Comp. Source Ref.
20 Amanita subjunquillea 6
  Anemone rivularis Buch.-Ham. 7
  Bulgaria inquinans 11
  Datura stramonium L. 16
  Helianthus tuberosus 27
  Lentinus polychrous 37
  MaMacrolepiota neomastoidea 39
  Rhizopus sp. 58
  Topsentia sp. 75
  Sinularia flexibilis 67
  Stereum hirsutum 70
  Solanum violaceum 68
  Ganoderma lucidum 20-22
  Sarcodon aspratus 59,61
  Stereum subtomentosum 71
  Trichosanthes kirilowii 76
21 Anemone rivularis Buch.-Ham. 7, 97
Table 3: Steroidal endoperoxides 20 and 21 their natural sources.