An object of the present invention is to provide a method for producing a peptide with high purity and high efficiency, a protective group-forming reagent having excellent deprotective properties, and a novel condensed polycyclic compound. According to the present invention, there are provided a method for producing a peptide including a step of using a polycyclic compound represented by Formula (1), a protective group-forming reagent containing the polycyclic compound, and the polycyclic compound. At least one of R.sup.1 to R.sup.8 and R.sup.110 has R.sup.A, R.sup.A represents an aliphatic hydrocarbon group or an organic group having an aliphatic hydrocarbon group, and at least one aliphatic hydrocarbon group has 3 or more carbon atoms.

##STR00001##

Disclosed herein is an improved process for preparing abaloparatide. The process generally utilizes solid phase peptide synthesis employing an Fmoc-protection scheme. Incorporating a systematic recoupling step of a glutamine residue (Gln.sup.16) has been found to minimize the formation of an undesirable des-Gln.sup.16 abaloparatide impurity, which is often obtained in significant quantities in the conventional process.

The present invention relates to a method for the synthesis of a polypeptide comprising a pre-determined amino acid sequence. The method according to the invention comprises coupling cycles of coupling an N-terminally protected amino acid building block C-terminally at an unprotected N-terminal amino group of an amino acid chain, wherein at least one coupling cycle comprises a coupling step (a), a capping step (b), and a de-protecting step (c).

A bis-alkoxyl amide alkyl cationic peptide lipid has a chemical structure as below: ##STR00001##
wherein the bis-alkoxyl amide alkyl cationic peptide lipid is dispersed in water to obtain the cationic peptide liposome which are high in stability and uniform in dispersion and have about 120 nm of average grain diameter and Zeta electric potential between 30 and 50 mV. The liposome can effectively compress the plasmids DNA and siRNA, can efficient transfection both in-vitro and in-vivo, and almost does not have toxicity to cells and mice, so that the liposome can be widely applied in gene delivery as a gene vector.

To develop a protecting group that facilitates separation and purification, after reaction, of a compound including a protected functional group, without solidifying or insolubilizing the compound. A xanthene compound of by General Formula (1) ##STR00001## (wherein Y is OR.sup.17 (R.sup.17 is a hydrogen atom or an active ester-protecting group), NHR.sup.18 (R.sup.18 is a hydrogen atom, or a linear or branched C.sub.1-C.sub.6 alkyl group or aralkyl group), an azide, a halogen atom, or a carbonyl group formed together with a methylene group; at least one of R.sup.1 to R.sup.8 is represented by Formula (2);
OR.sup.9X-A(2) and a residue is a hydrogen atom, a halogen atom, a C.sub.1-C.sub.4 alkyl group, or a C.sub.1-C.sub.4 alkoxy group, wherein R.sup.9 is a linear or branched C.sub.1-C.sub.16 alkylene group; X is O or CONR.sup.19 (R.sup.19 is a hydrogen atom or a C.sub.1-C.sub.4 alkyl group); and A is represented by Formula (3) or the like ##STR00002## (wherein R.sup.10, R.sup.11, and R.sup.12, the same or different, are a linear or branched C.sub.1-C.sub.6 alkyl group or an aryl group optionally including a substituent; R.sup.13 is a single bond or a linear or branched C.sub.1-C.sub.3 alkylene group; and R.sup.14, R.sup.15, and R.sup.16 are a linear or branched C.sub.1-C.sub.3 alkylene group)).

The present invention relates to a method for the synthesis of a polypeptide comprising a pre-determined amino acid sequence. The method according to the invention comprises coupling cycles of coupling an N-terminally protected amino acid building block C-terminally at an unprotected N-terminal amino group of an amino acid chain, wherein at least one coupling cycle comprises a coupling step (a), a capping step (b), and a de-protecting step (c).

To develop a protecting group that facilitates separation and purification, after reaction, of a compound including a protected functional group, without solidifying or insolubilizing the compound.

A xanthene compound of by General Formula (1)

##STR00001## (wherein Y is OR.sup.17 (R.sup.17 is a hydrogen atom or an active ester-protecting group), NHR.sup.18 (R.sup.18 is a hydrogen atom, or a linear or branched C.sub.1-C.sub.6 alkyl group or aralkyl group), an azide, a halogen atom, or a carbonyl group formed together with a methylene group; at least one of R.sup.1 to R.sup.8 is represented by Formula (2);

OR.sup.9X-A(2) and a residue is a hydrogen atom, a halogen atom, a C.sub.1-C.sub.4 alkyl group, or a C.sub.1-C.sub.4 alkoxy group, wherein R.sup.9 is a linear or branched C.sub.1-C.sub.16 alkylene group; X is O or CONR.sup.19 (R.sup.19 is a hydrogen atom or a C.sub.1-C.sub.4 alkyl group); and A is represented by Formula (3) or the like

##STR00002## (wherein R.sup.10, R.sup.11, and R.sup.12, the same or different, are a linear or branched C.sub.1-C.sub.6 alkyl group or an aryl group optionally including a substituent; R.sup.13 is a single bond or a linear or branched C.sub.1-C.sub.3 alkylene group; and R.sup.14, R.sup.15, and R.sup.16 are a linear or branched C.sub.1-C.sub.3 alkylene group)).

Disclosed herein is an improved process for preparing abaloparatide. The process generally utilizes solid phase peptide synthesis employing an Fmoc-protection scheme. Incorporating a systematic recoupling step of a glutamine residue (Gln.sup.16) has been found to minimize the formation of an undesirable des-Gln.sup.16 abaloparatide impurity, which is often obtained in significant quantities in the conventional process.

Novel synthesized amino acids of glutamine and lysine that are directly PEGylated with small, monodisperse PEGs, and a novel process for creating novel amino acid monomers using PEGylation. These amino acids are readily incorporated into peptides for a range of different applications.

An object of the present invention is to provide a method for producing a peptide compound with an excellent yield, a protective group-forming reagent having an excellent yield, and a novel substituted benzyl compound. According to the present invention, there is provided a method for producing a peptide compound, including a step of using a substituted benzyl compound represented by Formula (1).

##STR00001##

In Formula (1), Y represents OH, NHR, SH, or X, R represents a hydrogen atom, an alkyl group, an arylalkyl group, a heteroarylalkyl group, or a 9-fluorenylmethoxycarbonyl group, X represents Cl, Br, or I, m represents 1 or 2, n represents an integer of 1 to 5, R.sup.B's each independently represent an aliphatic hydrocarbon group, R.sup.A, s each independently represent an aliphatic hydrocarbon group or an organic group having an aliphatic hydrocarbon group, where the number of carbon atoms in at least one aliphatic hydrocarbon group is 12 or more, and a benzene ring in Formula (1) may further have a substituent in addition to R.sup.A.