Glutamine antagonists and their use for treating oncological, immunological, and neurological diseases are disclosed. Also disclosed are methods for treating an oncological, immunological, infectious or neurological disease or disorder, the method comprising administering to a subject in need of treatment thereof a therapeutically effective amount of a glutamine antagonist of the disclosure or the pharmaceutical composition thereof. Also disclosed are methods of enhancing the effects of an immune checkpoint inhibitor, enabling a subject to respond to an immune checkpoint inhibitor, or enabling the toxicity or the dose or number of treatments with an immune checkpoint inhibitor to be reduced, comprising administering to a subject in need of treatment thereof a therapeutically effective amount of a glutamine antagonist of the disclosure or the pharmaceutical composition thereof, and an immune checkpoint inhibitor. Also disclosed are methods for treating an oncological, immunological, infectious or neurological disease or disorder that is refractory to checkpoint inhibitor therapy, the method comprising administering to a subject in need thereof, and having the refractory disease or disorder, a therapeutically effective amount of a glutamine antagonist of the disclosure or the pharmaceutical composition thereof.

Glutamine antagonists and their use for treating oncological, immunological, and neurological diseases are disclosed. Also disclosed are methods for treating an oncological, immunological, infectious or neurological disease or disorder, the method comprising administering to a subject in need of treatment thereof a therapeutically effective amount of a glutamine antagonist of the disclosure or the pharmaceutical composition thereof. Also disclosed are methods of enhancing the effects of an immune checkpoint inhibitor, enabling a subject to respond to an immune checkpoint inhibitor, or enabling the toxicity or the dose or number of treatments with an immune checkpoint inhibitor to be reduced, comprising administering to a subject in need of treatment thereof a therapeutically effective amount of a glutamine antagonist of the disclosure or the pharmaceutical composition thereof, and an immune checkpoint inhibitor. Also disclosed are methods for treating an oncological, immunological, infectious or neurological disease or disorder that is refractory to checkpoint inhibitor therapy, the method comprising administering to a subject in need thereof, and having the refractory disease or disorder, a therapeutically effective amount of a glutamine antagonist of the disclosure or the pharmaceutical composition thereof.

The present disclosure provides lyophilates comprising (S)-isopropyl 2-((S)-2-acetamido-3-(1H-indol-3-yl)propanamido)-6-diazo-5-oxohexanoate: and pharmaceutical compositions, pharmaceutical formulations, and uses thereof.

##STR00001##

The present disclosure provides lyophilates comprising (S)-isopropyl 2-((S)-2-acetamido-3-(1H-indol-3-yl)propanamido)-6-diazo-5-oxohexanoate: and pharmaceutical compositions, pharmaceutical formulations, and uses thereof.

##STR00001##

Methods and reagents for esterification of biological molecules including proteins, polypeptides and peptides. Diazo compounds of formula I: ##STR00001##
where R is hydrogen, an alkyl, an alkenyl or an alkynyl, R.sub.A represents 1-5 substituents on the indicated phenyl ring and R.sub.M is an organic group, which includes a label, a cell penetrating group, a cell targeting group, or a reactive group or latent reactive group for reaction to bond to a label, a cell penetrating group, or a cell targeting group, among other organic groups are useful for esterification of biological molecules. Also provided are diazo compounds which are bifunctional and trifunctional coupling reagents as well as reagents for the synthesis of compounds of formula I.

Methods and reagents for esterification of biological molecules including proteins, polypeptides and peptides. Diazo compounds of formula I: ##STR00001##
where R is hydrogen, an alkyl, an alkenyl or an alkynyl, R.sub.A represents 1-5 substituents on the indicated phenyl ring and R.sub.M is an organic group, which includes a label, a cell penetrating group, a cell targeting group, or a reactive group or latent reactive group for reaction to bond to a label, a cell penetrating group, or a cell targeting group, among other organic groups are useful for esterification of biological molecules. Also provided are diazo compounds which are bifunctional and trifunctional coupling reagents as well as reagents for the synthesis of compounds of formula I.

The present disclosure provides a method of preparing a compound of Formula I, wherein R.sup.1 is C.sub.1-C.sub.4 alkyl; R.sup.2 is C1-C4 alkyl; and R.sup.3 is selected from the group consisting of C.sub.1-C.sub.6 alkyl, (aryl)alkyl, and (heteroaryl)alkyl in >95% chemical purity and >95% enantiomeric excess.

##STR00001##

The present disclosure provides a method of preparing a compound of Formula I, wherein R.sup.1 is C.sub.1-C.sub.4 alkyl; R.sup.2 is C1-C4 alkyl; and R.sup.3 is selected from the group consisting of C.sub.1-C.sub.6 alkyl, (aryl)alkyl, and (heteroaryl)alkyl in >95% chemical purity and >95% enantiomeric excess.

##STR00001##

The present disclosure provides a method of preparing a compound of Formula I, wherein R.sup.1 is C.sub.1-C.sub.4 alkyl; R.sup.2 is C1-C4 alkyl; and R.sup.3 is selected from the group consisting of C.sub.1-C.sub.6 alkyl, (aryl)alkyl, and (heteroaryl)alkyl in >95% chemical purity and >95% enantiomeric excess. ##STR00001##

The present disclosure provides a method of preparing a compound of Formula I, wherein R.sup.1 is C.sub.1-C.sub.4 alkyl; R.sup.2 is C1-C4 alkyl; and R.sup.3 is selected from the group consisting of C.sub.1-C.sub.6 alkyl, (aryl)alkyl, and (heteroaryl)alkyl in >95% chemical purity and >95% enantiomeric excess. ##STR00001##