Limits...
Procerenone: a Fatty Acid Triterpenoid from the Fruit Pericarp of Omphalocarpum procerum (Sapotaceae).

Ngamgwe RF, Yankam R, Chouna JR, Lanz C, Furrer J, Schürch S, Kaiser M, Lenta BN, Ngouela S, Tsamo E, Brenneisen R - Iran J Pharm Res (2014)

Bottom Line: Phytochemical investigation of a dichloromethane-methanol (1:1) extract of the fruit pericarp of Omphalocarpum procerum which exhibited antiplasmodial activity during preliminary screening led to the isolation of the new fatty ester triterpenoid 3β-hexadecanoyloxy-28-hydroxyolean-12-en-11-one (1), together with five known compounds 2-6.The structure of the new compound as well as those of the known compounds was established by means of spectroscopic methods and by comparison with previously reported data.The tested compounds showed weak to moderate antiprotozoal activity and, no significant effect was detected regarding their cytotoxic potency.

View Article: PubMed Central - PubMed

Affiliation: Department of Organic Chemistry, Faculty of Science, TWAS Research Unit, University of Yaoundé 1, P. O. Box 812, Yaoundé, Cameroon.

ABSTRACT
Phytochemical investigation of a dichloromethane-methanol (1:1) extract of the fruit pericarp of Omphalocarpum procerum which exhibited antiplasmodial activity during preliminary screening led to the isolation of the new fatty ester triterpenoid 3β-hexadecanoyloxy-28-hydroxyolean-12-en-11-one (1), together with five known compounds 2-6. The structure of the new compound as well as those of the known compounds was established by means of spectroscopic methods and by comparison with previously reported data. Compounds 1- 4 were evaluated in-vitro for their cytotoxicity against L6 cell lines and antiprotozoal activities against Plasmodium falciparum, Leishmania donovani, Trypanosoma brucei rhodesiense and Trypanosoma cruzi (species responsible for human malaria, visceral leishmaniasis, African trypanosomiasis and Chagas disease, respectively). The tested compounds showed weak to moderate antiprotozoal activity and, no significant effect was detected regarding their cytotoxic potency.

No MeSH data available.


Related in: MedlinePlus

Fragmentation patterns of compound 1.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4232810&req=5

Figure 2: Fragmentation patterns of compound 1.

Mentions: Compound (1) was obtained as a white powder. It gave a positive reaction to Liebermann-Burchard test, as usual for a triterpenoid. Its molecular formula C46H78O4, with eight double bond equivalents, was deduced from the HRESIMS spectrum which showed the pseudo-molecular ion peak [M+H]+ at m/z = 695.5955 (calcd. m/z = 695.5973 for C46H79O4). The IR spectrum showed characteristic absorption bands at 3447 (OH), 1651 and 1698 (α,β-unsaturated ketone), and 1613 (C = C) cm-1. The 1H NMR spectrum (Table 1) revealed the presence of seven singlet resonances due to seven angular triterpenoids methyl protons (δH = 0.86, 0.90, 1.10, 1.14, 1.29, 1.39 and 1.59), a singlet of one methine proton (δH = 2.37) and one singlet of an olefinic proton (δH = 5.52). This spectrum also exhibited two doublets typical of an AB system (δH = 3.45 and 3.20, J = 10.8 Hz) and one doublet of doublets (δH = 4.47, J = 4.8, 12 Hz). Furthermore, the 1H NMR spectrum exhibited series of resonances at δH = 0.88 (3H, t, J = 6.0 Hz), 1.26 (brs) and 2.27 (2H, t, J =7.5 Hz) which could be assigned to protons of a long alkyl chain. The 13C NMR (Table 1) and DEPT spectra of compound 1 displayed resonances characteristic of a single double bond (δC 128.2 and 169.6), one conjugated ketone carbonyl (δC = 199.7), one oxymethine (δC = 80.2), and one oxymethylene (δC = 69.5). The 13C NMR also confirmed the presence of the long chain acyl ester with the carbon resonances at δC = 173.5 (-COOR), 29.8 [(CH2)n] and 14.0 (CH3). The 13C NMR spectrum also displayed eight resonances typical for eight methyl groups, from which seven could be assigned to the triterpene pattern (δC = 16.3, 16.6, 18.6, 22.8, 23.2, 29.3 and 32.7) and one to a terminal methyl of the long acyl chain (δC = 14.0). On the basis of these NMR data, compound 1 was assumed to be a fatty acid ester of an olean-12-ene-type triterpenoid with one hydroxyl group and one α,β-unsaturated ketone group (12,18). The location of the ketone carbonyl at C-11 was deduced from the correlations observed in the HMBC spectrum between the olefinic proton H-12 (δH 5.52) and the carbons C-9 (δC 61.7), C-11 (δC 199.7) on one hand and between H-9 (δH 2.37) and the carbonyl carbon C-11 (δC 199.7) (Figure 1) on the other hand. According to these findings, the triterpenoid moiety of 1 was identified as being 11-oxoerythrodiol (2) (19). The ester function at the C-3 position was deduced from the correlation observed in the HMBC spectrum between H-3 (δH 4.47) and the ester carbonyl carbon (δC 173.5). The length of the acyl chain ester was deduced from the MS/MSn spectrum which exhibits the characteristic ion peaks at m/z 677.58 [M–H2O]+, m/z = 665.59 [M–CH2O]+, and m/z = 439.36 [M–C16H31O2]+ (Figure 2). The axial orientation of the H-3 proton was deduced from the coupling constants with protons H-2 (δH3= 4.47, dd, J = 4.4 and 12.0 Hz) (17). Thus, the structure of compound 1 was unambiguously assigned to 3β-hexadecanoyloxy-28-hydroxyolean-12-en-11-one, named procerenone.


Procerenone: a Fatty Acid Triterpenoid from the Fruit Pericarp of Omphalocarpum procerum (Sapotaceae).

Ngamgwe RF, Yankam R, Chouna JR, Lanz C, Furrer J, Schürch S, Kaiser M, Lenta BN, Ngouela S, Tsamo E, Brenneisen R - Iran J Pharm Res (2014)

Fragmentation patterns of compound 1.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4232810&req=5

Figure 2: Fragmentation patterns of compound 1.
Mentions: Compound (1) was obtained as a white powder. It gave a positive reaction to Liebermann-Burchard test, as usual for a triterpenoid. Its molecular formula C46H78O4, with eight double bond equivalents, was deduced from the HRESIMS spectrum which showed the pseudo-molecular ion peak [M+H]+ at m/z = 695.5955 (calcd. m/z = 695.5973 for C46H79O4). The IR spectrum showed characteristic absorption bands at 3447 (OH), 1651 and 1698 (α,β-unsaturated ketone), and 1613 (C = C) cm-1. The 1H NMR spectrum (Table 1) revealed the presence of seven singlet resonances due to seven angular triterpenoids methyl protons (δH = 0.86, 0.90, 1.10, 1.14, 1.29, 1.39 and 1.59), a singlet of one methine proton (δH = 2.37) and one singlet of an olefinic proton (δH = 5.52). This spectrum also exhibited two doublets typical of an AB system (δH = 3.45 and 3.20, J = 10.8 Hz) and one doublet of doublets (δH = 4.47, J = 4.8, 12 Hz). Furthermore, the 1H NMR spectrum exhibited series of resonances at δH = 0.88 (3H, t, J = 6.0 Hz), 1.26 (brs) and 2.27 (2H, t, J =7.5 Hz) which could be assigned to protons of a long alkyl chain. The 13C NMR (Table 1) and DEPT spectra of compound 1 displayed resonances characteristic of a single double bond (δC 128.2 and 169.6), one conjugated ketone carbonyl (δC = 199.7), one oxymethine (δC = 80.2), and one oxymethylene (δC = 69.5). The 13C NMR also confirmed the presence of the long chain acyl ester with the carbon resonances at δC = 173.5 (-COOR), 29.8 [(CH2)n] and 14.0 (CH3). The 13C NMR spectrum also displayed eight resonances typical for eight methyl groups, from which seven could be assigned to the triterpene pattern (δC = 16.3, 16.6, 18.6, 22.8, 23.2, 29.3 and 32.7) and one to a terminal methyl of the long acyl chain (δC = 14.0). On the basis of these NMR data, compound 1 was assumed to be a fatty acid ester of an olean-12-ene-type triterpenoid with one hydroxyl group and one α,β-unsaturated ketone group (12,18). The location of the ketone carbonyl at C-11 was deduced from the correlations observed in the HMBC spectrum between the olefinic proton H-12 (δH 5.52) and the carbons C-9 (δC 61.7), C-11 (δC 199.7) on one hand and between H-9 (δH 2.37) and the carbonyl carbon C-11 (δC 199.7) (Figure 1) on the other hand. According to these findings, the triterpenoid moiety of 1 was identified as being 11-oxoerythrodiol (2) (19). The ester function at the C-3 position was deduced from the correlation observed in the HMBC spectrum between H-3 (δH 4.47) and the ester carbonyl carbon (δC 173.5). The length of the acyl chain ester was deduced from the MS/MSn spectrum which exhibits the characteristic ion peaks at m/z 677.58 [M–H2O]+, m/z = 665.59 [M–CH2O]+, and m/z = 439.36 [M–C16H31O2]+ (Figure 2). The axial orientation of the H-3 proton was deduced from the coupling constants with protons H-2 (δH3= 4.47, dd, J = 4.4 and 12.0 Hz) (17). Thus, the structure of compound 1 was unambiguously assigned to 3β-hexadecanoyloxy-28-hydroxyolean-12-en-11-one, named procerenone.

Bottom Line: Phytochemical investigation of a dichloromethane-methanol (1:1) extract of the fruit pericarp of Omphalocarpum procerum which exhibited antiplasmodial activity during preliminary screening led to the isolation of the new fatty ester triterpenoid 3β-hexadecanoyloxy-28-hydroxyolean-12-en-11-one (1), together with five known compounds 2-6.The structure of the new compound as well as those of the known compounds was established by means of spectroscopic methods and by comparison with previously reported data.The tested compounds showed weak to moderate antiprotozoal activity and, no significant effect was detected regarding their cytotoxic potency.

View Article: PubMed Central - PubMed

Affiliation: Department of Organic Chemistry, Faculty of Science, TWAS Research Unit, University of Yaoundé 1, P. O. Box 812, Yaoundé, Cameroon.

ABSTRACT
Phytochemical investigation of a dichloromethane-methanol (1:1) extract of the fruit pericarp of Omphalocarpum procerum which exhibited antiplasmodial activity during preliminary screening led to the isolation of the new fatty ester triterpenoid 3β-hexadecanoyloxy-28-hydroxyolean-12-en-11-one (1), together with five known compounds 2-6. The structure of the new compound as well as those of the known compounds was established by means of spectroscopic methods and by comparison with previously reported data. Compounds 1- 4 were evaluated in-vitro for their cytotoxicity against L6 cell lines and antiprotozoal activities against Plasmodium falciparum, Leishmania donovani, Trypanosoma brucei rhodesiense and Trypanosoma cruzi (species responsible for human malaria, visceral leishmaniasis, African trypanosomiasis and Chagas disease, respectively). The tested compounds showed weak to moderate antiprotozoal activity and, no significant effect was detected regarding their cytotoxic potency.

No MeSH data available.


Related in: MedlinePlus