| 摘要 |
1323377 Complexes of antibiotic AV290; sulphonic acids AMERICAN CYANAMID CO 25 Oct 1971 [3 Nov 1970] 49518/71 Headings C2A and C2C [Also in Division C3] Novel complexes of antibiotic AV290 and a syntan are prepared by acidifying a whole or filtered AV290-containing fermentation broth to pH 1À4 to 5À0, adding a syntan and recovering the precipitated complex. Syntans are defined as synthetic tanning agents which are condensation products of formaldehyde and sulphonated phenols (e.g. phenol, cresols, naphthols or bis-phenols) or naphthalene-sulphonic acids, or of formaldehyde, phenols and a bisulphite or SO 2 (see Division C3). The complexes are recovered by filtration or centrifugation and when a whole fermentation broth is used, they are obtained in the form of a composition of the complex together with the broth solids (e.g. mycelia and other insoluble matter), which is then dried, for example by reslurrying in water and freeze-drying or spraydrying, or by slurrying in a water-miscible organic non-solvent (e.g. acetone), filtering and air-drying. The syntan is preferably added as an aqueous solution, in slight excess of amount required to completely precipitate the complex. The antibiotic is loosely bonded to the syntan and may be isolated therefrom by absorption on cross-linked carboxymethyldextran gel and eluting with aqueous acid. Animal feed supplement compositions having growth-promoting and feed efficiency-enhancing activity comprise a dried mixture of fermentation broth solids and the antibiotic AV290- syntan complex, optionally together with an edible carrier and/or a nutritionally balanced animal feed. A sulphonated naphthalene-formaldehyde condensate probably having the formula wherein n is zero to 4, is prepared by sulphonating naphthalene at 105‹ C. with 93% H 2 SO 4 and treating the reaction mixture with aqueous formaldehyde. A sulphonated phenol-formaldehyde condensate probably having the formula: wherein R is -SO 3 H and n is zero to 4, is prepared by reacting phenolsulphonic acid and aqueous formaldehyde solution at 100‹ C. and then cooling to precipitate the said product. Reference has been directed by the Comptroller to Specification 1,194,365. |
