Antimicrobial and anticancer activity of tetrahedral, chelated, diphosphine silver(I) complexes: comparison with copper and gold.

Tetrahedral, bischelated Ag(I) diphosphine complexes [Ag(P-P)2]NO3, where P-P is Ph2P(CH2)2PPh2 (dppe), Et2P(CH2)2PPh2 (depe), and cis-Ph2P(CH = CH)PPh2 (dppey), are potently cytotoxic to B16 melanoma cells in vitro (IC50 4 microM) and exhibit good activity against ip P388 leukemia in mice. The complex [Ag(dppe)2]NO3 is active against M5076 reticulum cell sarcoma. The antibacterial and antifungal activities of Ag(I) diphosphine and related Cu(I) and Au(I) complexes were assessed.

Parvodicin, a novel glycopeptide from a new species, Actinomadura parvosata: discovery, taxonomy, activity and structure elucidation.

An extensive taxonomic investigation identified strain SK&F-AAJ-271 as a new species, designated Actinomadura parvosata. Fermentations of this organism produce a complex of acidic, lipophilic glycopeptide antibiotics, the parvodicins. Structures for seven of the isolated components were derived from a combination of mass spectral, high-field NMR and chemical techniques.

Actinoidin A2, a novel glycopeptide: production, preparative HPLC separation and characterization.

An unidentified Nocardia sp. (SK&F-AAJ-193) was isolated and found to produce actinoidin A and a novel analog which we have named actinoidin A2. This new glycopeptide antibiotic differs from actinoidin A by the presence of rhamnose instead of acosamine.

Kibdelins, novel glycopeptide antibiotics. I. Discovery, production, and biological evaluation.

A new subspecies of Kibdelosporangium aridum subsp. largum (SK&F AAD-609), was isolated and shown to produce novel glycopeptides related to aridicins, but containing a homologous series of glycolipids based on N-acylglucosamine. These compounds showed improvements over the aridicins in in vitro activity and were effective in mouse protection studies against a range of Gram-positive bacteria, including methicillin resistant staphylococci.

Aridicins, novel glycopeptide antibiotics. III. Preparation, characterization, and biological activities of aglycone derivatives.

The aglycone and two pseudoaglycones of aridicin A were prepared by selective hydrolysis and characterized, chemically and biologically. These new analogs demonstrate improved activities in vitro over the parent antibiotics against methicillin sensitive and resistant staphylococci. The major determinant of activity is the mannose substituent, the presence of which results in less potent compounds.