Provided herein are compounds for use as photochromic molecular switches having very long thermal isomerization half-lives and switchable fluorescence properties both in solution and the solid state.

Provided herein are compounds for use as photochromic molecular switches having very long thermal isomerization half-lives and switchable fluorescence properties both in solution and the solid state.

The present invention provides inventive conjugated polyethyleneimine (PEI) polymers and conjugated aza-macrocycles (collectively referred to herein as conjugated lipomers or lipomers) containing one or more groups of the formula (iii):

##STR00001##

wherein R.sup.3 and R.sup.4 are as defined herein. Also provided are compositions comprising the inventive conjugated lipomers, and methods of preparation and use.

The present invention provides inventive conjugated polyethyleneimine (PEI) polymers and conjugated aza-macrocycles (collectively referred to herein as conjugated lipomers or lipomers) containing one or more groups of the formula (iii):

##STR00001##

wherein R.sup.3 and R.sup.4 are as defined herein. Also provided are compositions comprising the inventive conjugated lipomers, and methods of preparation and use.

The present invention relates to methods of modulating an immune response mediated by a PD-1 signaling pathway and of treating a cancer or an infectious disease. A subject is administered a compound(s) or a pharmaceutically acceptable salt or pharmaceutically acceptable composition thereof of formula (I)

##STR00001##

In the ring Q is S or O. R.sub.1 substituents are an optionally substituted side chain of the amino acid Ser or Thr and R.sub.3 substituents are a side chain of the amino acids Asn, Asp, Gln, or Glu. R.sub.2 is hydrogen or CO-Aaa and Aaa is Thr or Ser with a free, amidated or esterified C-terminus. R.sub.4 and R.sub.5 are independently hydrogen or absent. R.sub.6 is hydrogen, alkyl or acyl.

The present invention relates to methods of modulating an immune response mediated by a PD-1 signaling pathway and of treating a cancer or an infectious disease. A subject is administered a compound(s) or a pharmaceutically acceptable salt or pharmaceutically acceptable composition thereof of formula (I)

##STR00001##

In the ring Q is S or O. R.sub.1 substituents are an optionally substituted side chain of the amino acid Ser or Thr and R.sub.3 substituents are a side chain of the amino acids Asn, Asp, Gln, or Glu. R.sub.2 is hydrogen or CO-Aaa and Aaa is Thr or Ser with a free, amidated or esterified C-terminus. R.sub.4 and R.sub.5 are independently hydrogen or absent. R.sub.6 is hydrogen, alkyl or acyl.

The present invention relates to pharmaceutical compositions of 1,2,4-oxadiazole compounds or a pharmaceutically acceptable salt thereof of formula (I) ##STR00001##
In the formula Q is O, R.sub.1 is the side chain of Ser, R.sub.2 is CO-Thr, R.sub.3 is the side chain of Asn or Glu, and R.sub.4, R.sub.5 and R.sub.6 are each H.

The present invention relates to pharmaceutical compositions of 1,2,4-oxadiazole compounds or a pharmaceutically acceptable salt thereof of formula (I) ##STR00001##
In the formula Q is O, R.sub.1 is the side chain of Ser, R.sub.2 is CO-Thr, R.sub.3 is the side chain of Asn or Glu, and R.sub.4, R.sub.5 and R.sub.6 are each H.

Antibacterial small molecule compounds, termed liptins, bind to phosphatidylglycerol in bacterial plasma membranes. The small molecule compounds comprise a three-dimensional complementary binding pocket for phosphatidylglycerol, disrupting membrane function in a bacteriostatic or bactericidal manner. Methods of inhibiting bacterial growth and/or treating Gram-positive or Gram-negative bacterial infection using such compounds are also disclosed.

The present invention relates to synthetic methods for 1,2,4-oxadiazole compounds. The general synthetic scheme is: ##STR00001##
R.sub.1 represents ?CH.sub.2O.sup.tBu or ?CH(CH.sub.3)O.sup.tBu, R.sub.3 represents ?CH.sub.2C(O)NHCPh.sub.3, ?CH.sub.2CH.sub.2C(O)NHCPh.sub.3, ?CH.sub.2C(O)O.sup.tBu, or ?CH.sub.2CH.sub.2C(O)O.sup.tBu, and Aaa is an amino acid residue selected from Thr and Ser; wherein the C-terminus thereof is esterified, and wherein the hydroxy moiety of the side chain of Thr or Ser is substituted with tbutyl; the base is triethylamine; and the solvent is tetrahydrofuran.