Cytotoxic polyprenylated phloroglucinol derivatives from Hypericum elodeoides Choisy modulating the transactivation of RXRα.

Hyperelodione D (1), an undescribed polyprenylated phloroglucinol derivative possessing 6/6/5/5 fused tetracyclic core, together with hyperelodiones E-F (2-3), two unreported analogues bearing 6/5/5 fused tricyclic structure, were isolated from Hypericum elodeoides Choisy. Their planar structures were elucidated by spectroscopic analysis (HRESIMS, 1D and 2D NMR) and their absolute configurations were determined by comparison of experimental and calculated ECD data. The cytotoxicity and retinoid X receptor-α (RXRα) related activities of the isolates were evaluated and the plausible biogenetic pathways of 1-3 were proposed.

[Preliminary study on chemical constituents seperated from Cayratia japonica].

OBJECTIVE: To study effective active constituents of Cayratia japonica,a genuine herbal medicine from Fujian. METHOD: Such chromatographic methods as Macroporous, Sephadex LH-20, ODS and normal phase silica gel column chromatography were adopted to separate the chemical components of C. japonica. RESULT: Thirteen compounds were obtained, and their structures were identified by analyzing multiple spectral data as luteolin(1), apigenin(2), triethyl citrate-(3), 3-formylindole(4), esculetin(5), bis(2-ethylhexyl)-phthalate(6), calendin(7), ethyl-trans-3,4-dihydr-oxycinnamate(8), luteolin7-O-D-glucoside(9),5-hydroxy-3,4-dimethyl-5-pentyl-2(5H-furanone(10),ethyl-3,4-dihydroxybenzoate(11), eriodictyol(12) and daucosterol(13). CONCLUSION: Among them, compounds 3-8 and 10-12 were separated from the plant for the first time.

Phenolic glycosides and flavonoids with antioxidant and anticancer activities from Desmodium caudatum.

Descaudatine A (1), an undescribed phenolic glycoside, along with a known analogue (2) and ten flavonoids (3-12), were isolated from the whole plant of Desmodium caudatum. Compounds 1 and 4 exhibited potent antioxidant activities with the IC50 of 58.59 µM and 31.31 µM, respectively, which were approached to that of the positive control Vitamin C (IC50 = 46.32 µM). Meanwhile, 12 showed moderate antioxidant activity with the IC50 of 173.9 µM. Besides, compounds 3 and 6 inhibited the proliferation of HeLa cells with IC50 values of 56.14 µM and 69.04 µM, respectively. Further studies indicated that 3 and 6 could dose-dependently induce PARP cleavage and might trigger caspase-3, 8, 9 activation to induce apoptosis. RXRα is an ideal anticancer target of nuclear receptor. The reporter gene assay of RXRα indicated that 3 and 6 could inhibited the 9-cis-RA induced RXRα transcription in a concentration-dependent manner.

Antifouling activity of simple synthetic diterpenoids against larvae of the barnacle Balanus albicostatus Pilsbry.

Five new pimarane diterpenoids 1-5 were synthesized using ent-8(14)-pimarene-15R,16-diol as starting material. The structures were elucidated by means of extensive NMR and MS analysis. The antifouling activity against larval settlement of the barnacle Balanus albicostatus were evaluated using capsaicin as a positive control. Compounds 1-3 and 5 showed more potent antifouling activity than capsaicin. Compound 5, which exhibited almost the same antifouling activity as starting material, showed better stability than starting material. These compounds all showed antifouling activity in a non-toxic way against larval settlement of the barnacle B. albicostatus. Analysis of structure-activity relationships (SAR) demonstrated that the substituents on the C-15 and C-16 position of pimarane diterpenoid were responsible for the antifouling activity.