Lithospermum erythrorhizon
Lithospermum erythrorhizon, commonly called purple gromwell, red gromwell, red-root gromwell and redroot lithospermum, is a plant species in the genus "Lithospermum". It is called "zǐcǎo" () in Chinese, "jichi" () in Korean, and "murasaki" (; ) in Japanese. The dried root of "Lithospermum erythrorhizon" (lithospermum root or "Lithospermi Radix") is a Chinese herbal medicine with various antiviral and biological activities, including inhibition of human immunodeficiency virus type 1 (HIV-1). The genome sequence of "Lithospermum erythrorhizon" is sequenced and has facilitated the discovery of a putative retrotransposition-derived duplication event that produced a 4-hydroxybenzoate geranyltransferase gene involved in alkannin biosynthesis. Biochemistry . The enzyme 4-hydroxybenzoate geranyltransferase utilizes geranyl diphosphate and 4-hydroxybenzoate to produce 3-geranyl-4-hydroxybenzoate and diphosphate. Biosynthetically, alkannin is produced in plants from the intermediates 4-hydroxybenzoic acid and geranyl pyrophosphate. This enzyme is involved in shikonin biosynthesis. The enzyme geranylhydroquinone 3"-hydroxylase uses geranylhydroquinone, NADPH, H and O to produce 3-hydroxygeranylhydroquinone, NADP and HO. Culture. It has been cultivated in Japan since the Nara period for its root, which can be used for herbal medicine and to make dyes. One Japanese word for the plant, "murasaki" (紫), inspired the pen name "Lady Murasaki" for the author of  The Tale of Genji and is also the source of the general Japanese term for the color purple, "murasaki iro" (紫色). The dyes made from its root also had other names, such as "shikon" (紫根), but all of them were difficult to work with because of their requirement for an alum-rich mordant and the resulting colors' extreme vulnerability to photobleaching. During the Heian Period, sumptuary laws restricted "murasaki"-dyed clothing to the Empress and her ladies in waiting.