naphthoquinones and alizarin

Some representative quinones, viz. one naphthoquinone (plumbagin) and five anthraquinones (alizarin, purpurin, chrysazin, emodin, and anthrarufin), were subjected to electrocoagulation. It was found that the rate and extent of coagulation of these compounds appears to correlate with the number and relative position of their phenolic substituent groups, and that all of the coagulated quinones could be recovered. Attempts were then made to electrochemically isolate three quinones, namely plumbagin, morindone and erythrolaccin, from natural sources.

Topics: Anthraquinones; Benzoquinones; Electrocoagulation; Morinda; Naphthoquinones; Pigments, Biological; Plumbaginaceae; Quinones

Recently dyes derived from natural sources have emerged as important alternatives to synthetic dyes. A study was initiated in the year 2000 at the RRL (CSIR), Jorhat to extract dyes from parts of five different plant species indigenous to northeastern India. The colour components responsible for dyeing were isolated and their chemical constituents were established based on chemical and spectroscopic investigations. The principal colour components from the species Morinda angustifolia Roxb., Rubia cordifolia Linn. and Tectona grandis Linn. were found to contain mainly anthraquinone moieties in their molecules. Those from the species Mimusops elengi Linn. and Terminalia arjuna (Roxb.) Wight & Arn. contained flavonoid moieties in their molecules. The absorption of dye (%) on fibres increased with increasing concentrations of dye in the dye-bath. Maximum absorption of dyes on fibres was obtained at 3% concentration of dyes obtained from R. cordfolia (35.350%), M. angustifolia (31.580%) and T. grandis (25.888%) and at 4% concentration of the dyes from M. elengi (31.917%) and T. arjuna (12.246%). The K/S values were found to increase with the increase in concentration of mordants. The colour co-ordinates of dyed samples were found to lie in the yellow-red quadrant of the colour space diagram. The dyes obtained from the native plants may be alternative sources to synthetic dyes for the dyeing of natural silk and cotton.

Topics: Anthraquinones; Azo Compounds; Colorimetry; Cotton Fiber; India; Magnetic Resonance Spectroscopy; Naphthoquinones; Pigmentation; Pigments, Biological; Plant Extracts; Plants; Quercetin; Silk; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Textiles

Quinones were studied for their growth inhibitory effect on cultured malignant cells. HCT-15 cells derived from human colon carcinoma were used for these experiments. Quinones used were arbutin in the benzoquinone group, juglone and lawsone in the naphthaquinone group, alizarin, emodin, 1,8-dihydroxyanthraquinone, and anthraquinone in the anthraquinone group, and xanthone. Cultured cells were incubated with various concentrations of the quinones for four days in a 5% CO2 incubator, after which cell numbers were counted and significance of differences was analyzed by Student's t test. Anthraquinones and naphthaquinones used in these experiments were more effective than the monocyclic quinone. The 50% suppression dose was less than 12.5 micrograms/ml for them. The number of OH groups seemed to play an important role in the degree of the cell growth inhibition: anthraquinones with 2 or 3 OH groups were more effective than those with no OH group like, 9,10-dioxoanthracene and xanthone. In fact, anthraquinones with no OH group and xanthone were not significantly effective. Flow cytometric histograms revealed a specific pattern; that is, lawsone and juglone in the naphthaquinone group and alizarin and 1,8-dihydroxy-anthraquinone in the anthraquinone group blocked mainly the S phase, and emodin in the anthraquinone group blocked the G1 to S phase of the cell cycle.

Topics: Anthraquinones; Antineoplastic Agents; Arbutin; Cell Division; Colonic Neoplasms; Humans; Naphthoquinones; Quinones; Tumor Cells, Cultured; Xanthenes; Xanthones