## Thymus:

The thymus is located behind the sternum and close to the heart. It is grayish red, flat and oval. It is divided into left and right lobes and consists of lymphoid tissue. Before puberty, the hair was well filled, and after puberty, it gradually degenerated, which was replaced by adipose tissue. Thymus is not only the place where T cells develop and mature, but also the important central immune organ of the body. It can also secrete many peptide hormones, and it is also an important endocrine organ. Thymic hormone regulates the development, differentiation and maturation of T cells in the way of paracrine in the thymus, and at the same time, it also enters the blood to affect the function of peripheral immune organs and neuroendocrine system. Therefore, thymus is an important organ in the immune neuroendocrine network

## Thymosin:

Thymosin is a kind of protein and polypeptide hormone produced by thymus. It is a kind of biological response regulating factor. It can promote lymphocyte maturation, regulate and enhance the immune mechanism of human body. It has the functions of anti-aging, anti-virus replication and anti-tumor cell differentiation in clinic. Thymosin preparation has been used in China for more than 20 years. Its main component is thymus tissue extract of healthy calves and other animals. However, due to the different production process and standards of various preparations, the product quality and clinical efficacy are also different.

## Thymopentin:

Thymopentin (TP-5) is composed of five amino acids: arginine, lysine, aspartic acid, valine and tyrosine. It is an effective part of thymogenin Ⅱ in thymic secretion. Thymogenin II is a single peptide compound separated from thymic hormone, which is composed of 49 amino acids, and the peptide chain segment composed of 5 amino acids has the same physiological functions as thymogenin II, so it is called thymopentin. At present, the preparation of thymopentin in our country is a kind of synthetic compound with clear structure and high purity, which is based on amino acids and synthesized by high-tech means.

## Thymalfasin for Injection:

Thymosin (t α 1) is a high-end product of thymosin. It is a small bioactive polypeptide separated from thymosin component 5 (tf-5). It is made of 28 amino acids. Its molecular weight is 3108.37, and its content is about 0.6% of tf-5. It has high immune enhancement activity. Thymopentin and thymogenin II are two kinds of thymic hormone components that are most well known by human beings. Therefore, the Thymopentin on the market, like thymopentin, has a clear structure with a purity of more than 99%.

In general, thymosin, thymopentin and thymus fasin are thymic hormone immunomodulators, which can regulate the development, differentiation and maturation of T-lymphocytes, repair damaged T-lymphocytes and play an important role in the human immune system. Thymosin is the extract of thymus of animals, which contains all kinds of thymic hormones. Thymopentin and thymus method are important active components in thymus hormone of human body. They are synthesized by artificial method, with definite effective components and clear mechanism of action, without skin test.