Jour nal of the Chinese Chem i cal So ci ety, 2000, 47,

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1 Jour nal of the Chinese Chem i cal So ci ety, 2000, 47, Aristolochic Acids as a De fen sive Sub stance for the Aristolochiaceous Plant-Feeding Swal low tail But ter fly, Pachliopta aristolochiae interpositus Tian-Shung Wu* ( d ѽà ), Yann-Lii Leu ( f«ûâ ) and Yu-Yi Chan ( â _½Ë ) De part ment of Chemistry, Na tional Cheng Kung University, Tainan, Tai wan, R.O.C. The chem i cal con stit u ents iso lated from ev ery stage of the Tai wan ese swal low tail but ter fly, Pachliopta aristolochiae interpositus, were stud ied and com pared with the con stit u ents of the in sect feed ing plant, A. cucurbitifolia. Two aristolochic acid de riv a tives ( 1 and 4) and three aristolactam an a logues ( 5, 6, and 7) were iso lated from the lar val osmeterial fluid and lar vae of the in sect. In ad di tion, four purin es ( 2, 3, 13, and 14 ), one indole al ka loid ( 11 ), one ste roid ( 10 ), two benzenoids ( 8 and 9) and allantoin ( 12 ) were also iso lated from the in sect. Among these com pounds, aristolochic acid - I (AA-I, 1) was de tected in all life stages of the in sect, es pe - cially in the lar val osmeterial fluid. The stud ies con firm that the toxic AAs are used as larv al feed ing stim u lants and de ter rent allomones against birds. INTRODUCTION It is known that sec ond ary me tab o lites of plants can serve as tox i co log i cal and be hav ioral bar ri ers to evo lu tion ary changes in host use by phytophagous in sects. 1-3 Rothschild et al. 4 re ported that the host ad ap ta tion in a large num ber of swal - low tail but ter fly spe cies (Papilionidae) is as so ci ated with the host-originated aristolochic acid de riv a tives (AAs). Nishida et al. 5,6 re ported that the toxic sub stances, an a logues of aristolochic ac ids, sec ond ary me tab o lites iso lated from the ge nus Aristolochia, are char ac ter ized as the lar val feed ing stim u lants of the swal low tail but ter fly spe cies (Papilioniae). For ex am ple, a Jap a nese pipevine swal low but ter fly, Atrophaneura alcinous, ap peared to se ques ter AAs in eggs, lar vae, pu pae and body tis sue of adults. 5 It dem on strated that AAs act as de ter rent allomones against birds. Ad di tionally, AAs and D-(+)-pinitol are sug gested to be an oviposition stim u lant for the fe male swal low tail but ter fly. 5-7 It was re ported that the Tai wan ese swal low tail but ter fly, Pachliopta aristolochiae interpositus, also ex clu sively feeds on the genus Aristolochia, namely, Aristolochia cucurbitifolia. 8 Pre vi ously, we re ported the con stit u ents of the leaves of A. cucurbitifolia, from which sev eral aristolochic ac ids, aristolactams and other com pounds were iso lated as shown in Fig. 1. 9,10 Thus, it is of great in ter est to com pare the pro files of AAs and their re lated com pounds that ap pear in the plant and the but ter fly. The stud ies may also dem on strate the pos si ble met a bolic route of these chem i cal sub stances in all life stages of the swal low tail but ter fly. Here, we de scribe the iso la tion, char ac ter iza tion and trans for ma tion of the con stit u ents from ev ery growth stage of P. aristolochiae interpositus. RESULTS AND DISCUSSION Ta ble 1 shows the chem i cal con stit u ents iso lated from ev ery growth stage of P. aristolochiae interpositus in clud ing lar val osmeterial fluid, larva, lar val ex cre ment, pu pal shell, and adult body with out wings af ter ex trac tion with MeOH and chro ma tog ra phy. Two aristolochic acid de riv a tives ( 1 and 4) and three aristolactam an a logues ( 5, 6, and 7) were iso lated from the lar val osmeterial fluid and lar vae of the in sect. In ad - di tion, four pur ines ( 2, 3, 13, and 14 ), one indol al ka loid ( 11 ), one ste roid ( 10 ), two benzenoids ( 8 and 9) and allantoin ( 12 ) were also iso lated from the in sect. Aristolochic acid-i (AA-I. 1), aristolic acid ( 4) and aristolactam de riv a tives 5, 6, and 7 (Fig. 1) were iso lated from the lar vae of the swal low tail but - ter fly. How ever, the toxic sub stance AA-I ( 1) ap peared to have the high est con cen tra tion in the lar val osmeterial fluid, al though this com pound was de tected in all life stages of the in sect. It in di cates that AAs act as de ter rent allomones of the lar vae of the in sect against birds. Our pre vi ous stud ies on the con stit u ents of A. cucurbitifolia re sulted in the iso la tion of aristolochic ac ids, denitroaristolochic ac ids and aristolactam de riv a tives. 9,10 In the pres ent study we found that aristolactams 5, 6 and 7 are de - tected only from the lar vae and lar val ex cre ment, but not in the lar val osmeterial flu ids, pu pal shells or adult bod ies. It dem - Ded i cated to the mem ory of the late Pro fes sor Ta-shue Chou ( P j ÓV )

2 222 J. Chin. Chem. Soc., Vol. 47, No. 1, 2000 Wu et al. Fig. 1. The con stit u ents iso lated from the leaves of A. cucurbitifolia and P. aristolochiae interpositus.

3 Aristolochic Acids from Swal low tail But ter fly J. Chin. Chem. Soc., Vol. 47, No. 1, Table 1. The Percentageof the Weight of Each Compound in All Growth Stages material compd. contain (%) Larval osmeterial fluid (14 mg) Larvae (71.24g) Larval excrement (0.68 g) Pupal shells (0.234g) Adults (2.067g) Aristolochic acid-i (1) Adenosine (2) 5.71 Inosine (3) Aristolic acid (4) Aristolactam-I (5) Aristolactam-N-β-D-glucoside (6) Cepharanone-N-β-D-glucoside (7) Methylparaben (8) Sodium (2R)-(p-hydroxyphenyl)lactate (9) Cholesterol (10) Indole-3-carboxylic acid methyl ester (11) Allantoin (12) Adenine (13) 0.05 Guanosine (14) 0.05 on strated that aristolochic ac ids might be me tab o lized to form aristolactam de riv a tives at the lar val stage. De riv a tives of aristolactam may be fur ther me tab o lized and ex creted when the in sects are ma tured in the adult stage, since we do not de - tect these com pounds from the pu pal shells and the bod ies of the but ter fly. In sum mary, we have iso lated the chem i cal sub stances from ev ery stage of the Tai wan ese swal low tail but ter fly, P. aristolochiae interpositus and com pared them with the con - stit u ents of the in sect s feed ing plant, A. cucurbitifolia. The study con firms the pre vi ous lit er a ture re ports that the toxic AAs are used as the lar val feed ing stim u lants and de ter rent allomones against birds. The pres ence of the AA-I in all life stages of the in sect, es pe cially in the lar val osmeterial flu ids and pu pal shells, sug gests a pos si ble adap tive mech a nism in this spe cies. In ad di tion, AA-I may be me tab o lized to form aristolactams and ex creted in the lar val stage, but the for ma - tion of aristolactams does not oc cur in the ma tured but ter flies. EXPERIMENTAL SECTION Swal low tail but ter fly : Swal low tail but ter flies, P. aristolochiae interpositus, were col lected and ver i fied by Prof. C. P. Wang (De part ment of Bi ol ogy, Na tional Cheng Kung Uni ver sity, Tainan, Tai wan.). Extraction and Isolation of Ingredients from Pachliopta aristolochiae interpositus Larvae : Sixty lar vae of P. aristolochiae interpositus (71.24 g) were ex tracted with MeOH ( 7) and H 2O ( 3) at room tem per a ture. The com bined meth a nol and wa ter ex - tracts were con cen trated in vacuo to give a brown syrup (5.87 g), which was par ti tioned be tween H 2O and CHCl 3. The CHCl 3 layer was sep a rated and di rectly chromatographed on a sil ica gel col umn and eluted with a gra di ent of CHCl 3 and MeOH to af ford 17 frac tions. Frac tions 6 and 7 were com - bined and crys tal lized from MeOH to give com pound 10 (8 mg). The main prod uct in frac tion 8 was pu ri fied on a sil - ica-gel col umn chro ma tog ra phy (C 6H 6 : EtOAc = 14 :1 v/v as the eluent) to af ford 11 (0.8 mg). From frac tion 9, com pound 8 (1 mg) was iso lated by pre para tive TLC (sil ica-gel, C 6H 6 : Me 2CO = 14 :1). Com pounds in frac tion 12 were sep a rated sim i larly to frac tion 8 to ob tain 4 (2 mg), 6 (1 mg), and 7 (0.5 mg). From the com bined frac tions 13 and 16, com pound 1 (15 mg) was iso lated by recrystallization. The wa ter layer was fil - tered and chromatographed on Sephadex LH-20 and eluted with a gra di ent of H 2O and MeOH to give 7 frac tions. From frac tion 3, com pound 9 (5 mg) was ob tained as a crys tal line solid. Lar val osmeterial flu ids : Lar val osmeterial flu ids were col lected from the ir ri tated P. aristolochiae interpositus by glass cap il lary tubes and con cen trated un der re duced pres sure to give a deep brown syrup (14 mg). The syrup was di rectly chromatographed on a sil ica gel col umn and eluted with gra di - ents of CHCl 3 and MeOH to af ford 7 frac tions. The crys tal line prod ucts ap pear ing in frac tion 2 and 3 were col lected by fil tra - tion to give com pounds 2 (0.8 mg) and 1 (1 mg), re spec tively. Com pound 3 (2 mg) was iso lated from com bined frac tions4 and 5 by pre para tive TLC (sil ica gel, CHCl 3 : MeOH = 7 :1 v/v). Dry lar val ex cre ment : Dry lar val ex cre ment (0.68 g)

4 224 J. Chin. Chem. Soc., Vol. 47, No. 1, 2000 Wu et al. was ex tracted with MeOH ( 3) and ac e tone ( 3) at room tem - per a ture. The com bined ex tracts were con cen trated un der re - duced pres sure to give a deep brown syrup (60 mg), which was chromatographed di rectly on a sil ica-gel col umn, eluted with gra di ents of CHCl 3 and MeOH to af ford 8 frac tions. Frac tion 4 was pu ri fied by pre para tive TLC (sil ica gel, CHCl 3 ) to give 5 (0.5 mg). Com pounds 6 (0.7 mg) and 7 (1 mg) were iso lated from frac tion 6 by pre para tive TLC (sil ica-gel, CHCl 3 : MeOH = 9 :1 v/v), while com pound 1 (0.5 mg) was ob tained from frac tion 8 af ter rechromatography on a sil ica gel col umn with gra di ent eluation (CHCl 3- MeOH). Pu pal shells : Fifty pu pal shells (0.234 g) were ex tracted with MeOH ( 2) and con cen trated in vacuo to a deep brown syrup (234 mg), which was di rectly chromatographed on a sil - ica gel col umn with gra di ent eluation (CHCl 3 - MeOH) to give 10 frac tions. Com pounds 1 (2 mg) and 12 (12 mg) were ob - tained from frac tions 6 and 7, re spec tively, by recrystalliza - tion from CHCl 3 /MeOH. Body of but ter fly with out wings : Twenty swal low tail but ter flies (2.07 g) were ex tracted with MeOH ( 3) and the sol vent was re moved in vacuo to give a deep brown syrup (219 mg), which was then di rectly chromatographed on a sil ica gel col umn and eluted with a gra di ent of CHCl 3 and MeOH to give 9 frac tions. Frac tion 1 was rechromatographed (SiO 2, sol vent: a gra di ent of n-c 6H 14 and Me 2CO) to yield 9 (3 mg). Com pound 13 (0.5 mg) was ob tained from frac tion 3 af ter chro ma tog ra phy (SiO 2, CHCl 3 : MeOH, 14 : 1 v/v). Frac tions 4 and 5 were com bined, and com pounds 1 (2 mg), 13 (0.5 mg) and 2 (2 mg) were ob tained af ter chro ma tog ra phy. In a sim i lar man ner, com pounds 12 (4 mg) and 14 (1 mg) were iso lated from frac tions 6 and 7. Structural determination of the isolated compounds UV spec tra were re corded in MeOH, and IR spec tra were de ter mined as KBr disc. 1 H NMR spec tra were ob tained with a Bruker and Varian NMR (200 or 400 MHz) spec trom e - ter, with tetramethylsilane (TMS) as in ter nal stan dard. EIMS were mea sured by 70 ev di rect in let sys tem on a VG70-250AS spec trom e ter. Melting points are un cor rected. Four teen com pounds in clud ing aristolochic acid ( 1), adenosine ( 2), inosine ( 3), aristolic acid ( 4), aristolactam ( 5), aristolactam-n-β-d-glucoside ( 6), aristolactam-ii-n-β-d- glucoside ( 7), methylparaben ( 8), so dium (2R)-3-( p- hydrophenyl) lactate ( 9), cho les terol ( 10 ), indole-3-carboxylic acid methyl es ter ( 11 ), allantoin ( 12 ), ad e nine ( 13 ), guanosine (14) were isloated from ev ery growth stage (lar val osmeterial fluid, larva, lar val ex cre ment, pu pal shells and adults) of Pachliopta aristolochiae interpositus. Their struc tures were de ter mined by spec tral meth ods. Aristolochic acid-i ( 1) Or ange pow der (CHCl 3/MeOH), C 17 H 11 NO 7, mp 283~285 o C., UV λ max nm: 220, 246, 248, 310, 385., IR ν max cm - 1 : 1701, 1593, 1521, 1467, 1269, 1150, 1041, 945., FAB- MS m/z (rel. int.): 342 (M + +1, 14), 341 (26), 295 (33), 280 (10)., 1 H NMR (DMSO-d 6, 200 MHz): δ 8.66 (1H, d, J = 8.0 Hz, H-5), 8.59 (1H, s, H-9), 7.86 (1H, t, J = 8.0 Hz, H-6), 7.82 (1H, s, H-2), 7.38 (1H, d, J = 8.0 Hz, H-7), 6.50 (2H, s, OCH 2 O), 4.07 (3H, s, OMe). Adenosine ( 2) Col or less pow der (CHCl 3 /MeOH), C 10 H 13 N 5 O 4, mp 235~237 o C., UV λ max nm: 209, 260., IR ν max cm - 1 : (br., -NH, -OH), 1660(C=N)., FAB-MS m/z (rel. int.): 268 (M + +1, 20), 166 (10), 165 (13), 155 (40), 154 (100), 107 (45), 89 (46), 77 (46)., 1 H NMR (CD 3OD, 400 MHz): δ 8.30 (1H, s, H-2), 8.17 (1H, s, H-8), 5.95 (1H, d, J = 7.2 Hz, H-1 ), 4.72(1H, dd, J = 7.2, 4.8 Hz, H-2 ), 4.30(1H, dd, J = 4.8, 2.4 Hz, H-3 ), 4.16(1H, ddd, J = 2.4, 2.4, 2.4 Hz, H-4 ), 3.87 (1H, dd, J = 12.4, 2.4 Hz, H-5 ), 3.73(1H, dd, J = 12.4, 2.4 Hz, H-5 ). Inosine ( 3) Col or less pow der (CHCl 3 /MeOH), C 10 H 12 N 4 O 5, mp 227~229 o C., UV λ max nm: 203, 249, 266(sh)., IR ν max cm - 1 : (br., -NH, -OH), 1701(C=O)., 1 H NMR (DMSOd 6, 400 MHz): δ (1H, s, NH), 8.31 (1H, s, H-2), 8.05 (1H, s, H-8), 5.84 (1H, d, J = 5.6 Hz, H-1 ), 5.47 (1H, d, J = 6.4 Hz, OH), 5.19 (1H, d, J = 4.8 Hz, OH), 5.06 (1H, t, J = 5.6 Hz, OH), 4.46(1H, ddd, J = 6.4, 5.6, 4.4 Hz, H-2 ), 4.10(1H, ddd, J = 4.8, 4.4, 3.6 Hz, H-3 ), 3.91(1H, ddd, J = 3.6, 3.6, 3.6 Hz, H-4 ), 3.62 (1H, m, H-5 ), 3.52(1H, m, H-5 ). Aristolic acid ( 4) Yel low nee dles, C 17 H 12 O 5, mp: 290~291 o C., UV λ max nm: 222, 258, 283, 295, 322, 356, 374., IR ν max cm - 1 : 2918, 1685, 1591, 1541, 1448, 1409, 1350, 1282, 1072, 983. FAB-MS m/z (rel. int.): 297 (M + +1, 19), 296 (41), 219 (19), 176 (20), 149 (71), 57 (100)., 1 H NMR (ac e tone-d 6, 200 MHz): δ 8.97 (1H, d, J = 9.8 Hz, H-10), 8.73 (1H, d, J = 8.6 Hz, H-5), 8.16 (1H, d, J = 9.8 Hz, H-9), 7.98 (1H, s, H-2), 7.61 (1H, dd, J = 8.6, 8.2 Hz, H-6), 7.21 (1H, d, J = 8.2 Hz, H-7), 6.44 (2H, s, -OCH 2O-), 4.05 (3H, s, OCH 3). Aristolactam-I ( 5) Yel low-green nee dles (CHCl 3/ MeOH), C 17 H 11 NO 4, mp > 300 o C., UV λ max nm: 230 (sh), 260, 276, 287, 326, 392., IR ν max cm - 1 : 3205, 1700, 1546, 1464, 1280, 1060, 938., EI-MS m/z (rel. int.): 293 (M +,42), 278 (34), 263 (100), 262 (13), 177 (13), 150 (14), 131 (14), 106 (42), 78 (14), 57 (10)., 1 H NMR

5 Aristolochic Acids from Swal low tail But ter fly J. Chin. Chem. Soc., Vol. 47, No. 1, (CDCl 3, 200 MHz): δ (1H, brs, NH), 8.14 (1H, d, J = 8.1 Hz, H-5), 7.65 (1H, s, H-2), 7.51 (1H, t, J = 8.1 Hz, H-6), 7.37 (1H, s, H-9), 7.20 (1H, d, J = 8.1 Hz, H-7), 6.47 (2H, s, OCH 2O), 3.99 (3H, s, OCH 3). Aristolactam-N-β-D-glucoside ( 6) Yellow nee dles (CHCl 3/ MeOH), C 23 H 21 NO 9, mp > 300 o C., UV λ max nm: 239, 243, 249, 259, 275, 289, 299, 330, 342(sh), 394., IR ν max cm - 1 : 3400, 1690, 1610, 1430, 1363., FAB-MS m/z (rel. int.): 456(M + +1, 1)., 1 H NMR (DMSO-d 6, 200 MHz): δ 8.20 (1H, d, J = 8.2 Hz, H-5), 7.76 (1H, s, H-2), 7.63 (1H, s, H-9), 7.58 (1H, t, J = 8.2 Hz, H-6), 7.23 (1H, d, J = 8.2 Hz, H-7), 6.50 (2H, s, OCH 2O), 5.34 (1H, d, J = 9.2 Hz, anomeric pro ton), 5.26 (3H, m, OH), 5.14 (1H, d, J = 5.3 Hz, OH), 4.62 (1H, m), 4.01 (3H, s, OCH 3 ), 3.75 (2H, m), 3.30~3.40 (3H, m). Aristolactam-II-N-β-D-glucoside ( 7) Yellow nee dles (MeOH), C 22 H 19 NO 8, mp > 280 o C., UV λ max nm: 211, 232, 264, 277, 288, 328, 342, 374, 393., IR ν max cm - 1 : 3442, 1679, 1616, 1419, 1369, 1197, 1058, 885., 1 H NMR (DMSO-d 6, 200 MHz): δ 8.57 (1H, m, H-5), 8.04 (1H, m, H-8), 7.64 (1H, s, H-2), 7.57 (2H, m, H-6, 7), 7.45 (1H, s, H-9), 6.51 (2H, s, OCH 2 O), 5.32 (1H, d, J = 9.3 Hz, H-1 ), 5.22 (1H, d, J = 5.3 Hz, OH), 5.10 (2H, brd, J = 8.3 Hz, OH), 4.57 (1H, brt, J = 5.9 Hz, OH), 3.73 (2H, m), 3.10~3.50 (4H, m). Methylparaben (8) Col or less nee dles (CHCl 3/ Me 2CO), C 8H 8O 3, mp : 129~131 o C., UV λ max nm: 257, 310., IR ν max cm - 1 : 3400, 1690, 1610, 1595, 1518., EI-MS m/z (rel. int.): 152 (M +, 44), 121 (100), 65 (24)., 1 H NMR (CDCl 3, 200 MHz): δ 7.96 (2H, d, J = 8.6 Hz, H-2, 6), 6.86 (2H, d, J = 8.6 Hz, H-3, 5), 5.52 (1H, br.s, OH), 3.89 (3H, s, OCH 3). Sodium (2R)-3-( p-hydroxyphenyl)lac tate (9) Col or less pow der (MeOH), mp > 300 o C. [ α] D- 33 o ( c 0.01, MeOH)., UV λ max nm: 225, 279, 285., IR ν max cm - 1 : 3200, 1590, 1520, 1470, 1455, 1420, 1360, 1335, 1250., 1 H NMR(D 2O, 200 MHz): δ 7.13 (2H, d, J = 8.6 Hz, H-5,9), 6.83 (2H, d, J = 8.6 Hz, H-6,8), 3.82 (1H, dd, J = 7.6, 5.2 Hz, H-2), 3.13 (1H, dd, J = 14.4, 5.2 Hz, H-3), 2.93 (1H, dd, J = 14.4, 7.6 Hz, H-3). Cho les terol (10) Col or less pow der, C 27 H 46 O, mp : 147~149 o C., IR ν max cm - 1 : 3423, 1462, 1375, 1051., 1 H NMR (CDCl 3, 400 MHz): δ 5.35 (1H, d, J = 5.2 Hz, H-6), 3.52 (1H, m, H-3), 1.00 (3H, s, CH 3), 0.90 (3H, d, J = 6.8 Hz, CH 3), 0.87 (3H, d, J = 8.8 Hz, CH 3 ), 0.86 (3H, d, J = 6.8 Hz, CH 3 ), 0.67 (3H, s, CH 3 ). Indole-3-carboxylic acid methyl ester ( 11 ) Col or less oil, C 10 H 9 NO 2, UV λ max nm: 226, 246 (sh), 281, 286., IR ν max cm - 1 : 3300, 2900, 1670, 1450, 1198, 1128, 1057, 733., EI-MS m/z (rel. int.): 175 (M +, 69), 144 (100), 116 (22), 89 (22)., 1 H NMR (CDCl 3, 200 MHz): δ (1H, br.s, NH), 8.12 (1H, m, H-7), 8.04 (1H, d, J = 3.0 Hz, H-2), 7.51 (1H, m, H-4), 7.20 (2H, m, H-5&6), 3.84 (3H, s, OCH 3). Allantoin ( 12 ) Col or less nee dles (MeOH), C 4H 6N 4O 3, mp: 237~238 o C., IR ν max cm - 1 : 3440, 3344, 3188, 1780, 1713, 1660, 1532, 1431, 1326., FAB-MS m/z (rel. int.): 159 (M + +1, 6), 93 (80), 75 (25)., 1 H NMR (DMSO-d 6, 400 MHz): δ (1H, br.s, NH), 8.06 (1H, s, NH), 6.93 (1H, d, J = 8.1 Hz, NH), 5.81 (2H, s, NH 2), 5.22 (1H, dd, J = 8.1, 1.1 Hz, H-5). Adenine ( 13 ) Col or less pow der (MeOH), C 5H 5N 5, mp >300 o C., UV λ max nm: 209, 261., IR ν max cm - 1 : 3298, 3116, 1670 (C=N), 1603 (C=C)., EI-MS m/z (rel. int.): 135 (M +, 100), 108 (22), 81 (8), 66 (5), 54 (10), 53 (8)., 1 H NMR (DMSO-d 6, 200 MHz): δ (1H, s, NH), 8.08 (2H, s, H-2, H-8), 7.07 (2H, s, NH 2 ). Guanosine ( 14 ) Col or less pow der (CHCl 3 /MeOH), C 10 H 13 N 5 O 5, mp 240 o C (decomp.), UV λ max nm: 254, 273(sh)., IR ν max cm - 1 : (br., -NH, -OH), 1695 (C=O), 1610, 1540 (C=C)., FAB-MS m/z (rel. int.): 284 (M + +1, 36), 154 (100), 135 (79), 107 (28), 77 (33)., 1 H NMR (DMSO-d 6, 200 MHz): δ (1H, s, OH), 7.92 (1H, s, H-8), 6.43 (1H, s, NH), 5.67 (1H, d, J = 6.0 Hz, H-1 ), 5.38 (1H, d, J = 6.0 Hz, OH), 5.11 (1H, d, J = 4.6 Hz, OH), 5.03 (1H, t, J = 5.5 Hz, OH), 4.37 (1H, ddd, J = 6.0, 6.0, 5.8 Hz, H-2 ), 4.06 (1H, ddd, J = 5.8, 4.6, 3.5 Hz, H-3 ), 3.81 (1H, ddd, J = 3.5, 3.5, 3.5 Hz, H-4 ), 3.56 (2H, m, H-5 ). ACKNOWLEDGMENT We thank the Na tional Sci ence Coun cil of the Re pub lic of China for fi nan cial sup port (NSC M ). We also thank Prof. T. L. Su (In sti tute of Bio med i cal Sci - ences, Ac a de mia Sinica, R.O.C.) for com ments.

6 226 J. Chin. Chem. Soc., Vol. 47, No. 1, 2000 Wu et al. Re ceived Oc to ber 19, Key Words Aristolochia cucurbitifolia ; Aristolochiaceae; Pachliopta aristolochiae interpositus ; Me tab o lite. REFERENCE 1. Fraenkel, G. S. Sci ence 1959, 129, Ehrlich, P. R.; Ra ven, P. H. Evo lu tion 1964, 18, Feeny, P.P. in In sect-plants ; Labeyrie, G.; Farbes, G.; Lachaise, D. (eds.), 1987 ; pp Rothschild, M.; Eur, J. V. In sect Biochem. 1972, 2, Nishida, R.; Fukami, H. J. Chem. Ecol. 1989, 15, Nishida, R.; Fukami, H. J. Chem. Ecol. 1989, 15, Papaj, D. R.; Feeny, P.; Sachdev-Gupta, K.; Rosenberry, L. J. Chem. Ecol. 1992, 18, Lee, J. Y.; Wang, H. Y. in Il lus tra tions of But ter flies in Tai - wan ; Pub lished by the Tai wan Mu seum, Tai pei, 1997 ; Vol. 4; pp Wu, T.-S.; Lee, Y. L.; Chan, Y. Y. Chem. Pharm. Bull. 1998, 46, Wu, T.-S.; Lee, Y. L.; Chan, Y. Y. Chem. Pharm. Bull. 1999, 47,