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1.
2.
The abscisic acid (ABA) analog 8′ acetylene ABA methyl ester (PBI 429) was evaluated for its potential to alter the growth and moisture use of bedding plants during nursery production. Treating seedlings with the ABA analog as a root-dip slowed moisture use and growth of tomato seedlings under greenhouse conditions. In marigolds, comparable ABA analog treatments had no effect on growth and limited effects on plant moisture use. To determine whether these differences in response to treatment with the ABA analog were associated with differences in absorption of the analog and/or its persistence, the ABA analog was applied either as a foliar spray or root-dip, and the resulting concentrations of the ABA analog were monitored over a 10-day interval in both the roots and the leaves. In both crops, the ABA analog was detected in both leaf and root tissues irrespective of the mode of application, suggesting systemic movement of the analog. Tissue concentrations of the ABA analog were consistently lower in the foliar treatment than in the root-dip. The uptake and the retention of the ABA analog over time was similar in leaves of the two test crops, but less of the ABA analog was absorbed and retained in the roots of marigold plants than in the tomatoes. This suggests that the observed differences in responses of these two plant species to application of ABA analogs may be related to differences in retention or accumulation of ABA in the roots rather than to differences in the total amount of ABA analog absorbed or its movement and retention in the plant system. Levels of endogenous ABA were not significantly altered by application of the ABA analog.  相似文献   

3.
(±)-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.  相似文献   

4.
5.
An alternative synthesis of (±)-tubaic acid (I), a key intermediate compound of rotenone synthesis, has been accomplished by the Wittig reaction.  相似文献   

6.
The effects of drinking deaerated water on serum biochemical values, and on the concentrations of short-chain fatty acids (SCFAs) derived from bacterial fermentation in the colon were examined in rats. Drinking deaearted water decreased the levels of serum alkaline phosphatase (SAP) and serum urea nitrogen (SUN), and increased the serum potassium (SK) and serum phosphorus (SP) levels. Although the concentration of propionic acid in the cecum was decreased by drinking deaerated water, the concentrations of isobutyric, valeric, and isovaleric acids in the cecum were increased.  相似文献   

7.
Phosphodiesterase production with bis-p-nitrophenyl phosphate as a substrate by alkalophilic Bacillus No. A-40-2 increased with increasing Mn2+ concentration, showing maximum productivity at 10 mm. The enzyme production was negligible in the medium without Mn2+. The simultaneous addition of 10 mm Mn2+ and one of the several cations Mg2+, Co2+, Mo6+, and Pb2+ at suitable concentrations stimulated the enzyme production 1.8-fold at most over that with only 10 mm Mn2+. Inorganic phosphate hardly repressed the enzyme production. The enzyme was purified homogeneously. The purified enzyme had the optimum pH of 7.5 and was fairly stable from pH 7–11. The enzyme hydrolyzed 2′,3′-cyclic-nucleotides and 3′-nucleotides, but did not hydrolyze 3′,5′-cyclic-nucleotides or 5′-nucleotides, indicating it to be a 2′,3′-cyclic-nucleotide 2′-phosphodiesterase (EC 3.1.4.16). The enzyme had activity without metals, but Mg2+, Ca2+, Ba2+, and Mo6+ activated the enzyme reaction.  相似文献   

8.
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.  相似文献   

9.
Enzymic deacetylation of methyl 2,3-di-O-acaetyl-α- and β-D-threofuranoside using porcine liver esterase affords monoacetates only (in the case of the α-anomer, the 3-O-acetylderivative exclusively) without any further hydrolysis to the corresponding diols.  相似文献   

10.
By microorganisms or esterase they produce, (±)-1 and 2-decalyl acetates were asymmetrically hydrolyzed to (?)-1-(R)-trans,cis-1-decalol (IIa), (+)-1-(S)-cis,cis-1-decalol (IIIb), (+)-1-(R)-cis,trans-1-decalol (IVa) and (+)-1-(S)-trans,trans-2-decalol (VIIb), (?)-cis,cis-2-decalol (IXb) with the acetates of their antipodes, whereas the axial acetates of (±)-decalols were scarecely hydrolyzed.  相似文献   

11.
Enzymes and microorganisms were screened for the enantioselective hydrolysis of (±)-1-acetoxy-2,3-dichloropropane (1) which is convertible to epichlorohydrin. Pancreatin and steapsin from hog pancreas were found to hydrolyze (±)-1 asymmetrically to give (S)-1 of 90% enantiomeric excess (e.e.). From (S)-1 was synthesized the optically pure (S)-isomer of propranolol[1-isopropylamino-3-(1-naphthoxy)-2-propanol], one of the typical β-adrenergic blocking agents.  相似文献   

12.
Treatment of 18-glycyrrhizic acid with a methanolic solution of HCl resulted in 1 : 1 mixture of methyl esters of 18- and 18-glycyrrhetinic acids. Benzoylation of the mixture led to methyl esters of 3-benzoyl-18-glycyrrhetinic acid and 3-benzoyl-18-glycyrrhetinic acid, which were separated by chromatography on silica gel. 18-Glycyrrhetinic acid was prepared by alkaline hydrolysis of methyl 3-benzoyl-18-glycyrrhetinate and was further used for the syntheses of 3-keto-18-glycyrrhetinic acid and methyl esters of 18-glycyrrhetinic acid and 3-keto-18-glycyrrhetinic acid.  相似文献   

13.
The racemic total synthesis of elegansidiol, farnesiferol B, and farnesiferol D has been obtained following a Diels–Alder approach. Gillman addition, cross metathesis reaction are the other key steps involved in the target synthesis.  相似文献   

14.
A new synthesis of (±)-9-demethylmunduserone (2) is described. Thermal rearrangement of l-(4-benzyloxy-2-hydroxyphenyl)-4-(3′,4′-dimethoxyphenoxy)-2-butyn-1-one (7) afforded 4-(4-benzyloxy-2-hydroxybenzoyl)-6,7-dimethoxy-2H-chromene (8), 3-(4-benzyloxy-2-hydroxyberrzoyl)-5,6-dimethoxy-2-methylbenzofuran (9) and 9-benzyloxy-2,3-dimethoxy-6a,12a-dihydrorotoxen-12(6H)-one (3). 4-Aroyl-2H-chromene (8) was smoothly converted to 3 in quantitative yield by the treatment with sodium acetate. The structure of 3 was confirmed by an alternative synthesis from methyl tephrosate (10). Debenzylation of 3 with aluminum bromide afforded (±)-9-demethylmunduserone (2) in high yield.  相似文献   

15.
The fungitoxic sesquiterpene (±)-chokolic acid A (1) was synthesized stereoselectively by starting from 2-methoxycarbonyl-(3-isopropenyl)cyclopentanone (2) in a 9% overall yield from 10 steps.  相似文献   

16.
17.
Abstract

The title compound was prepared and found to be a potent and selective inhibitor of HSV-I thymidine kinase. This compound delayed the reactivation of latent virus from explanted mouse ganglia but exacerbated the primary HSV-I infection in mice.  相似文献   

18.
(±)-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.  相似文献   

19.
(±)-Lamprolobine, the (+)-enatiomer of which was isolated from the leaves of Lamprolobium fruticosum, and (±)-epilamprolobine were synthesized from δ-valerolactam.  相似文献   

20.
An inhibitor of plant virus infection from leaves of Yucca recurvifolia was purified by a method using gel filtration on Sephadex G-75, and column chromatography on CM-Toyopearl 650M. The purified inhibitor thus obtained was homogeneous on disc and SDS disc electrophoreses, and the molecular weight of the inhibitor was 23,000. The inhibitor consisted of 17.7% nitrogen, which was found to be a basic simple protein, and contained no neutral sugar, hexosamine nor sialic acid. The inhibitor was estimated to be composed of about 208 amino acid residues. This inhibitor was named “yucca leaf protein (YLP).”  相似文献   

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