TRITERPENES OF POUTERIA TORTA (SAPOTACEAE)

PLiST \24TERIiL.-The twigs examined in this stud>- -were collected in Brazil in Oc- erythrodiol and dammarenediol I1. EXTRKTIOX ARD FR~CTIOhATIOP.-The...
0 downloads 0 Views 188KB Size
TRITERPENES OF POUTERIA TORTA (SAPOTACEAE) C.-T. CHE, K. KoIhE, G . A. CORDELL, H.H. S. FOKG and R . H. DOBBERSTEIN Department of, Pliarnmcognosy and Piiarmacology, College of Pl:arntacy, Unaverszty of Illznois at the illedacal Center, Chicago, Illznozs 60612

Although the genus Pouteria emEXPERIIIESTALi braces 435 or more species (I), phytoP L i S T \24TERIiL.-The twigs examined in this stud>- -were collected in Brazil in Occhemical information pertaining to this taxon is limited. Lupeol. a-ampin, tober, erythrodiol and dammarenediol I1 EXTRKTIOX A R D FR~CTIOhATIOP.-The dried, milled plant material (55.0 kg) was have been isolated from an unsaponifiwith ether (hp 60-80") able fraction of Pouteria camiinito t o yield fraction .I (550 g). S f t e r being airRuiz et Pav. fruits ( 2 ) , and investigadried, the defatted plant material was exhaustively extracted with methanol. The Of the bark Yielded tarax-14-enepetroleum ether and methanol extracts --ere 3/3-01 acetate, tarax-14-ene+one, tascreened for phytochemical constituents as rax-14-ene-3P-01 and p-sitosterol ( 3 ) . previously described (8) and were found t o contain triterpenes, but were devoid of /3-Amyrin has been Obtained alkaloids. The methanol extract was confrom the bark of P . toineiztosa (Roxb.) centrated, 21: taczio, t o a syrupy consistency and partitioned bet--een petroleum ether Baehni (4). ( 3 x 2 liters) and m-ater ( 3 x 2 liters). The d n alkaloid, tentatively identified as methanolic aqueous phase &-as further extracted with chloroform (6x0liters) t o yield yollimbine, ~ ~ isolated a c b!- L ~ l t m a p) n 212 g of chloroform-soluble fraction B. from a plant believed to be a species of A 100 g portion of fraction B was redisPouteria. However, this finding mis solved in chloroform and partitioned against questioned by Stellfeld (6). a 5% KazC03 solution ( 5 x 1 liter) to remove -__field survey of Xew Guinea plants for 'lleltlng points mere determined on a alkaloids, HartIelY et ('7) found the Kofler hot plate and are uncorrected. I r leaf and bark of P . luzoizieitsis (AIerr.) spectra m-ere determined using a Beckman model 18 sPectroPhotometer with POlYBaehni var. popuafza Erlee. the leaf styrene calibration a t 1601 cm-l. P m r and fruit of p . lnaclayaiza (F. lIue11.) spectra were recorded on a 7-arian model Baehni and the leaf of p . malacce?zsis T-GOA instrument with a Kicolet T T - i Fourier Transform attachment. samples (Clarke) ~ ~ to be~devoid h of all;a~ i were dissolved in CDC13 n-ith tetramethjlloids. The bark of P . malaccensis gave silane as the internal standard. Low resoan equivocal test for the presence of lution mass spectra were obtained with a Hitachi Perkin Elmer, model Rl\lU-SD, alkaloids (71, and the fruit of P . single-focusing spectrometer operating a t i o ev. A Perkin Elmer model 881 gas chrocaimito n-as reported to be devoid of matograph equipped x i t h a hydrogen flame alkaloids ( 2 ) . ionization detector was employed for glc determinations on a 6 ft x in. O.D. spiral 1T-e have beell unable to find any glass column packed with 3% OT -17 on Gas references t o prerrious Chrom (2. Operating conditions m-ere inor pharmacologic literature on P . jector temperature, 370". detector temt o y t a (llart.) Radlk. A phytochemical perature, 310°, column temperature, 290"; flow rate of carrier gas (nitrogen) 20 ml/min. evaluation of a methanol extract of 2The plant material was collected and the twigs of this plant in our laboraidentified by the Economic Botany Laboratory, BARC-East, United States Departtories sho"-ed to be ment of hgriculture, Beltsville, LID, and but triterpenes to be Present. The funded by the Sational Cancer Institute. present study \vas undertaken to ex.4voucher speciman representing the collection (PR-43914) is deposited in the Heramine the triterpene constituents of barium of the National this plant. Washington, D.C. 420

MAT-JCS 19801

CHE ET A L . :

TRITERPESES OF POUTERIA TORTS

phenolic constituents. The chloroform estract was dried over anhydrous sodium sulfate, filtered and concentrated t o yield 42 g of a viscous fraction C.

ISOLATIOS OF ~ - . ~ M T R I SA C E T . ~ T E . - - ~ portion of fraction -1 (100 g) xas chromatographed on silica gel PF-2543 with benzene as the eluting solvent. Fractions 3-4 (500 ml each) from the column were combined, evaporated t o drvness in ;'aczto and cr>-stallized from petroleum ether-ether t o afford crude fbarnyrin acetate (2.0 g ) . Recr>-stallization from petroleum ether-ether yielded 1.52 g 10.01525 I of analytical sample, nip 235-236", identical ipmr, ms, ir and tlc) with a reference sample.4 Concentration of the crude 3-aniyrin acet a t e mother-liquor t o dryness i n ~ ~ a c iaf~o forded a residue n-hich w-as crystallized from methanol-acetone t o yield 14.0 g of a mixture of triterpenes. SEP.IR.iTIOS OF T R I T E R P E S E M I S T T R E . i S D or C ~ - . ~ ~ I Y RACET.ITE.--.~ IS 3 g portion of the triterpene mixture x a s rechromatographed on silica gel PF-254 with petroleum ether-benzene 12:l) as the solvent : fractions 120 ml each) were monitored b?- glc. Fractions 412-431 gave a single peak ( R , = 17 min 24 s e e ) identified as 8-am>-rinacetate by direct comparison with reference sample.? Analysis of fractions 418-490 by glc showed a ma,jor component a t R , 20.0 min. Cr>-stallization of the combined fractions from acetone-methanol afforded a-amyrin acetate (630 mg, 0.0291$1, identical ipmr, ms, ir, tlc and glc) n-ith a reference sample.? ISOLATIOS

1SOL.ITIOS OF BETL-LISIC .icIo.-Fraction c (42 g) was chromatographed on JlS silica gel P UT--2515 with chloroform. Combined fractions 201-29T afforded a crystalline compound from methanol and recrystallization from the Fame solvent yielded 414 mg of betrilinic acid (0.0016$ ), mp 277-279: identical ipmr, ms, ir, and t l c ) n-ith an authentic siniple.4

I S O L L T OF I O1-RSOLIC ~ icID.-Crystallization and recrystallization of the combined column fractions 430-497 iCHC1331eOH, Y6:2j from 9 5 5 ethanol afforded 16 mg (0.000065) of iirsolic acid, mp 283-285", identical (pmr, ms, ir, and tlc) n i t h an aut bent ic sample. 3E. Merck. Darmstadt, K.Germany. lFrom our Laboratories. Wacherc>- Sage1 and Co., Doreii, W Germany.

42 1

DISCCSSIOS The isolation of 0-amyrin acetate, a-amyrin acetate, betulinic acid and ursolic acid from Pouteria torta is reported and adds further phytochemical information on this poorly-studied genu.s. I n Tien- of the negative alkaloid test re-ults and the isolation of triterpenes from Pouieria species in our laboratories and elsen here, the reported occurrence of the indole alkaloid. yohimbine. in a >pecies of this genus should be viewed with caution. Indeed. hltman (5) reported only the isolation of an alkaloid with a nip and chroniogenic reaction similar to yohimbine from the bark of a plant believed t o be a Poziteria specie.. -1CKSOWLEDGlIEST The authors n-ish t o thank the Economic Botany Laboratory, BARC-East, USDA, Beltsville, M d , for supplying the plant material used in this investigation. Recei; ed 18 Ociober 1979.

LITERATURE CITED 1. J. D . Hooker and B . D. Jackson, Index Kewensis, 2 1-olsS.14 suppls., Oxford, England, 1895-1963. 2. R . Pellicciari, .-I.-1rdon and I-. Bellavita. P l a n f a X e d . . 22. 196 11972). 3. A . -1rdon and T . ' S a k a n o , Planin N e d . , 23, 348 (1973). 4. B. -1njaneyulu, V. Babu Rao, -2.K. Ganguly, T. R . Govindachari, B . S. Joshi, T . S . K a m a t , H. Manmade, P. Jlohamed. D . Rahimtula. -1. K. Sakseiia, 13,'s. 1-arde and S . visn-anathan, Idin71 J . Chem., 3, 237 (1965). 5. R . F. .1.-1ltnian, I u s / . -\-at/. Pesqitisas Anici:o~iia, Publ. S o . 1, 3 (1958): Cheni. -4bsir., 52, 17613f (195Sj. 6. C. Stellfeld, T r i b i c m F n m i . ( B r a r i l ) , 30, 35 (1962). 7 . T. G . Hartley, E. A . Dunstone, J . S. Fitzgerald, S.R . Johns and J. Larnberton, L l o y d i n , 36, 217 (1973). 8. H . H. S. Fong, 11.Tin-Wa, S . R . Farnsworth and R . H. Dohberstein, "Phytochemical 8creening", College of Pharmacy, University of Illinois a t the Medical Center, Chicago, Ill. 60612, pp. 30-43, 1977.