ChemInform Abstract: Chemistry of Naphthazarin Derivatives. Part 8. Determination of Structures of Substituted 2‐Hydroxy‐6(7)‐methoxynaphthazarins and 7(8)‐Hydroxypyranonaphthazarins by IR Spectroscopy.

Abstract

2001quinones quinones (naphthalene compounds) Q 0910 -079Chemistry of Naphthazarin Derivatives. Part 8. Determination of Structures of Substituted 2-Hydroxy-6(7)-methoxynaphthazarins and 7(8)-Hydroxypyranonaphthazarins by IR Spectroscopy.-Several pairs of substituted 2-hydroxy-6 (7)-methoxynaphthazarins [cf. (III), (VI)] and 7(8)-hydroxypyranonaphthazarins [cf. (IX)] are synthesized and characterized by IR-spectroscopy. Their spectroscopic regularities confirm the structures of cristazarin (VIb) and its 6-methyl-analogue, which are metabolites of a lichen species. -(GLAZUNOV, V. P.; TCHIZHOVA, A. YA.; SHESTAK, O. P.; SOPEL'NYAK, G. I.; ANUFRIEV, V. PH.; Russ. Chem. Bull. 50 (2001) 1, 95-100; Pac. Inst. Bio-Org. Chem., Russ. Acad. Sci., Vladivostok 690022, Russia; EN)

Naphthoquinone-Based Meroterpenoids from Marine-Derived Streptomyces sp. B9173

“…The NMR data for new compounds ( 1 – 3 ) are presented in Figures S3–S5 and summarized in Table 1 , Table 2 and Table 3 . The 1 H-NMR spectra and HR-ESI MS data of known compounds ( 4 – 7 ) are listed in Figures S6–S9 and Table S1 , which are matched by the literature [ 10 , 23 , 24 , 25 , 26 ].…”

“…Chemical investigations into the fermentation cultures led to the isolation of a group of naphthoquinone-containing compounds. Among them, 1 – 3 are previously unreported naphthoquinone-containing derivatives, and others are biogenetically related compounds including flaviogeranin A and substituted 5-hydroxy-1,4-naphthoquinones [ 10 , 25 , 26 ].…”

Antioxidant Activity of 1’-Hydroxyethylnaphthazarins and their Derivatives

“…The IR absorption spectra were recorded on a Bruker Vector 22 spectrophotometer. 1 H and 13 C NMR spectra were recorded on Bruker Avance-300 (300 and 75 MHz, respectively), Bruker Avance-III-500 HD (500 and 125 MHz, respectively), and Avance-III-700 (700 and 176 MHz, respectively) spectrometers [6] were synthesized according to described methods. Physicochemical and spectroscopic data for 2 are in agreement with the data published for the pigment lomazarin isolated from Lomandra hastilis [1].…”

“…The parent compound of lomazarin, trimethyl ether of echinochrome A (1), and the parent compound of isonorlomazarin, dimethyl ether of echinochrome A (11), were also tested. Compounds 1-5, 9-11 were synthesized early [2, [4][5][6], compounds 6-8, 12, and 14 were synthesized for the first time ( Figure 1, Schemes 1, 2). These compounds can be easily obtained by nucleophilic substitution of a bromine atom by an acetoxy function in 1'bromoalkyl derivatives of a naphthazarin followed by hydrolysis of corresponding 1'-acetoxyalkyl derivatives [7].…”

Antiradical Activity of Naphthazarin-Carbohydrate Nonglycoside Conjugates

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The ABTS •+ scavenging activity of known (4, 6-8) and new (5,(9)(10)(11)(12) naphthazarin-carbohydrate nonglycoside conjugates, and methoxynaphthazarins 1-3 was evaluated. The study of structure-activity relationships showed that the presence of carbohydrate fragments in the structure of naphthazarin-carbohydrate conjugates increased their antiradical activity compared with starting methoxynaphthazarins.

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