Table 1.

Effects of sulfur fumigation or reaction with sulfiting agents on chemical constitution and pharmacokinetics of various TCM herbs.

Herb	Processing	Chemical alteration	Pharmacokinetic alteration	Reference
Paeoniae Radix Alba (Bai Shao)	Sulfur fumigation	Formation of peoniflorin sulfonate (9–16 mg/g herb) and benzoylpaeoniflorin sulfonate (0.16–0.43 mg/g herb)	Oral absorption of peoniflorin sulfonate was slower than that of peoniflorin. Benzoylpaeoniflorin sulfonate but not benzoylpaeoniflorin was present in blood circulation after oral administration	Cheng et al. (2010a,b)
	Reaction with sodium bisulfite	Formation of peoniflorin sulfonate	N.A.	Wang et al. (2005)
	Sulfur fumigation	Almost all of peoniflorin converted to peoniflorin sulfonate	N.A.	Hayes et al. (2005)
Angelicae Dahuricae Radix (Bai Zhi)	Sulfur fumigation	Loss of major furocoumarins: i.e., at least 60% loss of imperatorin, and significant loss of isoimperatorin and oxypeucedanin	N.A.	Wang et al. (2009b)
Ginseng Radix et Rhizoma (Ren Shen)	Sulfur fumigation	Formation of two ginsenoside sulfonates	N.A.	Li et al. (2010b)

N.A., data not available.