Four lathyrane diterpenoids from the seeds of Euphorbia lathyris.

Four new diterpenoids, including three secolathyrane diterpenoids (1-3) and one lathyrane diterpenoid (4), together with seven known diterpenoids, were obtained in the shelled seeds of Euphorbia lathyris. In particular, 1-3 possess a rare split ring structure, and currently only one compound with the same skeleton has been identified in E. lathyris. Compound 4 furnishes an unprecedented oxygen bridge structure. The structures were identified using various spectral techniques, including NMR, HR-ESI-MS, single-crystal X-ray diffraction and calculated electronic circular dichroism (ECD). The biosynthetic pathway of 1-4 was inferred. Furthermore, the cytotoxic activities of all compounds (1-11) were measured on three human tumor cells. New compounds 2 and 3 showed moderate cytotoxic activities against U937 cells with IC50 values of 22.18 and 25.41 µM, respectively.

Two Novel Sesquiterpenoid Glycosides from the Rhizomes of Atractylodes lancea.

Secoatractylohexone A (1), an unprecedented secoguaiane lactone glycoside featuring 6/7 cores and dihydroxy-9-guaine-3-one 11-O-ß-d-glucopyranoside (2), a 9,10-unsaturated guaiene-type glycoside possessing an uncommon scaffold, were isolated from the water-soluble portion of the ethanolic extract of Atractylodes lancea rhizomes together with five known compounds (3-7). The structures of 1 and 2 were elucidated on the basis of extensive spectroscopic data and application of the CD technique. The potential biological activities of secoatractylohexone A were predicted by network pharmacology in silico, the result of which indicated that secoatractylohexone A may be used to treat type II diabetes.

The Essential Oil from Acori Tatarinowii Rhizome (the Dried Rhizome of Acorus tatarinowii Schott) Prevents Hydrogen Peroxide-Induced Cell Injury in PC12 Cells: A Signaling Triggered by CREB/PGC-1α Activation.

Acori Tatarinowii Rhizome (ATR, the dried rhizome of Acorus tatarinowii Schott), a well-recognized traditional Chinese herbal medicine, is prescribed to treat neurological disorders. The essential oil is considered as the active fraction of ATR, and the neuroprotection of ATR essential oil (ATEO) is proven, including the protection against oxidative stress. However, the cellular mechanism of ATEO against oxidative stress has not been fully illustrated. In this study, to investigate the cellular mechanism of ATEO, the cytoprotective effect of ATEO against H2O2-induced injury was revealed in PC12 cells. ATEO treatment increased the viability of cells affected by H2O2-mediated injury, inhibited reactive oxygen species (ROS) accumulation, and induced the expression of several antioxidant proteins (SODs, GPx, and UCPs). The cytoprotective effect of ATEO was related to upregulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression, which was counteracted by PGC-1α specific knockdown. Using inhibitor of protein kinase A (PKA), we found that cAMP-response element binding protein (CREB) activation was involved in ATEO-induced PGC-1α expression. Taken together, we suggest that ATEO effectively prevents H2O2-induced cell injury possibly through the activation of CREB/PGC-1α signaling in PC12 cells. The results provide a molecular insight into the effect of ATEO on cytoprotection against oxidative stress.

Triterpenoids from the Herbs of Salicornia bigelovii.

A new nortriterpene saponin, 3-O-ß-d-glucuronopyranosyl-30-norolean-12,20(29)-dien-23- oxo-28-oic acid, namely bigelovii D (11), was isolated from the hydroalcoholic extract of herbs of Salicornia bigelovii along with 10 known saponins (1-10). Their chemical structures were identified on the basis of spectroscopic analyses including two-dimensional NMR and a comparison with literature data. Some of these compounds showed potent antifungal activities in vitro. Compounds 3, 4, 5, 6, 7, 10 and 11 demonstrated potent inhibitory activities against Colletotrichum gloeosporioides and compound 11 displayed broad-spectrum inhibitory activity against Alternaria alternata, A. solani, Botrytis cinerea, C. gloeosporioides, Fusarium graminearum, F. verticilloides, Thanatephorus cucumeris and Sclerotinia sclerotiorum, with EC50 values ranging from 13.6 to 36.3 µg/mL.

Isolation, identification and cytotoxicity of a new noroleanane-type triterpene saponin from Salicornia bigelovii Torr.

Salicornia bigelovii Torr. has been consumed not only as a popular kind of vegetable, but also as a medicinal plant to treat hypertension, cephalalgia, scurvy and cancer. The present study was designed to investigate its chemical components and cytotoxic activity. A new noroleanane-type triterpene saponin, bigelovii C (1), was separated and purified from Salicornia bigelovii Torr., along with four known triterpene saponins 2-5. The structure of bigelovii C was elucidated as 3-O-(6-O-butyl ester)-ß-D-glucuropyranosyl-23-aldehyde-30-norolean-12, 20 (29)-dien-28-oic acid-28-O-ß-D-glucopyranoside, according to various spectroscopic analysis and chemical characteristics. Besides Compounds 3 and 5, bigelovii C had potent cytotoxicity against three human cancer cell lines, MCF7 (breast cancer), Lovo (colon cancer) and LN229 (glioblastoma), especially MCF7. Bigelovii C inhibited the growth of MCF7 cells in dose- and time-dependent manners. Flow cytometry analysis revealed that the percentage of apoptotic cells significantly increased upon bigelovii C treatment. Rh123 staining assay indicated that bigelovii C reduced the mitochondrial membrane potential. The mechanism of cell death by bigelovii C may be attributed to the downregulation of Bcl-2 and upregulation of Bax, cleaved caspase-9, caspase-7 and PARP. These results suggested that bigelovii C may impart health benefits when consumed and should be regarded as a potential chemopreventative agent for cancer.

A new quinoline alkaloid from the roots of Dictamnus angustifolius.

AIM: To investigate the quinoline alkaloids from the roots of Dictamnus angustifolius G.Don ex Sweet (Rutaceae). METHOD: The quinoline alkaloids were isolated by various column chromatographic methods and their structures were elucidated on the basis of spectral analysis. RESULTS: A new quinoline alkaloid, 5-methoxylrobustine (1), along with five known quinoline alkaloids were obtained, and their structures were identified as dictamnine (2), robustine (3), isopteleine (4), γ-fagarine (5), and skimmianine (6). Cytotoxicity testing of these alkaloids showed that all of them had weak cytotoxic activities against human breast cancer cells (MCF7). CONCLUSION: Compound 1 is a new quinoline alkaloid. Alkaloid 3 showed stronger anti-proliferation effect than the other alkaloids.

New cytotoxic diarylheptanoids from the rhizomes of Alpinia officinarum Hance.

Two new dimeric diarylheptanoids, named Alpinin C (1) and D (2), a new natural product of diarylheptanoid (3) along with three known diarylheptanoids (4-6) were isolated from the rhizomes of Alpinia officinarum Hance. Their structures were elucidated based on extensive spectroscopic analyses (1D and 2D NMR, HRTOFMS, IR). The isolated compounds were evaluated for their cytotoxicity against human tumor cell lines HepG2, MCF-7, T98G and B16-F10. Compound 1 showed selective cytotoxicity against cell lines of MCF-7 and T98G, while compound 6 showed significant cytotoxicity to the all tested tumor cell lines with IC50 in the range from 8.46 to 22.68 µmol/L.

A new dimeric diarylheptanoid from the rhizomes of Alpinia officinarum.

AIM: To study the chemical constituents of the rhizomes of Alpinia officinarum Hance. METHOD: Compounds were isolated by repeated column chromatography, and their structures were elucidated on the basis of spectral analysis. The cytotoxic activities of these compounds were evaluated with the T98G and B16F10 cell lines by the MTT assay. RESULTS: A dimeric diarylheptanoid, named alpinin B (1), along with three known diarylheptanoids were obtained, and their structures were identified as alpinin B (1), 1, 7-diphenyl-3,5-heptanedione (2), (4E)-1, 7-diphenylhept-4-en-3-one (3) and (4E)-7- (4-hydroxyphenyl)-1-phenylhept-4-en-3-one (4). CONCLUSION: Compound 1 is a new dimeric diarylheptanoid. The biosynthetic pathway of 1 was speculated to originate from a Michael reaction between compounds 2 and 3. Compound 3 showed cytotoxicity against the human glioblastoma T98G cell line with IC50 of 27 µmol·L(-1).

Caesappin A and B, two novel protosappanins from Caesalpinia sappan L.

Two novel protosappanins, named Caesappin A (1) and B (2), along with three known protosappanins were isolated from Caesalpinia sappan L. Caesappin A is a new type protosappanin with a seven-membered ring fusing an acetal-type section. Compound 4 was isolated from the genus Caesalpinia for the first time. The structures were elucidated on the basis of spectral analysis and the absolute configuration was determined by the ECD experiment coupled with calculated ECD spectra. Their cytotoxic activities were evaluated using MTT assay.

Two new nortriterpenoid saponins from Salicornia bigelovii Torr. and their cytotoxic activity.

Investigation of characteristic constituents of Salicornia bigelovii Torr. led to isolation of two new 30-nortriterpenoid glycosides, Bigelovii A (1), Bigelovii B (2), together with two known 30-nortriterpenoid glycosides 3-4 and three known oleanane-type triterpenoid glycosides 5-7. The structures of new compounds were elucidated by extensive 1D and 2D NMR, and MS spectroscopic analysis, and chemical evidences. All compounds were isolated for the first time from Chenopodiaceae. Thus compounds 1-4 were evaluated for their cytotoxicity and compouds 1, 3 showed moderate activity against four cell lines, HL-60 (promyelocytic leukemia), MCF-7 (breast carcinoma), HepG2 (liver carcinoma) and A549 (lung carcinoma), with IC(50) values of 6.18, 78.08, 13.64 and >100µM for 1; 31.87, >100, ~100, >100µM for 3, respectively.