Chinoin Gyogyszer Es Vegyeszeti Termekek Gyara Rt.

Biogal Gyogyszergyar Rt.

Richter Gedeon Nyrt.

Aniko Tegdes

Vilmos Keri

Csaba Szabo

Gábor Balogh

Endre Kasztreiner

Gyorgy Cseh

Laszlo Jaszlits

Istvan Barta

Peter Matyus

Gyorgy Rabloczky

Valeria Szell

Andras Varro

Laszlo Sebestyen

Margit Bidlo Nee Igloy

Maria Kuhar Nee Kurthy

Katalin Olasz

Nandor Makk

János Wellmann

János Salát

Gabor Hantos

Judit Sarossy Nee Kincsesy

Eszter Diesler

Sándor Erdélyi

Edit Nagy Nee Arvai

Gyula Jerkovich

Laszlo Szam

IIdiko Lang

Sarolta Vegvari Nee Gyurki

Valéria Gancsos

David Leonov

Kalman Könczöl

A process for the isolation of the pseudomonic acid A antibiotic of pharmaceutical quality from the culture broth of one of the pseudomonic acid A-producing species of the Pseudomonas bacterium genus comprising the extraction of the biosynthesized pseudomonic acid A from the culture broth at acidic pH with a chlorinated aliphatic hydrocarbon or isobutyl acetate, followed by purification, is disclosed. The invention includes processes for purification of the isolated pseudomonic acid A, including (a) by the distribution of the evaporated extract residue between the aqueous-alcohol and some aliphatic or aromatic hydrocarbon, and then the extraction of the increased water-containing aqueous-alcoholic phase with methylene chloride, ethyl acetate, or isobutyl acetate; (b) by the extraction of the extract with aqueous ammonium hydrogen carbonate, alkali metal hydroxide or ammonium hydroxide solution and the acidification of the resulting alkaline aqueous extract, then reextraction again with a chlorinated aliphatic hydrocarbon or isobutyl acetate; and (c) by the concentration of the extract and the recrystallization of the crystalline pseudomonic acid A in a mixture of isobutyl acetate and petroleum ether, or acetonitrile, or aqueous acetonitrile.

Process for the isolation of pseudomonic acid A from pseudomonic acid complex-containing culture broth

The invention relates to novel pyrimido [5,4-b][1,4]oxazine derivatives of the formula (I), and the acid addition salts thereof, pharmaceutical compositions containing them and a process for their preparation. In the formula (I) ##STR1## wherein R.sup.1 stands for a C.sub.1-4 alkyl group;

Pyrimido[5,4-B][1,4]oxazine derivatives and pharmaceutical compositions

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Budapest, Hungary

Aniko Tegdes