AMPHIDINIUM OPERCULATUM VAR. NOV. GIBBOSUM (DINOPHYCEAE), A FREE‐SWIMMING MARINE SPECIES PRODUCING CYTOTOXIC METABOLITES¹

Abstract

A single‐cell isolate of Amphidinium from the northern Caribbean Sea was identified as A. operculatum Clap. et Lack. var. nov. gibbosum Maranda et Shimizu based on a morphological and ultrastructural study. This free‐swimming dinoflagellate, which was found to produce potent antitumor metabolites, is elongate and asymmetrical. It is compared with two close relatives A. klebsii Kofoid et Swezy and A. carterae Hulburt. Amphidinium operculatum var. gibbosum can be distinguished from A. klebsii on the basis of shape while it differs from A. carterae on the basis of size, shape, cell surface, and chloroplast arrangement. The shape and size of the nucleus and the presence of mucocysts also differentiate the gibbosum variety from its two relatives. The architecture of the pusule may ultimately provide the best ultrastructural discriminating character. Otherwise, the general ultra‐structure of the Caribbean isolate is typical of many unarmored photo synthetic dinoflagellates with amphiesma, condensed chromosomes, trichocysts, mitochondria with tubular cristae, and trilamellar chloroplasts.

AMPHIDINIUM REVISITED. II. RESOLVING SPECIES BOUNDARIES IN THE AMPHIDINIUM OPERCULATUM SPECIES COMPLEX (DINOPHYCEAE), INCLUDING THE DESCRIPTIONS OF AMPHIDINIUM TRULLA SP. NOV. AND AMPHIDINIUM GIBBOSUM. COMB. NOV.1

“…The strains analyzed in this study previously found to produce amphidinolides or amphidinols, biotoxins produced by some Amphidinium species, were the strain of A. carterae , CAWD57 (Houdai et al 2001), and the strain of A. gibbosum SI‐36‐5 (Maranda and Shimizu 1996). A further strain, which appears to be of A. gibbosum , has also been reported in the literature to produce amphidinolides (Kobayashi et al 1991).…”

“…This species has been found as an endosymbiont in the flatworms Amphiscolops langerhansii , Amphiscolops sp., and Haplodiscus sp. isolated from Florida, USA (Taylor 1971a,b, Blanco and Chapman 1987, Trench and Winsor 1987) as well as free‐living in the plankton from the U.S. Virgin Islands (Maranda and Shimizu 1996).…”

“…This species has been previously identified under the names A. operculatum var. gibbosum (Maranda and Shimizu 1996), A. klebsii (Taylor 1971a,b, Blanco and Chapman 1987), and A . “belauense” (McNally et al 1994).…”

(3S)-4-[(4R)-2,2-dimethyl-1,3-dioxolan-4-yl]-3-methylbutan-1-ol—A universal building block for the synthesis of principal fragments of amphidinolides G and H

“…They have occupied the leading position in the search for new drugs and base model structures in life sciences for the determination of mechanisms of functioning of biosystems [2,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”

Synthesis of ethyl (2E,5S)-7-{[tert-butyl(dimethyl)silyloxy]-methyl}-5-methylocta-2,7-dienoate, a universal C7–C14 building block for the preparation of amphidinolides B, D, G, H, and L

“…Up to now, more than 30 amphidinolides A-Y and related substances have been isolated and studied [2,3]. Amphidinolides possess a unique structure and exhibit very high cytotoxicity and are therefore potential anti-tumor agents, which attract attention of researchers in the fields of chemistry, biology, and medicine over several decades [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”