Cytochalasin

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cytochalasin

[¦sīd·ō·kə′lā·sən]
(biochemistry)
One of a series of structurally related fungal metabolic products which, among other effects on biological systems, selectively and reversibly block cytokinesis while not affecting karyokinesis; the molecule with minor variations consists of a benzyl-substituted hydroaromatic isoindolone system, which in turn is fused to a small macrolide-like cyclic ring.

Cytochalasin

 

one of a group of related antibiotics produced by certain types of Fungi Imperfecti. Cytochalasins were isolated in 1967 by a British research group (S. B. Carter and coworkers). The cytochalasins that have been identified— designated A, B, C, D, E, and F—have the structural formula

and are differentiated by the side groups R1 and R2, representing different radicals.

Cytochalasins are crystal compounds with a molecular weight of 477 to 507 and a melting point of 182° to 270°C; they are insoluble in water but freely soluble in organic solvents. In a low concentration of 1 microgram per milliliter (μg/ml), cytochalasins inhibit the formation of an intracellular dividing membrane after the complete separation of the chromosomes that takes place in cell division, or mitosis, and thus lead to the formation of multinucleate cells. In concentrations of 10 μg/ml, cytochalasins cause the nucleus to be drawn out of the cell (enucleation). Another effect of cytochalasins is to block endocytosis in macrophages. The action of cytochalasins is reversible: upon their removal, endocytosis is reestablished; the nucleus, which having left the cell has remained connected to it by a cytoplasmic bridge, reenters the cell. Cytochalasins are believed to affect the microfilaments that are elements of the cell contraction system. Cytochalasins are used in research work in cytology and physiology.

REFERENCES

Carter, S. B. “Effects of Cytochalasins on Mammalian Cells.” Nature, 1967, vol. 213, no. 5073.
Carter, S. B. “The Cytochalasins as Research Tools in Cytology.” Endeavour, 1972, vol. 31, no. 113.

A. D. MOROZKIN

References in periodicals archive ?
05 which differentiates cytochalasin C from others such as S, G, H, [N.
5]N) indicated a close similarity between this compound and cytochalasin C.
Unlike the previous two compounds, this cytochalasin has four methyl groups; two singlets at [[delta].
TLC studies showed that the solid was an impure cytochalasin.
Abbreviations: CB, cytochalasin B; MF, microfilament; MT, microtubule; PI, post insemination; PW, pondwater.
Cytochalasin B blocks sperm incorporation but allows activation of the sea urchin egg.
The effect of cytochalasin B and D on the fertilization of sea urchins.
Cytochalasin B inhibits sperm penetration into eggs of Urechis caupo (Echiura).
In addition, isolation of cytochalasin J, dechlorogriseofulvin, griseofulvin, demethylharzianicacid, harzianic acid and 2-hexylidene-3methyl-succinic acid from the present study shows that plants from Malaysia rainforest could be hosts to a great diversity of endophytic fungi that serve as a remarkable source of bioactive compounds.
Toxicity and plant growth regulator effects of cytochalasin H isolated from Phomopsis sp.
Disordered pathfinding by pioneer neuron growth cones deprived of filopodia by cytochalasin treatment.
Cytochalasin B: effects on membrane ruffling, growth cone and microspike activity, and microfilament structure not due to altered glucose transport.