A Benzochromene from the Roots of Pentas bussei

Abstract

A new homoprenylated benzochromene, methyl-5,10-dihydroxy-7-methoxy-3-methyl-3-[4-methyl-3-pentenyl]-3H-benzo[f]chromene-9-carboxylate (1), was isolated from the roots of Pentas bussei, collected from Kenya. The structure of this new compound was determined by spectroscopic data interpretation.

Synergistic effect of three benzopyrans isolated from Hypericum polyanthemum in U‐373 MG glioblastoma cell line

“…Plants of the genus Hypericum (Gutiferae) present several kinds of phenolic compounds such as polycyclic quinones, xanthones, flavonoids, phloroglucinols and benzopyrans that can produce antiproliferative effects (Bukuru et al, 2002). In a previous study, our group detected this effect in four of six Hypericum native species studied (Ferraz et al, 2004).…”

Synthesis of fused cyclic chromene and alicyclic chromene derivatives from 2-amino-4-[4-(dimethylamino)phenyl]5-oxo-4H,5H-pyrano [3,2-c]chromene-3-carbonitrile

“…K 2 CO 3 was added to neutralize the acid till no bubble occurs. The reaction mixture was filtered, and washed with a small amount of ethanol, dried to give (11,12,13). FT-IR -1 ): 3424 cm -1 (NH), 1735 cm -1 (C=O lacton), 1678 cm -1 (C=O amid), 1…”

“…Scheme (2): preparation compounds (7)(8)(9)(10) Preparation and characterization of compound (11)(12)(13) For synthesis these compounds, compound (2) was also selected as a key intermediate for the synthesis of new fused and non-fused chromene derivatives. The synthetic reactions are summarized in Scheme (3).…”

Synthetic approaches to 3H‐naphtho[2,1‐b]pyrans and 2,3‐dihydro‐1H‐naphtho[2,1‐b]pyrans

“…Photochromic properties of 3H-naphtho [2,1-b]pyrans also make them valuable to be used for a variety of other applications such as electronic display systems, optical switches, and temporary or permanent memories [4][5][6]. Furthermore, 3H-naphtho [2,1-b]pyrans and their oxygenated and/or partially reduced congeners have also been isolated from natural sources [7][8][9]; several analogs are reported to posses interesting biological activities [8][9][10][11][12]. Molecular structures of several representative examples are shown in Figure 2.…”

“…Molecular structures of several representative examples are shown in Figure 2. A homoprenylated 3H-naphtho[2,1-b]pyran 3 was isolated from the roots of Pentas bussei [7]. In another case, several naphthopyrans including Adenaflorins C (4) were isolated from young leaves of Adenaria floribunda and bioassays show these compounds have cytotoxic effect against human cancer cells [8].…”