ABSTRACT
Swertia, commonly known as Chirata in indigenous systems of medicine, are used for treatment of a variety of ailments. Literature survey revealed that much phytochemical analysis has been done on genus Swertia by several groups. In this study, we had planned to document the active chemical constituents of valuable medicinal plants of genus Swertia. The major bioactives of Swertia are xanthones, however, other secondary metabolites such as flavonoids, iridoid glycosides and triterpenoids are also active constituents of this genus. These secondary metabolites played significant role in biological activities such as hepatoprotective, antihepatotoxic, antimicrobial, anti-inflammatory, anticarcinogenic, antileprosy, hypoglycemic, antimalarial, antioxidant, anticholinergic, CNS depressant and mutagenicity.
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DOI: 10.3923/crc.2011.1.15
URL: https://scialert.net/abstract/?doi=crc.2011.1.15
INTRODUCTION
Swertia (family Gentianaceae) is a large genus of herbs distributed in the mountainous regions of tropical area at an altitude of 1200-3600 m. The herbal drug chiretta obtained from the dried plants of swertia species. The whole plants of Swertia are medicinal but roots are the most powerful parts (Anonymous, 1976). These are useful as a tonic without aroma or astringency. In Indian medical system chiretta is used as remedy for bronchial asthma, liver disorders, chronic fever, anemia, stomachic and diarrhoea. Chiretta is also used in dying cotton cloth and in liquor industry as bitter ingredients. In Ayurveda, S. chirayita is used as antipyretic, anthelminitic, antiperiodic, laxative and in asthma and leucorrhoea. In Yunani system the plant is used as astringent, tonic, stomachic, lessens inflammation, sedative to pregnant uterus and chronic fevers (Kirtikar and Basu, 1984).
S. chirayita has an established domestic (India) and international market which is increasing at a rate of 10% annually. In spite of the increasing demand by herbal industry the plant is still collected from wild. It is sparsely cultivated and negligible efforts have gone into developing proper agro-techniques of plant. It is harvested for the drug industry (Bentley and Trimen, 1880). S. chirayita is also used in British and American pharmacopoeias as tincture and infusions (Joshi and Dhawan, 2005). S. angustifolia resembles to S. chirayita very closely but differs from it in having thinner root, small wings and ridges on the stem. The dried plants of S. angustifolia and S. paniculata are used as substitute for S. chirayita. About 22,000 kg of the drug are said to be collected and sold annually in Himanchal Pradesh while the annual demand for chiretta in India is reported to be 37,300 kg. Plants belonging to these families are found in all parts of world. They have been widely used in folk medicine. Simple polyoxygenated xanthones have been isolated from most of them. Xanthone derivatives, flavonoids, iridoid glycosides, triterpenoids and dimeric xanthones have been isolated from the genus Swertia (Tan et al., 1991; Zhou et al., 1989). The genus Swertia exhibit variety of biological activity such as hepatoprotective, antihepatotoxic, antimicrobial, anti-inflammatory, anticarcinogenic, antileprosy, hypoglycemic, antimalarial, antioxidant, anticholinergic, CNS depressant and mutagenicity. The pharmacological properties of Swertia have raised great interest. The purpose of this review to collect all the possible information regarding the chemical constituents and biological effects of the genus Swertia, thus will help to the researchers and scientists to take action for future study in this discipline.
CHEMICAL CONSTITUENTS
Xanthones are main secondary metabolites of Swertia species. Structures of xanthones are related to that of flavonoids and their chromatographic behaviors are also similar. Although flavonoids are frequently encountered in nature, xanthones have been found in limited number of families. They always occur in Gentianaceae and Guttiferae. Xanthones are sometimes found as the parent polyhydroxylated compounds but most xanthones are mono or poly methyl ethers or are found as glycosides (Hostettmann and Miura, 1977). Unlike iridoids, xanthones are apparently not present in all plant species investigated in the family Gentianaceae. This is documented by the systematic study of Hostettmann-Kaldas et al. (1981). The natural xanthones have been isolated mainly from about 150 plants associated with four families; Guttiferae, Gentianaceae, Moraceae and Polygalaceae. According to Vieira and Kijjoa (2005), 278 natural xanthones were reported from total of 515 xanthones. In this period, the xanthones from higher plants appear to be associated mainly with the families Clusiaceae (55 species in 12 genera) and Gentianaceae (28 species in 8 genera). Isolated compounds and biological activities of Swertia species are listed in Table 1. Xanthones isolated from nature are classified into six main groups; simple xanthones, xanthone glycosides, prenylated xanthones, xanthonolignoids, bis-xanthones and miscellaneous xanthones. These are further subdivided according to the degree of oxygenation into non-, mon-o, di-, tri-, tetra-, penta- and hexa-oxygenated substances (Mandal et al., 1992b; Sultanbawa, 1980; Demirkiran, 2007).
Xanthones and their glycosides (Fig. 1) have been isolated from Swertia species. Mangiferin is the most common C-glycosides in S. chirayita, S. mussotii, S. cordata, S. macrosperma and S. connata. Xanthone O-glycosides (swertianolin) from S. japonica and S. ciliata (Plouvier et al., 1967) have been reported. The first xanthone O-glycoside, norswertianin-1-O-glucosyl-3-O-glucoside has been isolated from S. perennis (Hostettmann and Wagner, 1977). The isolated chemical constituents, ethno-pharmacology as well as the biological activities and pharmacological applications of Swertia species, covering the literature up to 2003 are compiled by Brahmachari et al. (2004). Xanthones in Swertia chirata, S. speciosa and S. paniculata were determined by HPLC (Negi et al., 2009a, 2010a, b). Mineral elements, based on their concentration can play different roles in human health and plant life. Nine elements (Zn, Cu, Mn, Fe, Co Na, K, Ca and Li) in S. chirayita and S. speciosa have been analyzed by atomic absorption spectrometry (Negi et al., 2009b, 2010c). Kaempferol, catechin, epicatechin and Polyphenol Contents were also isolated and identified from Swietenia macrophylla, Rhus coriaria and Rhus typhina (Falah et al., 2008; Kossah et al., 2010). Extracts of G. senegalensis are rich in flavonoid content and showed anti-inflammatory activity (Sombie et al., 2011). Leaf and stem of Swertia chirata showed significant antimicrobial activities against some Gram-positive and Gram-negative bacteria (Alam et al., 2009).
Table 1: | Isolated compounds and activity of different parts of Swertia species |
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Several isolated chemical constituents viz, coumarins, flavonoids, phytosterol, phenols, tenins, alkaloids, triterpenes, anthraquinons and biological activities of Toona species were documented by Negi et al. (2011).
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Fig. 1: | Structures of some isolated xanthones from Swertia |
BIOLOGICAL PROPERTIES
Plants belonging to the family Gentianaceae, are best known for their bitter taste and used in traditional remedies against loss of appetite, fever and are still included in many tonic formulations (Gaur, 1999). Some specific activities have been reported for xanthones and iridoids from Gentianaceae. Iridoids such as swertiamarin have anticholinergic propertiy (Bhattacharya et al., 1974). For sweroside and gentiopicroside hepatoprotective activities have been reported (Kondo et al., 1994) and both compounds are being used as antihepatitis drugs. Xanthones (especially mangiferin) are reported to give CNS stimulation (Bhattacharya et al., 1972). They should also have anti-inflammatory activity (Mandal et al., 1992a). For bellidifolin and swerchirin a strong hypoglycemic activity has been reported by Saxena et al. (1993) and Basnet et al. (1994). S. paniculata is used in the Indian System of Medicine as a bitter tonic and in the treatment of some mental disorders (Prakash et al., 1982). S. hookeri extract is used in the treatment of microbial infections and as a mood elevator (Ghosal et al., 1980). Swertifrancheside isolated from S. franchetiana was found to be potent inhibitor of the DNA polymerase activity of human immunodeficiency virus-1 reverse transcriptase (HIV-1RT). Naturally occurring xanthones have emerged out as an important class of organic compounds in view of their remarkable pharmacological and other biological activities. It has now been observed that a number of plant products which are in regular use as chemotherapeutic agents contain xanthones as active constituents. Mangiferin was the first xanthone to be investigated pharmacologically and has been found to exhibit a broad spectrum of biological activities. It shows monoamine oxidase inhibition, cardiotonic, convulsant and choleretic activities (Ghosal et al., 1973; Bhattacharya et al., 1972). Pronounced anti-inflammatory activity has also been observed in mangiferin. Oral and topical compounds containing mangiferin are useful for the treatment of diseases caused by herpes virus. Mangiferin has been found to protect the liver of the rats from high altitude hypoxia. On the other hand Ghosal et al. (1975) have observed the opposite CNS depressant effect for xanthone-O-glycosides in mice and rats. The extract of most of Swertia species showed mutagenic activities. The antimalarial drug AYUSH-64 contains S. chirayita as one of the ingredients. Xanthones of S. chirayita are reported to produce CNS depression (Ghosal et al., 1973). The total extract of S. chirayita showed significant antifeedant activity against Jute semilooper (Malic et al., 1985). Norswertianolin, an O-glycoside has been reported to produce antitubercular activity. The O-glycosides of S. purpurescens are known to produce CNS depression in albino rate and mice (Ghosal et al., 1974). 1,8-Dihydroxy-3,5-dimethoxyxanthone (swerchirin), isolated from the hexane fraction of Swertia chirayita, has a very significant blood sugar lowering effect in fasted, fed, glucose loaded and tolbutamide pre-treated albino rats.
CONCLUSION
As a conclusion, the present study has shown that mainly xanthones from genus Swertia are responsible for several types of biological activities. Apart from these flavonoids, iridoid glycosides and triterpenoids are also secondary metabolites isolated from this genus which also contribute their role in biological activities.
ACKNOWLEDGMENT
The authors are thankful to Dr. Asha Budakoti, NCL, Pune for providing some references.
REFERENCES
- Alam, K.D., M.S. Ali, S. Mahjabeen, S. Parvin, M.A. Akbar and R. Ahamed, 2010. Report: Analgesic activities of ethanol extract of leaf, stem and their different fractions of Swertia chirata. Pak. J. Pharm. Sci., 23: 455-457.
PubMed - Alam, K.D., M.S. Ali, S. Parvin, S. Mahjabeen, M.A. Akbar and R. Ahamed, 2009. In vitro antimicrobial activities of different fractions of Swertia chirata ethanolic extract. Pak. J. Biol. Sci., 12: 1334-1337.
CrossRefDirect Link - Ashida, S., S.F. Noguchi and T. Suzuki, 1994. Antioxidative components, xanthone derivatives, in Swertia japonica Makino. J. Am. Oil Chem. Soc., 71: 1095-1099.
Direct Link - Atta-ur-Rahman, A. Pervin, M. Feroz, M.I. Choudhary and M.M. Qureshi et al., 1994. Phytochemical studies on Swertia cordata. J. Nat. Prod., 57: 134-137.
CrossRef - Bajpai, M.B., R.K. Asthana, N.K. Sharma, S.K. Chaterjee and S.K. Mukherjee, 1991. Hypoglycemic effect of swerchirin from the hexane fraction of Swertia chirayita. Planta Med., 57: 102-104.
CrossRef - Banerjee, S., T.K. Sur, S. Mandal, P.C. Das and S. Sikdar, 2000. Assessment of the anti-inflammatory effects of Swertia chirata in acute and chronic experimental models in male albino rats. Ind. J. Pharmacol., 32: 21-24.
Direct Link - Basnet, P., S. Kadota, T. Namba and M. Shimizu, 1994. The hypoglycaemic activity of Swertia japonica extract in streptozotocin induced hyperglycaemic rats. Phytother. Res., 8: 55-57.
CrossRefDirect Link - Bhana, S., R. Kumar, A.K. Kalla and K.L. Dhar, 1988. Triterpenoids from Swertia petiolata. Phytochem., 27: 539-542.
CrossRef - Bhattacharya, S.K., S. Ghosal, R.K. Chaudhuri and A.K. Sanyal, 1972. Canscora decussata (Gentianaceae) xanthones III: Pharmacological studies. J. Pharm. Sci., 61: 1838-1840.
PubMed - Bhattacharya, S.K., P.K.S.P. Reddy, S. Ghosal, A.K. Singh and P.V. Sharma, 1974. Chemical constituents of Gentianaceae, XIX, CNS depressant effects of swertiamarin. J. Pharm. Sci., 65: 1547-1549.
CrossRef - Brahmachari, G., S. Mondal, A. Gangopadhyay, D. Gorai, B. Mukhopadhyay, S. Saha and A.K. Brahmachari, 2004. Swertia (Gentianaceae): Chemical and pharmacological aspects. Chem. Biodivers., 1: 1627-1651.
CrossRefPubMedDirect Link - Chakravarty, A.K., S. Mukhopadhyay, S.K. Moitra and B, Das, 1994. (-)-Syringaresinol, a hepatoprotective agent and other constituents from Swertia chirata. Ind. J. Chem., 33: 405-408.
Direct Link - Chandrasekar, B., M.B. Bajpai and S.K. Mukherjee, 1990. Hypoglycemic activity of Swertia chirayita (Roxb ex Flem) Karst. Ind. J. Exp. Biol., 28: 616-628.
PubMedDirect Link - Chintalwar, G.J. and S. Chattopadhyay, 2006. Structural confirmation of decussatin, a Swertia decussata xanthone. Nat. Prod. Res., 20: 53-56.
PubMed - Jiang, D.J., J.L. Jiang, H.Q. Zhu, G.S. Tan, S.Q. Liu, K.P. Xu and Y.J. Li, 2004. Demethylbellidifolin preserves endothelial function by reduction of the endogenous nitric oxide synthase inhibitor level. J. Ethnopharmacol., 93: 295-306.
CrossRef - Denisova, O.A., V.I. Glyzin, A.V. Patudin and D.A. Fesenko, 1980. Xanthones from the roots of Swertia iberica. Chem. Nat. Compounds, 16: 145-149.
CrossRef - Du, X.G., W. Wang, S.P. Zhang, X.P. Pu and Q.Y. Zhang et al., 2010. Neuroprotective xanthone glycosides from Swertia punicea. J. Nat. Prod., 73: 1422-1426.
CrossRef - El-Sedawy, A., Y.Z. Shu, M. Hattori, K. Kobashi and T. Namba, 1989. Metabolism of Swertiamarin from Swertia japonica by human intestinal bacteria. Plant. Med., 55: 147-151.
CrossRef - Fukamiya, N., M. Okano, K. Kondo and K. Tagahara, 1990. Xanthones from Swertia punicea. J. Nat. Prod., 53: 1543-1547.
CrossRef - Geng, C.A., Z.Y. Jiang, Y.B. Ma, J. Luo and X.M. Zhang et al., 2009. Swerilactones A and B, anti-HBV new lactones from a tradtional Chinese herb: Swertia mileensis as a treatment for viral hepatitis. Org. Lett., 11: 4120-4123.
PubMed - Geng, C.A., X.M. Zhang, Y.B. Ma, Z.Y. Jiang, J.F. Liu, J. Zhou and J.J. Chen, 2010. Three new secoiridoid glycoside dimers from Swertia mileensis. J. Asian Nat. Prod. Res., 2: 542-548.
PubMed - Ghosal, S., K. Biswas and D.K. Jaiswal, 1980. Xanthone and flavonol constituents of Swertia hookeri. Phytochem., 19: 123-126.
CrossRefDirect Link - Ghosal, S., V.P. Sharma and R.K. Chaudhuri, 1974. Chemical constituents of gentianaceae. X. Xanthone-O-glucosides of Swertia purpurascens Wall. J. Pharm. Sci., 63: 1286-1290.
PubMed - Ghosal, S., P.V. Sharma, R.K. Chaudhuri and S.K. Bhattacharya, 1973. Chemical constituents of the gentianaceae V: Tetraoxygenated xanthones of Swertia chirata buch.-ham. J. Pharm. Sci., 62: 926-930.
CrossRef - Ghosal, S., P.V. Sharma, R.K. Chaudhuri and S.K. Bhattacharya, 1975. Chemical constituents of gentianaceae XIV: Tetraoxygenated and pentaoxygenated xanthones of Swertia purpurascens Wall. J. Pharm. Sci., 64: 80-83.
PubMed - Hajimehdipour, H., Y. Amanzadeh, S.E. Sadat-Ebrahimi and V. Mozaffarian, 2003. Three tetraoxygenated xanthones from Swertia longifolia. Pharm. Biol., 41: 497-499.
Direct Link - Hajimehdipoor, H., M.G. Dijoux-Franca, A.M. Mariotte, Y. Amanzadeh, S.E. Sadat-Ebrahimi and M. Ghazi-Khansari, 2006. Two new xanthone diglycosides from Swertia longifolia Boiss. Nat. Prod. Res., 20: 1251-1257.
PubMed - Hase, K., J. Li, P. Basnet, Q. Xiong, S. Takamura, T. Namba and S. Kadota, 1997. Hepatoprotective principles of Swertia japonica Makino on d-galactosamine/lipopolysaccharide-induced liver injury in mice. Chem. Pharm. Bull., 45: 1823-1827.
PubMed - Hostettmann, K. and I. Miura, 1977. A new xanthone diglucoside from Swertia perennis L. Helvetica Chimica Acta, 60: 262-264.
CrossRefDirect Link - Hostettmann, K. and H. Wagner, 1977. Xanthone glycosides. Phytochemistry, 16: 821-829.
CrossRefDirect Link - Hostettmann-Kaldas, M., K. Hostettmann and O. Sticher, 1981. Xanthones, flavones and secoiridoids of american Gentiana species. Phytochemistry, 20: 443-446.
CrossRefDirect Link - Ikeshiro, Y., T. Kubota and Y. Tomita, 1983. Two bitter biphenyl glucosides from Swertia japonica. Plant. Med., 47: 26-29.
CrossRef - Ikeshiro, Y. and Y. Tomita, 1984. A new iridoid glucoside of Swertia japonica. Planta Med., 50: 485-488.
Direct Link - Ikeshiro, Y. and Y. Tomita, 1985. Iridoid glucoside of Swertia japonica. Planta Med., 5: 390-393.
Direct Link - Ikeshiro, Y. and Y. Tomita, 1987. Senburiside II, a new iridoid glucoside from Swertia japonica. Planta Med., 53: 158-161.
Direct Link - Iqbal, Z., M. Lateef, M.N. Khan, A. Jabbar and M.S. Akhtar, 2006. Anthelmintic activity of Swertia chirata against gastrointestinal nematodes of sheep. Fitoterapia, 77: 463-465.
CrossRefDirect Link - Ishimaru, K., H. Sudo, M. Satake, Y. Matsunaga, Y. Hasegawa, S. Takemoto and K. Shimomura, 1990. Amarogentin, amaroswerin and four xanthones from hairy root cultures of Swertia japonica. Phytochem., 29: 1563-1565.
CrossRef - Ishimaru, K., H, Sudo, M. Satake and K. Shimomurat, 1990. Phenyl glucosides from a hairy root culture of Swertia japonica. Phytochem., 29: 3823-3825.
CrossRef - Kanamori, H., I. Sakamato and M. Mizuta, 1984. Studies on the mutagenicity of Swertia herba. III: Components which become mutagenic on nitrite treatment. Chem. Pharm. Bull., 32: 2290-2295.
Direct Link - Karan, M., K. Vasisht and S.S. Handa, 1999. Antihepatotoxic activity of Swertia chirata on carbon tetrachloride induced hepatotoxicity in rats. Phytother. Res., 13: 24-30.
PubMed - Karan, M., K. Vasisht and S.S. Handa, 1999. Antihepatotoxic activity of Swertia chirata on paracetamol and galactosamine induced hepatotoxicity in rats. Phytother. Res., 13: 95-101.
PubMed - Khan, M.I. and M.H. Haqqani, 1981. Chemical investigation of Swertia cordata. Fitoterapia, 52: 165-166.
Direct Link - Khan, T.A., M.H. Haqqani and N.M. Nisar, 1979. Chemical investigation of Swertia alata. Planta Med., 37: 180-181.
Direct Link - Khetwal, K.S. and R.S. Bisht, 1988. A xanthone glycoside from Swertia speciosa. Phytochem., 27: 1910-1911.
CrossRef - Khetwal, K.S., B. Joshi and R.S. Bisht, 1990. Tri- and tetraoxygenated xanthones from Swertia petiolata. Phytochem., 29: 1265-1267.
CrossRef - Khetwal, S., S. Pande and U. Tiwari, 1997. Xanthones from Swertia alata. Ind. J. Pharm. Sci., 59: 190-191.
Direct Link - Kikuchi, M. and M. Kikuchi, 2004. Studies on the constituents of Swertia japonica Makino I. On the structures of new secoiridoid diglycosides. Chem. Pharm. Bull., 52: 1210-1214.
CrossRefDirect Link - Kikuchi, M. and M. Kikuchi, 2005. Studies on the constituents of Swertia japonica Makino II. on the structures of new glycosides. Chem. Pharm. Bull., 53: 48-51.
CrossRefDirect Link - Kikuzaki, H., Y. Kawasaki, S. Kitamura and N. Nakatani, 1996. Secoiridoid glucosides from Swertia mileensis. Planta Med., 62: 35-38.
CrossRef - Kondo, Y., F. Takano and H. Hojo, 1994. Suppression of chemically and immunologically induced hepatic injuries by gentiopicroside in mice. Planta Med., 60: 414-416.
PubMed - Kulanthaivel, P. and S.W. Pelletier, 1988. Isolation of a new xanthone and 2-hydroxydimethylterephthalate from Swertia petiolata. J. Nat. Prod., 51: 379-381.
Direct Link - Li, J.C., L. Feng, B.H. Sun, T. Ikeda and T. Nohara, 2005. Hepatoprotective activity of the constituents in Swertia pseudochinensis. Biol. Pharm. Bull., 28: 534-537.
PubMedDirect Link - Luo, Y.H. and R.L. Nie, 1992. Studies on iridoid glycosides from Swertia angustifolia. Yao Xue Xue Bao, 27: 125-129.
PubMed - Mandal, S., P.C. Das and P.C. Joshi, 1992. Naturally occuring xanthones from terrestrial flora. J. Ind. Chem. Soc., 69: 611-636.
Direct Link - Menkovic, N., K. Savikin-Fodulovic, V. Bulatovic, I. Aljancic and N. Juranic et al., 2002. Xanthones from Swertia punctata. Phytochemistry, 61: 415-420.
CrossRefDirect Link - Mukherjee, B. and S.K. Mukherjee, 1987. Blood Sugar Lowering Activity of Swertia chirata (Buch-Ham) Extract. Pharm. Biol., 25: 97-102.
CrossRef - Niu, B., J. Guo, J. Chen and J. Ma, 1991. Chemical constituents of Swertia tetraptera Maxim. Zhongguo Zhong Yao Za Zhi, 16: 549-550.
PubMedDirect Link - Patro, B.S., G.J. Chintalwar and S. Chattopadhyay, 2005. Antioxidant activities of Swertia decussata xanthones. Nat. Prod. Res., 19: 347-354.
PubMed - Tan, P., C.Y. Hou, Y.L. Liu, L.J. Lin and G.A. Cordell, 1992. 3-O-Demethylswertipunicoside from Swertia punicea. Phytochem., 31: 4313-4315.
Direct Link - Plouvier, V., J. Massicot and P. Rivaille, 1967. [On gentiacauleine, a new tetra-substituted xanthone, aglycone of gentiacauloside of Gentiana acaulis L.]. C. R. Acad. Sci. Hebd. Seances Acad. Sci. D, 264: 1219-1222, (In French).
PubMedDirect Link - Prakash, A., P.C. Basumatary, S. Ghosal and S.S. Handa, 1982. Chemical constituents of Swertia paniculata. Planta Med., 45: 61-62.
CrossRefPubMedDirect Link - Ramesh, N., M.B. Viswanathan, A. Saraswathy, K. Balakrishna, P. Brindha and P. Lakshmanaperumalsamy, 2002. Antimicrobial and phytochemical studies of Swertia corymbosa. Fitoterapia, 73: 160-164.
CrossRefPubMedDirect Link - Saha, P., S. Mandal, A. Das, P.C. Das and S. Das, 2004. Evaluation of the anticarcinogenic activity of Swertia chirata Buch-Ham, an Indian medicinal plant, on DMBA-induced mouse skin carcinogenesis model. Phytother. Res., 18: 373-378.
PubMed - Sakamoto, I., T. Tanaka, O. Tanaka and T. Tsuyoshi, 1982. Xanthone glucosides of Swertia japonica Makino and a related plant: Structure of a new glucoside, isoswertianolin and structure revision of swertianolin and norswertianolin. Chem. Pharm. Bull., 30: 4088-4091.
Direct Link - Saxena, A.M., M.B. Bajpai, P.S. Murthy and S.K. Mukherjee, 1993. Mechanism of blood sugar lowering by a swerchirin-containing hexane fraction (SWI) of Swertia chirayita. Indian J. Exp. Biol., 31: 178-181.
PubMedDirect Link - Tan, G.S., K.P. Xu, F.S. Li, P.S. Xu, G.Y. Hu, D.J. Jiang and Y.J. Li, 2003. Daviditin B from Swertia davidi Franch. Yao Xue Xue Bao, 38: 931-933.
PubMed - Tan, P., C. Hou, Y. Liu, L.J. Lin and G.A. Cordell, 1991. Swertipunicoside. The first bisxanthone C-glycoside. J. Org. Chem., 56: 7130-7133.
CrossRef - Tan, P., Y. Liu and C.Y. Hou, 1993. Swertiapunimarin from Swertia punicea Hemsl. Acta. Pharm. Sin., 28: 522-525.
PubMed - Tan, P., Y.L. Liu and C.Y. Hou, 1992. Structure of swertiapuniside from Swertia punicea Hemsl. Yao Xue Xue Bao, 27: 476-479.
PubMed - Vieira, L.M.M. and A. Kijjoa, 2005. Naturally-occurring xanthones: Recent developments. Curr. Med. Chem., 12: 2413-2446.
CrossRef - Wang, J.N., C.Y. hou, Y.L. liu, L.Z. lin, R.R. Gil and G.A. cordell, 1994. Swertiflanchesides an HIV-reverse transcriptase inhibitor and the first flavone-xanthone dimmer from Swertia franchetiana. J. Nat. Prod., 57: 211-217.
Direct Link - Wang, S.S., X.W. Han, Q. Xu, H.B. Xiao, X.M. Liu, Y.G. Du and X.M. Liang, 2005. Xanthone glycosides from Swertia franchetiana. J. Asian Nat. Prod. Res., 7: 175-179.
PubMed - Wang, S.S., W.J. Zhao, X.W. Han and X.M. Liang, 2005. Two New iridoid glycosides from the Tibetan Folk Medicine Swertia franchetiana. Chem. Pharm. Bull., 53: 674-676.
PubMed - Xia, C.L., G.M. Liu and H. Zhang, 2008. Chemical constituents from herbs of Swertia delavayi. Zhongguo Zhong Yao Za Zhi, 33: 1988-1990.
PubMed - Yamahara, J., M. Kobayashi, H. Matsuda and S. Aoki, 1991. Anticholinergic action of Swertia japonica and an active constituent. J. Ethnopharmacol., 33: 31-35.
CrossRef - Yang, H., C. Ding, Y. Duan and J. Liu, 2005. Variation of active constituents of an important Tibet folk medicine Swertia mussotii Franch. (Gentianaceae) between artificially cultivated and naturally distributed. J. Ethnopharmacol., 98: 31-35.
CrossRef - Zhang, Y., X. Xu, C. Hou and J. Yang, 1996. Chemical constituents of Swertia pubescens Franch. Zhongguo Zhong Yao Za Zhi, 21: 103-104.
PubMed - Zhou, H.M. and Y.L. Liu, 1990. Structure of swertiamacroside from Swertia macrosperma C. B. Clark. Acta. Pharm. Sin., 25: 123-126.
PubMed - Zhou, H.M., Y.L. Liu, G. Blasko and G.A. Cordell, 1989. Swertiabisxanthone-I from Swertia macrosperma. Phytochem., 28: 3569-3571.
CrossRef - Negi, J.S., P. Singh, G.J. Pant and M.S.M. Rawat, 2010. RP-HPLC analysis and antidiabetic Activity of Swertia paniculata (Wall.). Nat. Prod. Comm., 5: 907-910.
PubMed - Negi, J.S., P. Singh, M.S.M. Rawat and G.J. Nee Pant, 2009. Study on the trace elements in Swertia chirayita (Roxb.) H. Karsten. Biol. Trace Elem. Res., 133: 350-356.
CrossRef - Negi, J.S., P. Singh, G.J. Nee Pant and M.S.M. Rawat, 2009. Quantitative assessment of xanthone derivatives in Swertia chirata (Wall.) by RP-HPLC with UV detection. Med. Plants Int. J. Phytomed. Relat. Ind., 1: 97-101.
Direct Link - Negi, J.S., P. Singh, M.S.M. Rawat and G.J. Pant, 2010. Qualitative and quantitative determination of major xanthones in Swertia speciosa by high performance liquid chromatography. Med. Plants Int. J. Phytomed. Relat. Ind., 2: 45-50.
Direct Link - Negi, J.S., P. Singh, G.J. Nee Pant and M.S.M. Rawat, 2010. Study on the variations of mineral elements in Swertia speciosa (G. Don). Biol. Trace Element Res., 138: 300-306.
CrossRef - Falah, S., T. Suzuki and T. Katayama, 2008. Chemical constituents from Swietenia macrophylla bark and their antioxidant activity. Pak. J. Biol. Sci., 11: 2007-2012.
CrossRefPubMedDirect Link - Kossah, R., C. Nsabimana, H. Zhang and W. Chen, 2010. Optimization of extraction of polyphenols from syrian sumac (Rhus coriaria L.) and chinese sumac (Rhus typhina L.) fruits. Res. J. Phytochem., 4: 146-153.
CrossRefDirect Link - Sombie, P.A.E.D., A. Hilou, C. Mounier, A.Y. Coulibaly, M. Kiendrebeogo, J.F. Millogo and O.G. Nacoulma, 2011. Antioxidant and anti-inflammatory activities from Galls of Guiera senegalensis J.F. Gmel (Combretaceae). Res. J. Med. Plant, 5: 448-461.
CrossRefDirect Link - Negi, J.S., V.K. Bisht, A.K. Bhandari, M.K. Bharti and R.C. Sundriyal, 2011. Chemical and pharmacological aspects of Toona (Meliaceae). Res. J. Phytochem., 5: 14-21.
CrossRef - Bhan, S., R. Kumara, A.K. Kalla and K.L. Dhar, 1987. Isomeric 2,3-seco-hopene lactones from Swertia petiolata. Phytochem., 26: 3363-3364.
CrossRef - Saxena, M.A., P.S. Murthy and S.K. Mukherjee, 1996. Mode of action of three structurally different hypoglycemic agents: A comparative study. Ind. J. Exp. Biol., 34: 351-355.
PubMedDirect Link - Tian, L.Y., X. Bai, X.H. Chen, J.B. Fang, S.H. Liu and J.C. Chen, 2010. Anti-diabetic effect of methylswertianin and bellidifolin from Swertia punicea Hemsl. and its potential mechanism. Phytomed., 17: 533-539.
Direct Link - Zhang, J.S., X.M. Wang, X.H. Dong, H.Y. Yang and G.P. Li, 2009. Studies on chemical constituents of Swertia mussotii. Zhong Yao Cai, 32: 511-514.
PubMed
Vinod Visht Reply
The MS is very well written in informative way