scholarly journals Incorporation of dl-[2−14C]mevalonic acid lactone into β-carotene and the phytol side chain of chlorophyll in cotyledons of four species of pine seedlings

1967 ◽  
Vol 105 (1) ◽  
pp. 89-92 ◽  
Author(s):  
S. Wieckowski ◽  
T W Goodwin
Keyword(s):  
Mevalonic Acid ◽  
Side Chain ◽  
Pinus Silvestris ◽  
Pine Seedlings ◽  
Acid Lactone ◽  
Β Carotene

1. The incorporation of dl-[2−14C]mevalonic acid lactone into β-carotene and the phytol side chain of chlorophyll has been investigated in cotyledons of four species of pine seedlings (Pinus silvestris, P. contorta, P. radiata and P. jeffrei) grown in darkness and in light. 2. The relative incorporation of label into β-carotene and the phytol side chain of chlorophyll is similar to that observed in experiments on monocotyledons and dicotyledons. 3. The relative incorporation of 14CO2 into β-carotene and phytol is much higher than the incorporation of [2−14C]mevalonic acid.

scholarly journals Biosynthesis of ergotamine by Claviceps purpurea (Fr.) Tul

1973 ◽  
Vol 134 (1) ◽  
pp. 1-10 ◽  
Author(s):  
R. A. Bassett ◽  
E. B. Chain ◽  
K. Corbett
Keyword(s):  
Amino Acid ◽  
Time Course ◽  
Ergot Alkaloids ◽  
Mevalonic Acid ◽  
Defined Medium ◽  
Chemical Degradation ◽  
Side Chain ◽  
Claviceps Purpurea ◽  
Incubation Experiments ◽  
Acid Lactone

High-yielding strains of Claviceps purpurea (Fr.) Tul, grown on a defined medium, have been used for a study of the biosynthesis of the peptide ergot alkaloid, ergotamine. l-[U-14C]tryptophan, dl-[2-14C]mevalonic acid lactone, sodium [2-14C]acetate, sodium [14C]formate and the methyl group of l-[methyl-14C]methionine were efficiently incorporated into the peptide alkaloids and specifically labelled the ergoline moiety of ergotamine. These results are the same as previously found for the biosynthesis of other ergot alkaloids. Time-course incubation experiments demonstrated that l-[U-14C]phenylalanine, l-[U-14C]proline and l-[U-14C]alanine were incorporated into the peptide ergot alkaloids. Chemical degradation of the radioactive alkaloid derived from additional precursor incubation experiments showed that phenylalanine and proline function as the most efficient precursors, and specifically label the constitutive side-chain phenylalanyl and prolyl moieties of the alkaloid. The evidence obtained from l-[U-14C]alanine-incorporation experiments was inconclusive. However, degradation of ergotamine isolated after incubation with dl-[1-14C]alanine, showed that the carboxyl group of the labelled amino acid was specifically incorporated into the α-hydroxy-α-amino acid residue of the alkaloid. This, in conjunction with the l-[U-14C]alanine-incorporation results, showed conclusively that all three carbon atoms of alanine were incorporated as a biosynthetic unit into the α-hydroxy-α-amino acid moiety of ergotamine.

scholarly journals The effect of the photoperiod on the level of endogenous growth regulators in pine (Pinus silvestris L.) seedlings

2014 ◽  
Vol 51 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Krystyna Kriesel ◽  
Sławomir Ciesielska
Keyword(s):  
Abscisic Acid ◽  
Growth And Development ◽  
Morphological Characters ◽  
Axillary Buds ◽  
Pinus Silvestris ◽  
Low Intensity ◽  
Pine Seedlings ◽  
Terminal Bud ◽  
Development Processes ◽  
High Level

The investigations were performed on pine seedlings growing under 12, 16 and 20 hour photoperiods. In 4 succesive stages of seedling development i.e. after 2, 12, 18 and 30 weeks of culture morphological characters of the seedlings were measured and the levels of auxins-, gibberellins-, cytokininsand abscisic acid-like inhibitor were determined. The intensity of growth and development of juvenile leaves, needles and of the shoot was the lowest in plants growing under 12 hour photoperiod conditions. As the length of the photoperiod increased so did the intensity of these processes. Under the 12 hour photoperiod the development of scale leaves, axillary buds and the formation of the terminal bud started earliest. This process reached completion under the 12 hour photoperiod and the bud remained in a state of dormancy. Seedlings growing under the 12 hour photoperiod were characterized by a low level of stimulators, and at the same time by a high level of inhibitors. On the other hand in seedlings grown at 16 and 20 hour photoperiods the content of stimulators was higher and that of inhibitors lower. A high intensity of growth and development processes was correlated with a high level of stimulators while a high level of inhibitors was correlated with a low intensity of these processes.The obtained results suggest the participation of gibberellins and cytokinins in the processes of regulation of the initiation of scale leaves and axillary buds, and the participation of these hormones and of abscisic acid in the regulation of needle elongation.

Sterol Synthesis in Human Endothelial Cells

1975 ◽  
Author(s):  
S. A. Evensen ◽  
T. Henriksen
Keyword(s):  
Endothelial Cells ◽  
Mevalonic Acid ◽  
Acid Synthesis ◽  
Sterol Fraction ◽  
Sterol Synthesis ◽  
Human Endothelial Cells ◽  
Intermediary Product ◽  
Acid Lactone ◽  
Umbilical Cords ◽  
Progressive Accumulation

Endothelial cells were isolated by collagenase digestion of the intima of the vein of umbilical cords and grown in medium 199 or RPMI 1640 supplemented with 20% FCS. After 3–5 days in primary culture fresh medium was added containing either sodium acetate-2-14C or mevalonic acid lactone-2-14C. Following further 24, 48 or 96 h incubation the harvested cells and media were extracted according to Folch and separated on TLC. About 35% of the total cellular radioactivity accumulated in the sterol fraction after 48 h incubation with labelled acetate. Delipidation of the medium resulted in markedly increased incorporation. Incorporation of mevalonic acid into cellular sterols was maximal at 48 h, and larger in RPMI 1640 than in medium 199. In the medium a progressive accumulation of labelled sterols with time was observed. Approximately 20% of the cellular radioactivity was found in the FFA fraction and was saponifiable. Whether this finding represents fatty acid synthesis from mevalonic acid or an intermediary product in sterol synthesis has not yet been clarified.

BIOSYNTHESIS OF C19 STEROIDS FROM 4-14C-CHOLESTEROL AND 7-3H-PREGNENOLONE IN VIVO: CONSIDERATION OF NEW PATHWAYS

1962 ◽  
Vol 40 (2) ◽  
pp. 188-202 ◽  
Author(s):  
Shlomo Burstein ◽  
Ralph I. Dorfman
Keyword(s):  
Adrenal Adenoma ◽  
Mevalonic Acid ◽  
Compartment Model ◽  
Side Chain ◽  
Partition Chromatography ◽  
Steroid Nucleus ◽  
Single Intravenous Injection ◽  
Two Compartment Model ◽  
Specific Activities

ABSTRACT 3H and 14C specific activities of dehydroepiandrosterone, androsterone, 3α-hydroxy-5β-androstan-17-one and 3α-hydroxy-5α-androst-16-ene (without dilution) have been determined following a single intravenous injection of 4-14C-cholesterol and 7α-3H-pregnenolone to a virilized woman with an adrenal adenoma and massive dehydroepiandrosterone excretion. Assuming a one compartment model, or a two compartment model in which the injected radioactivity enters the compartment in which the precursor is secreted exclusively, a new pathway by which dehydroepiandrosterone is formed from cholesterol not through pregnenolone and possibly by cleavage of the side chain C-17 and C-20 is indicated. Analysis of the data by a model in which pregnenolone is secreted into two separate compartments in which progesterone and dehydroepiandrosterone are made, respectively, would explain the findings without necessitating the assumption of a new pathway. 3α-Hydroxy-5α-androst-16-ene was isolated from urine following incubation with β-glucuronidase and partition chromatography on celite suggesting that this steroid is a genuine natural product as surmised by Prelog & Ruzicka (1944) and Brooksbank & Haslewood (1950). 2-14C-Mevalonate was shown to give rise to C19 steroids which is the first in vivo demonstration that mevalonic acid is a precursor of the steroid nucleus in man.

The synthesis of 5S-5-[3H1]mevalonic acid lactone

1970 ◽  
pp. 1396 ◽  
Author(s):  
A. I. Scott ◽  
G. T. Phillips ◽  
P. B. Reichardt ◽  
J. G. Sweeny
Keyword(s):  
Mevalonic Acid ◽  
Acid Lactone

scholarly journals Synthesis of (±)-mevalonic acid lactone via a meso-dialdehyde: a model for desymmetrization

ARKIVOC ◽  
2002 ◽  
Vol 2002 (8) ◽  
pp. 46-56 ◽  
Author(s):  
Shirley L. J. Buckley ◽  
Laurence M. Harwood ◽  
Antonio J. Macías-Sánchez
Keyword(s):  
Mevalonic Acid ◽  
Acid Lactone

scholarly journals 374 Evidence that α-farnesene Biosynthesis during Fruit Ripening is Involved in Ethylene-regulated Gene Expression

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 508C-508
Author(s):  
Zhiguo Ju ◽  
Eric A. Curry
Keyword(s):  
Gene Expression ◽  
Fruit Ripening ◽  
Exponential Growth ◽  
Actinomycin D ◽  
Mevalonic Acid ◽  
Growth Equation ◽  
Farnesyl Pyrophosphate ◽  
Fruit Peel ◽  
Acid Lactone ◽  
Regulated Gene Expression

In `Delicious' and `Granny Smith' apples, fruit did not produce α-farnesene until internal ethylene reached about 1 μL•L-1. The correlation between internal ethylene and α-farnesene production was highly significant (r2 = 0.71 and 0.76, respectively) and fitted the exponential growth equation. Aminoethoxyvinylglycine (AVG) inhibited both internal ethylene and α-farnesene production, while ethephon stimulated them. When applied to discs from preclimacteric fruit peel, cycloheximide and actinomycin D inhibited ethylene and α-farnesene production. In discs from AVG-treated fruit, ethephon induced α-farnesene synthesis. Cycloheximide, actinomycin D, and silver ion counteracted the stimulation effect of ethephon. When added to discs from preclimacteric fruit peel or AVG-treated fruit peel, hydroxymethylglutarc acid, mevalonic acid lactone, and farnesyl pyrophosphate induced α-farnesene synthesis, which was not affected by cycloheximide or actinomycin D.

scholarly journals Incorporation of [2−14C]mevalonic acid into phytoene by isolated chloroplasts

1967 ◽  
Vol 105 (1) ◽  
pp. 205-212 ◽  
Author(s):  
Josephine M. Charlton ◽  
K J. Treharne ◽  
T W Goodwin
Keyword(s):  
Ultrasonic Treatment ◽  
Magnesium Chloride ◽  
Mevalonic Acid ◽  
Side Chain ◽  
Isolated Chloroplasts

1. Chloroplasts prepared by the non-aqueous technique will, after fragmentation by ultrasonic treatment, incorporate [2−14C]mevalonic acid into phytoene, the first C40 compound formed in the biosynthetic sequence to coloured carotenoids. 2. With suspensions containing 3·5mg. of chlorophyll, the optimum amounts of cofactor required were ATP (10μmoles), magnesium chloride (20μmoles) and glutathione (20μmoles); neither NAD+ nor NADP+ was required. 3. Very small amounts of squalene are also formed and synthesis is stimulated by addition of NADH or NADPH. Phytoene synthesis was not affected by the presence of these cofactors and no lycopersene (the C40 homologue of squalene) was detected. 4. The phytol side chain of chlorophyll is also labelled under these conditions. 5. Preparations of developing chloroplasts are more active than preparations of mature chloroplasts.

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