Chemical and biological studies on the aerial parts of sida cordifolia linn. (Barla)

Abstract

Sida cordifolia (locally knOMl as Barla) of the family Malvaceae is an important medicinal plant of Bangladesh and is used for the treatment of several di~ses hke chronic dysentery, asthma and gonorrhea and specially for rheumatism (Kirtiker and Basu, 1981; Yusufand Kabir, 1994). Different classes of compounds c_g_ glycosides, flaVQnoids, alkaloids, steroids and amino acids have been reported from the plants of the genus Sida. Quinazoline alkalOIds e g. vasicine, vasicinone, vasicinol, along Wlth ephedrine, ]3-phenethylamine and N-methyl tryptophan (Asha and Bannerjee, 1985; Ghosal et al., 1975; Gunalilaka et aI., 1980; Ghosh and Dutt, J930) were reported from Sida cordi/olia Glycoside;; were reported from other members of the genus SiJa hilt not from Sida cordi/olia. The purpose of the present work was a thorough phytochemical investigation on the aerial parts of Sida cordi/olio for isolation of secondary metabolites principally tlavonoids, alkaloids and glycoside.-; as well as to study the biological actiVIties of the isolated pure compounds and crude extracts for discovery of drugs or lead compounds on the way of drug discovery, PART A Matured, fresh and flowering plants of Sida cnrdifhlia were collected from the hilly region of the Chittagong district during the month of November 2002, The dried IXlwdered aerial parts of the plants (5.5 kg) wefe SllC(:essivcly extracted with CHCI), MeOH and 80% EtOH (Fractionation Schcmc 2.4.1). Removal ofthc solvcnts from the CHGI " MeOH and 80% EtOH extracts gave Masses CE (100.0 g), ME (150,0 g) and EE (170.0 g) respectively, Fractionation and pwification of CHCb extract (Mass CE) resulted into the isolation of three pure comlXlunds Gt, G2 and GJ respectively. Cbemic.aJ and spectroscopic analyses (lTV, IR, IH NMR, Be NMR, COSY, HMBC and mass spectra) of Gt confirmed it as II mixture of 13-sitosterol (73) and stigmasterol (74) (0,0023%), G2 as 5,7-dihydroxy-3-isoprenyl flavone (7S) (0.OO22%) and G3 as 5- hydroxy-3-isoprenyl flavone (76) (D.OO29%) respectively. • v " " " '" " " '" '" " " '" 10'" lJ " " " " " " " , '" 0 '"" " " " '" 0 " '" " , 0' 00 '" " , , HO , ,"- , HO , , , P-Sitosterol(73) , ; ,, "" ,, HO • , " I ,7 • 0 , #, ;' • " .'" ,'" ;", H ," 5,7-dihydroxy-3-isoprenyl flavone (75) Stigmasterol (74) ,, " I "",, • ,0 #, , ,7 • ,, ,, ,'" " ," ," w , ; , '" ;" H ," 5-hydroxy-3-isoprenyl flavone (76) The crude methanol extmct (Mass ME) responded to the preliminary tests for alkaloids. Acid,base separation of the extract yielded a crude alkaloidal material (4.2 g, 0.38%). Fractionation and purification by various chemical and chromatographic methods of the crude led to the isolation of four pure alkaloids AI, A2, A3 and A4 respectively. Chemil;al and spectroscopic analyses (UV, IR, IH m1R, IJC NMR, COSY, HJ..1BCand mass spectra) established alkaloid Al (82) as 1,2,3,9-tetrahydro-pyrrol0 [2,1_b] quinazolin-3_ylamine(O.005%), A2 as 5'. hydroxymethyl-l '-(l,2,3,94etrahydro- pyrrolo [2, I-b] quinazolin-l-yl)-heptan-l '-one (83 a) or 4'. hydroxymethyl-l '-(1,2,3,9.tetrahydro" pyrrolo [2,I-b] quinazolin.l.yl)-heptan.l'_one (83 b) (0.007%), A3 (84) as 2-( ['.aminobulyl) indol.3-oue (0.008%) and A4 (85) as 2'-(3H.indol.3.ylmethylrbutan-] '-01 (0.007%) respectively. VI 'cc'~' ~~--\' 6 ;~2 ~~l NH, 1,2,3,9-tetrahydm-pyrrolo [2,l.b] quinazolin-3-yll1mine (82) o Cllr-OH 0 eRr-oR . l' 11' l' 11 , C--(CHz)J-CH-CH.l-cH, C-{CHllr-CR-(CH21,--eH] 813 9:00 1 5' 6' 7' 8 13 9:00 1 4' 7' '~N 2 7~N 2 6~\1"2"~"1l 3 6~5,1,:2?~JI 3 5'-hydro~ethyl-l '-( 1,2,3, 9-tetrah ydro-pyrrolo 4' -hydro><ymethy\-1 '_(1,2,3,9-tetrahydro- pyrrolo (2,I-bjquinazolin-I-yJ}-heptan-1'-one (83 8) (2,I-blquirulzolin-I-yl)-heptan-l '-one (83 b) 2-(1'-amino-hutyl) indol-3-o~ (84) 2'-{JA-indol-3-ylmethyl)-butan-l "01 (85) Fmctionation and purification of the 80% EtOH extract (Mass EE) by chromatographic methods afforded fOUTpure glycosidic compollllds EI (0.0027%), £1 (0,0029 %), E3 (0.0028%) and HI (0.0045 %) respectively. The glycosides El, E2, E3 lind HI were characterized as )'-{3", 7"-dimethyl-l",6"-octadiene }-8-C-Il-D-g1ucosyl-kaempferol 3-O-~- D-gluooside (87), 3'-(3", 7"-dimethyl-2",6"-octadiene )-8-e-fJ.D-glucosyl-kacmpferol 3- O+D-glucosyl [1.....4•] a-D-gluooside (90), 6-(3 "-methyl-2"-butene )-3'_methoxyl-8-C-fJ- • VlI V-gluensy! -kaempferol 3-0-B- D-gJucosyJ[ 1--->4]-P-D-glucoside (92) and 3'-(3",7"- dirne!hy 1-2",6"-octadicne )-8-C-B-D-glllcosyl.kaempferol 3-G-B-D-galaclOside (93) respectively on the basis of chemical analyses supported by spectroscopic analyses (UV, JR, 'H N;\1R, IJC NMR, COSY, HMBC and Ma.,s spectral data). HO HO HO ,." HO , OH , o o ,'. I I ' ,. O~~OH H6~OH OH }'-(3", 7" -dimethyl- 2",6" -octadicne )-8-C -B-D-glllCOSy ]-hempfcrol 3-0-P-D-glucoside (87) liD HO HO HO , .'", OH 3'-(3", 7"-dirnethyl-2" ,6" -octadicnc)-H-C-B- D-glucosyl-bempfcrol 3-0-B-D-glucosyl [1---. 4] u- D-glucoside (90) VIII yH3 j CH,-C=CH-CH2 HO HO HO ,'" , , 0 OH 6- (3 "-methyl- 2".butenc)- 3'- mcthoxyl-8- C-~-D-glucosy1-kaempfero1 3-0-~-[)-glucosy 1[1-+ 4] -~-D.g1llcosidc (92) 1 2 CIH3 CI I:I3 CH2-CI I=C-CH)-CH2-CH=C -CH} ,, 3',,'",j OH I' I 4;' I 2, 6' OJ'''' 0 OH ~OH OH o o '" HO HO HO 3'-(3" ,7"-dimethy 1-2",6"-octadiene)-8-C-~- D-g1ucosylkaempfcroI3- 0-~-D-ga1actll;ide (93) • IX PART B The crude extracts CE, ME unci EE when examined for assessing their toxicity, the animals did not show ,my sign of intoxication at the dose, of 1600 imd 2400 rug/kg body weight. Bllt when a dose of 4000 mglkg body weights wm, ,Idminislered, the animals Ihough ,howed ~omc signs of intoxication, all of them <:ould be ea~illyreeo,ered aner 24 hour~ without any mortality. No LDjo % could be delermin~d_ For determining the analgesic potcncy, tile cmclc extracts "'ere ndrni~i:;tered 10 the illlimub urally in lWO doses ]{)O and lOn mglkg body weight taking AMP as standard iI~d ;ali~e a, conlrul, The e,\traCL\ CE, ME, HE, DE. AE, MA and MN showed significant inhibition or wrilhing reflex i.e. ('is.S6. 66.53 %), (45,56, 52,81%), (48.78, 55,64(70), (26.20.56.44%), (26.61, 52.43'}b), (43.55, 56.06%) and (41.13, 54,85%) respectively with the stati.\tical significance of (p < 0, 01) (Table 3,14.1). CHC!) extract (CE) :,howed ma).imum but ,,-B uOH extract (BE) showed minimum analgesic activities (Fig, 3.14.1), The compollnds 01, 02 and 03 from CHC!} extract, E I, E2, and E3 from EtOAe extract and BI from II-BnOl.1 e:>,tr~ctwere evaluated for their analge,ic aetivitie\ hy acelic acid induced wl'ilhing test in mice (Vogel and Vogel, ]997), 25 amI 50 mglkg hody weight dose were considered for all the compound, while AMP, PEl and DCF were used a, standJl'ds and norma! saline as conllOl. COll1polmcls(iI, 02 and GJ \howedI4.J5, 19.48 and 38,97 % inhibuion at 25 mgfkg body weight while 25.64. 56,92 ilnd 54.35 % inhibition at 50 mglkg body weight respectively in comparison to the control (Table 3,15.1). G2 and 03 showed significant analgesic adivitie" when compared t[) the .\w.ndard, PBZ (54.35 %), AMP (67.69 %) and DCF (70.25 %). Compounds EI, E2. E3 and Bl showed 25.12, 14.35.27.17 and 39.48 % inhibition at 25 mgfkg body weight reopectively and 52,30, 24.10, 47,69 and 51.28 % inhibition ~(50 rngfkg !Jody weight l'espectiYely Crable 3.15.2) in comparison to Ihe conlrol. Compound\ El aIld Bl showed ~igoificant analgesic activities (Table 3.15,2) when eornp~red ![) the \tand~rd<; PBZ (54.35 %), AMP (67.69 %) and DCF (70 25 '?o) The order nfanalgcsie activity was G2 > G3 > EI > BI > E3 > GI > E2 (pig. 3,15.1), x The alkaloids Al, A2, A3 aml A<1at doses or 25 ,lI1d 50 mg/kg body weight showed ,ignificant reduction in the numher of wrilhing wilh 25.4, 17.30,24.32, 18,37 % (p< 0,05) and 52.43, 47.03, 44,86 and 37,84 % (p< O.OJ) re:;pectively (Table 3.15,3). The reS\Lllswere slatistically <;ignilicant and compar~d l(J thal 01 standard drug AMP (67.57%) at ~ dose of 50 mgfkg body weight~_ In radiant heal (ail-Did model, (he alkaloids also produced signi ricanl increase in the tail tl, ck laleney (Tahle 3. J 5.4) Anti-mfJammatory activities of dlffcl'cm crude extracts ,n the dme 01 200 mg/kg body weight., \.•c..rc smdied wIth umg Evan rat.1using PEZ as standard at a do,e of 100 mg/kg hody weight. The uclivilies or all the crude extract; were compared to the standard drug PBZ, The exlra<:\; CEo ME. AE. BE and MA exhibiled significant inhibilion of paw edema e,g. 33.61. 32,97, 34.46. 39.35 and 40.85 % I'clpcctivcly at Ihc cnd of fourth hour (Fig. 3.16,1), Compound,1 Gl, G2. G3. El, E2, E3 and B1 were al.\o evaluated for lheir anti.inflammalory activuy 1Il carragecnan induced rat paw edema model (Wmter el ai, 19(2) with two doscs of 25 and 50 mg/kf! body weighl in Long Evan rats lL'iingPBI': and DCF as standard and saline as control. The perccnt inhibItion of cdcma vn1ume, at third hour of carrageenan administralion at Ihe dose of 25 mg/ kg hody weight~, by le;l 'compounds GI. G2, G3. El, E2,E3 and BI were 15.12,20.27,18.04.16.15,18,21,14.09 and 15.29 % respectively (Table 3.17.1 and 3.17.2). The percenl inhibition of edema volumc, al third hour of carrageenan adminiSlralion al Ihe do:;e of 50 mg/kg body weighls, by Ibe ~ompound; GI, 02, G3, l:J, E2, EJ and 131 wcre n,()'), 37.11, 3058, 28.52. 26.80, 22.66 arid 26.18 % re.lre<;\i\'ely (Table J,17,3 and 3,17.4). The ant;- innammatory aclh'ilics of thc compounds WCfe compared to th'Be of "tandil[(ls PIlZ (32,98 %) and DCF (35.05 '/0). Compounds G2. G3, E1. E2 and 131 were found to he more aelive Ihan the others, The ordcr of a!lli-inn~mm~!ory response \V~sG2 > GJ > EI >E2>Bl>Gl>E3. In c~rrag:eenan induced rat paw cdema test for acute innammation, the alkaloid; A1. A2, A3 and A4 exhibited significant inhibition of paw ~olume by 16.93, 14.49, 15,18, 17,95 and 24.43. 25.65, 23.39, 22,69 % at do<;e<;01'25 ~lld 50 mg/kg body weight respectively, which was compared 10 that of standard drt1g PEZ (31.94 %) at the dO.le of 80 mg/kg body weight at Jrd hom of carl'ogeenall administrallon (Table 3.17.5).