Table 1.

Approximate number of known halogenated natural products and redox potential and natural abundance of the halogenides in sea water.

Halogenide	Natural productsa	Redox potential [V]b	Sea water [mg L−1]b
F−	30	+2.87	1.4
Cl−	2200	+1.36	18100
Br−	1900	+1.07	68
I−	100	+0.54	0.06

^aEstimated number of known natural products in 2002 according to reference [2]. ^bRedox potentials and concentrations in sea water as given in reference [3].