Table 2.

Number of compounds and basic skeleton extracted from articles.

No.	Number of Compounds	Basic Skeleton	Ref.
1	9	Isoflavones and Isoflavanones	[9]
2	3	Three β-Diketones	[10]
3	6	Styrylchromones	[11]
4	3	Nocobactins NA-a, NA-b and Their Ferric Complexes	[12]
5	5	Betulinic Acid and Its Derivatives	[13]
6	2	Berberines	[14]
7	20	Coumarin and Its Derivatives	[15]
8	1	Mitomycin C, Bleomycin and Peplomycin	[16]
9	13	4-Trifluoromethylimidazole Derivatives	[17]
10	15	Phenoxazine Derivatives	[18]
11	7	Vitamin K2 Derivatives	[19]
12	2	4-Trifluoromethylimidazoles	[20]
13	10	Phenoxazines	[21]
14	18	Vitamin K2 Derivatives and Prenylalcohols	[22]
15	10	3-Formylchromone Derivatives	[23]
16	12	5-Trifluoromethyloxazole Derivatives	[24]
17	19	1,2,3,4-Tetrahydroisoquinoline Derivatives	[25]
18	19	1,2,3,4Tetrahydroisoquinoline Derivatives	[26]
19	12	Dihydroimidazoles	[27]
20	24	Tropolones	[28]
21	24	Trihaloacetylazulenes	[29]
22	22	Trihaloacetylazulene Derivatives	[30]
23	10	Licorice Flavonoids	[31]
24	4	1,2,3,4-Tetrahydroisoquinoline Derivatives	[32]
25	19	2-Aminotropones	[33]
26	12	Phenylpropanoid Amides	[34]
27	12	Piperic Acid Amides	[35]
28	15	3-Styrylchromones	[36]
29	16	3-Styryl-2H-chromenes	[37]
30	18	Oleoylamides	[38]
31	17	3-Benzylidenechromanones	[39]
32	18	Licorice Root Extracts	[40]
33	15	Chalcones	[41]
34	11	Piperic Acid Esters	[42]
35	17	Aurones	[43]
36	24	2-Azolylchromones	[44]
37	10	Cinnamic Acid Phenetyl Esters	[45]
38	10	Azulene Amide Derivatives	[46]
39	10	Alkylaminoguaiazulenes	[47]