Evidence-Based Complementary and Alternative Medicine

Review Article

Naturally Occurring Anthraquinones: Chemistry and Therapeutic Potential in Autoimmune Diabetes

Table 1

Chemical structure of NOAQs in different plants.


S. number	IUPAC names	Structure								Species
S. number	IUPAC names	R1	R2	R3	R4	R5	R6	R7	R8	Species

1	Tectoquinone (2-methyl-AQ)	H	Me	H	H	H	H	H	H	Prismatomeris malayana [40], Rubia cordifolia [41], Rubia oncotricha [32],and Rubia tinctorum [42]
2	2-(Hydroxymethyl)-AQ	H	HOCH₂	H	H	H	H	H	H	Rubia yunnanensis [43] and Rubia tinctorum [44]
3	2-Methoxy-AQ	H	MeO	H	H	H	H	H	H	Rubia tinctorum [42]
4	2-Hydroxy-AQ	H	OH	H	H	H	H	H	H	Rubia tinctorum [42]
5	1-Methoxy-AQ	OH	H	H	H	H	H	H	H	Rubia cordifolia [45, 46]
6	1-Hydroxy-2-methyl AQ	OH	Me	H	H	H	H	H	H	Rubia tinctorum [42], Rubia cordifolia [46], Rubia akane [39], Rubia lanceolata [39], Rubia oncotricha [39], Rubia sylvatica [39], and Rubia yunnanensis [43]
7	1-Hydroxy-2-(hydroxymethyl)-AQ	OH	HOCH₂	H	H	H	H	H	H	Rubia cordifolia [32]
8	2-(Ethoxycarbonyl)-1-hydroxy-AQ	OH	EtOOC	H	H	H	H	H	H	Rubia akane [39]
9	1-Methoxy-2-methyl-AQ	MeO	Me	H	H	H	H	H	H	Rubia tinctorum
10	Alizarin (1,2-dihydroxy-AQ)	OH	OH	H	H	H	H	H	H	Rubia lanceolata [39], Rubia akane [39], and Galium sinaicum [47]
11	Alizarin 2-methyl ether (1-hydroxy-2-methoxy-AQ)	OH	MeO	H	H	H	H	H	H	Rubia tinctorum [42], Rubia oncotricha [39], Rubia cordifolia [32], and Galium sinaicum [47]
12	Alizarin 1-methyl ether (2-hydroxy-1-methoxy-AQ)	MeO	OH	H	H	H	H	H	H	Rubia tinctorum [42]
13	Alizarin 1,2-dimethyldiether (1,2-dimethoxy-AQ)	MeO	MeO	H	H	H	H	H	H	Rubia tinctorum [42]
14	Rubiadin (1,3-dihydroxy-2- methyl-AQ)	OH	MeO	OH	H	H	H	H	H	Prismatomeris malayana [40], Rubia tinctorum [42], Rubia cordifolia [32], and Rubia lanceolata [39], Rubia yunnanensis [43]
15	Lucidin (1,3-dihydroxy-2- (hydroxymethyl)-AQ)	OH	HOCH₂	OH	H	H	H	H	H	Rubia cordifolia [32], Rubia tinctorum [42], and Rubia iberica [33]
16	Nordamnacanthal (1,3-dihydroxy-2-formyl-AQ)	OH	CHO	OH	H	H	H	H	H	Rubia cordifolia [32] and Rubia iberica [33]
17	Munjistin (1,3-dihydroxy-2-carboxy-AQ)	OH	HOOC	OH	H	H	H	H	H	Rubia tinctorum [42]
18	1,3-Dihydroxy-2-(methoxycarbonyl)-AQ	OH	MeOOC	OH	H	H	H	H	H	Rubia tinctorum [32]
19	2-(Ethoxymethyl)-1,3-dihydroxy-AQ	OH	EtOCH₂	OH	H	H	H	H	H	Rubia cordifolia [32]
20	1,3-Dihydroxy-2-(methoxymethyl)-AQ	OH	MeOCH₂	OH	H	H	H	H	H	Rubia cordifolia [32]
21	Lucidin dimethyl ether	MeOH	HOCH₂	MeO	H	H	H	H	H	Rubia lanceolata [39]
22	Munjistin dimethyl ether (2-carboxy- 1,3-dimethoxy-AQ)	MeOH	HOOC	MeO	H	H	H	H	H	Rubia cordifolia [32]
23	2-Benzylxanthopurpurin	OH	PhCH₂	OH	H	H	H	H	H	Rubia tinctorum [32]
24	Anthragallol 3-methyl ether	OH	OH	MeO	H	H	H	H	H	Rubia tinctorum [42]
25	Anthragallol 2,3-dimethyl ether	OH	MeO	MeO	H	H	H	H	H	Rubia tinctorum [32]
26	2-Carboxy-1-hydroxy-3-methoxy-AQ	OH	HOOC	MeO	H	H	H	H	H	Rubia cordifolia [48]
27	3-Hydroxy-1-methoxy-2-(methoxymethyl)-AQ	MeO	MeOCH₂	OH	H	H	H	H	H	Rubia cordifolia [49]
28	Anthragallol (1,2,3-trihydroxy-AQ)	OH	OH	OH	H	H	H	H	H	Rubia tinctorum [32]
29	Purpurin (1,2,4-trihydroxy AQ)	OH	OH	H	OH	H	H	H	H	Rubia tinctorum [32, 42], Rubia cordifolia [32], Rubia munjista [33], Rubia sikkimensis [33], and Rubia tetragona [32]
30	Quinizarin (1,4-dihydroxy-AQ)	OH	H	H	OH	H	H	H	H	Rubia cordifolia [32] and Rubia tinctorum [32]
31	1,4-Dihydroxy-2-(hydroxymethyl)-AQ	OH	HOCH₂	H	OH	H	H	H	H	Rubia cordifolia [32] and Rubia yunnanensis [32]
32	2-(Ethoxycarbonyl)-1,4-dihydroxy-AQ	OH	EtOOC	H	OH	H	H	H	H	Rubia cordifolia [32]
33	Christophine (2-(ethoxymethyl)- 1,4-dihydroxy-AQ)	OH	EtOCH₂	H	OH	H	H	H	H	Rubia tinctorum [32]
34	1,4-Dihydroxy-2-methyl-AQ	OH	Me	H	OH	H	H	H	H	Rubia cordifolia [32] and Rubia lanceolata [32]
35	Xanthopurpurin (1,3-dihydroxy-AQ)	OH	H	OH	H	H	H	H	H	Rubia tinctorum [32], Rubia cordifolia [32], Rubia oncotricha [39], and Rubia yunnanensis [43],
36	Xanthopurpurin 3-methyl ether (1-hydroxy-3-methoxy-AQ)	OH	H	MeO	H	H	H	H	H	Rubia tinctorum [32]
37	Xanthopurpurin dimethyl ether (1,3-dimethoxy-AQ)	MeO	H	MeO	H	H	H	H	H	Rubia tinctorum [32]
38	1-Hydroxy-3-(methoxycarbonyl)-AQ	OH	H	MeOOC	H	H	H	H	H	Rubia tinctorum [32], Rubia lanceolata [39], and Rubia oncotricha [39]
39	Pseudopurpurin (3-(carboxy)-1,2,4-trihydroxy-AQ)	OH	OH	HOOC	OH	H	H	H	H	Rubia tinctorum [32], Rubia cordifolia [32], and Rubia peregrine [32]
40	1,4-Dihydroxy-2-methyl-5-methoxy-AQ	OH	Me	H	OH	MeO	H	H	H	Rubia cordifolia [50]
41	1,4-Dihydroxy-2-methyl-8-methoxy-AQ	OH	Me	H	OH	H	H	H	MeO	Rubia cordifolia [50]
42	1,4-Dihydroxy-6-methyl-AQ	OH	H	H	OH	H	Me	H	H	Rubia cordifolia [51]
43	1,5-Dihydroxy-2-methyl-AQ	OH	Me	H	H	OH	H	H	H	Rubia cordifolia [51]
44	Physcion (1,8-dihydroxy-3-methoxy-6-methyl-AQ)	OH	H	Me	H	H	Me	H	OH	Rubia cordifolia [50] and Fallopia japonica [52]
45	2-Methyl-1,3,6-trihydroxy-AQ	OH	Me	OH	H	H	OH	H	H	Rubia cordifolia [32], Rubia sylvatica [32], Rubia yunnanensis [43], Rubia lanceolata [32], and Rubia schumanniana [32]
46	1,4-Dihydroxy-7-methyl-AQ	OH	H	H	OH	H	H	Me	H	Rubia cordifolia [50]
47	4,5-Dihydroxy-2-methoxy-7-methyl-AQ	H	Me	H	OH	OH	H	MeO	H	Rubia cordifolia [50]
48	2,7-Dihydroxy-4-methoxy-3-methyl-AQ	H	OH	Me	MeO	H	H	OH	H	Rubia yunnanensis [32]
49	2-Hydroxy-7-methyl-AQ	H	Me	H	H	H	H	OH	H	Rubia tinctorum [32]
50	2-Carboxy-4-hydroxy-AQ	H	HOOC	H	OH	H	H	H	H	Rubia cordifolia [32]
51	3-(-D-Glucopyranosyloxy)-1,6-dihydroxy-2-methyl-AQ	OH	Me	GluO	H	H	OH	H	H	Rubia cordifolia [32]
52	3-(6-O-Acetyl--D-glucopyranosyloxy)-1,6-dihydroxy-2-methyl-AQ	OH	Me	6-OAc- GluO	H	H	OH	H	H	Rubia cordifolia [32]
53	3-[(2-O-6-Deoxy--L-mannopyranosyl--D-glucopyranosyl)oxy]-1,6-dihydroxy-2-methyl-AQ	OH	Me	6-dManO-GluO	H	H	OH	H	H	Rubia cordifolia [32], Rubia schumanniana [32], Rubia akane [39], and Rubia yunnanensis [43]
54	3-[(3-O-Acetyl-2-O-6-deoxy--D-mannopyranosyl--D-glucopyranosyl)oxy]-1,6-dihydroxy-2-methyl-AQ	OH	Me	3-OAc- 6-dManO-GluO	H	H	OH	H	H	Rubia cordifolia [32]
55	3-[(6-O-Acetyl-2-O-6-deoxy--D-mannopyranosyl--D-glucopyranosyl)oxy]-1,6-dihydroxy-2-methyl-AQ	OH	Me	6-OAc- 6-dManO-GluO	H	H	OH	H	H	Rubia cordifolia [32], Rubia akane [39], Rubia yunnanensis [43], and Rubia schumanniana [32]
56	3-[(3,6-O-Diacetyl-2-O-6-deoxy--D-mannopyranosyl--D-glucopyranosyl)oxy]-1,6-dihydroxy-2-methyl-AQ	OH	Me	3,6-[OAc]₂-6-dManO- GluO	H	H	OH	H	H	Rubia cordifolia [32]
57	3-[(4,6-O-Diacetyl-2-O-6-deoxy--D-mannopyranosyl--D-glucopyranosyl)oxy]-1,6-dihydroxy-2-methyl-AQ	OH	Me	4,6-[OAc]₂-6-dManO- GluO	H	H	OH	H	H	Rubia cordifolia [32]
58	3-[(4-O-Acetyl-2-O-6-deoxy--D-mannopyranosyl--D-glucopyranosyl)oxy]-1,6-dihydroxy-2-methyl-AQ	OH	Me	4-OAc-6- dManO- GluO	H	H	OH	H	H	Rubia cordifolia [32]
59	3-[(6-O-Acetyl-2-O--D-xylopyranosyl--D-glucopyranosyl)oxy]-1,6-dihydroxy-2-methyl-AQ	OH	Me	6-OAc- XylO- GluO	H	H	OH	H	H	Rubia cordifolia [32]
60	Ruberythric acid (1-hydroxy-2-[(6-O--D-xylopyranosyl--D-glucopyranosyl)oxy]-AQ)	OH	XylO- GluO	H	H	H	OH	H	H	Rubia cordifolia [32], Rubia tinctorum [32], and Rubia iberica [45]
61	Lucidin primeveroside (1-hydroxy-2-(hydroxymethyl)-3-[(6-O--D-xylopyranosyl--D-glucopyranosyl)oxy]-AQ)	OH	HOCH₂	XylO- GluO	H	H	OH	H	H	Rubia cordifolia [32], Rubia tinctorum [32], Rubia iberica [45], and Rubia yunnanensis [43]
62	1-Acetyl-3-[(4-O-6-deoxy--D-mannopyranosyl--D-glucopyranosyl)oxy]-6-hydroxy-2-methyl-AQ	MeCO	Me	6-dManO-GluO	H	H	OH	H	H	Rubia cordifolia [32]
63	2-[(6-O--D-Glucopyranosyl--D-glucopyranosyl)oxy]methyl-11-hydroxy-AQ	H	H	H	H	H	H	H	GluO-GluO	Rubia cordifolia [32] and Rubia schumanniana [32]
64	3-[(2-O-6-Deoxy--D-mannopyranosyl--D-glucopyranosyl)oxy]-1-hydroxy-2-(methoxycarbonyl)-AQ	OH	MeOOC	6-dManO-GluO	H	H	H	H	H	Rubia cordifolia [32]
65	3-(-D-Glucopyranosyloxy)-2-(hydroxymethyl)-AQ	H	HOCH₂	GluO	H	H	H	H	H	Rubia tinctorum [32]
66	3-(-D-Glucopyranosyloxy)-8-hydroxy-2-(hydroxymethyl)-AQ	H	HOCH₂	GluO	H	H	H	H	OH	Rubia tinctorum [32]
67	2-(-D-Glucopyranosyloxy)-1,3-dihydroxy-AQ	OH	GluO	OH	H	H	H	H	H	Rubia tinctorum [32]
68	3-(-D-Glucopyranosyloxy)-1-hydroxy-2-(hydroxymethyl)-AQ	OH	HOCH₂	GluO	H	H	H	H	H	Rubia cordifolia [32]
69	Emodin (1,3,8-trihydroxy-6-methyl-AQ)	OH	H	Me	H	H	OH	H	OH	F. japonica [28, 52]
70	Cascarin (emodin 6-O-rhamnoside)	OH	H	Me	H	H	RhaO	H	OH	Rhamnus sp. [28]
71	Rhein (1,8-dihydroxy-3-carboxyl-AQ)	OH	H	HOOC	H	H	H	H	OH	Cassiasp. [28]
72	Catenarin (1,4,6,8-tetrahydroxy-3-methyl-AQ)	OH	H	Me	OH	H	OH	H	OH	Helminthosporium catenarium [28]
73	Aloe-emodin (1,8-dihydroxy 3-hydroxy methyl anthraquinone)	OH	H	CH₂OH	H	H	H	H	OH	Aloe vera [53], Cassiasp. [53], Rhamnus frangula,Cascara Sagrada [53], Rhamnus purshiana [53], and Rheum rhaponticum [53]
74	Chrysophanol (1,8-dihydroxy-3-methyl-AQ)	OH	H	Me	H	H	MeO	H	OH	Cassia sp. [54]
75	Rhein-8-glucoside	OH	H	HOOC	H	H	H	H	GluO	Cassia sp. [54]
76	Alatinone (1,5,7-trihydroxy-3-methyl-AQ)	OH	H	Me	H	OH	H	OH	H	Cassia sp. [54]
77	Diacerein (diacerhein)	OAc	H	HOOC	H	H	H	H	OAc	Cassia sp. [54]
78	Fistulic acid	OH	Me	HOOC	OH	H	MeO	MeO	OH	Cassia sp. [54]
79	5-Hydroxy emodin	OH	H	Me	H	OH	OH	H	OH	Cassia sp. [54]
80	1,3-hihydroxy-6,8-dimethoxy-AQ	OH	H	OH	H	H	MeO	H	MeO	Cassia sp. [54]
81	1,3,5,8-Tetrahydroxy-2-methyl-AQ	OH	Me	OH	H	OH	MeO	H	OH	Cassia sp. [54]
82	1,2-Dihydro-1,3,8-trihydroxy-2-methyl-AQ	OH	Me	OH	H	H	H	H	OH	Cassia sp. [54]
83	1,8-Dihydroxy-6-methoxy-2-methyl-AQ	OH	Me	H	H	H	MeO	H	OH	Cassia sp. [54]
84	1,8-Dihydroxy-6-methoxy-3-methyl-AQ	OH	H	Me	H	H	MeO	H	OH	Cassia sp. [54]
85	Citreorosein (1,3,8-trihydroxy-6-hydroxymethyl-AQ)	OH	H	CH₂OH	H	H	OH	H	OH	Cassia sp. [54]
86	Emodic acid (1,6,8-trihydroxy-AQ-3-carboxylic acid)	OH	H	HOOC	H	H	OH	H	OH	Cassia sp. [54]
87	Obtusifolin (2,8-dihydroxy-1-methoxy-3-methyl-AQ)	MeO	OH	Me	H	H	H	H	OH	Cassia sp. [54]
88	2-Formyl-1,3,8-trihydroxy-AQ	OH	CHO	OH	H	H	H	H	OH	Cassia sp. [54]
89	3-Formyl-1-hydroxy-8-methoxy-AQ	OH	H	CHO	H	H	H	H	MeO	Cassia sp. [54]

Glu: glucosyl; dMan: deoxymannosyl; Rha: rhamnosyl; Xyl: xylosyl; Me: methyl; Et: ethyl; Ph: phenyl; Ac: acetyl.