Dichroines

A further contribution to this subject has been made by the Chinese workers quite recently, in which they describe briefly five bases, of which the three dichroines are interconvertible isomerides of the formula, CjgHgjOgNg. Thc mclting points of the salts are also decomposing points —... 

They also state that analytical studies of the oxidation products of dichroine-a indicate that the dichroines are quinazoline derivatives, as already indicated by Koepfli et al. for their alkaloids. With the probable exception of dichroine-a, these bases are active against malaria in chicks in the descending order dichroine-y (1), dichroine- (4) dichroidine quinazolone (40) the figures in brackets are effective doses (mgm./kilo.). There are also two neutral substances present, umbelliferone (dichrin-A) and dichrin-B, m.p. 179-181°. 

Adamia chinensis Gard. et Champ. A. cyanea Wall. A. versicolof Fortune (Syn. Dichroa febrifuga) Chang Shan (Chinese quinine, fever flower) (root) Alpha-dichroine, beta-dichroine, gamma-dichroine.49 This herb is toxic. Antimalarial, antipyretic. 

Acid-mordant dyes have characteristics similar to those of acid dyes which have a relatively low molecular weight, anionic substituents, and an affinity to polyamide fibers and mordant dyes. In general, brilliant shades cannot be obtained by acid-mordant dyes because they are used as their chromium mordant by treatment with dichroinate in the course of the dyeing procedure. However, because of their excellent fastness fur light and wet treatment, they are predominantly used to dye wool in heavy shades (navy blue, brown, and black). In terms of chemical constitution, most of the acid-mordant dyes are azo dyes some are triphenylmethune dyes and very few anlhraquinone dyes are used in this area. Cl Mordant Black 13 is one of the few examples of currently produced anlhraquinone ueid-mordant dyes. 

A different color coupler is used for each layer of the emulsion and, although the complete color picture is formed in this step, the film is coal black because of the metallic silver produced at the same time. The silver then is oxidized to silver bromide with dichroinate solution containing bromide ion and removed with thiosulfate solution. The final image thus contains no silver. 

On treating phenols in concentrated sulphuric acid solution at 40°-50° C. with nitrous acid, peculiar violet or blue compounds are formed. They are of distinctly acid character, and are reprecipitated from alkaline solutions on addition of acids. Their alkaline solutions exhibit a remarkable fluorescence, and for this reason this class of compounds is also known as Dichroines. 

This experiment should only be carried out in a well-ventilated hood, since chromates and dichroinates are strongly cancerogenic. Safety glasses and protective gloves must be worn. 

In a book about herbs, the Chinese scholar-emperor Shen Nung described in 2735 BC the beneficial effects of Ch ang Shan in the treatment of fevers [8]. This preparation is the powdered root of a plant, Dichroafehrifitga Lour. Modern medicinal chemistry has identified several alkaloids with antimalarial properties in the plant, and it is therefore clear that the ancient use of Ch ang Shan in fevers was not entirely without basis. One of the antimalarial compounds from Ch ang Shan is fihrugine (/J-dichroine), a relatively simple unichiral compound 1. Modem attempts to develop these agents as antimalarial drugs failed, due to significant toxicity [8]. 

The chromate, especially potassium dichromate (q. .), are irritants, and have a distinctly poisonous action as well. Workmen handling the dichroinate are liable to a form of chronic poisoning. 

Heterocycles have been used medicinally since the beginning of written records. Shen Nung, a Chinese scholar-emperor who lived in 2735 B.C., wrote of the herb Ch ang Shan, as being helpful in treating fevers. Ch ang Shan was later found to contain dichroins," ... 

Febrifugine dichroine B, 3-[3-((25)-(ranj-3-hy-droxy-2-piperidinyl)-2-oxopropyl]-4(3//)-quinazoli-nonel. 

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