**3. Design and synthesis of boron-containing agents for boron neutron capture therapy (BNCT)**

#### **3.1 General**

As described in the Introduction, BNCT is one of the powerful cancer treatment methods utilizing two heavy particles, 4 He and 7 Li, which are produced from 10B by a neutron capture reaction [10B (n, α) 7 Li] and induce the damage of biomolecules such as DNA, RNA, and so on within a short range of 5–9 μm [4–8]. For this BNCT to be achieved, the development of cancer-specific 10B carriers is urgently needed. To date, *Design, Synthesis, and Biological Applications of Boron-Containing Polyamine and Sugar… DOI: http://dx.doi.org/10.5772/intechopen.105998*

**Figure 12.** *Structures of representative BNCT agents.*

only two boron compounds, namely disodium mercaptoundecahydrododecaborate (BSH) **23** and L-4-boronophenylalanine (BPA) **24** (used as a complex with D-fructose), have been approved for use as BNCT agents in clinical settings (**Figure 12**) [31, 32], but they are not sufficiently effective for the treatment of various tumor types. Because more selective and more efficient BNCT agents are required, the design and synthesis of new boron carriers based on sugar and macrocyclic polyamine scaffolds were conducted.
