Anti-inflammatory triterpenoids from the stems of Microtropis fokienensis.

Three new ursane- and four new oleanane- type triterpenoids 1-7 were isolated, along with six known compounds 8-13, from the methanolic extract of Microtropis fokienensis. All structures were elucidated by mass and NMR spectroscopic methods. The isolates 4-10 and known compounds 14-17 that were previously isolated from this material were evaluated for anti-inflammatory activity based on effects against superoxide anion generation and elastase release by neutrophils in response to fMLP/CB. 11α,30-Dihydroxy-2,3-seco-olean-12-en-2,3-dioic anhydride (7) was the first triterpene anhydride from the genus of Microtropis to have the ring A expanded to a seven-membered ring; it showed significant anti-inflammatory activity against superoxide anion generation and elastase release. Unexpectedly, 30-hydroxy-2,3-seco-lup-20(29)-ene-2,3-dioic acid (17) showed the best effect against superoxide anion generation and elastase release with IC50 values of 0.06±0.01 and 1.03±0.35 µg/mL, respectively. Compound 17 had a dioic acid function, and compound 7 had an anhydride function modification in ring A; both showed promising activity in the target assays.

Anti-neutrophilic inflammatory steroidal glycosides from Solanum torvum.

Torvpregnanosides A and B, two pregnane glycosides, and torvoside Q, a 23-keto-spirostanol glycoside, along with twelve known steroidal saponins were isolated from aerial parts of Solanum torvum. Of the latter, four of the 23-hydroxy-spirostanol glycosides, and, a yamogenin glycoside, were in this plant discovered. All structures were identified from spectroscopic data, and all the compounds were tested for in vitro anti-neutrophilic inflammatory activity. Two compounds showed selective inhibition against elastase release and superoxide anion generation, respectively, by human neutrophils with IC50 values of 5.66 and 3.59 µM, while two others inhibited both inflammatory mediators with IC50 values of 0.66-3.49 µM. Structure-activity relationships are discussed.

Indiosides G-K: steroidal glycosides with cytotoxic and anti-inflammatory activities from Solanum violaceum.

Five new steroidal glycosides (1-5) and nine known compounds were isolated from Solanum violaceum. Indiosides G (1) and H (2) are spirostene saponins with an iso-type F ring, indioside I (3) is a spirostane saponin, and indiosides J (4) and K (5) are unusual furostanol saponins with a deformed F ring. These structures represent rare naturally occurring steroidal skeletons. The structures of the new compounds were elucidated using 1D and 2D spectroscopic techniques and acid hydrolysis. Compounds 2, 3, and 7-9 exhibited cytotoxic activity against six human cancer cell lines (HepG2, Hep3B, A549, Ca9-22, MDA-MB-231, and MCF-7) with IC(50) values of 1.83-8.04 µg/mL. Steroidal saponins 3, 8, and 9 showed inhibitory effects on superoxide anion generation with IC(50) values of 2.84 ± 0.18, 0.62 ± 0.03, and 1.62 ± 0.59 µg/mL, respectively. Saponins 8 and 9 also inhibited elastase release with IC(50) values of 111.05 ± 7.37 and 4.04 ± 0.51 µg/mL, respectively. Structure-activity relationship correlations of these compounds with respect to cytotoxic and anti-inflammatory effects are discussed.

New cytotoxic lupane triterpenes from Perrottetia arisanensis.

Eight new lupane triterpenes, including 7beta-cis-coumaroylbetulinic acid (1), 7beta-trans-coumaroylbetulinic acid (2), 7beta-cis-coumaroyl-3-epi-betulinic acid (3), 7beta-trans-coumaroyl-3-epi-betulinic acid (4), 7beta-cis-coumaroylbetulonic acid (5), 7beta-trans-coumaroylbetulonic acid (6), 7beta-hydroxybetulinaldehyde (7) and 28-norlup-20(29)-ene-3alpha,17beta-diol (8), together with fifteen known compounds were isolated from the bioactive methanol extract of the stems of Perrottetia arisanensis. The structures of the new compounds were elucidated by spectroscopic and HR-ESI-MS analysis. All new compounds were evaluated for their cytotoxicity against six human cancer cell lines. Among them, lupane triterpene coumaroyl esters 1-6 showed moderate cytotoxicity with IC (50) values ranging from 3.75 to 21.29 microM. This is the first report for lupane triterpenes with a phenylpropane moiety substituted at C-7.

Lupane-type triterpenoids from Microtropis fokienensis and Perrottetia arisanensis and the apoptotic effect of 28-hydroxy-3-oxo-lup-20(29)-en-30-al.

Seven new lupane triterpenoids were isolated from bioactive methanol extracts of Microtropis fokienensis (1- 4) and Perrottetia arisanensis (4-7), along with 18 known compounds. The structures of the new compounds were elucidated on the basis of spectroscopic data analysis. All triterpenoids were evaluated for their in vitro cytotoxicity toward seven human cancer cell lines. Compound 8 (28-hydroxy-3-oxo-lup-20(29)-en-30-al) was among the most cytotoxic substances obtained and was found to induce apoptosis of human leukemia HL60 cells and mediate cleavage of PARP and up-regulation of Bax proteins.

Cytotoxic ent-abietane diterpenes from Gelonium aequoreum.

Seventeen ent-abietane diterpenes, including gelomulides K-X (1-14), and three known compounds, were isolated from a dichloromethane-soluble extract of Gelonium aequoreum through bioassay-guided fractionation. Their structures were identified by spectroscopic methods, and stereochemistry was confirmed by X-ray crystallographic analysis, CD spectral data, and Mosher's method. The isolates were evaluated for in vitro cytotoxic activity, and compounds 1 and 3 showed moderate cytotoxicity against lung (A549), breast (MDA-MB-231 and MCF7), and liver (HepG2) cancer cell lines.

Cytotoxic withanolides from Tubocapsicum anomalum.

Fifteen new withanolides (1-8, 11-17) and two known withanolides, withanolide D (9) and 17alpha-hydroxywithanolide D (10), were isolated from the stems, roots, and leaves of Tubocapsicum anomalum using bioassay-directed fractionation. The structures were determined by spectroscopic and chemical methods, and the absolute configurations were established by CD analysis and by the Mosher ester method. The structure of 1 and 3 were further confirmed by X-ray crystallographic analysis. Compounds 1, 4-6, 8-10, and 13 showed significant cytotoxic activity against Hep G2, Hep 3B, A-549, MDA-MB-231, MCF-7, and MRC-5 cell lines.

Novel flavonoids of Thelypteris torresiana.

In our continuing research on cytotoxic components from the Formosan pteridophyte Thelypteris torresiana (GAUD.) ALSTONONE, two new compounds, a novel flavonoid, flavotorresin (1), and a flavonoid diglycoside, multiflorin C (2), along with five known compounds, were isolated. The structural elucidation was established on the basis of spectroscopic data analysis. The possible biosynthetic pathway of the flavonoids from this fern is summarized.

Cytotoxic triterpenoids from the leaves of Microtropis fokienensis.

Five new triterpenoids, microfokienoxanes A-D (1-4) and 3beta,28-dihydroxy-11alpha-methoxyurs-12-ene (5), were isolated and identified from the leaves of Microtropis fokienensis, along with nine known compounds. The structures of the new compounds were elucidated by spectroscopic methods. The compounds obtained in this investigation were evaluated against a small panel of human cancer cell lines for cytotoxicity. Only compounds 3 and 5 exhibited cytotoxicity (IC50 < or = 5 microg/mL) for one or more cell lines.

Longicalycinin A, a new cytotoxic cyclic peptide from Dianthus superbus var. longicalycinus (MAXIM.) WILL.

A new cyclic peptide, longicalycinin A (1), and six known compounds, vaccaroside A, dianoside A, dianoside G, 3-(4-hydroxy-3-methoxy-phenyl)propionic acid methyl ester, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde were isolated from the MeOH extract of Dianthus superbus var. longicalycinus. The amino acid sequences of 1 was elucidated as cyclo(Gly(1)-Phe(2)-Tyr(3)-Pro(4)-Phe(5)-) on the basis of ESI tandem mass fragmentation analysis, chemical evidence, and extensive 2D NMR methods. Furthermore, compound 1 showed cytotoxicity to Hep G2 cancer cell line.