for C/5XVE vs. F/5XVE on 10-5M SNP). The number of leaky sites after I/R and histamine stimuli in vitamin E supplemented animals decreased (-25.1% and -15.3% for F vs. F/5XVE; and -21.7% and -16% of leaky sites comparing C vs. C/5XVE, respectively for I/R and histamine stimuli) pointing to tightening of the endothelial barrier for macromolecular permeability. Our results strongly suggest that vitamin E could improve the endothelial function and permeability barrier and also reverse impairments elicited by sugar overload. 相似文献
9.
Variations in the β-carotene, vitamin C and vitamin E content of D. tertiolecta have been shown to result from the nitrogen source used in the culture medium. Differences of 101%, 38% and 69% have been found in β-carotene, ascorbic acid and tocopherol content in mg/g of dry matter, respectively, and differences of 147%, 63% and 37% occurred in β-carotene, vitamin C and E concentrations in mg/litre of culture, respectively. Considering the β-carotene, vitamin C and vitamin E content in mg/g of chlorophyll a, maximum variations occurred in β-carotene content, with differences of 145% among the different nitrogen sources. Maximum β-carotene and vitamin C values were found in urea cultures, whereas urea cultures showed the minimum values for vitamin E. 相似文献
10.
Vitamins K1 K3 and K5 induced flowering in Lemna paucicostata151, a short-day plant, cultured in 1/10 strength M medium (1/10M medium) under continuous light, and their activity was greatlyintensified by simultaneous application of benzyladenine. Themost active of these was vitamin K5 L. paucicostata 6746 ismore sensitive to vitamin K5 than strain 151, but the effectof vitamin K5 on strain 6746 was not intensified by benzyladenine.The flower-inducing activity of vitamin K5 was intensified bythe addition of benzoic acid in both strains and by the additionof copper or ferricyanide in Strain 6746, when these chemicalswere added at such low concentrations that they would scarcelyinduce flowering. In strain 6746, vitamin K5 added to 1/10 M had little effecton flowering under a subcritical photoperiod, while it clearlyinduced flowering under continuous light. In this strain, vitaminK5 added to full strength M medium, in which this plant wasmore sensitive to short photoperiods than in 1/10 M medium,did not induce flowering even under continuous light, and wasrather inhibitory under short photoperiods. (Received August 14, 1984; Accepted October 16, 1984) 相似文献
11.
The oxidative modification of low-density lipoprotein (LDL) plays an important role in atherosclerosis. Protecting LDL from oxidation has been shown to reduce the risk of coronary heart disease. In this study, we compared the protective effects of two lipophilic antioxidants (vitamin E and lazaroid) with two hydrophilic antioxidants (trolox and vitamin C) in the presence of several different free radical generating systems. Vitamin E (IC50 = 5.9 μM) and lazaroid (IC50 = 5.0 μM) were more effective in inhibiting lipid peroxidation caused by a Fe-ADP free radical generating system than vitamin C (IC50 = 5.2 × 103 μM) and trolox (IC5 = 1.2 × 103 μM). Preincubation of lipoproteins with a lipophilic antioxidant increased the protective effect against various free radicals. Preincubation with hydrophilic antioxidants did not have an effect. We also tested the efficacy of the antioxidants when the free radicals were generated within the lipid or the aqueous environment surrounding the LDL. For this purpose, we used the peroxyl generating azo-compounds AMVN (2,2′-azobis(2,4-dimethylvaleronitrile)) and AAPH (2,2′azobis (2-amidinopropane) dihydrochloride). All of the antioxidants tested were more effective against free radicals generated in a water soluble medium than they were against free radicals generated in a lipid environment. In conclusion, our data demonstrate that lipid solubility is an important factor for both the antioxidant and the free radical generating systems in determining the extent of lipid peroxidation in LDL. Our data also demonstrate that antioxidant efficacy in one set of experimental conditions may not necessarily translate into a similar degree of protection in another set of conditions where lipophilicity is a variable. 相似文献
12.
Harrington DJ Soper R Edwards C Savidge GF Hodges SJ Shearer MJ 《Journal of lipid research》2005,46(5):1053-1060
We describe a method for the determination of the two major urinary metabolites of vitamin K as the methyl esters of their aglycone structures, 2-methyl-3-(3'-3'-carboxymethylpropyl)-1,4-naphthoquinone (5C-aglycone) and 2-methyl-3-(5'-carboxy-3'-methyl-2'-pentenyl)-1,4-naphthoquinone (7C-aglycone), by HPLC with electrochemical detection (ECD) in the redox mode. Urinary salts were removed by reversed-phase (C18) solid-phase extraction (SPE), and the predominantly conjugated vitamin K metabolites were hydrolyzed with methanolic HCl. The resulting carboxylic acid aglycones were quantitatively methylated with diazomethane and fractionated by normal-phase (silica) SPE. Final analysis was by reversed-phase (C18) HPLC with a methanol-aqueous mobile phase. Metabolites were detected by amperometric, oxidative ECD of their quinol forms, which were generated by postcolumn coulometric reduction at an upstream electrode. The assay gave excellent linearity (typically, r2 > or = 0.999) and high sensitivity with an on-column detection limit of < 3.5 fmol (< 1 pg). The interassay precision was typically 10%. Metabolite recovery was compared with that of an internal standard [2-methyl-3-(7'-carboxy-heptyl)-1,4-naphthoquinone] added to urine samples just before analysis. Using this methodology, we confirmed that the 5C- and 7C-aglycones were major catabolites of both phylloquinone (vitamin K1) and menaquinones (vitamin K2) in humans. We propose that the measurement of urinary vitamin K metabolite excretion is a candidate noninvasive marker of total vitamin K status. 相似文献
13.
Ken-ichiro Tanaka Ippei Kanazawa Toru Yamaguchi Shozo Yano Hiroshi Kaji Toshitsugu Sugimoto 《Biochemical and biophysical research communications》2014
Vitamin D deficiency and advanced glycation end products (AGEs) are suggested to be involved in the pathogenesis of osteoporosis and sarcopenia. However, the effects of vitamin D and AGEs on myogenesis and the interaction between muscle and bone remains still unclear. We previously showed that osteoglycin (OGN) is secreted from myoblasts and stimulates osteoblastic differentiation, suggesting that it plays important roles in the interaction between muscle and bone. The aim of this study is thus to examine the effects of vitamin D and AGEs on myoblastic differentiation of C2C12 cells and osteoblastic differentiation of osteoblastic MC3T3-E1 cells through OGN expression. 1α,25-dihydroxyvitamin D3 (1,25D) and eldecalcitol, an active vitamin D analog, induced the expression of MyoD, myogenin and OGN, and these effects were abolished by vitamin D receptor (VDR) suppression by siRNA in C2C12 cells. Moreover, conditioned medium from 1,25D-pretreated C2C12 cells stimulated the expression of type 1 collagen and alkaline phosphatase in MC3T3-E1 cells, compared to control medium from 1,25D-untreated C2C12 cells. In contrast, conditioned medium from VDR-suppressed and 1,25D-pretreated C2C12 cells showed no effects. AGE2 and AGE3 suppressed the expression of MyoD, myogenin and OGN in C2C12 cells. Moreover, 1,25D blunted the AGEs’ effects. In conclusion, these findings showed for the first time that active vitamin D plays important roles in myogenesis and muscle-induced osteoblastogenesis through OGN expression. Active vitamin D treatment may rescue the AGEs-induced sarcopenia as well as – suppressed osteoblastic differentiation via OGN expression in myoblasts. 相似文献
14.
In this work a new spectrofluorimetric method for the determination of vitamin B1, based on the catalytic activity of horseradish peroxidase (HRP) in the presence of hydrogen peroxide (H2O2), has been developed. Non‐fluorescent vitamin B1 was easily converted through catalytic oxidation in alkaline medium into a fluorescent compound, even without exposure to light. The linear range for vitamin B1 observed was 0.026–16.83 µg/mL (RSD = 1.75%). The correlation coefficient for the calibration curve and limit of detection were found to be 0.9964 and 0.015 µg/mL, respectively. The developed method is practical, simple, sensitive and relatively free from interference by coexisting substances and has been successfully applied for the determination of vitamin B1 in pharmaceutical preparations. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
15.
Study on the polarographic catalytic wave of vitamin P in the presence of persulfate and its application 总被引:1,自引:0,他引:1
The polarographic catalytic wave of vitamin P in the presence of persulfate was studied by linear potential scan polarography and cyclic voltammetry. Vitamin P yielded a single reduction wave in acidic aqueous solution, which was ascribed to a 2e(-), 2H(+) reduction of the carbonyl group in the C-4 position. Actually, the carbonyl group C=O first underwent a 1e(-), 1H(+) reduction to form a neutral free radical, and the further 1e(-), 1H(+) reduction of the free radical was simultaneous with its following chemical reactions. When S(2)O(2-)(8) was present, the free radical of vitamin P was oxidized by both S(2)O(2-)(8) and its reduction intermediate, the sulfate radical anion SO(*-)(4), to regenerate the original, which resulted in the production of a polarographic catalytic wave of vitamin P. Based on this catalytic wave, a novel method for the determination of vitamin P was proposed. In 0.02 M tartaric acid-sodium tartrate (pH 3.3) buffer containing 5.0 x 10(-3) M K(2)S(2)O(8), the peak potential of the catalytic wave was -1.42 V (vs SCE) and the peak current was rectilinear to the vitamin P concentration in the range of 8.0 x 10(-9)-1.0 x 10(-6) M (r = 0.9994, n = 13). The catalytic wave of 2.0 x 10(-7) M vitamin P enhanced the polarographic current 70 times compared with the corresponding reduction wave. The detection limit was 2.0 x 10(-9) M, and the relative standard deviation at the 2.0 x 10(-7) M level was 0.7% (n = 15). The proposed method was used for the determination of vitamin P content in the pharmaceutical preparation of tablets and the medicinal plant Sophora japonica L. without previous separation. 相似文献
16.
Pengfei Kong Qingqing Cai Qirong Geng Jing Wang Yadong Lan Youqing Zhan Dazhi Xu 《PloS one》2014,9(12)
Aim
The association between vitamin intake and gastric cancer (GC) has been widely debated due to the relatively weak evidence. In this study, a meta-analysis of prospective and well designed observational studies were performed to explore this association.Methods
MEDLINE, Cochrane Library, and Sciencedirect were searched for studies of vitamin consumption and gastric cancer. This produced 47 relevant studies covering 1,221,392 human subjects. Random effects models were used to estimate summary relative risk (RR). Dose-response, subgroup, sensitivity, meta-regression, and publication bias analyses were conducted.Results
The RR of gastric cancer in the group with the highest vitamin intake was compared to that of the lowest intake group. Total vitamin intake was 0.78 (95% CI, 0.71−0.83). In 9 studies that individuals were given doses at least 4 times above the tolerable upper intake (UL) vitamins, the RR was 1.20 (95% CI, 0.99−1.44). However, in 17 studies that individuals received doses below the UL, the RR was 0.76 (95% CI, 0.68−0.86). Dose-response analysis was conducted on different increments in different types of vitamins (vitamin A: 1.5 mg/day, vitamin C: 100 mg/day, vitamin E: 10 mg/day) intake with a significant reduction in the risk of gastric cancer, respectively, 29% in vitamin A, 26% in vitamin C, and 24% in vitamin E.Conclusion
This meta-analysis clearly demonstrated that low doses of vitamins can significantly reduce the risk of GC, especially vitamin A, vitamin C, vitamin E. 相似文献17.
We have developed an assay to measure the affinity of serum vitamin D binding protein for 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and vitamin D3, using uniform diameter (6.4 microns) polystyrene beads coated with phosphatidylcholine and vitamin D metabolites as the vitamin D donor. The lipid metabolite coated beads have a solid core, and thus all of the vitamin D metabolites are on the bead surface from which transfer to protein occurs. After incubating these beads in neutral buffer for 3 h, essentially no 3H-labeled vitamin D metabolites desorb from this surface. Phosphatidylcholine/vitamin D metabolite-coated beads (1 microM vitamin D metabolite) were incubated with varying concentrations of serum vitamin D binding protein under conditions in which the bead surfaces were saturated with protein, but most of the protein was free in solution. After incubation, beads were rapidly centrifuged without disturbing the equilibrium of binding and vitamin D metabolite bound to sDBP in solution was assayed in the supernatant. All three vitamin D metabolites became bound to serum vitamin D binding protein, and after 10 min of incubation the transfer of the metabolites to serum vitamin D binding protein was time independent. The transfer followed a Langmuir isotherm, and the Kd for each metabolite binding to serum vitamin D binding protein was derived by nonlinear least-squares fit analysis. From this analysis the following values for the Kd were obtained: 5.59 x 10(-6) M, 25-hydroxyvitamin D; 9.45 x 10(-6) M, 1,25-dihydroxyvitamin D; and 9.17 x 10(-5) M, vitamin D. In conclusion, we have developed a method which avoids problems encountered in previous assays and allows the precise and convenient determination of binding affinities of vitamin D metabolites and serum vitamin D binding protein. 相似文献
18.
2,3,5,6-Tetramethylpyrazine (TTMP) was produced using a newly isolated Bacillus mutant. Culture medium optimization studies showed that soytone, an enzyme-hydrolysate of soybean meal, with the supplementation of vitamins, can fully replace yeast extract plus peptone in supporting TTMP production from glucose. In a 5-l fermenter, using the optimized medium which contained 20% glucose, 5% soytone, 3% (NH4)2HPO4, and vitamin supplements, fermentations were carried out with stirring at 700 rpm, air flow at 1.0 vvm, controlled pH at 7.0, and temperature at 37 °C. TTMP reached 4.33 g l−1 after 64.6 h cultivation. A product recovery method was described, which involved evaporation, crystallization, and lyophilization. The product purity was 99.88%, determined by GC with the normalization method. The main impurities were 2,3,5-trimethylpyrazine (0.09%) and 2-ethyl-3,5,6-trimethylpyrazine (0.02%), which were identified by GC/MS. 13C NMR determination also gave a consistent result. Natural and high purity of the product and the utilization of cheap green renewable materials make this process promising to compete with TTMP chemical synthetic methods. 相似文献
19.
Y Akedo T Hosoi S Inoue A Ikegami Y Mizuno M Kaneki T Nakamura Y Ouchi H Orimo 《Biochemical and biophysical research communications》1992,187(2):814-820
A human osteosarcoma cell line, HOS TE85 cells, and a mouse osteoblastic cell line, MC3T3-E1 cells, were cultured for 3 days in a medium containing various concentrations of menaquinone-4 (vitamin K2). As a result, the proliferation of HOS cells was suppressed by vitamin K2 in a dose dependent manner up to 56% of control by 10(-7)M of vitamin K2 and that of MC3T3-E1 cells was suppressed to 84% of control by 10(-6)M of vitamin K2. Vitamin K2 increased alkaline phosphatase activity in both kinds of cells. Warfarin counteracted the effect of vitamin K2 on osteoblastic cell proliferation. Our results show that vitamin K2 modulates proliferation and function of osteoblastic cells by some mechanisms including gamma-carboxylation system. 相似文献
20.
To examine the mechanism by which vitamins C and E alter phagocyte function, a series of in vitro manipulations were conducted with cells isolated from the head-kidney of hybrid striped bass (average weight 680 g) fed a diet supplemented with minimum requirement levels of vitamins C and E for 2 weeks. Head-kidney phagocytes were cultured in media containing physiologically deficient (23 microM, adequate (45 microM) or excessive (182 microM) concentrations of vitamin C, and physiologically deficient (5 microM), adequate (9 microM) or excessive (32 microM) concentrations of vitamin E for 18 h. Following culture and stimulation, levels of reactive oxygen intermediates and hydrogen peroxide were determined. There were no effects of vitamin C or vitamin E concentrations on hydrogen peroxide or extracellular O2- generation. Intracellular O2- production, however, was significantly (P < or = 0.05) affected. When vitamin C was supplied at deficient levels to the medium, vitamin E elevated O2- production to levels not different from those of cells incubated with requirement levels of both vitamins. Similarly, when vitamin E was deficient in the media, vitamin C supplementation at requirement levels normalised intracellular O2- production. This data provides support for the presence of a vitamin C and vitamin E sparing mechanism in phagocytic head-kidney cells of hybrid striped bass and yield some insight into the mechanisms by which vitamin C and vitamin E function in immunomodulation. 相似文献