Abstract: There are disclosed a novel polypeptide represented by the formula shown below or its acid addition salt or complex: ##STR1## wherein Ala represents alanine, Ser serine, Leu leucine, Thr threonine, Val valine, Gly glycine, Lys lysine, Gln glutamine, Glu glutamic acid, His histidine, Tyr tyrosine, Pro proline, Arg arginine, Asp aspartic acid, and n represents an integer of 3 to 7,and a process for producing the same comprising forming a peptide or polypeptide represented by the above formula and subjecting the structural units containing a peptide residue represented by the formula: ##STR2## wherein R represents an active ester residue, Ala, Ser, Leu, Thr and n have the same meanings as defined above,formed in any step of the reaction to cyclization reaction.

Abstract: A water soluble extract from nonpathogenic aerobic corynebacteria such as Corynebacterium equi Ko-85 strain, the said water soluble extract having the following characteristics:(a) protein content: 3.9-5.5 mg/ml (on the basis of Bovine Serum Albumin),(b) sugar component: 0.41-0.52 mg/ml (on the basis of glucose),(c) nucleic acid like substance: optical density in 260 nm/280 nm (ratio) of 1.56-1.62, and(d) isoelectric point: 3.75-3.80.The extract possesses an anti-allergic effect, an anti-cancer effect, and an immunopotentiative effect and is particularly useful as an anti-allergic agent.