Zhong-Rong Li

Kuguacins F-S, cucurbitane triterpenoids from Momordica charantia.

Chemical investigation of the vines and leaves of Momordica charantia resulted in isolation of fourteen cucurbitane triterpenoids, kuguacins F-S (1-14), including two pentanorcucurbitacins (6 and 7), one octanorcucurbitacin (8), and two trinorcucurbitacins (11 and 12), along with six known analogues. Their structures were elucidated on the basis of extensive spectroscopic and single-crystal X-ray diffraction analyses. Compounds 1-14 exhibited weak anti-HIV-1 activities in vitro.

Cytotoxicity of naturally occurring rhamnofolane diterpenes from Jatropha curcas

Twelve rhamnofolane diterpenoids, including curcusecons A-E with unusual seco-rhamnofolane skeletons, curcusones F-J, 4-epi-curcusone E, and 3-dehydroxy-2-epi-caniojane, together with seven known analogues, curcusones A-E, jatrogrossidione, and 2-epi-jatrogrossidione, were isolated from the roots of Jatropha curcas. Their structures were determined by extensive spectroscopic methods, and the relative stereochemistry of curcusecon B was further confirmed by X-ray crystallographic data. Their cytotoxity against five human cancer cells was studied and the results indicated that the dienone system in ring B was essential for cytotoxicity of these compounds.

Rational design and synthesis of highly potent anti-acetylcholinesterase activity huperzine A derivatives

By targeting multi-active sites of acetylcholinesterase (AChE), a series of huperzine A (Hup A) derivatives with various aromatic ring groups were designed and synthesized by Schiff reaction. They were evaluated as AChE and butyrylcholinesterase (BChE) inhibitors. Results showed very significant specificity that the group of imine derivatives could inhibit TcAChE and hAChE, but no inhibitory effect on hBChE was detected. The experiment was explained by a docking study. In the docking model, we confirmed that aromatic ring of Hup A derivatives played the pi-pi stacking against aminophenol residues of AChE, and the structure-activity relationship (SAR) was discussed.

Antioxidant farnesylated hydroquinones from Ganoderma capense.

Phytochemical investigation of the fruiting bodies of Ganoderma capense led to isolation of eight aromatic meroterpenoids (1-8). Ganocapensins A and B (1, 2) possessed a thirteen-membered and a fourteen-membered ether rings, respectively. The structures of new isolates including absolute configuration were elucidated on the basis of extensive spectroscopic technologies and Moshers method. All isolated compounds showed significant antioxidant effects with IC50 values ranging from 6.00±0.11 to 8.20±0.30μg/ml in the DPPH radical scavenging assay.

Cytotoxic diterpenoids from Jatropha curcas cv. nigroviensrugosus CY Yang Roots

An investigation of phytochemicals from the roots of Jatropha curcas cv. nigroviensrugosus resulted in the isolation of twenty diterpenoids, including lathyranlactone, an unusual diterpenoid lactone possessing a 5/13/3 tricyclic skeleton, jatrocurcasenones A-E and jatrophodiones B-E, as well as 10 known analogues. All isolates were evaluated for cytotoxicity against the HL-60, SMMC-772, A-549, MCF-7 and SW480 human tumor cell lines using the MTS viability assay. Four of the known analogues showed cytotoxic activity in these cell lines, with IC50 values ranging from 2.0 to 23.0 μM. Moreover, the assessment of their cytotoxic structure-activity relationships showed the epoxy ring between C-5 and C-6 and the hydroxyl group at C-2 were the key functionalities for cytotoxicity.

Diterpenoids and Limonoids from the Leaves and Twigs of Swietenia mahagoni

Three new compounds, including two diterpenoids, nemoralisins H and I (1 and 2), and a limonoid, 2-methoxy khayseneganin E (3), along with four known constituents (4–7), were isolated from the leaves and twigs of Swietenia mahagoni. Their chemical structures were elucidated by means of spectroscopic analysis. The cytotoxities of these isolated constituents were assayed.

New jatropholane-type diterpenes from Jatropha curcas cv. Multiflorum CY Yang

Three new jatropholane-type diterpenoids, jatropholones C-E (1–3), along with seven other known compounds, including sikkimenoid B (4), jatrophaldehyde (5), epi-jatrophaldehyde (6), epi-jatrophol (7), jatrophol (8), jatropholone A (9), and jatropholone B (10), were isolated from the roots of a natural cultivar of Jatropha curcas (J. curcas cv. Multiflorum CY Yang). The structural elucidations of 1–3 were accomplished by extensive NMR analysis. Compounds 4, 6, and 8 demonstrated inhibition activity against the microorganisms with the MIC values from 0.10 to 0.18 mg/mL.

New eudesmenoic acid methyl esters from the seed oil of Jatropha curcas.

Three new eudesmenoic acid methyl esters (1-3), as well as five known compounds, including three germacranolides (4-6) and two eudesmanolides (7 and 8), were isolated from the seed oil of Jatropha curcas. The new compounds were elucidated by means of spectroscopic methods, including extensive NMR spectra. In addition, the structure of 8 was confirmed by a single-crystal X-ray diffraction analysis. Among the isolates, compounds 4-6 were the first reported from the genus Jatropha. Using MTS viability assay, the cytotoxicity of compounds 2-8 were evaluated against HL-60, SMMC-7721, A-549, MCF-7, and SW480 human tumor cell lines. Compounds 4 and 5 showed remarkable cytotoxicity against all the tested cell lines with IC50 values from 0.5 to 3.5 μM, and the new compound 3 displayed selective cytotoxic activity against A-549 cell with an IC50 value of 7.24 μM, but slight cytotoxicity against HL-60 and MCF-7 with IC50 values of 23.77 and 22.37 μM, respectively.

Characterization of New Ent-kaurane Diterpenoids of Yunnan Arabica Coffee Beans

Abstract Five new ent-kaurane diterpenoids, named mascaroside III–V (1–3), and 20-nor-cofaryloside I–II (4–5), together with seven known diterpenoids, were isolated from methanol extracts of the green coffee beans of Yunnan Arabica Coffee. Their chemical structures were elucidated by extensive spectroscopic analyses. Meanwhile, cytotoxicity assay against HL-60, A-549, SMMC-7721, MCF-7 and SW480 cell lines showed that they have not evident inhibition of cytotoxicity.Graphical Abstract

New triterpenoids from the kernels of Azadirachta indica

Three new limonoids (1–3) and a new intact triterpenoid (4), along with three known constituents (5–7), were isolated from the dried kernels (after extracting azadirachtin) of Azadirachta indica. The structures of the new compounds 1-benzoyl-3-deacetyl-1-detigloyl salannin (1), 7-tigloyl-12-oxo vilasini (2), azadiralactone (3) and azadirahemiacetal (4) were elucidated by means of spectroscopic analysis. The cytotoxities of these isolated constituents were assayed.Graphical abstract