the prenylated 
 monomeric phloroglucinols 1114 and 1618 ( scheme 1 ) were synthesized by prenylation of either 
 2,4,6-trihydroxyacetophenone ( 15 ) or 2,6-dihydroxy-4-methoxyacetophenone 
 ( 10 ) ( scheme 1 ) . prenylation of the precursors 10 and 15 was achieved by reaction of the phenol with either sodium 
 hydroxide or lithium hydroxide and the appropriate alkenyl halide 
 in 80% aqueous ethanol at room temperature ; the solvent was chosen 
 based on a previous study of the effect of solvent on the c - alkylation 
 of phloroglucinols and on trials of various solvents for the synthesis 
 of 11 . the use of sodium hydroxide led 
 to higher yields of 11 , 12 , 16 , and 17 than the use of lithium hydroxide . compounds 11,16,17 , and 18(17,20 ) have previously been synthesized , and their structures were confirmed 
 by ms and by comparison of their h and c 
 nmr spectra with previously published spectra . thus , treatment of 10 with 3,3-dimethylallyl bromide ( prenyl bromide ) in 80% 
 aqueous ethanol with 1.1 equiv of naoh at room temperature for 16 
 h gave the monoprenylated product 11 in 33% yield . alkylation 
 of 10 with geranyl bromide and farnesyl bromide under 
 the same conditions yielded the corresponding geranylated and farnesylated 
 products 12 and 13 , with the yields decreasing 
 with increasing chain length . purification of the final product was 
 carried out in each case by reversed - phase chromatography over c18-silica gel . purification of 11 over silica 
 gel in the presence of 0.1% formic acid yielded the hydroxylated product 14 . alkylation of 15 with prenyl , geranyl , and 
 farnesyl 
 bromides gave the alkylated derivatives 1618 in low to moderate yields . the synthesis of dimeric 
 phloroglucinols such as mallatojaponin 
 c ( 1 ) required the coupling of the monomeric compounds 1012 , 14 , and 1617 . the initial coupling conditions used were 
 based upon previous work with similar substrates , but it was 
 apparent that the alkene moiety was readily hydrated under the standard 
 acidic conditions . most of the previously published work was on derivatives 
 not containing an alkene moiety , so this problem did not arise in 
 these cases . the coupling conditions were thus optimized by a study 
 of synthetic conditions for compound 8 , and various solvents , 
 catalysts , and reaction durations were investigated . the best conditions 
 were found to be the use of acetonitrile as solvent and a small amount 
 of concentrated sulfuric acid as catalyst to reduce hydration of the 
 alkene . these conditions allowed the reaction to be completed in less 
 than 30 min , and this short reaction time also reduced the amount 
 of hydration . although the reaction yield was low , the desired product 
 could easily be purified . these conditions were then applied to the 
 synthesis of mallatojaponin c ( 1 ) and compounds 59 . the latter compounds were prepared 
 in an attempt to improve upon the antiparasitic activity of the coupled 
 compounds and specifically to investigate the effect of the length 
 of the alkenyl chain and the substituent at c-5 on the bioactivity 
 of the resulting compounds . in the case of the known compound 1 the structure was confirmed by comparison of spectroscopic 
 data with the published data , and the 
 structures of the other compounds were established by analysis of 
 their spectroscopic data . the synthesis of other derivatives was attempted by replacing 
 formaldehyde 
 with various aldehydes . the synthesis of the p - fluorophenyl 
 derivative 19 initially appeared to be successful , as 
 judged by its h nmr spectrum , consistent with its assigned 
 structure , and the compound showed promising bioactivity , with an 
 ic50 value in the 24 m range . unfortunately , 
 the compound proved to be unstable on storage in the freezer and decomposed 
 before ms data could be obtained and an accurate ic50 value 
 could be determined . attempts to synthesize other proposed derivatives 
 were unsuccessful , presumably because of the stability of the secondary 
 benzylic carbocation that would be formed in an acid - catalyzed retrocoupling 
 reaction . the synthetic compounds 118 were 
 evaluated for their antiplasmodial activities against the dd2 strain 
 of p. falciparum . the results are presented in table 1 , together with the 
 data for some of the same compounds from the recent cariou and dubois 
 et al . the potencies against the 
 two different strains of p. falciparum show similar 
 trends , but the dd2 strain is more sensitive to these compounds than 
 the fcb1/columbia strain . nr = not reported in ref ( 8) . for the dimeric phloroglucinols ( 1 , 59 ) , it was found that the prenyl side 
 chain 
 maximized the bioactivity , with the bis - prenylated natural product 1 having the best potency . both the monoprenylated compound 4 and the bisgeranylated compound 6 were less 
 potent than 1 against the dd2 strain . thus , the bisgeranyl compound 6 , with methylation at both the 4- and 4-hydroxy groups , 
 has an ic50 value of 1.7  0.8 m , while the 
 corresponding unmethylated compound 8 is much less potent , 
 with an ic50 value greater than 20 m . this difference 
 may be partly due to polarity , since the hydrated derivative 7 is much less active than the unhydrated natural product 1 . the situation is somewhat different with the monomeric 
 phloroglucinol 
 derivatives . with these compounds potency increases as the alkenyl 
 side chain increases in length from prenyl to geranyl to farnesyl 
 in both the 4-methylated series ( compounds 1113 ) and the unmethylated series ( compounds 1618 ) . as with the dimeric phloroglucinols , the 
 compounds in the 4-methylated series are more potent than those in 
 the unmethylated series , but the differences are smaller . thus , the 
 unmethylated farnesyl compound 18 is only about 9-fold 
 less potent than its methylated analogue 13 . finally , 
 the excellent potencies of the monomeric compounds 12 and 13 are worth noting . both compounds show 
 submicromolar activities , with the farnesylated compound 13 having an ic50 value of 0.56 m against the dd2 
 strain , comparable to the dimeric lead compound 1 . it 
 is thus conceivable that further explorations in this chemical space 
 could yield relatively simple compounds with significant antiparasitic 
 activities . nmr 
 spectra were recorded on varian 400 or bruker avance 500 mhz spectrometers . preparatory 
 hplc separations were performed using shimadzu lc-8a pumps coupled 
 with a shimadzu spd - m10a diode array detector , a scl-10a controller , 
 and a varian dynamax c18 column ( 250  21.4 mm ) . semipreparative 
 hplc separations were performed using shimadzu lc-10at pumps coupled 
 with a shimadzu spd - m10a diode array detector , a scl-10a system controller , 
 and a phenomenex luna c18 column ( 250  10 mm ) . bioactive 
 compounds were checked for purity by analytical hplc analysis using 
 shimadzu lc-10at pumps coupled with a shimadzu spd - m10a diode array 
 detector , a sedex 75 evaporative light scattering detector , a scl-10a 
 system controller , and a phenomenex luna c18 column ( 250 
  4.6 mm ) . compounds 10 and 15 were 
 purchased from indofine chemical company and tested for bioactivity 
 without further purification . compounds 2 and 3 were isolated from m. oppositifolius , and compound 4 was previously synthesized from 1 . geranyl bromide was purchased from alfa aesar , 
 and prenyl and farnesyl bromides were purchased from sigma - aldrich . compound 10 or 15 ( 1 equiv ) was dissolved in a solution 
 of 80% etoh ( 40 ml ) containing lioh or naoh ( 2 equiv ) . prenyl , geranyl , 
 or farnesyl bromide ( 1.1 equiv ) was added , and the reaction mixture 
 was stirred for 16 h at rt . the reaction mixture was acidified with 
 3 n hcl and extracted with ch2cl2 ( 3  
 50 ml ) . the organic solution was washed with saturated aqueous nacl 
 ( 50 ml ) and dried with mgso4 , and the solvent was removed 
 under reduced pressure . the residue was purified utilizing c18 hplc ( meoh / h2o gradient with 0.1% formic acid ) to yield 
 the alkylated phloroglucinol ( 1114 , 1618 ) . the alkylated 
 phloroglucinol ( 1012 , 14 , 16 , or 17 , 0.10.5 mmol ) was dissolved 
 in ch3cn . formaldehyde ( 37% aqueous , 10 equiv ) was added , 
 followed by the addition of concentrated h2so4 ( 1 drop ) . the 
 reaction mixture was diluted with water ( 10 ml ) and extracted with 
 etoac ( 3  10 ml ) . the organic solution was washed with saturated 
 nacl ( 10 ml ) and dried with mgso4 , and the solvent was 
 removed under reduced pressure . the residue was purified utilizing 
 c18 hplc ( meoh / h2o gradient with 0.1% formic 
 acid ) to yield the dimeric phloroglucinol derivatives 1 and 59 . standard procedure a was 
 used with naoh to convert 10 ( 495 mg , 2.72 mmol ) to 11 ( 228 mg , 0.91 mmol , 33% ) . uv ( meoh ) max ( log  ) 215 ( 4.06 ) , 
 288 ( 4.09 ) , 333 ( 3.36 ) nm ; h nmr ( meoh - d4 , 400 mhz )  1.60 
 ( 3h , s , h-5 ) , 1.71 ( 3h , s , h-4 ) , 2.60 ( 3h , s , coch3 ) , 3.15 ( 2h , d , j = 7.2 hz , h-1 ) , 
 3.78 ( 3h , s , och3 ) , 5.10 ( 1h , m , h-2 ) , 
 5.96 ( 1h , s , h-5 ) ; c nmr ( meoh - d4 , 100 mhz )  17.8 , 22.0 , 25.9 , 33.1 , 55.8 , 90.9 , 106.0 , 
 108.9 , 124.3 , 131.1 , 162.3 , 163.5 , 165.0 , 205.0 ; hresims [ m + h]m / z 251.1274 ( calcd for 
 c14h19o4 251.1278 ) , [ m 
 + na]m / z 273.1114 ( calcd 
 for c14h18nao4 273.1097 ) . standard procedure a was 
 used with lioh as base to convert 10 ( 150 mg , 0.82 mmol ) 
 to 12 ( 78 mg , 0.25 mmol , 30% ) . when naoh was used as 
 base , the yield of 12 from 100 mg ( 0.55 mmol ) of 10 was 37 mg ( 0.12 mmol , 22% ) . uv ( meoh ) max ( log  ) 216 ( 4.16 ) , 
 289 ( 4.14 ) , 333 ( 3.38 ) nm ; h nmr ( meoh - d4 , 400 mhz )  1.60 
 ( 3h , s , h-10 ) , 1.67 ( 3h , s , h-9 ) , 1.87 ( 3h , s , h-8 ) , 
 2.08 ( 4h , m , h-4 , h-5 ) , 2.67 ( 3h , s , coch3 ) , 3.33 ( 2h , d , j = 7.0 hz , h-1 ) , 
 3.81 ( 3h , s , och3 ) , 5.06 ( 1h , m , h-6 ) , 
 5.19 ( 1h , m , h-2 ) , 6.02 ( 1h , s , h-5 ) ; c nmr ( meoh - d4 , 100 mhz )  16.2 , 17.7 , 21.4 , 25.7 , 
 26.3 , 32.9 , 39.7 , 55.7 , 91.8 , 105.4 , 121.6 , 123.7 , 131.9 , 163.1 , 203.7 ; 
 hresims [ m + h]m / z 319.1896 
 ( calcd for c19h27o4 319.1904 ) , 
 [ m + na]m / z 341.1707 
 ( calcd for c19h26nao4 341.1723 ) . the yield of 13 from 100 mg ( 0.55 
 mmol ) of 10 was 61 mg ( 0.16 mmol , 29% ) . uv ( meoh ) max ( log  ) 
 213 ( 4.21 ) , 288 ( 4.14 ) , 333 ( 3.38 ) nm ; h nmr ( meoh - d4 , 400 mhz )  1.60 
 ( 3h , s , h-10 ) , 1.67 ( 3h , s , h-9 ) , 1.87 ( 3h , s , h-8 ) , 
 2.08 ( 4h , m , h-4 , h-5 ) , 2.67 ( 3h , s , coch3 ) , 3.33 ( 2h , d , j = 7.0 hz h-1 ) , 
 3.81 ( 3h , s , och3 ) , 5.06 ( 1h , m , h-6 ) , 
 5.19 ( 1h , m , h-2 ) , 6.02 ( 1h , s , h-5 ) ; c nmr ( meoh - d4 , 100 mhz )  16.2 , 17.7 , 21.4 , 25.7 , 
 26.3 , 32.9 , 39.7 , 55.7 , 91.8 , 105.4 , 121.6 , 123.7 , 131.9 , 163.1 , 203.7 ; 
 hresims [ m + h]m / z 387.2535 
 ( calcd for c24h35o4 387.2530 ) , 
 [ m + na]m / z 409.2346 
 ( calcd for c24h34o4na 409.2349 ) . the residue was purified by column chromatography 
 on silica gel ( 9:1 hexanes / etoac/0.1% formic acid ) . the yield of 14 from 49.6 mg ( 0.27 mmol ) of 10 was 24 mg ( 0.096 
 mmol , 36% ) . uv ( meoh ) max ( log  ) 216 ( 4.03 ) , 290 ( 4.07 ) , 331 ( 3.39 ) nm ; h nmr ( meoh - d4 , 400 mhz )  1.37 
 ( 6h , s , h-4 , h-5 ) , 1.77 ( 2h , t , j = 6.9 hz , h-3 ) , 2.53 ( 2h , t , j = 6.9 hz , 
 h-2 ) , 2.58 ( 3h , s , coch3 ) , 3.83 ( 3h , s , 
 och3 ) , 6.01 ( 1h , s , h-5 ) ; c nmr ( meoh - d4 , 100 mhz )  17.4 , 26.9 , 32.5 , 33.6 , 
 56.2 , 77.1 , 92.3 , 102.1 , 107.0 , 157.7 , 165.2 , 166.5 , 204.7 ; hresims 
 [ m  oh]m / z 251.1278 ( calcd for c14h19o4 251.1278 ) , [ m the yield of 16 from 980 mg ( 5.8 
 mmol ) of 15 was 365 mg ( 1.55 mmol , 27% ) . h nmr ( meoh - d4 , 400 mhz )  1.63 ( 3h , s , h-5 ) 
 1.73 ( 3h , s , h-4 ) , 2.60 ( 3h , s , coch3 ) , 
 3.17 ( 2h , d , j = 7.2 hz , h-1 ) , 5.16 ( 1h , 
 m , h-2 ) , 5.89 ( 1h , s , h-5 ) ; c nmr ( meoh - d4 , 100 mhz )  17.8 , 22.1 , 26.0 , 32.8 , 
 94.7 , 105.5 , 107.9 , 124.5 , 131.1 , 161.8 , 163.9 , 164.8 , 204.6 ; hresims 
 [ m + h]m / z 237.1119 
 ( calcd for c13h17o4 237.1121 ) , 
 [ 2 m + nh4]m / z 490.2405 ( calcd for c26h36no8 490.2435 ) . the yield of 17 from 253 mg ( 1.5 
 mmol ) of 15 with lioh was 147 mg ( 0.48 mmol , 32% ) , and 
 with naoh as base the yield of 17 from 100 mg ( 0.60 mmol ) 
 of 15 was 65 mg ( 0.48 mmol , 35% ) . h nmr ( cdcl3 , 400 mhz )  
 1.60 ( 3h , s , h-10 ) , 1.68 ( 3h , s , 
 h-9 ) , 1.82 ( 3h , s , h-8 ) , 2.10 ( 4h , m , h-4 , 
 h-5 ) , 2.67 ( 3h , s , coch3 ) , 3.37 ( 2h , d , j = 7.1 hz , h-1 ) , 5.05 ( 1h , m , h-6 ) , 5.25 
 ( 1h , h-2 ) , 5.85 ( 1h , s , h-5 ) ; c nmr ( cdcl3 , 100 mhz )  16.2 , 17.7 , 21.5 , 25.7 , 26.2 , 32.9 , 39.7 , 
 95.3 , 105.2 , 105.4 , 121.4 , 123.6 , 132.2 , 140.1 , 161.2 , 203.6 ; hresims 
 [ m + h]+ m / z 305.1744 ( calcd for 
 c18h25o4 305.1747 ) , [ m 
 + na]m / z 327.1539 ( calcd 
 for c18h24nao4 327.1567 ) . the yield of 18 from 101 mg ( 0.60 
 mmol ) of 15 was 61 mg ( 0.16 mmol , 27% ) . light yellow powder ; uv ( meoh ) 
 max ( log  ) 214 ( 4.21 ) , 291 ( 4.19 ) nm ; h nmr ( cd3od , 400 mhz )  1.54 ( 3h , s , h-15 ) , 
 1.56 ( 3h , s , h-14 ) , 1.65 ( 3h , s , h-13 ) , 1.79 ( 3h , 
 s , h-12 ) , 1.97 ( 8h , m , h-4 , h-5 , h-8 , 
 h-9 ) , 2.59 ( 3h , s coch3 ) , 3.18 ( 2h , d , j = 7.1 hz , h-1 ) , 5.05 ( 2h , m , h-6 , h-10 ) , 
 5.17 ( 1h , m , h-2 ) , 5.89 ( 1h , s , h-5 ) ; c nmr ( cd3od , 100 mhz )  14.7 , 14.7 , 16.3 , 20.6 , 24.5 , 26.0 , 26.3 , 
 31.4 , 39.4 , 39.4 , 93.3 , 104.1 , 106.5 , 123.3 , 123.9 , 124.1 , 130.4 , 
 133.0 , 134.3 , 160.4 , 162.5 , 163.4 , 203.1 ; hresims [ m + h]m / z 373.2366 ( calcd for c23h33o4 373.2373 ) , [ m + na]m / z 395.2169 ( calcd for 
 c23h32nao4 395.2193 ) . standard 
 procedure b was used with 3 ml of ch3cn and hcl instead 
 of h2so4 . the yield of 1 from 26.2 
 mg ( 0.1 mmol ) of 11 was 6.1 mg ( 0.011 mmol , 10% ) . light yellow powder ; h nmr 
 ( cdcl3 , 400 mhz )  1.68 ( 6h , s , h3 - 5 , 
 h3 - 5 ) , 1.77 ( 6h , s , h3 - 4 , h3 - 4 ) 2.70 ( 6h , s , 2  coch3 ) 3.31 ( 4h , d , j = 6.5 hz , h2 - 1 , 
 h2 - 1 ) , 3.68 ( 2h , s , h2 - 5a ) , 3.98 ( 2 
  och3 , 6h , s ) , 5.21 ( 2h , m , h-2 , 
 h-2 ) , 9.06 ( 2h , s , oh ) , 13.49 ( 2h , s , oh ) ; 
 hresims [ m + h]+ m / z 513.2469 ( calcd 
 for c29h37o8 513.2483 ) , 
 [ m + na]m / z 535.2297 
 ( calcd for c29h36o8na 535.2302 ) . the residue was purified utilizing silica 
 gel cc ( 1:1 hexanes / etoac ) . the yield of 5 from 100 mg 
 ( 0.55 mmol ) of 10 was 53.7 mg ( 0.14 mmol , 26% ) . h nmr ( dmso - d6 , 400 mhz )  2.56 ( 6h , s coch3 ) , 
 3.61 ( 2h , s , h-5a ) , 3.69 ( 6h , s , och3 ) , 6.00 ( 2h , 
 s , h-3 ) , 10.87 ( 2h , s , oh ) , 13.48 ( 2h , s , oh ) ; c nmr ( dmso - d6 , 100 mhz ) 15.2 , 
 30.7 , 32.7 , 39.5 , 55.4 , 90.2 , 104.4 , 160.8 , 162.3 , 163.9 , 203.1 ; hresims 
 [ m + h]m / z 377.1197 
 ( calcd for c19h21o8 377.1231 ) , 
 [ m + na]m / z 399.1020 
 ( calcd for c19h20nao8 399.1050 ) . the yield of 6 from 49.9 mg ( 0.16 mmol ) of 12 was 2.2 mg ( 0.0034 mmol , 2% ) . uv ( meoh ) max ( log  ) 204 ( 4.32 ) , 
 289 ( 3.95 ) nm ; h nmr ( cdcl3 , 400 mhz )  
 1.56 ( 6h , s , h-10 ) , 1.63 ( 6h , s , 
 h-9 ) , 1.77 ( 6h , s , h-8 ) , 1.98 ( 4h , m , h-5 ) , 
 2.05 ( 4h , bt , j = 7.4 hz , h-4 ) , 2.70 ( 6h , 
 s , coch3 ) , 3.31 ( 4h , d , j = 6.9 
 hz , h-1 ) , 3.68 ( 2h , s , h-5a ) , 3.97 ( 6h , s , och3 ) , 5.04 ( 2h , m , h-6 ) , 5.22 ( 2h , m , h-2 ) , 9.09 
 ( 2h , s , oh ) , 13.47 ( 2h , s , oh ) ; c nmr 
 ( cdcl3 , 100 mhz )  16.2 , 17.7 , 22.7 , 25.7 , 26.6 , 
 33.7 , 39.6 , 62.8 , 108.4 , 109.0 , 114.1 , 122.6 , 124.2 , 131.3 , 135.7 , 
 157.4 , 159.6 , 162.7 , 205.3 ; hresims [ m the yield of 7 from 12.1 mg ( 0.045 mmol ) of 14 was 6.2 mg ( 0.011 mmol , 25% ) . uv ( meoh ) max ( log  ) 213 ( 4.33 ) , 
 287 ( 4.25 ) , 354 ( 3.70 ) nm ; h nmr ( cdcl3 , 400 
 mhz )  1.37 ( 12h , s , h-4 , 
 h-5 ) , 1.74 ( 4h , t , j = 6.7 hz , h-2 ) , 
 2.63 ( 6h , s , 2  coch3 ) , 2.66 ( 4h , t , j = 6.8 hz , h-1 , h-1 ) , 3.65 ( 2  och3 , 6h , s ) , 3.94 ( h-5a , 2h , s ) , 13.80 ( oh , 2h , s ) ; c nmr ( cdcl3 , 100 mhz )  17.1 , 27.0 , 31.9 , 
 33.8 , 60.3 , 75.6 , 104.8 , 108.2 , 114.4 , 155.2 , 162.7 , 163.4 , 204.4 . standard procedure b was 
 used . the yield 
 of 8 from 14.3 mg ( 0.061 mmol ) of 16 was 
 3 mg ( 0.0062 mmol , 10% ) . h nmr ( dmso - d6 , 400 mhz )  1.59 ( 6h , s , h-5 , 
 h-5 ) , 1.68 ( 6h , s , h-4 , h-4 ) , 2.63 ( 6h , s , 
 2  coch3 , ) , 3.23 ( 4h , d , j = 6.7 hz , h-1 , h-1 ) , 3.68 ( 2h , s , h-5a ) , 5.04 ( 2h , 
 m , h-2 , h-2 ) ; c nmr ( dmso - d6 , 100 mhz )  17.0 , 17.8 , 21.5 , 25.5 , 32.6 , 48.6 , 
 105.8 , 106.4 , 108.1 , 123.0 , 130.4 , 159.5 , 203.7 ; hresims [ m + h]m / z 485.2140 ( calcd for 
 c27h33o8 485.2170 ) , [ m 
 + na]m / z 507.1946 ( calcd 
 for c27h32o8na 507.1989 ) . the yield of 9 from 49.3 mg ( 0.16 mmol ) of 17 was 10.5 mg ( 0.017 mmol , 11% ) . attempts at recrystallizing 
 the compound in meoh / h2o were unsuccessful and resulted 
 in decomposition before ms data could be obtained . uv ( meoh ) max ( log  ) 
 208 ( 4.27 ) , 230 ( 4.17 ) , 292 ( 4.11 ) nm ; h nmr ( cdcl3 , 400 mhz )  1.60 ( 6h , s , h-10 , 
 h-10 ) , 1.68 ( 6h , s , h-9 , h-9 ) , 1.83 ( 6h , s , 
 h-8 , h-8 ) , 2.11 ( 8h , m , h-4 , h-5 , 
 h-4 , h-5 ) , 2.67 ( 2  coch3 , 6h , s ) , 3.41 ( 4h , d , j = 6.7 hz , h-1 , 
 h-1 ) , 3.79 ( 2h , s , h-5a , ) , 5.05 ( 2h , m , h-6 , h-6 ) , 
 5.21 ( 2h , m , h-2 , h-2 ) ; partial c nmr 
 ( cdcl3 , 100 mhz )  16.2 , 17.7 , 25.7 , 26.2 , 32.7 , 
 39.6 , 105.7 , 121.4 , 123.4 , 132.2 , 140.7 , 204.2 .
the phloroglucinol mallotojaponin 
 c ( 1 ) from mallotus oppositifolius , 
 which was previously shown by us 
 to have both antiplasmodial and cytocidal activities against the malaria 
 parasite plasmodium falciparum , was synthesized in 
 three steps from 2,4,6-trihydroxyacetophenone , 
 and various derivatives were synthesized in an attempt to improve 
 the bioactivity of this class of compounds . 
 two derivatives , the simple 
 prenylated phloroglucinols 12 and 13 , were 
 found to have comparable antiplasmodial activities to that of mallotojaponin 
 c.