Cytotoxic and Anti-Inflammatory Triterpenoids in the Vines and Leaves of Momordica charantia.

The vines and leaves of Momordica charantia L. are used as herbal medicines to treat inflammation-related disorders. However, their safety profile remains uncharacterized, and the constituents in their extracts that exert anti-inflammatory and adverse effects remain unclear. This study isolated the characteristic cucurbitane-type triterpenoid species in the vines and leaves of M. charantia L. and analyzed their cytotoxicity, anti-inflammatory effects, and underlying mechanisms. Four structurally related triterpenoids-momordicines I, II, IV, and (23E) 3ß,7ß,25-trihydroxycucurbita-5,23-dien-19-al (TCD)-were isolated from the triterpenoid-rich fractions of extracts from the vines and leaves of M. charantia. Momordicine I was cytotoxic on normal cells, momordicine II exerted milder cytotoxicity, and momordicine IV and TCD had no obvious adverse effects on cell growth. TCD had anti-inflammatory activity both in vivo and in vitro. In lipopolysaccharide-stimulated RAW 264.7 cells, TCD inhibited the inhibitor kappa B kinase/nuclear factor-κB pathway and enhanced the expression of nuclear factor erythroid 2-related factor 2, heme oxygenase-1, and glutamate-cysteine ligase modifier subunit through the extracellular signal-regulated kinase1/2 and p38. Thus, the vines and leaves of M. charantia should be used with caution. An extraction protocol that can enrich TCD but remove momordicine I would likely enhance the safety of the extract.

Bitter Melon Extract Yields Multiple Effects on Intestinal Epithelial Cells and Likely Contributes to Anti-diabetic Functions.

The intestines have been recognized as important tissues for metabolic regulation, including glycemic control, but their vital role in promoting the anti-diabetic effects of bitter melon, the fruit of Momordica charantia L, has seldom been characterized, nor acknowledged. Evidence suggests that bitter melon constituents can have substantial interactions with the intestinal epithelial cells before circulating to other tissues. We therefore characterized the effects of bitter melon extract (BME) on intestinal epithelial cells. BME was found to contain substantial amounts of carbohydrates, proteins, and triterpenoids. TNF-α induced insulin resistance in an enterocyte cell line of IEC-18 cells, and BME promoted glucose utilization of the insulin-resistant cells. Further analysis suggested that the increased glucose consumption was a result of the combined effects of insulin sensitizing and insulin substitution functions of BME. The functions of insulin substitution were likely generated due to the activation of AMP-activated protein kinase. Meanwhile, BME acted as a glucagon-like peptide 1 (GLP-1) secretagogue on enteroendocrine cells, which may be mediated by the activation of bitter-taste receptors. Therefore, BME possesses insulin sensitizing, insulin substitution, and GLP-1 secretagogue functions upon intestinal cells. These effects of BME on intestinal cells likely play a significant part in the anti-diabetic action of bitter melon.

Mollisolactones A and B, novel dinormonoterpenes from the soft coral Sinularia mollis.

Two novel dinormonoterpenes, designated as mollisolactones A and B, were discovered from the soft coral Sinularia mollis on the basis of a chromatographic and NMR spectroscopy-based fractionation. Their structures were solved through analysis of comprehensive 1D and 2D NMR spectroscopic data and HRESIMS experiments. The biological activities of the obtained metabolites were evaluated for cytotoxicity against A-459 (human lung carcinoma), HT-29 (human colon adenocarcinoma), and P-388 (mouse lymphocytic leukemia) cancer cell lines as well as antiviral activity against HCMV (human cytomegalovirus).

Sandensone A, a novel sesquiterpenoid from the Formosan soft coral Sinularia sandensis.

A chromatographic and NMR spectroscopy-based fractionation on the acetone extracts of the soft coral Sinularia sandensis led to the isolation of a novel sesquiterpenoid, sandensone A (1). The structure of 1 was elucidated based on comprehensive 1D and 2D NMR spectroscopic data as well as HRESIMS spectrometry. The absolute configuration at C-12 of 1 was determined as R using a modified Mosher's method. The cytotoxicity against A549 (human lung carcinoma), HT-29 (human colon adenocarcinoma), and P-388 (mouse lymphocytic leukemia) cancer cell lines as well as antiviral activity against HCMV (human cytomegalovirus) were evaluated in vitro.

Polyoxygenated cembrane diterpenoids from the soft coral Sarcophyton ehrenbergi.

Five new polyoxygenated cembranoids, named (+)-1,15-epoxy-2-methoxy-12-methoxycarbonyl-11E-sarcophytoxide (1), (+)-2-epi-12-methoxycarbonyl-11E-sarcophine (2), 3,4-epoxyehrenberoxide A (3), ehrenbergol D (4) and ehrenbergol E (5), were obtained from the soft coral Sarcophyton ehrenbergi. The structures of 1-5 were established on the basis of comprehensive NMR and HR-ESI-MS analyses and by comparison with reported data in the literature. Compounds 4 and 5 showed moderate cytotoxicity against P-388 (mouse lymphocytic leukemia) cancer cell line with EC50 values of 2.0 and 3.0 µM, respectively. Compound 2 exhibited slight antiviral activity against HCMV (human cytomegalovirus) with IC50 values of 25.0 µg/mL.

Sinugyrosanolide A, an unprecedented C-4 norcembranoid, from the Formosan soft coral Sinularia gyrosa.

Chemical investigations on the acetone extract of the Formosan soft coral Sinularia gyrosa have obtained a novel C-4 norcembranoid possessing an unprecedented tricyclo[9.3.0.0(3,8)]tetradecane skeleton, namely sinugyrosanolide A. The NMR spectroscopic data of the novel norcembranoid were completely assigned by using a combination of 2D NMR experiments including (1)H-(1)H COSY, HSQC, HMBC, and NOESY. The cytotoxicities, anti-HCMV (human cytomegalovirus) endonuclease activities and antibacterial activities were evaluated in vitro. It showed moderate cytotoxicity against P-388 (mouse lymphocytic leukemia) cancer cell line with an EC50 of 11.8µM.

Kelsoenethiol and dikelsoenyl ether, two unique kelsoane-type sesquiterpenes, from the Formosan soft coral Nephthea erecta.

Two new kelsoane-type sesquiterpenes, namely kelsoenethiol (1) and dikelsoenyl ether (2), were obtained from the Formosan soft coral Nephthea erecta. Their structures were elucidated through extensive spectroscopic analyses, ESI orbitrap mass and quantum chemical calculations (QCC). The cytotoxicity against A-459 (human lung carcinoma), P-388 (mouse lymphocytic leukemia), and HT-29 (human colon adenocarcinoma) cancer cell lines of 1 and 2 was evaluated in vitro. Compound 1 showed cytotoxicity against P-388 and HT-29 cells with ED50s of 1.3 and 1.8 µg/mL, respectively.

Secocrassumol, a seco-cembranoid from the Dongsha Atoll soft coral Lobophytum crassum.

Chemical investigations on the Dongsha Atoll soft coral Lobophytum crassum led to the purification of a new seco-cembranoid, secocrassumol. The structural elucidation was established by extensive NMR, HRESIMS and CD data. The absolute configuration at C-12 was determined as S using a modified Mosher's acylation. Secocrassumol differs from previously known marine seco-cembranoid in that it possesses an unprecedented skeleton functionalized at C11-C12 bond cleavage. Secocrassumol showed antiviral activity against human cytomegalovirus (HCMV) with an IC50 value of 5.0 µg/mL.

Biological activity of oleanane triterpene derivatives obtained by chemical derivatization.

Nine new derivatives of oleanane triterpenoids isolated from Fatsia polycarpa Hayata were synthesized through chemical transformations. Acetylation was effected by reaction with acetic anhydride in pyridine to afford compounds 1-5, while compound 6 was obtained using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) in CH2Cl2. The others derivatives 7-9 were obtained in reactions of the corresponding triterpenoids with EDC·HCl, 4-N,N-dimethylaminopyridine hydrochloride and 4-N,N-dimethylaminopyridine in CH2Cl2. The structures of 1-9 were elucidated from extensive spectroscopic and HRESIMS data, while the structure of 9 was further confirmed by X-ray diffraction analysis. The cytotoxic, anti-hepatitis B virus (HBV), antibacterial, hypoglycaemic and Wnt signaling activities of these derivatives were evaluated in vitro.

Oleanane-type triterpenoids from the leaves and twigs of Fatsia polycarpa.

Seven new oleanane-type triterpenoids (1-7), named fatsicarpains A-G, and the known compounds 3α-hydroxyolean-11,13(18)-dien-28-oic acid (8) and 3α-hydroxyolean-11-en-28,13ß-olide (9) were isolated from the leaves and twigs of Fatsia polycarpa on the basis of bioassay-guided fractionation. The structures of compounds 1-7 were elucidated through spectroscopic analyses and single-crystal X-ray crystallography of 1, 8, and 9. Cytotoxicity against HepG2 2.2.15 and AGS cells and antihepatitis B virus (HBV) and antibacterial activities of 1-9 were also evaluated in vitro.

New cembranolides from the Dongsha Atoll soft coral Lobophytum durum.

Chemical investigations of the Dongsha Atoll soft coral Lobophytum durum resulted in the isolation of five new cembranolides, durumolides M-Q (1-5). The structures of compounds 1-5 were characterized by the interpretation of extensive spectroscopic analysis. Compound 4 exhibited cytotoxicity against P-388 (mouse lymphocytic leukemia) cell line with an ED50 of 3.8 µg/mL. Moreover, compound 5 showed significant antiviral activity against human cytomegalovirus with an IC50 of 5.2 µg/mL.

Capilloquinol: a novel farnesyl quinol from the Dongsha atoll soft coral Sinularia capillosa.

Capilloquinol (1), possessing an unprecedented farnesyl quinoid skeleton, was isolated from the Dongsha Atoll soft coral Sinularia capillosa. The structure of capilloquinol was elucidated by extensive analysis of spectroscopic data. The cytotoxicity and antiviral activity against human cytomegalovirus of 1 was evaluated in vitro.

Bioactive norditerpenoids from the soft coral Sinularia gyrosa.

Chemical investigations of the soft coral Sinularia gyrosa resulted in the isolation of six new norcembranolides, gyrosanolides A-F (1-6), a new norcembrane, gyrosanin A (7), and 11 known norditerpenoids 8-18. The structures of the isolated compounds were elucidated through extensive spectroscopic data and by comparison with reported data in the literature. Compounds 1-3, 7-9, 12, and 13 at concentration of 10microM did not inhibit the COX-2 protein expression, but significantly reduced the levels of the iNOS protein (55.2+/-14.6%, 18.6+/-6.7%, 10.6+/-4.6%, 66.9+/-5.2%, 10.2+/-5.1%, 17.4+/-7.2%, 47.2+/-11.9%, and 56.3+/-5.1%, respectively) by LPS stimulation. Compound 8 showed significant antiviral activity against HCMV (human cytomegalovirus) cells with an IC(50) of 1.9microg/mL.

Cembranoids from the octocoral Sarcophyton ehrenbergi.

Chemical investigation of the octocoral Sarcophyton ehrenbergi led to the isolation of six new cembranoids, (+)-12-carboxy-11Z-sarcophytoxide (1), (+)-12-methoxycarbonyl-11Z-sarcophine (3), ehrenberoxides A-C (4-6), and lobophynin C (2), along with two known compounds, (+)-sarcophytoxide (7) and (+)-sarcophine (8). The structures of these isolated metabolites were elucidated through extensive spectroscopic analyses, while the relative configuration of 1 was confirmed by X-ray diffraction analyses. The chemical evidence combined with spectroscopic and physical data suggested that the locations of the epoxide and the methyl carboxylate for lobophynin C should be exchanged. Moreover, metabolites 1-6 were evaluated in vitro for their cytotoxicity against selected cancer and normal cells lines, antiviral activity against human cytomegalovirus, and antibacterial activity against Salmonella enteritidis.

Antiviral and anti-inflammatory metabolites from the soft coral Sinularia capillosa.

Chemical investigations of the soft coral Sinularia capillosa resulted in the isolation of one new tetraprenylbenzoquinone, capilloquinone (1), two new furanobenzosesquiterpenoids, capillobenzopyranol (2) and capillobenzofuranol (3), one new furanosesquiterpenoid, capillofuranocarboxylate (4), and five previously characterized metabolites, comprising (E)-5-(2,6-dimethylocta-5,7-dienyl)furan-3-carboxylic acid (5), 2-[(2E,6E)-3,7-dimethyl-8-(4-methylfuran-2-yl)octa-2,6-dienyl]-5-methylcyclohexa-2,5-diene-1,4-dione (6), 2-[(2E,6E)-3,7-dimethyl-8-(4-methylfuran-2-yl)octa-2,6-dienyl]-5-methylbenzene-1,4-diol (7), (-)-loliolide (8), and 3,4,11-trimethyl-7-methylenebicyclo[6.3.0]undec-2-en-11alpha-ol (9). The structures of 1-4 were elucidated through extensive spectroscopic analysis. The cytotoxicity, anti-HCMV (human cytomegalovirus) activity, antibacterial activity, and anti-inflammatory effects of 1-9 were evaluated in vitro.

Antiviral and anti-inflammatory diterpenoids from the soft coral Sinularia gyrosa.

Chemical investigation of the soft coral Sinularia gyrosa led to the purification of three new diterpenoids, designated as gyrosanols A-C (1-3). The structures of 1-3 were elucidated through extensive spectroscopic analyses. Compounds 1 and 2 exhibited antiviral activity against HCMV with IC(50)'s of 2.6 and 3.7 microM, respectively. In addition, compounds 1 and 2 showed significant anti-inflammatory activity by reducing the levels of the COX-2 protein (19.6 + or - 3.9% and 29.1 + or - 9.6%, respectively) in RAW 264.7 macrophages.

Ylangene-type and nardosinane-type sesquiterpenoids from the soft corals Lemnalia flava and Paralemnalia thyrsoides.

Chemical investigations of the Formosan soft coral Lemnalia flava have obtained a new ylangene-type sesquiterpenoid, (1S,2S,4R,6S,7R,8S)-4alpha-formyloxy-beta-ylangene (1), along with two known sesquiterpenoids, lemnalol (2) and isolemnalol (3). Three new nardosinane-type sesquiterpenoids, designated as paralemnolins J-L (4-6), and five known sesquiterpenoids (7-11), were isolated from the other soft coral Paralemnalia thyrsoides. The structures of metabolites 1 and 4-6 were elucidated through extensive spectroscopic analysis and chemical methods. Moreover, the anti-inflammatory activity of metabolites 1-7 and 11 was evaluated in vitro.

Two new verticillane-type diterpenoids from the formosan soft coral Cespitularia hypotentaculata.

Chemical investigations of the Formosan soft coral Cespitularia hypotentaculata ROXAS led to the isolation of two new verticillane diterpenoids, cespitularins R and S (1, 2), along with seven known compounds (3-9). The structures of these isolated compounds were elucidated on the basis of extensive spectroscopic analysis and by comparison with those of reported in literature. The anti-inflammatory activity using RAW 264.7 macrophages of compounds 1-9 were evaluated in vitro.

New 19-oxygenated and 4-methylated steroids from the Formosan soft coral Nephthea chabroli.

Chemical investigation of the Formosan soft coral Nephthea chabroli resulted in the isolation of four new 19-oxygenated steroids, nebrosteroids I-L (1-4), together with a new 4alpha-methylated steroid, nebrosteroid M (5). The molecular structures of these isolated metabolites were elucidated on the basis of extensive spectroscopic analysis and by comparison of the data with those of related metabolites. Compounds 1-5 were evaluated for anti-inflammatory activity using RAW 264.7 macrophages.

Anti-inflammatory cembranolides from the soft coral Lobophytum durum.

Chemical investigation of the soft coral Lobophytum durum resulted in the isolation of seven new cembranolides, durumolides F-L (1-7), as well as one previously characterized cembranolides, sinularolide D (8). The molecular structures of these isolated metabolites were determined mainly through NMR techniques and HRESIMS analysis. Moreover, the absolute configurations of 1 and 5 were established by application of modified Mosher's method. The antibacterial activities, anti-inflammatory effects, and anti-HCMV (Human cytomegalovirus) endonuclease activity of metabolites 1-8 were also evaluated in vitro. Anti-inflammatory activity of metabolites 1 and 6 (10 microM) significantly reduced the levels of the iNOS protein to 0.8+/-0.6% and 5.7+/-2.2%, respectively, and COX-2 protein to 47.8+/-9.0% and 71.6+/-5.8%, respectively. Metabolites 1-8 (100 microg/disk) exhibited weak antibacterial activity against Salmonella enteritidis.