Can I power the 45 Series blocks from my pedal power supply board?

This is a yes and no answer. While it is true the MicroBlock 45 and InterBlock 45 may work on reduced power, it would be at reduced volume and may not work at all so it is not recommended. 

That said, if you are wondering if you can use the AC accessory outlet on some power supplies to plug in your 24 volt adapter, that should be fine.