Clusiaceae; Quercetin; Quercitrin.
|PUBLISHED DATE||March 14, 2016|
|PUBLISHER||The Author(s) 2016. This article is published with open access at www.chitkara.edu.in/ publications|
Calphyllum inophyllum Linnaeus C.von (Syn.) Calophyllum bintagar Roxb of Guttifereae (Clusiaceae) is commonly known as ‘ Indian laurel’ or ‘Alexandhian laurel’ a broad leaved evergreen tree occurring as a littoral species along the beach crests, sometimes seen inland . It is widely distributed and cultivated throughout tropics from West Africa to Pacific islands (as far) Eastas Tahiti. It blossoms during March to October. Fresh flowers of calophyllum inophyllum have been treated for their flavonoids contents. They are rich flavonol quercetin and flavonol glycosides quercitrin. They have been characterized with the help of modern physical methods like UV, H-1 NMR , C-13 NMR, chemical reactions, chromatographic techniques and hydrolytic studies.
The antibacterial / antineoplastic, anti-inflammatory, antiplatelet, antipsychotic, antiviral and photoprotection have been observed in C. Inophyllum. The bark of the plant has astringent activities and its decoction is used to cure the diarrhoea and dysentery. However, the juice of the bark and the fruits are also found to be purgative. The latex of the palnt is also an emetic [10-11]. Investigations on cancer chemopreventive acivity of 4 – phenylcoumarins from C. inophyllum establishes the property of the species . Examinations on healing of ocular burns shows considerable activity of C. Inophyllum. The cytoprotective effects of C. inophyllum against UV induced damage show the efficacy of the species. The toxicities have also been studied in detail. Myricetin 7 - glucoside has been isolated from C. Inophyllum. With a view to locating additional flavonoids, the flowers of C. Inophyllum have been investigated and the results are presented hereunder.
|ISSN||Print : 2349-7564, Online : 2349-7769|
The fresh flowers of C. inophyllum have been found to contain quercetin and its glycoside (quercitrin).
The UV spectrum of the Et2O soluble exhibited λmax at 370 nm (band I) and 255 nm (band II) indicating a flavonol skeleton. A bathochromic shift of +58 nm on the addition of AlCl3 – HCl indicates the presence of free –OH at C-5 in A ring. A comparison of AlCl3 and AlCl3 – HCl spectrum revealed an additional bathochromic shift of 30nm in the case of AlCl3 spectrum (without acid) which again points to the presence of catechol type of B –ring. It is further substantiated by the bathochromic shift of 18 nm noticed in band I on the addition of H3BO3. The presence of a free –OH at C-7 is evident from the bathochromic shift of 19nm in band II on the addition of NaOAc.
In the 1H –NMR spectrum (400MHz, DMSO – d6, TMS) (Fig.1) of the aglycone, the hydroxyl proton at C-5 shows up at d12.49pppm as a distinct singlet. The sharp singlets at d10.9 and d9.56ppm correspond to –OH protons at C-7 and C-3. The doublet at d9.31ppm (J = 9Hz) accounts for the hydroxyl protons at C-3’ and C-4’. The C-5’ proton appears as a doublet at d 6.68ppm (J = 9 HZ). The signals due to the protons at C-2’ and C-6’ overlap at d7.54ppm. a ring protons at C-6 and C-8 could be located at d 6.16 (d, J = 2.5Hz) and d 6.41ppm (d, J = 2.5 Hz) respectively.
The supporting evidence for the structure of the flavonols is provided by the 13C-NMR (100MHz, DMSO –d6, TMS) Fig.2 spectra data. A complete assignment of the various signals is provided in Table.4.