Chemical constituents and their biological activities from the roots of diospyros filipendula

Abstract

Phytochemical investigation of Diospyros filipendula (Ebenaceae) resulted in the isolation of eighteen compounds. Their structures were identified by analysis of mass spectrometric and spectroscopic (IR, 1D and 2D NMR) data. We report three benzoic acid derivatives (1-3), one peptide (4), one coumarin (5), three phthalides (6-8), three steroids (9-11) and seven triterpenes (12-18). Nine compounds (1, 4-8, 10, 17 and 18) are reported from the Ebenaceae family for the first time while the other nine are new to the species D. filipendula.Compounds 7, 17 and 18 showed low to moderate cytotoxicity against NCI-H187 and Vero cell lines while compound 18 showed moderate cytotoxicity against KB cell line. In addition, compounds 17 and 18 showed moderate to significant antimalarial activity against Plasmodium falciparum.

Isolation and Characterization of Triterpenoids from the Stem of Diospyros gracilis

“…All of them gave a positive result for Liebermann-Burchard test, implying the triterpenoid or steroid nature. Analysis of their 1 H-and 13 C-NMR spectral data, confirmed by comparison with the previously reported values [6 -10], revealed that the isolated compounds were all pentacyclic triterpenoids. Compounds 1 and 2 were identified as friedelin [6] and epifriedelanol [6] of the friedelane type, and 3 -6 as lupeol [7], betulin [8], betulinic acid [9] and betulinaldehyde [10] of the lupane type, respectively.…”

“…The carbon signal due to the methyl group at C-4, the most upfield signal, was observed at δ 11.6 (C-23). This signal was significantly more downfield than the corresponding signal in the 13 C-NMR spectrum of 1 owing to the different substituents at C-3.…”

“…Compound 4, betulin, is a derivative of 3 which contains a primary alcoholic group at C-17 instead of the methyl group. This feature was represented by a pair of one-proton signals at δ 3.35 (d, J = 10.8 Hz, H-28a) and 3.82 (dd, J = 10.8, 1.6 Hz, H-28b) in the 1 H-NMR spectrum and the hydroxymethylene signal at δ 60.5 in the 13 C-NMR spectrum. Compounds 5 and 6, betulinic acid and betulinaldehyde, have structures similar to that of 3 except that the methyl group at C-17 of 3 is replaced by the carboxyl and formyl groups, respectively.…”

“…The friedelane skeleton of the compound contains one secondary and seven tertiary methyls which could be observed in the 1 H-NMR spectrum as one doublet at δ 0.90 (J = 6.4 Hz, Me-23) and seven singlets at δ 0.74 (Me-24), 0.89 (Me-25), 0.97 (Me-29), 1.02 (Me-26), 1.03 (Me-30), 1.07 (Me-27), 1.20 (Me-28), respectively. In the 13 C-NMR spectrum, the most downfield signal at δ 213.3 was indicative of the 3keto group while the most upfield signal at δ 6.8 (C-23) represented the secondary methyl group at C-4.…”

“…This study, dealing with phytochemical investigation on the stem of the plant, led to the isolation of six triterpenoids, namely friedelin (1), epifriedelanol (2), lupeol (3), betulin (4), betulinic acid (5), and betulinaldehyde (6). Epifriedelanol (2): white amorphous powder (methanol), IR  max cm -1 : 3400, 2924, 2851, 1449, 1386; Hz, H-28); 13 C-NMR (CDCl 3 , 100 MHz): see Table 1.…”