Table 5: Inhibition of compounds from D.  loddigesii and D.  nobile species on NO and DPPH formation.

SpeciesChemical constituentNODPPH

D.  loddigesiiPhenanthrenes (1a)2.626.1
Phenanthrenes (2a)6.459.8
Phenanthrenes (3a)5.312
Phenanthrenes (4a)10.9
Dihydrophenanthrenes (5a)4.662.2
Dihydrophenanthrenes (6a)29.1
Dihydrophenanthrenes (7a)29.2
Loddigesiinols A2.6
Loddigesiinols B10.9
Loddigesiinols C23.7
Loddigesiinols D69.7

D.  nobile  Nobilin D (1)15.3
Nobilin E (2)19.2
Nobilone F (3)38.1
Phenanthrenes and bibenzyls related-composition  (4–10)
ROR1 = R2 = OCH3 R3 = OH R4 = H (4)
ROR1 = R2 = R3 = OCH3 R4 = H (5)48.2
ROR1 = R2 = OH R3 = R4 = H (6)
ROR1 = R3 = OCH3 R2 = OH R4 = H (7)
ROR1 = OCH3 R2 = R3 = OH R4 = H (8)36.8
ROR1 = R3 = OH R2 = R4 = H (9)32.9
ROR1 = R3 = OH R2 = H R4 = OCH3 (10)13.4

Notes: —: no tests; RO: relation composition.
Inhibitory effects of different compounds from D.  loddigesii and D.  nobile species on NO production. Result shown in Table 5, ranked from high to low as follows: loddigesiinol D > R1 = R2 = R3 = OCH3 R4 = H (5) > nobilone F (3) > R1 = OCH3 R2 = R3 = OH R4 = H (8) > R1 = R3 = OH R2 = R4 = H (9) > dihydrophenanthrenes (7a) > dihydrophenanthrenes (6a) > nobilin E (2) > nobilin D (1) > R1 = R3 = OH R2 = H R4 = OCH3 (10) > phenanthrenes (4a) = loddigesiinols B > phenanthrenes (2a) > phenanthrenes (3a) > dihydrophenanthrenes (5a) > phenanthrenes (1a) > loddigesiinols A, and all of the compounds inhibit DPPH prodruction (from high to low): dihydrophenanthrenes (5a) > phenanthrenes (2a) > phenanthrenes (1a) > loddigesiinol C > phenanthrenes (3a).