No, obviously not. But where there's a serial port, there's generally a host system nearby - and therefore, likely a USB port. It is no different from the suggestions to tap a PC's internal power supply, but with only a modification made to a cheap USB-serial port dongle. If the OP is connecting his 'max232 and transceiver' to another embedded device, I doubt he would ask about using it for power.
I hate USB-serial adapters, they cause no end of trouble with host software, and latency issues, but they are necessary since the venerable serial port is being dropped from portable computers, and some desktops.
Whilst many RF transciever's can operate at very low power using burst comms and low duty cycles, your average MAX232 equivilent uses up a fair few mA. I doubt both can be powered from a standard serial port, and I doubt even more than the serial port it is connected to is 'standard'. So, for the OP's application, I'm going to say 'no' - not without modifying the PC's serial port and/or cable.