An x-ray crystal structure determination of a dinostanol from the dinoflagellate Protoceratium reticulatum and zooxanthellae from Orbulina universa was completed. The novel sterol was shown to be 3 beta-hydroxy-4 alpha, 23R,24R-trimethyl-5 alpha-cholestane and may be one of the molecular fossils found in sediment cores from the deepest Black Sea trench.

Chemical Phenomena↗

PubMedDate not supplied

The antineoplastic quassinoids of Simaba cuspidata spruce and Ailanthus grandis Prain.

The South American Simaba cuspidata Spruce and North Indian Ailanthus grandis Prain were investigated as sources of potentially useful antineoplastic agents. Both of these Simaroubaceae plant species were found to produce 6 alpha-tigloyloxychaparrinone (4a) and the new quassinoid 6 alpha-tigloyloxychaparrin (3b). The latter structure was determined by interpretation of spectral data and oxidation to 6 alpha-tigloyloxychaparrinone (4a). While both glycol 3b and alpha-ketol 4a were found to significantly inhibit growth of the murine P388 lymphocytic leukemia cell line, only the alpha-ketol (4a) inhibited growth of the corresponding in vivo system.

Animals↗

PubMedDate not supplied

Marine animal biosynthetic constituents for cancer chemotherapy.

A fifteen year investigation of marine animal components as sources for new and potentially useful cancer chemotherapeutic drugs has led to our discovery of a number of such valuable substance. The especially productive Indian Ocean sea hare Dolabella auricularia has yielded (100 kg leads to or approximately 1 mg each) a series of very potent cell growth inhibitory substances designated dolastatins 1-9. The first member of this new series, dolastatin 1, may represent the most potent anticancer agent so far uncovered with, e.g., a curative response (33%) using a dose of 11 microgram/kg (T/C 240, to T/C 139 at 1.37 microgram/kg) in the National Cancer Institute's murine B16 melanoma. Structural elucidation of the new antineoplastic agents is underway, and recent progress is illustrated with peptide dolastatin 3 (P388 ED 50 2.7 x 10(-7) microgram/ml).

Animals↗

PubMedDate not supplied

Antineoplastic agents. 76. The sea urchin Strongylocentrotus droebachiensis.

An improved procedure based on centrifugation at 37,000 g has been developed for isolating the antineoplastic glycoprotein strongylostatin 1 from Strongylocentrotus droebachiensis (Müller). The green sea urchin has also been found to contain a second protein anticancer constituent designated strongylostatin 2. Treatment of the murine P388 lymphocytic leukemia with strongylostatin 2 resulted in 39-42% life extension at a dose of 4.5 mg/kg.

Animals↗

PubMedDate not supplied

Evaluation of limonoids against the murine P388 lymphocytic leukemia cell line.

A structure/activity study of selected limonoids from two plant families (Meliaceae and Rutaceae) of the Rutales order against the murine P-388 lymphocytic leukemia system was undertaken. The presence of both a 19 leads to 28 lactol and a 14,15 beta-epoxide group was found especially important for pronounced inhibition of the PS in vitro cell line. Substitution of an A-ring alpha,beta-unsaturated ketone (3-oxo-1-ene) for the lactol led to diminished activity, while reduction of the olefin caused complete loss of activity. At the dose levels employed, even very good PS in vitro inhibition was not translated into PS in vivo antineoplastic effects.

Animals↗

PubMedDate not supplied

Antineoplastic agents, 116. An evaluation of the marine ascidian Aplidium californicum.

The antineoplastic constituents of the marine ascidian Aplidium californicum were found to be bryostatins 4 and 5. Bioassay-directed isolation procedures using the National Cancer Institute's P-388 lymphocytic leukemia system led to the bryostatins. The probable symbiotic relationship between A. californicum and the bryozoan Bugula neritina was discussed.

Animals↗

PubMedDate not supplied

Antineoplastic agents, 118. Isolation and structure of bryostatin 9.

Explore the source record for details and available documents.

Acetylation↗

PubMedDate not supplied

Antineoplastic agents. 52. Baileya multiradiata.

The desert-marigold Baileya multiradiata Harv. and Gray (Compositae) has been found to produce a series of sesquiterpenes that markedly inhibit growth of the murine lymphocytic leukemia P388 and the corresponding in vitro cell line. Separation guided by bioassay led to the isolation of baileyin (1), fastigilins B and C (3a and 2a), radiatin (3b), pleniradin (4a), and the new pseudoguaianolide multiradiatin (2b). The most significant antitumor activity was displayed by fastigilin C (2a) and radiation (3b).

Animals↗