''Lithospermum erythrorhizon'', commonly called purple gromwell, red gromwell, red-root gromwell and redroot lithospermum, is a plant species in the genus ''

Lithospermum ''Lithospermum'' is a genus of plants belonging to the family Boraginaceae. The genus is distributed nearly worldwide, but most are native to the Americas and the center of diversity is in the southwestern United States and Mexico. Species a ...

''. 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 Alkannin is a natural dye that is obtained from the extracts of plants from the borage family '' Alkanna tinctoria'' that are found in the south of France. The dye is used as a food colouring and in cosmetics. It is used as a red-brown food add ...

biosynthesis.

Biochemistry

The enzyme 4-hydroxybenzoate geranyltransferase utilizes

geranyl diphosphate Geranyl pyrophosphate (GPP), also known as geranyl diphosphate (GDP), is the pyrophosphate ester of the terpenoid geraniol. Its salts are colorless. It is a precursor to many natural product A natural product is a natural compound or subst ...

and

4-hydroxybenzoate 4-Hydroxybenzoic acid, also known as ''p''-hydroxybenzoic acid (PHBA), is a monohydroxybenzoic acid, a phenolic derivative of benzoic acid. It is a white crystalline solid that is slightly soluble in water and chloroform but more soluble in polar ...

to produce 3-geranyl-4-hydroxybenzoate and diphosphate. Biosynthetically,

is produced in plants from the intermediates 4-hydroxybenzoic acid and

geranyl pyrophosphate Geranyl pyrophosphate (GPP), also known as geranyl diphosphate (GDP), is the pyrophosphate ester of the terpenoid geraniol. Its salts are colorless. It is a precursor to many natural products. Occurrence GPP is an intermediate in the isoprenoid ...

. This enzyme is involved in shikonin biosynthesis. The enzyme geranylhydroquinone 3''-hydroxylase uses geranylhydroquinone, NADPH, H⁺ and O₂ to produce 3-hydroxygeranylhydroquinone, NADP⁺ and H₂O.

Uses

It has been cultivated in Japan since the

Nara period The of the history of Japan covers the years from CE 710 to 794. Empress Genmei established the capital of Heijō-kyō (present-day Nara, Nara, Nara). Except for a five-year period (740–745), when the capital was briefly moved again, it remai ...

for its

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the sur ...

, which can be used for herbal medicine and to make

dyes A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and ...

. Before the introduction of synthetic dyes to

Meiji period The is an era of Japanese history that extended from October 23, 1868 to July 30, 1912. The Meiji era was the first half of the Empire of Japan, when the Japanese people moved from being an isolated feudal society at risk of colonization ...

Japan, the roots were commonly used as a dyestuff for luxury textiles, typically high-end

kimono The is a traditional Japanese garment and the national dress of Japan. The kimono is a wrapped-front garment with square sleeves and a rectangular body, and is worn left side wrapped over right, unless the wearer is deceased. The kimon ...

and . The process of extracting purple dyestuff from the roots was an exceedingly long, complex and time-consuming process, necessitating its relatively high expense: For a deep purple, up to 50 dips could be needed. dye loses colour remarkably fast, literally as the fibers are being dipped, meaning it was often used for ( ombré) dying, and the resulting colour was varied and uneven, with each strand a slightly different shade. One Japanese word for the plant, ''murasaki'' (紫), inspired the

pen name A pen name, also called a ''nom de plume'' or a literary double, is a pseudonym (or, in some cases, a variant form of a real name) adopted by an author and printed on the title page or by-line of their works in place of their real name. A pen na ...

"Lady Murasaki" for the author of '' The Tale of Genji'' and is also the source of the general Japanese term for the color

purple Purple is any of a variety of colors with hue between red and blue. In the RGB color model used in computer and television screens, purples are produced by mixing red and blue light. In the RYB color model historically used by painters, ...

, ''murasaki iro'' (紫色). Additional terms were used for specific shades of purple within this range, particularly during the

Heian period The is the last division of classical Japanese history, running from 794 to 1185. It followed the Nara period, beginning when the 50th emperor, Emperor Kanmu, moved the capital of Japan to Heian-kyō (modern Kyoto). means "peace" in Japanese ...

; names such as ("pale purple") and ("light purple") formed important distinctions when dressing in specifically-layered clothing, and could also indicate (typically high) rank. 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 An alum () is a type of chemical compound, usually a hydrated double sulfate salt of aluminium with the general formula , where is a monovalent cation such as potassium or ammonium. By itself, "alum" often refers to potassium alum, with t ...

-rich

mordant A mordant or dye fixative is a substance used to set (i.e. bind) dyes on fabrics by forming a coordination complex with the dye, which then attaches to the fabric (or tissue). It may be used for dyeing fabrics or for intensifying stains in ...

and the resulting colors' extreme vulnerability to

photobleaching In optics, photobleaching (sometimes termed fading) is the photochemical alteration of a dye or a fluorophore molecule such that it is permanently unable to fluoresce. This is caused by cleaving of covalent bonds or non-specific reactions between t ...

. During the

Heian Period The is the last division of classical Japanese history, running from 794 to 1185. It followed the Nara period, beginning when the 50th emperor, Emperor Kanmu, moved the capital of Japan to Heian-kyō (modern Kyoto). means "peace" in Japanese ...

sumptuary Sumptuary laws (from Latin ''sūmptuāriae lēgēs'') are laws that try to regulate consumption. '' Black's Law Dictionary'' defines them as "Laws made for the purpose of restraining luxury or extravagance, particularly against inordinate expend ...

laws restricted ''murasaki''-dyed clothing to the

Empress An emperor (from la, imperator, via fro, empereor) is a monarch, and usually the sovereign ruler of an empire or another type of imperial realm. Empress, the female equivalent, may indicate an emperor's wife ( empress consort), mother ( em ...

and her

ladies in waiting A lady-in-waiting or court lady is a female personal assistant at a court, attending on a royal woman or a high-ranking noblewoman. Historically, in Europe, a lady-in-waiting was often a noblewoman but of lower rank than the woman to whom sh ...

References

{{Taxonbar, from=Q15592453 erythrorhizon Plants described in 1846

Biochemistry

Uses

See also

References