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434 results on '"Ochromonas"'

401. Stereochemistry of hydride migration from C-24 to C-25 in the biosynthesis of priferasterol in Ochromonas malhamensis

Author

Francesco Nicotra, Bianca Maria Ranzi, Fiamma Ronchetti, Giovanni Russo, Lucio Toma, and Pierluigi Gariboldi

Subjects
chemistry.chemical_classification, chemistry.chemical_compound, Ochromonas, Biosynthesis, Double bond, Chemistry, Stereochemistry, Hydride, medicine.medical_treatment, medicine, Molecular Medicine, Steroid
Abstract

2 H-N.m.r. analysis of (2 S, 3 R)-2-([2H2]methyl)-[1,1,1,2-2H4]pentan-3-ol obtained from [2H22]poriferasterol, biosynthesized in the Chrysophyte Ochromonas malhamensis from C2H3CO2Na, shows that the hydride migration from C-24 to C-25 occurs on the si-face of the Δ24-precursor double bond.

Published
1984

402. Notizen: 'Synthetische' Aiptasia mutabilis RAPP (Coelenterata) / 'Synthetical' Aiptasia mutabilis RAPP (Coelenterata)

Author

Franz-Christian Czygan

Subjects
Ochromonas, Nostoc, Oscillatoria, biology, Algae, Botany, Chlorophyceae, Dunaliella, biology.organism_classification, Aiptasia, Coelenterata, General Biochemistry, Genetics and Molecular Biology
Abstract

After being cultivated in the dark for some months and after being fed with food free of carotenoids during the time Aiptasia mutabilis (Coelenterata) loses its symbiontic algae (rich in brown fucoxanthin) and becomes transparent white. This disarranged symbiosis may be regenerated under light cultivation by adding different species of Chlorophyceae (Chlorella, Dunaliella) and Chrysophyceae (Ochromonas, Cyclotella), but not of Cyanophyceae (Anabaena, Nostoc, Oscillatoria, Anacystis). - This changeable life system between coelenterata and algae may be a good example for further studies of the endosymbiosis problem.

Published
1976

403. Validation of Paraphysomonas diademifera and Polylepidomonas vacuolata (Chrysophyceae)

Author

David J. Hibberd and Hans Rudolf Preisig

Subjects
Ochromonas, Algae, Basionym, Botany, Taxonomy (biology), Plant Science, Biology, biology.organism_classification, Ecology, Evolution, Behavior and Systematics
Abstract

An account is given on the validation of the combinations Paraphysomonas diademifera (Takahashi) Preisig & Hibberd (basionym: Ochromonas diademifera Taka_ hashi) and Polylepidomonas vacuolata (Thorasen) Preisig & Hibberd (basionym: Paraphysomonas vacuolata Thomsen).

Published
1987

404. Biosynthesis of the C29-phytosterol side-chain: evidence that the same stereochemistry at C-25 can originate from different mechanisms

Author

Lucio Toma, Fiamma Ronchetti, and Giovanni Russo

Subjects
chemistry.chemical_classification, chemistry.chemical_compound, Ochromonas, Polycyclic compound, chemistry, Biosynthesis, Stereochemistry, Phytosterol, Side chain, Molecular Medicine, Organic chemistry, Molecule, Hydrogen atom
Abstract

It has been demonstrated that in poriferasterol, biosynthesized in Ochromonas malhamensis, the hydrogen atom originally present at C-24 of the Δ24-precursor is located at C-25.

Published
1988

405. Origin of the 28-pro-R and 28-pro-S hydrogens in the biosynthesis of poriferasterol in Ochromonas malhamensis

Author

Lucio Toma, Francesco Nicotra, Fiamma Ronchetti, Bianca Maria Ranzi, and Giovanni Russo

Subjects
Ochromonas, chemistry.chemical_compound, Biosynthesis, Stereochemistry, Chemistry, Molecular Medicine, Hydrogen atom, Spectroscopy
Abstract

It is shown, by 2H n.m.r. spectroscopy, that in the biosynthesis of poriferasterol in Ochromonas malhamensis the hydrogen atom at C-28 arising from S-adenosylmethionine assumes the 28-pro-S position, whereas the hydrogen atom coming from the reducing system assumes the 28-pro-R position.

Published
1980

407. The conversion of 24-ethylidene-sterols into poriferasterol by Ochromonas malhamensis

Author

L. J. Goad, F. F. Knapp, J. B. Greig, and Trevor W. Goodwin

Subjects
Ochromonas, Chemistry, Stereochemistry, Fucosterol
Abstract

The 24-ethylidene-sterols fucosterol, 28-isofucosterol and 5α-strigmasta-7,Z-24(28)-dien-3β-ol are converted into poriferasterol by Ochromonas malhamensis, the efficiency of conversion being dependent on the configuration of the ethylidene group.

Published
1971

409. Level of Vitamin B12 in Propionate-grown Prototheca zopfii

Author

David Lloyd

Subjects
chemistry.chemical_classification, Multidisciplinary, Prototheca zopfii, biology, Chemistry, fungi, Eukaryota, biology.organism_classification, Euglena, Microbiology, Vitamin B 12, Ochromonas, Propionate, Vitamin B12, Propionates, Flagellate
Abstract

THE colourless alga Prototheca zopfii does not require vitamin B12 as a growth factor, whereas at least half the marine algal flagellates and diatoms which have been investigated in pure culture1, the protozoan flagellate Ochromonas malhamensis2, and Euglena gracilis3, have all been shown to have a growth requirement for this compound.

Published
1966

410. ACTIVITY OF CYANOCOBALAMIN, DIMETHYLBENZIMIDA-ZOLYLCOBAMIDE COENZYME AND SOME OF THEIR ANALOGUES FOR THE METABOLISM OF OCHROMONAS MALHAMENSIS.

Author

ARNSTEIN HR and WHITE AM

Subjects
Amides, Anilides, Aspartic Acid, Benzimidazoles, Carbohydrate Metabolism, Carbon Isotopes, Coenzymes, Eukaryota, Flavobacterium, Formates, Glucose, Metabolism, Methionine, Ochromonas, Organic Chemicals, Pharmacology, Phenylalanine, Propionates, Proteins metabolism, Research, Vitamin B 12
Published
1964
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415. Chloroplast development in Ochromonas danica.

Author

GIBBS SP

Subjects
Chlorophyll A, Membranes, Carotenoids, Cell Nucleus, Chlorophyll, Chloroplasts, Cytoplasm, Eukaryota, Light, Nuclear Envelope, Ochromonas
Abstract

When dark-grown cells of Ochromonas danica are placed in the light, the amount of chlorophyll a per cell increases 82-fold; the content of carotenoid pigment, 24-fold. Concomitantly with this increase in chlorophyll and carotenoid pigment, the small proplastid of dark-grown cells develops into a large lamellate chloroplast. During the first 12 hours in the light, vesicles appear within the loose clusters of dense chloroplast granules, enlarge, align themselves into rows (plates in three dimensions), and fuse into discs. Double discs may form from the more or less simultaneous fusion of two adjacent plates of vesicles or by the addition of vesicles to an already formed single disc. Three-disc bands arise by the addition of a disc to an already formed two-disc band through the approach and fusion of more vesicles. After 24 hours in the light, most of the chloroplast bands contain three discs, but the chloroplasts are still small. After 48 hours in the light, almost all the cells contain full-sized chloroplasts with a full complement of three-disc bands. However, at this time the amount of chlorophyll a and carotenoid pigment is only one-half of maximum. During the next 3 days in the light, as the number of chlorophyll and carotenoid molecules per chloroplast approximately doubles, there is a compression of the discs in each band (from 180 to 130 A) and a precise alignment of their membranes. Changes also occur in the nucleus when dark-grown cells are placed in the light. There is an increase in the number of small nucleolar bodies, many of which lie directly against the nuclear envelope, and in a few cells a dense mass of granules is seen between the two membranes of the nuclear envelope.

Published
1962
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