Habitat
It is found in the temperate Himalayas at altitudes of 1,200-3,000 m. from Kashmir to Bhutan, and in the Khasi hills in Meghalaya at 1,200-1,500 m.

Morphology Description (Habit)
The plant is an erect annual. The stems are robust, branching, cylindrical below and 4-angled upwards, containing a large pith; the leaves are broadly lanceolate, 5-nerved and sub-sessile; the flowers occur in large panicles, are lurid greenish yellow, tinged with purple; the capsules are egg-shaped, many-sided, sharp-pointed; the seeds are smooth and many- angled. The drug (chiretta) is obtained from the dried plant.

Principal Constituents
Chiretta is reported to contain a yellow bitter acid, ophelic acid, two bitter glucosides, chiratin and amarogentin, gentiopicrin, two yellow crystalline phenols, a neutral, yellow crystalline compound, and a new xanthone, swerchirin. Amarogentin is one of the most bitter substances known¹.The herb contains swertanone, swertenol, episwertinol, chiratenol, gammacer-16-en-3ß-ol, 21-a-H-hop-22(29)-en-3ß-ol, taraxerol, oleanolic acid, ursolic acid, swerta-7,9(11)-dien-3ß-ol, pichierenol, besides ß-amyrin, y-taraxasterol, lupeol and erythrodiol. It also yields, 1,3,6,7-tetrahydroxyxanthone-C-2-ß-D-glucoside (mangiferin) having a significant immunomodulatory potential. A new xanthone, 1,5-dihydroxy-3,8-dimethoxyxanthone (chiratol) besides swerchirin and 7-O-Me swertiarin and monohydroxy terephthalic acid and 2,5-dihydroxy terephthalic acid were isolated from the herb². The herb also yields 1,5,8-trihydroxy-3-methoxyxanthone, 1-hydroxy-3,5,8-trimethoxyxanthone, 1-hydroxy-3,7,8-trimethoxy xanthone, 1,8-dihydroxy-3,5-dimethoxy-xanthone, 1,8-dihydroxy-3,7- dimethoxy xanthone, 1,3,6,7-tetrahydroxy xanthone C-2-ß-D-glucoside (mengiferin), 1,3,8-trihydroxy-5- methoxy xanthone, 1,3,5,8-tetrahydroxy xanthone and 1,3,7,8- tetrahydroxy xanthone, a novel dimeric xanthone (chiratanin) and the alkaloids gentianine, gentiocrucine and enicoflavine³.

Pharmacology
The ethanolic extract of S.chirayita exhibits hypoglycemic activity. The hexane fraction containing swerchirin, the main hypoglycemic principle, induced a significant fall in blood sugar in albino rats. The compound may have clinical application in control of diabetes⁴. It also possesses anti-microbial activity against gram-negative and gram-positive bacteria. An herbal antiseptic and antifungal Veterinary ointment Melicon V is prepared from the herb⁵. The extract of the plant exhibits a significant anti-inflammatory activity. The plant extract shows anti-leishmanial activity against Leishmania donovani in golden hamsters⁶.

References

1. Prasad et. al., loc. cit.; Dalal & Shah, Chem. & Ind.,1956, 664; Bose, J. Indian chem. Soc.,1960, 37, 6532.

2. Chakravarty & Mukhopadhyay, Indian J Chem, 1992, 31B, 70; Chakravarty et. al., Phytochemistry, 1991, 30, 4087;

3. Asthana et. al., ibid, 1991, 30, 1037; Ghosal, Indian J Indigenous Med, 1991, 8(1), 3; Chem Abstr, 1991, 114, 139828; Fevre-Bonvin et. al., J Nat Prod, 1988, 51, 9773. Asthana et. al., Phytochemistry, 1991, 30, 10374.

4. Chandrasekar et. al., Indian J Exp Biol, 1990, 28, 616; 6 Saxena et. al., ibid, 1993, 31, 178; Bajpai et. al., Planta Med, 1991, 57, 102 5.

5. Pandey et. al., J Res Ayurv Siddha, 1991, 12 (1 & 2) 33; Leslie & Jolly, Indian Drugs, 1988, 25, 143; Pandya et. al., ibid, 1991, 28, 225; Mukherjee, Fitoterapia, 1991, 62, 1976.

6. Mandal et. al., Fitoterapia, 1992, 63, 122; Singha et. al., Int J Pharmacongn, 1992, 30, 289.