Branched PEG Derivatives for PEGylation
Branched PEG derivatives, also known as "Y-shaped" PEG derivatives, contain two linear methoxy PEG chain attached to a central core. The sterically bulky structure of these "Y-shaped" PEG derivatives will facilitate the single point attachment of the modified molecules.
The typical structure of "Y-shaped" branched PEG is as the following:

JenKem Technology now provides the following three kinds of "Y-shape" PEG derivatives. They are all JenKem's patented products. Y-NHS-40K can be used for amine PEGylation, Y-MAL-40K can be used for thiol PEGylation, and Y-ALD-40K (Y-AALD-40K and Y-PALD-40K) can be used for N-terminal PEGylation.
JenKem's "Y-shaped" PEG derivatives are chemically purified during synthesis so that they are low in polydispersity and are essentially free of activated bifunctional PEG side products.
List of Branched PEG Derivatives:
Y-NHS-40K: Y-Shape PEG NHS Ester, MW 400001
Y-COOH-40K: Y-Shape PEG Carboxyl, MW 400002
Y-MAL-40K: Y-Shape PEG Maleimide, MW 400002
Y-AALD-40K: Y-shape PEG Acetaldehyde, MW 400003
Y-PALD-40K: Y-shape PEG Propionaldehyde, MW 400003
Y-NH2-40K: Y-Shape PEG Amine, MW 400003
For Amine PEGylation
This "Y-shape" NHS ester will react with the amino group of lysine(s) or the N-terminal amine in biological active molecules to produce a stable amide linkage(s). This NHS ester will couple with the targeted molecules at pH 7-8. The PEGylation reaction can be finished in about 1 hour.
Average molecular weight of Y-NHS-40K is 40,000 Da. Substitution is 95% or greater. This product is basically free of activated bifunctional PEG side products.

ITEM CODE | ITEM NUMBER | ITEM DESCRIPTION | PRICE (USD) |
A0001-1 | Y-NHS-40K,1g | Y-shape PEG NHS Ester, MW 40000 | $150 |
A0001-10 | Y-NHS-40K,10g | Y-shape PEG NHS Ester, MW 40000 | $1200 |
Y-COOH-40K: Y-Shape PEG Carboxyl, MW 40000
Y-COOH-40K is the precursor to make Y-NHS-40K. Y-COOH is chromatographically purified with purity of 95% or greater.

ITEM CODE | ITEM NUMBER | ITEM DESCRIPTION | PRICE (USD) |
A0019-1 | Y-COOH-40K,1g | Y-shape PEG Carboxyl, MW 40000 | $130 |
A0019-10 | Y-COOH-40K,10g | Y-shape PEG Carboxyl, MW 40000 | $1040 |
For Thiol PEGylation
This "Y-shape" PEG maleimide will react with the thiol groups in biological active molecules to generate a stable 3-thiosuccinimidyl ether linkage. “Y-shape” PEG maleimide will couple with the targeted molecules at pH 5.0-6.5 in the presence of other functional groups.
Average molecular weight of Y-MAL-40K is 40,000 Da. Substitution is 95% or greater. This product is basically free of activated bifunctional PEG side products.
ITEM CODE | ITEM NUMBER | ITEM DESCRIPTION | PRICE (USD) |
A0002-1 | Y-MAL-40K,1g | Y-shape PEG Maleimide, MW 40000 | $180 |
A0002-10 | Y-MAL-40K,10g | Y-shape PEG Maleimide, MW 40000 | $1440 |
For N-Terminal PEGylation
The "Y-shape" PEG aldehyde will preferably react with the N-terminal amine in biological active molecules to produce a stable amine linkage in the presence of a reducing reagent such as sodium cyanoborohydride. "Y-shape" PEG aldehyde will couple with the N-terminal amine of the targeted molecules at pH 5-8.
Average molecular weight of "Y-shape" PEG aldehyde is 40,000 Da. Substitution is 95% or greater. This product is basically free of activated bifunctional PEG side products.
Compare with linear PEG aldehyde, Y-shape PEG aldehyde is less reactive but more selective.
We now provide the following two kinds of Y-shape PEG Aldehyde.
Y-AALD-40K: Y-shape PEG Acetaldehyde, MW 40000
Y-AALD-40K is more selective but less reactive compared with Y-PALD-40K.

ITEM CODE | ITEM NUMBER | ITEM DESCRIPTION | PRICE (USD) |
A0003-1 | Y-AALD-40K,1g | Y-shape PEG Acetaldehyde, MW 40000 | $180 |
A0003-10 | Y-AALD-40K,10g | Y-shape PEG Acetaldehyde, MW 40000 | $1440 |
Y-PALD-40K: Y-shape PEG Propionaldehyde, MW 40000
Y-PALD-40K is a great branched PEG aldehyde with relatively good reactivity and selectivity.

ITEM CODE | ITEM NUMBER | ITEM DESCRIPTION | PRICE (USD) |
A0017-1 | Y-PALD-40K,1g | Y-shape PEG Propionaldehyde, MW 40000 | $180 |
A0017-10 | Y-PALD-40K,10g | Y-shape PEG Propionaldehyde, MW 40000 | $1440 |
Other Y-shaped PEG products
Y-NH2-40K is a Y-shaped PEG with primary amine group at the termini. The amine end group is more reactive toward acylating agents than the hydroxyl group. The amine group is also readily undergo reductive amination reactions. The substitution of Y-NH2-40K is 95% or greater.
ITEM CODE | ITEM NUMBER | ITEM DESCRIPTION | PRICE (USD) |
A0010-1 | Y-NH2-40K,1g | Y-shape PEG Amine, MW 40000 | $180 |
A0010-10 | Y-NH2-40K,10g | Y-shape PEG Amine, MW 40000 | $1440 |
Please check our 2011 PEG Products Catalog
2011 JENKEM USA PEG PRODUCTS CATALOG
Storage and Handling Conditions for PEGs and PEG Derivatives
To order, please contact us at
sales@jenkemusa.com
Other molecular weights are available.
Quotations for bulk orders are available.
Prices are subject to change without notice.
Shipping and Handling Fee is not included in the price.
PEG Derivatives Custom Synthesis
JenKem Technology has the expertise and experience on the synthesis of many kinds of special PEG derivatives. JenKem Technology can design and synthesize to meet your special needs. Please contact JenKem USA's technical support at tech@jenkemusa.com for your custom synthesis requests.