Binuclear lanthanide complexes of 2,3-dihydroxy-1,4-naphthoquinone

Complete 1H and 13C NMR assignments of an uncommon 2,3‐dihydroxynaphthoquinone isolated from Cordia multispicata (Cham.)

“…The first study, dated of 1976, reported the 13 C NMR data for a series of substituted naphthoquinones, including a 2,3‐bis‐(trifluoroacetoxy) compound, where the chemical shifts of C‐2 ( δ C 142.2) and C‐3 ( δ C 142.6) are strongly shielded in comparison to the monosubstituted derivative . Posteriorly, Khandagale et al . described the 13 C NMR data of a 2,3‐dihydroxy‐1,4‐naphthoquinone (isnphth) in comparison with the 13 C NMR data of the 2‐hydroxy‐1,4‐naphthoquinone (lawsone).…”

Crystal structure, spectroscopic and thermal properties of [Zn(Lap)2(DMF)(H2O)] and isomorphous [M(Lap)2]n (M: Cd, Mn) complexes

“…In the 1283-1249 cm -1 (Mn) and 1281-1248 cm -1 (Cd) spectral ranges are observed two medium intensity and sharp bands which are attributed to C-C and phenol C-O stretching modes, and to C-H and phenol C-O stretching modes [24,25].…”

Effect of methionine on production of naphthoquinones inImpatiens balsaminaroot cultures and detection of some secondary metabolites

“…Ten known compounds were isolated and identified as luteolin (1) (Miyazawa & Hisama, 2003), phthalic acid (2), phthalic anhydride (3), methyl linolenate (4) (Gunstone, 1990), spinasterol (5) (Jeon et al, 2005), p-hydroxybenzoic acid (6) (Dhakal et al, 2009), isofraxidin (7) (Panichayupakaranant et al, 1995), scopoletin (8) (Kumar et al, 1994), 2,3-dihydroxy-1,4-naphthoquinone (9) (Khandagale et al, 2005), and echinocystic acid (10) (Khajuria et al, 2007) (Figure 3), by comparison of their NMR data with the reported values in the literature. Isofraxidin and scopoletin are coumarins previously found in I. balsamina root cultures (Panichayupakaranant et al, 1995).…”

“…obtained by chemical synthesis and is known to form a complex with lanthanide (Khandagale et al, 2005). Thus, I. balsamina root cultures could be considered as a new source of this compound although it would be required to find a method to increase its yield.…”