Sulforaphane is an isothiocyanate, made from the combination of myrosinase and glucoraphanin which happens as cell walls are crushed - same way sulfur compounds come from alliums.

One problem is that myrosinase breaks down (AKA 'denatures') when cooked - so cooked broccoli has glucoraphanin but no active myrosinase, so crushing the cells does pretty much nothing (exception: some of us have microflora that can convert glucoraphanin, but there's no way to know if you're one of those people). So, I cook broccoli as little as possible, and eat it with something that has myrosinase - stone ground mustard.

Also, you might think about removing cauliflower from that list as it has none - and adding moringa "trees", which have another isothiocyanate, moringin, in abundance.

Isothiocyanates, and the KEAP-NRF2 signaling pathway, are pretty interesting. There are plenty of studies on PubMed - start with the ones with Jed Fahey as one of the authors.

BTW/FWIW, the best edible source is broccoli sprouts (highest in seeds, but those contain toxic erucic acid). The moringa 'tree' is also very good - excellent news for anyone who lives where it's too warm to grow broccoli.