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Two new highly rearranged trichiliton-type limonoids (trichilitons G-H, 1-2), and two new cycloartane-type triterpenoids, 21-(E)-coumaroyloxy-5α-cycloart-24-ene-3,23-dione (3) and 21-(E)-feruloyloxy-5α-cycloart-24-ene-3,23-dione (4), were isolated from the stem and bark of Trichilia connaroides. These isolates were elucidated on the basis of detailed spectroscopic analysis, and inhibitory effect of these compounds on lipopolysaccharide-induced nitric oxide production in mouse macrophage RAW264.7 cells was evaluated.

Two new apo-tirucallane triterpenoids with six-membered hemiketal, polystanins A (1) and B (2), and two new tirucallane triterpenoids, polystanins C (3) and D (4) were isolated from the fruits of Aphanamixis polystachya. They were elucidated on the basis of detailed spectroscopic analysis including IR, high resolution-electrospray ionization (HR-ESI)-MS, 1 dimensional (1D)- and 2D-NMR. Their absolute configurations were determined by a combination of modified Mosher's method, and electronic circular dichroism (ECD) calculation.

A series of novel and structurally related C-15-acyl 16-norphragmalin-type limonoids, chuktabrins C-J (1-8) and chuktabularins U-X (9-12), were isolated from the stem bark of Chukrasia tabularis var. velutina. Their structures were established on the basis of detailed spectroscopic analysis, and the absolute configuration of compound 1 was determined by a single-crystal X-ray study using a mirror CuKα radiation. Compounds 7 and 8 were unprecedent C-15-acyl 16-norphragmalins with ketonic alkyl appendage at C-15, and compounds 4 and 8 were first examples of limonoid with a characteristic carbonate moiety esterified at OH-9/OH-8 or OH-1/OH-8 respectively. A biosynthetic pathway of these limonoids was reasonably presumed based on the novel and diverse structures isolated, which provides a new insight into the plausible biosynthesis of C-15-acyl 16-norphragmalin-type limonoids. The anti-inflammatory activity of major isolates were evaluated for inhibitory activity against lipopolysaccharide (LPS) induced nitric oxide (NO) production in macrophage (RAW264.7) cell line, with IC(50) value ranging from 2.40 to 16.90 μM.

One new disesquiterpenoid (1), two new sesquiterpenoids (2, 3), were isolated from the dry flos of Chrysanthemum indicum. The structures were elucidated by spectroscopic analysis, the absolute configurations of 1 and 3, were determined by single X-ray diffraction study.

A series of tirucallane triterpenoids isolated from the stem barks of Aphanamixis grandifolia were assessed for their anti-inflammatory activity, exhibiting from weak to strong anti-inflammatory activity, by testing their inhibitory effects on nitric oxide (NO) production and tumor necrosis factor-α (TNF-α) level in lipopolysaccharide (LPS) induced RAW264.7 murine macrophages. To explore the relationship between the structures and anti-inflammatory activity, a vast pool of molecular descriptors for each isolate were calculated. Genetic algorithms (GA) or simulated annealing (SA) based partial least squares (GA-PLS and SA-PLS) algorithms identified some important descriptor combinations, which were correlated with both sets of the anti-inflammatory data by partial least squares 2 (PLS2) method. S-Plot was used to visualize the descriptor influence in the PLS2 model, disclosed five most important molecular descriptors, nOHt, RDF150m, lip_violation, Mor32m and JhetZ.

Four novel nortriterpenoids, 24,25-epoxy-tirucall-7,20(E)-diene-3,23-dione (1), 24,25,26,27-tetranortirucall-1,7-diene-23(21)-lactone (2), 3α-hydroxy-tirucall-7-ene-20-one (3), and 3-oxo-tirucall-7-ene-3,20-dione (4), together with one known compound mombasol (5) were isolated from the stem barks of Aphanamixis grandifolia. Their structures were elucidated on the basis of various spectroscopic analysis including electrospray ionization (ESI)-MS, high resolution (HR)-ESI-MS, IR, 1D- and 2D-NMR techniques (heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and rotating frame Overhauser enhancement spectroscopy (ROESY)), and by comparison of their spectral data with those reported. The absolute configuration of compound 1 was determined by circular dichroism (CD) exciton chirality.

Two new norsesquiterpenoids, oxyphyllenotriol A (1) and oxyphyllone G (2), and two new sesquiterpenoids, oxyphyllol D (3) and oxyphyllol E (4), together with two known compounds (5, 6) were isolated from the fruits of Alpinia oxyphylla. Their structures were determined on the basis of spectroscopic analysis, including high resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1D- and 2D-NMR, and the absolute configurations of 2 and 4 were determined by theoretical calculation of electronic circular dichroism (ECD) and comparison with the experimental ECD spectra.

Nine new phragmalin-type limonoid orthoesters, tabulalides F-N (1-9), together with three known compounds, tabulalides C and D, and tabularisin N (10-12), were isolated from the stem bark of Chukrasia tabularis var. velutina. Extensive spectroscopic technologies were applied to elucidate the structures of these new compounds, including the application of circular dichroism (CD) exciton chirality method for the determination of the absolute configurations of 1 and 2. Tabulalide F (1) has a rare orthoisobutylate moiety in phragmalin-type limonoid orthoesters. These compounds were evaluated for cytotoxic activity against five human cancer cell lines in vitro. Tabulalide G (2) exhibits moderate cytotoxic activity against MCF-7 with IC(50) value of 20.4 µmol/l, and other compounds have weak inhibitory effects on the growth of tested tumor cells.