Table 3.

Comparison of EC₅₀ values (DPPH assay) for the CDs studied with those of some reported materials.

Antioxidant Material	Synthesis Method	EC50 μg mL−1	Ref.
Coconut husk-CDs	HT 200 °C, 3 h. Autoclave	60	[15]
Coconut Shell-CDs	HT 200 °C, 3 h Autoclave	25	[16]
Ascorbic acid	Pure compound	15.0	[49]
Vitamin E	Pure compound	13.58	[50]
HcEd *	Methanol extraction	16.7	[51]
Essential oil of Teucrium orientale subsp. taylori	Hydrodistillation extraction	121.60	[52]
Ginger essential oil	Hydrodistillation extraction	11,680	[53]
TCDs	HT 200 °C, 6 h Oven	50	This work
P2CDs	HT 180 °C, 4 h Oven	75
GCDs	HT 180 °C, 5 h Oven	175

* Essential oil extracted in methanol from Hyptis crenata Pohl ex Bentham.