New Anthracene Derivatives from Coussarea macrophylla

Abstract

Five new naturally occurring anthracene derivatives, 1,4,10-trimethoxyanthracene-2-carbaldehyde (1), (1,4,10-trimethoxy-2-anthracen-2-yl)methanol (2), 1,4,8,10-tetramethoxyanthracene-2-carbaldehyde (3), 1,4,10-trimethoxyanthracene-2-carboxylic acid (4), and 1,3-dimethoxy-2-methoxymethylanthraquinone (5), were isolated from Coussarea macrophylla along with three known compounds, 3-hydroxy-1-methoxy-2-methoxymethylanthraquinone (6), scopoletin, and 3-epi-pomolic acid. The structures of 1-5 were determined on the basis of analysis of their spectroscopic data and by total synthesis.

Highly brominated anthracenes as precursors for the convenient synthesis of 2,9,10-trisubstituted anthracene derivatives

“…in the synthesis of other substituted anthracene derivatives, which can be easily converted to hydroxyanthracenes, and also in the synthesis of anthraquinones. In addition, there are many naturally occurring methoxyanthracene derivatives [ 31 – 32 ].…”

Phytochemistry and Ethnopharmacology of the Ecuadorian Flora. A Review

“…Coussarea macrophylla (Rubiaceae) is a woody plant, occurring in the tropical swamp forests of Ecuador. Five naturally occurring anthracene derivatives: 1,4,10-trimethoxyanthracene-2carbaldehyde (235), 1,4,10-trimethoxy-2-anthracen-2-yl methanol (236), 1,4,8,10-tetramethoxyanthracene-2-carbaldehyde (237), 1,4,10-trimethoxyanthracene-2-carboxylic acid (238), methyl 1,4,10-trimethoxyanthracene-2-carboxylate (239) and 1,3dimethoxy-2-methoxymethylanthraquinone (240), were isolated from C. macrophylla, along with three known compounds: 3hydroxy-1-methoxy-2-methoxymethylanthraquinone (241), scopoletin, and 3-epi-pomolic acid [91]. Some of us have also isolated eight triterpene acid derivatives [92], with seco-cycloartane and seco-dammarane type structure; six of these compounds, called The bark of Calycophyllum acreanum is used by the Waorani natives to prepare a decoction to treat fungal infections [18,19].…”

Structural Revision of Wentiquinone C and Related Congeners from Anthraquinones to Xanthones Using Chemical Derivatization and NMR Analysis

“…One of them is an aromatic methoxy group (δ C 56.3), and another is a methyl ester (δ C 53.2). A literature survey indicated the interesting distinction for the chemical shifts of aromatic methoxy and methyl ester groups [5,6,7,8,9,10] (Figure 2), which supported the undoubted difference in chemical shifts between the two types of methoxy groups. That is, in the 13 C NMR spectrum the chemical shifts for aromatic methoxy groups are always bigger than δ C 55.0, while those for methyl esters are usually smaller than δ C 55.0.…”