Purple of the ancients

It was of this Purple of the Ancients that Browning wrote ... 

Marine natural products. The history of natural products from marine organisms ranges from the purple of the ancient Phoenicians who had a flourishing industry around 1600 BC to the most complicated low-molecular-weight structures known to date the polyether toxins maitotoxin and palytoxin. 

The color purple also plays an important role in the development of biological stains. From ancient times, purple was considered to be the most beautiful, stable and precious of all colors. Today, it is critical to the staining of blood. The journey of the Tyrian purple of the ancients to the Tyrian purple of Wilham Henry Perkin and beyond is beautifully documented by Krafts, et al. A major stage on this journey was the 1891 discovery by Ernst Malachowski of a borax-alkalinized methylene blue stain that rendered the nucleus of Plasmodium falciparum, the malarial parasite, visible for the first time - in all its purple glory [63]. 

Tyrian Purple was the most expensive and rare dye of the ancient world principally because only a small amount of dye could be obtained from each moUusk, roughly 0.12 mg (95). It was always considered a color of distinction and restricted to regal and ecclesiastical uses ia the Eastern Roman Empire, the heir to the throne at By2antium bore the proud name Porphjro-Genitur, bom to the purple. The Hebrews used purple ia many decorations of the Tabernacle (23). 

The most famous halogenated bis-indole is Tyrian purple, the dibromo analog of indigo (1). This colorful mollusc metabolite, which was the major component of the ancient dye, continues to receive attention (1369-1374). Additional studies of Tyrian purple from various molluscs have revealed the presence of 6,6 -dibromoin-dirubin (1441) (1375), 6-bromoindigotin (1442) (1375, 1376), 6-bromoisatin (1443) (1377, 1378), 6-bromoindoxyl (1444) (1378), 1445 (1378), 1446 (1378), 6-bromoindirubin (1447) (1379), and 6 -bromoindirubin (1448) (1379). The bromi-nated indirubins are potent and selective kinase inhibitors (1379). A direct-exposure... 

McGovern, P.E., and R.H. Michel. 1990. Royal purple dye the chemical reconstruction of the ancient Mediterranean industry. Accounts of Chemical Research 23 152-158. 

The dye industry. This tale refers to one of the most important dyes of the ancient world Tyrian purple. Species of mollusk known as Murex brandaris and Murex trunculus produce a purple color, which supposedly stained Hercules s dog. 

Fig. 1.1 6,6 -Dibromoindigotin and its reduced form. This compound was the basis of the ancient dye Royal Purple, references to which go back to biblical times.

Vat Dyes. Vat dyes are insoluble in water. Indigo, for example, an ancient blue dye, is probably the best-known example of an ancient vat dye others include woad and Tyrian purple. Since the process of dyeing requires that the dye be in solution, dyeing with a vat dye (or vat dyeing, as the process is known) is possible only after the vat dye has been made soluble by a relatively long and somewhat complicated chemical procedure. The terms vat dye and vat dyeing are probably derived from the large tanks or "vats", in which the process was carried out in ancient times. 

Berke, H. (2007), The invention of blue and purple pigments in ancient times, Chem. Soc. Rev. 36, 15-30. 

Debromination with ageing has been observed in the indigoid components of purple [171,172], and photochemical breakdown patterns of the three anthocyanidins contained in Arrabidaea chica red dye, produced by Andean Indian cultures in the tenth to fifteenth centuries, have been hypothesized [173]. Although identifying dye sources in ancient artefacts is quite difficult, it is helped considerably by understanding the fading and degradation mechanisms. 

Another early use of iron oxides was as a cosmetic. The cosmetic boxes (cockleshells) found in the Royal Cemetery in the ancient Sumerian city of Ur contained a range of different colours. XRD analysis by the Research Department of the British Museum showed that the principal components of the red and yellow colours were hematite and goethite, respectively (Bimson, 1980). One box also contained a purple powder consisting of a mixture of quartz grains and large crystals of hematite. 

Technological compounds and laboratory tools The technological use of natural products is as old as humanity, although mixtures of unknown conqjosition were mostly used before the advent of chemistry. Mummification in ancient Egypt is one such exan le. In contrast, that of the Phoenician Tyrian Purple was an advanced technology based on a practically pure substance. 

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