DIURNAL CHANGES IN THE CARBOHYDRATES OF WHEAT LEAVES

1943 ◽  
Vol 21c (1) ◽  
pp. 26-40 ◽  
Author(s):  
G. Krotkov

Data are presented on the diurnal variations in the sugars of wheat leave, as well as on changes in the sugar content of detached and attached leaves, which were taken progressively during the 24 hr. and were starved under the adopted standardized conditions.It was found that in some samples of leaves there was a considerable decrease in their sugars under the conditions of starvation, but on the other hand leaf samples taken either in the first part of a day, or after sunset, usually contained more sugars after starvation than before it. This last observation suggested a considerable hydrolysis of some complex substances in leaves, with the consequent appearance of sugars. From the analysis of the data obtained it was concluded that the observed diurnal variations in the extent of hydrolysis, synthesis, or in translocation of sugars are greatly influenced by the conditions of illumination.

2020 ◽  
Vol 237 ◽  
pp. 03011
Author(s):  
Yasukuni Shibata ◽  
Chikao Nagasawa ◽  
Makoto Abo

We have conducted the measurement of high accurate CO2 mixing ratio profiles by measuring the temperature profiles simultaneously using the three wavelength CO2 DIAL. The measurements of CO2 diurnal variation in the lower atmosphere were carried out on sunny and cloudy days respectively. We find out that increasing of the CO2 mixing ratio occurs over the altitude of about 2 km from the surface during nighttime. On the other hand, the CO2 mixing ratio decreases over the lower atmosphere during daytime. In particular, the CO2 mixing ratio decreases earlier on sunny days than on cloudy days after sunrise. This result suggests that CO2 absorption by photosynthesis greatly contributes to the strength of the solar radiation.


1983 ◽  
Vol 96 (5) ◽  
pp. 1480-1485 ◽  
Author(s):  
S Tsukita ◽  
S Tsukita ◽  
J Usukura ◽  
H Ishikawa

With the rapid-freeze, deep-etch replica technique, the structural conformations of outer dynein arms in demembranated cilia from Tetrahymena were analyzed under two different conditions, i.e., in the absence of ATP and in the presence of ATP and vanadate. In the absence of ATP, the lateral view of axonemes was characterized by the egg-shaped outer dynein arms, which showed a slightly baseward tilt with a mean inclination of 11.1 degrees +/- 3.4 degrees SD from the perpendicular to the doublet microtubules. On the other hand, in the presence of 1 mM ATP and 100 microM vanadate, the outer arms were extended and slender and showed an increased baseward tilt with a mean inclination of 31.6 degrees +/- 4.9 degrees SD. In ATP-activated axonemes, these two types of arms coexisted, each type occurring in groups along one row of outer arms. These findings strongly suggest that the interdoublet sliding is caused by dynamic structural changes of dynein arms that follow the hydrolysis of ATP.


1952 ◽  
Vol 30 (1) ◽  
pp. 28-39 ◽  
Author(s):  
G. Krotkov ◽  
W. Constance G. Bennett

Using the technique of vacuum infiltration, either a mixture of glucose plus fructose or a solution of sucrose alone was introduced into detached wheat leaves, and the rates of sucrose synthesis or hydrolysis from these infiltrated sugars were observed. It was found that these rates were not constant during 24 hr., but depended on the time of the day or night when the leaves were cut. Synthesis was high in leaves detached in the forenoon, before sunset, and in the first part of the night. Changes in the rate of hydrolysis were usually mirror images of those of synthesis. It has been concluded that in wheat leaves there exists a diurnal rhythm in their synthetic and hydrolytic potential and that the observed diurnal changes in the rates of sucrose synthesis and hydrolysis represent one of the manifestations of such a rhythm. Sodium fluoride, sodium cyanide, iodoacetate, and dinitrophenol always increased hydrolysis, and usually decreased synthesis. When glucose-1-phosphate, fructose-6-phosphate, and fructose-1, 6-diphosphate were substituted for the corresponding free sugar in a mixture of glucose plus fructose, a decrease in sucrose synthesis was observed. After 24 hr. of starvation the rate of sucrose synthesis declined, and eventually dropped practically to zero at the end of five days. In the same time there was a progressive increase in the rate of hydrolysis.


1957 ◽  
Vol 35 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Ch. R. Engel

The synthesis of 17α-methylcorticosterone, a new biologically active homologue of corticosterone and analogue of cortisol, is described. In the course of the work it was observed that the 17-methyl group greatly impeded both the formation and the hydrolysis of a 20-ketal. On the other hand, evidence was obtained that the 11-keto group is not completely unreactive towards ethylene glycol, in the presence of p-toluenesulphonic acid.


2007 ◽  
Vol 13 (2) ◽  
Author(s):  
Zs. Varga ◽  
F. Bényei ◽  
P. Jr. Bodor ◽  
I. Fazekas

Most of the cultivars grown before the disaster of phylloxera in Tokaj can be found only in grapevine collections. The aim of our study was to determinate the cultivation values of six old grapevine cultivars of the wine-region, namely 'Balafánt', 'Budai gohér', 'Purcsin', 'Török gohér, 'Piros (red) furmint' and 'Változó (altering) furmint'. Based on the results of the investigations from 2004 to 2006 it can be concluded that among from the examined cultivars of Tokaj `Budai gohér', Turcsin' and 'Változó furmint' match the best with the technological and consumer requirements of recent days. However the yield of 'Budai gohér' in certain vintages is not acceptable and red wine cultivars are not permitted at this time in the wine-region, but in qualitative responses these presented steadily good data. On the other hand the lowest sugar content was measured and development of noble rot was not registered at all in case of Piros furmint' and `Balafánt'. Their spread in Tokaj is not probable.


OENO One ◽  
1997 ◽  
Vol 31 (1) ◽  
pp. 23 ◽  
Author(s):  
Virginie Moine-Ledoux ◽  
A. Perrin ◽  
I. Paladin ◽  
Denis Dubourdieu

<p style="text-align: justify;">Some mannoproteins which are extracted by enzymatic hydrolysis of yeast's cell wall with the aid of commercial preparation composed with beta-glucanases (Glucanex™) inhihits the tartaric acid's salt breakdown in model solution as well as in wines for an addition between 10 and 25 g/hl. On the other hand, heat extracted mannoproteins arc inactive on the tartaric precipitation stabilization. Furthermore, the crystallization inhibitor activity of the enzymatic extracted mannoproteins is due to the presence of sharply glycosylated mannoproteins of mediummolecular weight (30 to 50 kda) which are not heat extracted. That is why the heat extracted mannoproteins are inactive. The enzymatic extracted mannoproteins are produced at a pilot plan. This preparation (Mannostab™), soluble in wines, colourless and without any flavour, stabilize with the same efficiency than a freeze treatment and this effective live is superior to the metatartric acid. Moreover, the necessary steps were been taked to permit experimentally this new product : Mannostab™</p>


1976 ◽  
Vol 31 (11) ◽  
pp. 1511-1514 ◽  
Author(s):  
Gert Kollenz ◽  
Erich Ziegler ◽  
Walter Ott ◽  
Herwig Igel

Hydrolysis of 4-Benzoyl-5-phenyl-2,3-dihydrofuran-2,3-dione (1) in water (ethanol) gives dibenzoylmethane and oxalic acid (ethyl ester). 1 reacts with aniline or p-toluidine yielding the 2-pyrrolones (2), which on the other hand are synthesized by addition of the corresponding anilines to the pyrrol-2,3-diones (8). 3 a adds methanol to give the 2-pyrrolone (4), which with aniline can be converted into 2 a. 2 a, b show fragmentation to oxalic acid anilides by heating (2 b) or treating with diazomethane (2 a). The reaction of 1 with p-nitroaniline leads via the furanone-derivative 6 to oxalic acid-di-p-nitroanilide. 1 and N-methylaniline combine to acrylic acid-N-methylanilide (7), which by heating gives the dibenzoyl acetic acid-N-methylanilide


1972 ◽  
Vol 50 (12) ◽  
pp. 1886-1890 ◽  
Author(s):  
June G. Winter ◽  
J. M. W. Scott

The rates of neutral hydrolysis of a series of 4-substituted benzyl trifluoroacetates 4-X-C6H4CH2OCOCF3, X = NO2, Cl, H, CH3, and OCH3 have been studied in water and deuterium oxide, both solvents containing 0.012 mol fraction of acetone. The alteration of the rates with the nature of the 4-substituent and the kinetic solvent isotope effect (k(H2O)/k(D2O)) are consistent with the proposal that the esters with X = NO2, Cl, H, and CH3 all react by an acyl–oxygen BAc2 mechanism. On the other hand, the same mechanistic criteria indicate that the 4-methoxybenzyl ester reacts by both the BAc2 and the SN1 alkyl–oxygen fission paths in equal amounts.


1985 ◽  
Vol 63 (12) ◽  
pp. 3418-3432 ◽  
Author(s):  
Edward Piers ◽  
Brian F. Abeysekera ◽  
David J. Herbert ◽  
Ian D. Suckling

Total syntheses of the stemodane-type diterpenoids (±)-stemodin (2) and (±)-maritimol (4), as well as formal total syntheses of (±)-stemodinone (3) and (±)-2-desoxystemodinone (5), are described. The known ketol 12 was converted into the tricyclic enone 7. Photoaddition of aliène to 7 gave (96%) a mixture of the photoadducts 20–23 (40:51:6:3, respectively). Ozonolysis of 20, followed by treatment of the resultant dione 24 with MeONa–MeOH (room temperature, 2.5 h), provided the keto ester 26 (94%). Subjection of 21 to an identical sequence of reactions gave (86%) the same product 26. On the other hand, when the dione 25 was treated with MeONa–MeOH under much milder conditions (0 °C, 5 min), the isomeric keto esters 27 (39%) and 28 (33%) were produced. Both 27 and 28, upon reaction with MeONa–MeOH at room temperature, were converted efficiently into 26. Reduction (NaBH4 or Lisec-Bu3BH) of 26 provided separable mixtures of the ester alcohol 32 and the lactone 33, which could be transformed readily into the dimesylates 35 and 39, respectively. Reaction of 35 and 39 with NaCN in warm hexamethylphosphoramide afforded the dinitriles 37 and 40, both of which, upon treatment with t-BuOK in refluxing t-BuOH, produced the sameenaminonitrile 41. Acid hydrolysis of 41 provided the dione 42. Preparatively, compound 26 could be transformed conveniently into the dione 42 (52% overall yield) without separation of mixtures of isomeric synthetic intermediates. Treatment (CH2Cl2, −95 °C) of 42 with Mc3Sil–Et3N, followed by oxidation of the resultant products 46 and 47 with Pd(OAc)2 in acetonitrile, gave the bis enones 48 (67%) and 49 (19%). Compound 48 was converted into the dione 52 which, upon reaction with (i-PrO)3 TiMe in ether, provided an 86:14 mixture of the keto alcohols 53 and 54 (63% from 48). Reduction (NaBH4) of 53 afforded (±)-maritimol (4). On the other hand, conversion of the 86:14 mixture of 53 and 54 into the p-toluenesulfonylhydrazones 55 and subsequent reaction of 55 with NaH in refluxing toluene gave the alkene alcohols 56 (58%) and 57 (12%). Hydroboration–oxidation (9-BBN, refluxing tetrahydrofuran; NaOH, H2O2) of 56 afforded (88%) (±)-stemodin (2).


2015 ◽  
Vol 43 (1) ◽  
pp. 229-234
Author(s):  
Gregor OSTERC ◽  
Franci STAMPAR ◽  
Valentina SCHMITZER

Leafy cuttings of Prunus subhirtella Miq. ‘Autumnalis’ were harvested from mature, semi-mature and juvenile stock plants at four dates during the vegetative period 2011 (on 16th of May, on 30th of May, on 20th of June and on 11th of July) and their auxin levels (IAA, IAA-Asp) and sugar content (glucose, sucrose, sorbitol) were quantified. The IAA and IAA-Asp contents in cutting bases increased over the vegetative period, whereby aspartate values were higher than IAA values. The IAA-Asp values ranged from 6.3 µg g-1 to 22.7 µg g-1 FW and reached two great peaks on 30th of May and on 11th of July. The IAA values ranged from 0.29 µg g-1 to 4.51 µg g-1 FW, reaching a small fall on 20th of June. Significantly higher levels of IAA and IAA-Asp were measured at the base of mature cuttings compared to cuttings of semi-mature and juvenile origin, when the cuttings were harvested on 30th of May and on 11th of July. On the other hand, mature leafy cuttings accumulated significantly less fructose and glucose in their root emergence zone (16.3 g kg-1 DW, 45.2 g kg-1 DW) compared to semi-mature cuttings (26.4 g kg-1 DW, 62.5 g kg-1 DW) and juvenile cuttings (27.3 g kg-1 DW, 73.9 g kg-1 DW). All measured rooting parameters (rooting success, number of main roots and root length) were significantly improved when cuttings of a more juvenile origin (semi-mature and juvenile) were used.


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