Biosynthesis of anthraquinones and related compounds in Galium mollugo cell suspension cultures

Biosynthesis of anthraquinones in cell cultures of Cinchona ‘Robusta’ proceeds via the methylerythritol 4-phosphate pathway

“…1). Early work on feeding experiments established that rings A and B of AQs in Rubia (Leistner, 1981), Morinda (Leistner, 1975) and Galium (Bauch and Leistner, 1978;Inoue et al, 1984) are derived from shikimic acid (Leistner and Zenk, 1967), a-ketoglutarate via o-succinylbenzoate [ Fig. 1(I) and (II)], whereas ring C of Rubia type AQs is derived from mevalonic acid [Fig.…”

The chemical reactivity of naphthols and their derivatives toward α-cyanocinnamonitriles and ethyl α-cyanocinnamates: A review of synthesis, reactions and applications of naphthopyrano

“…A mechanism for the piperidine catalyzed formation of the naphtho [2,1-b]pyran derivatives 3 is outlined in Scheme 2. b) An efficient bifunctional thiourea catalyzed additioncyclization reaction of arylidenemalononitriles 2 with 2-naphthol (4) is realized under mild conditions to afford the corresponding 2-amino-3-cyano-4-aryl-4H-naphtho [2,1-b] pyrans (5), in high yields and moderate enantioselectivities (Scheme 4 ) [14]. Scheme 4 c) A novel bifunctional thiourea-tertiary-amine-catalyzed enantioselective Friedel-Craft-type addition reaction of 2-naphthol (4) with β,γ-unsaturated α-keto ester, 6, was developed.…”

“…e) The model reaction was carried out simply by mixing of 4-chlorobenzaldehyde, malononitrile and 2-naphthol (4) using Na2CO3 as catalyst afforded 2-amino-3-cyano-4-(p-chloro phenyl)-4H-naphtho[2,1-b]pyran (5). In the absence of catalyst no reaction was observed at room temperature (Scheme 13) [20].…”

“…2-Amino-5-methyl-benzo [5,6] Trinitriles 79 reacted with ammonium acetate in molar ratio 1:2 to afford 2,6-diamino-4-(2-hydroxy-1-naphthyl)-3,5-pyridine-dicarbonitrile (90). Compound 90 was converted, in the presence of hydrochloric acid, into 2,4-diamino-5-oxo-5H-benzo [5,6] …”

“…The dried roots and rhizomes of this plant are used officially as herbal medicine in the Chinese Pharmacopeia for treating arthritis, dysmenorrhea hemostasis, and other diseases [4]. In India, this plant has been used for treatment of rheumatism, menstrual pain, and urinary disorders [5]. Mollugin (I) was also isolated from rhizome of Galium mollugo, which is found in many rubiaceous herbs in Europe and Africa [6].…”