The invention relates to a
cyclic peptide capable of reducing
insulin, not increasing
blood sugar but properly reducing
blood sugar at the same time, and belongs to the technical field of biological
pharmacy. The
bifunctional cyclic peptide is obtained through in-vitro modification on the basis of an original linear short
peptide COX52-69; the effects of two seemingly contradictory aspects are achieved; namely, the effect of inhibiting
insulin secretion but not increasing
blood sugar at the same time is achieved; blood
sugar is reduced; and the mechanism of the
bifunctional cyclic peptide is possibly to improve the sensitivity of tissue to
insulin. It is called as a
bifunctional peptide. The bifunctional
peptide can be used for congenital insulinemia,
insulin tolerance,
hyperinsulinemia of obese people and the like; literatures report that insulin increase is the reason of
obesity; but people cannot lose weight through a method of reducing insulin all the time; and because blood
sugar is increased after insulin is reduced, hyperglycemia is more adverse to health. The cyclic peptide realizes the function that the blood
sugar is not increased but is reduced while insulin is reduced, so that a new
medicine is developed for treating
obesity; and the
medicine not only can be administrated by injection, but also can be conveniently administrated by
oral administration. The convenience of using the
medicine is greatly improved.