Six new compounds from the heartwood of Diospyros maritima

Anti-Adipogenic Activity of Secondary Metabolites Isolated from Smilax sieboldii Miq. on 3T3-L1 Adipocytes

Smilax sieboldii, a climbing tree belonging to Smilacaceae, has been used in traditional oriental medicine for treating arthritis, tumors, leprosy, psoriasis, and lumbago. To evaluate the anti-obesity effects of S. sieboldii (Smilacaceae), we screened methylene chloride (CH₂Cl₂), ethyl acetate (EtOAc), aqueous-saturated n-butanol, and ethanol (EtOH) extracts of the whole plant at various concentrations to inhibit adipogenesis in adipocytes. The 3T3-L1 cell line with Oil red O staining with the help of fluorometry was used as an indicator of anti-obesity activity. Bioactivity-guided fractionation of the EtOH extract and subsequent phytochemical investigation of the active CH₂Cl₂- and EtOAc-soluble fractions resulted in the isolation of 19 secondary metabolites (1-19), including a new α-hydroxy acid derivative (16) and two new lanostane-type triterpenoids (17 and 18). The structures of these compounds were characterized using various spectroscopic methods. All the isolated compounds were screened for adipogenesis inhibition at a concentration of 100 μM. Of these, compounds 1, 2, 4-9, 15, and 19 significantly reduced fat accumulation in 3T3-L1 adipocytes, especially compounds 4, 7, 9, and 19, showing 37.05 ± 0.95, 8.60 ± 0.41 15.82 ± 1.23, and 17.73 ± 1.28% lipid content, respectively, at a concentration of 100 μM. These findings provide experimental evidence that isolates from S. sieboldii extracts exert beneficial effects regarding the regulation of adipocyte differentiation.

Chemical constituents from Phyllanthus emblica and the cytoprotective effects on H2O2-induced PC12 cell injuries

Two new compounds (1-2), including a bisabolane-type sesquiterpenoid (1), one new diphenyl ether derivative (2), together with 23 known compounds (3-25), were isolated from the fruits of Phyllanthus emblica. Their structures were elucidated by detailed spectroscopic analysis. All the isolated compounds were screened for the DPPH scavenging effects and cytoprotective effects against H2O2 induced PC12 cells injury. Compounds 12-15 showed significant DPPH scavenging effects with the IC50 values in the range of 3.25-4.18 μM. Among these potential antioxidants, compound 14 improved the survival of PC12 cells after H2O2 exposure without showing any cytotoxicity at the tested concentrations.

Chemical constituents from the stems of Diospyros maritima

A new phenolic, bis(6-hydroxy-2,3,4-trimethoxylphen-1-yl)methane (1) and a new butanedioate, butylmethyl succinate (2), along with twenty-nine known compounds including one naphthoquinone derivative, two chromanones, eight benzenoids, one lignan, one tocopherol, and sixteen triterpenoids were isolated from the stems of Diospyros maritima. epi-Isoshinanolone (3) was isolated in pure form for the first time. In addition, 5,7-dihydroxy-2-methylchomanone (4) was isolated from a natural source for the first time. Their structures were established on the basis of spectroscopic data as well as direct comparison with authentic samples.

Secondary Metabolites from the Liverwort Ptilidium pulcherrimum

A new trinortriterpenoid, diospyrolide acetate (1) and a new diphenylmethane derivative, pulcherrimumin (12), together with ten known pentacyclic triterpenoids (2–11) and four aromatic compounds (13–16), were isolated from the liverwort Ptilidium pulcherrimum. Their structures were established on the basis of extensive analysis of NMR data and by chemical methods. The cytotoxicity of compounds 1–16 was evaluated against the PC3, MDA-MB-231, and Hela cells lines. Ursane triterpenoids 8–10 exhibited moderate cytotoxicity against PC3 cells with IC50 values ranging from 10.1 to 39.7 μM.

Two new naphthoquinones from the stem of Diospyros maritima

Two new naphthoquinones, 2-ethoxy-8'-hydroxyisodiospyrin (1) and 3-ethoxy-8'-hydroxyisodiospyrin (2), together with two known naphthoquinones, 6-hydroxy-5-methoxy-2-methyl-1,4-naphthoquinone and bisisodiospyrin were isolated from the stems of Diospyros maritima. The structures of 1 and 2 were established on the basis of spectroscopic data.

Lanostane-Type Triterpenoids from Diospyros discolor

Four new lanostane-type triterpenes, 24-ethyl-3beta-methoxylanost-9(11)-en-25-ol (1), 3beta-methoxy-24-methylenelanost-9(11)-en-25-ol (2), 3beta-methoxy-25-methyl-24-methylenelanost-9(11)-en-21-ol (3) and 3beta-methoxy-24-methyllanosta-9(11),25-dien-24-ol (4) together with three known triterpenes, betulinaldehyde, betulinic acid methyl ester, and ursaldehyde have been isolated from the methanol extract of the twigs of Diospyros discolor. The structures of those new compounds were elucidated by spectroscopic methods.