''O''⁶-Benzylguanine (O6-BG) is a synthetic

derivative In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. F ...

guanine Guanine () ( symbol G or Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is called ...

. It is an

antineoplastic agent Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) as part of a standardized ...

. It exerts its effect by acting as a

suicide inhibitor In biochemistry, suicide inhibition, also known as suicide inactivation or mechanism-based inhibition, is an irreversible form of enzyme inhibition that occurs when an enzyme binds a substrate analog and forms an irreversible complex with it thr ...

of the enzyme

O6-alkylguanine-DNA alkyltransferase ''O''6-alkylguanine DNA alkyltransferase (also known as AGT, MGMT or AGAT) is a protein that in humans is encoded by the ''O''6-methylguanine DNA methyltransferase (''MGMT'') gene. O6-methylguanine DNA methyltransferase is crucial for genome stabi ...

which leads to interruption of DNA repair. O6-BG was used clinically in combination with the

alkylating agent Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting al ...

temozolomide Temozolomide (TMZ), sold under the brand name Temodar among others, is a medication used to treat brain tumors such as glioblastoma and anaplastic astrocytoma. Text was copied from this source which is © European Medicines Agency. Reproduction i ...

for

glioblastoma Glioblastoma, previously known as glioblastoma multiforme (GBM), is one of the most aggressive types of cancer that begin within the brain. Initially, signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality ch ...

, however the combination was found to be overly toxic without adding significant benefit. O6-BG is also used as a biochemical tool in the study of DNA repair mechanisms.

References

External links

* {{DEFAULTSORT:Benzylguanine, O6- Purines Antineoplastic drugs Experimental cancer drugs Benzyl compounds