Compounds having a structure according to formula (I) or (II)

##STR00001##

where R.sup.1, R.sup.2, R.sup.3, R.sup.4, Ar and X.sup.1 are as defined herein, are agonists for the Toll-like receptor 7 (TLR7) and can be used as adjuvants for stimulating the immune system. Some such compounds can be used in conjugates for targeted delivery to the organ or tissue of intended action.

The disclosure relates to an entecavir intermediate, a synthetic method therefor, and the synthetic method for entecavir by using the intermediate. According to the disclosure, the synthetic methods for entecavir and the intermediate thereof have the advantages of being controllable in chirality, high in yield and product purity, wide in source of raw materials, cheap and available in reagents, simple in reactions, convenient to operate, environmentally friendly, and suitable for industrial amplification production.

The disclosure relates to an entecavir intermediate, a synthetic method therefor, and the synthetic method for entecavir by using the intermediate. According to the disclosure, the synthetic methods for entecavir and the intermediate thereof have the advantages of being controllable in chirality, high in yield and product purity, wide in source of raw materials, cheap and available in reagents, simple in reactions, convenient to operate, environmentally friendly, and suitable for industrial amplification production.

Provided are a long-acting prodrug of Entecavir, preparation method and use thereof, wherein the prodrug of Entecavir has a structure of formula I. The prodrug of Entecavir can be released slowly, sustainably and steady, and converted to active compound of Entecavir to achieve a long-acting effect.

Compounds of formula (I):

##STR00001##

wherein: R.sup.1 is butoxy or methylbutoxy; R.sup.2 is a group having the structure:

##STR00002##

where n is an integer having a value of five; Het is a six-membered saturated heterocycle containing five carbon atoms and one nitrogen atom, wherein Het is attached to the (CH2).sub.n-moiety at the carbon 4 position of the heterocycle; and R.sup.3 is hydrogen; or pharmaceutically acceptable salts thereof; and their use as vaccine adjuvants and in the treatment of various disorders.

Compounds of formula (I):

##STR00001##

wherein: R.sup.1 is butoxy or methylbutoxy; R.sup.2 is a group having the structure:

##STR00002##

where n is an integer having a value of five; Het is a six-membered saturated heterocycle containing five carbon atoms and one nitrogen atom, wherein Het is attached to the (CH2).sub.n-moiety at the carbon 4 position of the heterocycle; and R.sup.3 is hydrogen; or pharmaceutically acceptable salts thereof; and their use as vaccine adjuvants and in the treatment of various disorders.

Provided is a degrader for injured mitochondria based on an autophagy mechanism, the degrader including a compound or a salt thereof, the compound containing a ligand capable of binding to or accumulating in mitochondria and a substituent represented by the following general formula (1):

##STR00001##

where R.sup.1, R.sup.2, and R.sup.3 are identical to or different from each other, and each represent a hydrogen atom or the like.

Provided is a degrader for injured mitochondria based on an autophagy mechanism, the degrader including a compound or a salt thereof, the compound containing a ligand capable of binding to or accumulating in mitochondria and a substituent represented by the following general formula (1):

##STR00001##

where R.sup.1, R.sup.2, and R.sup.3 are identical to or different from each other, and each represent a hydrogen atom or the like.

Compound I and a compound II as well as preparation methods therefor and use thereof are disclosed. A newly synthesized compound of formula I is capable of stimulating congenital immunity and cellular immunity for tumor resistance while greatly improving the antitumor effect of ethacrynic acid (EA), and thus an integrated synergistic anti-tumor dual-immunity drug design is explored. The immune response mechanism for resisting melanoma of the compound as shown in the formula I is demonstrated. A compound that is as shown in a formula II and is prepared from the compound of formula I and ROR1 by means of covalency markedly slows down the growth of subcutaneously transplanted mammary cancer tumor, such that the immune response mechanism, for treating the mammary cancer, of the compound as shown in the formula II is demonstrated.

Compound I and a compound II as well as preparation methods therefor and use thereof are disclosed. A newly synthesized compound of formula I is capable of stimulating congenital immunity and cellular immunity for tumor resistance while greatly improving the antitumor effect of ethacrynic acid (EA), and thus an integrated synergistic anti-tumor dual-immunity drug design is explored. The immune response mechanism for resisting melanoma of the compound as shown in the formula I is demonstrated. A compound that is as shown in a formula II and is prepared from the compound of formula I and ROR1 by means of covalency markedly slows down the growth of subcutaneously transplanted mammary cancer tumor, such that the immune response mechanism, for treating the mammary cancer, of the compound as shown in the formula II is demonstrated.