Rapid screening and identification of lycodine-type alkaloids in Lycopodiaceae and Huperziaceae plants by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Lycodine-type alkaloids have gained significant interest owing to their unique skeletal characteristics and acetylcholinesterase activity. This study established a rapid and reliable method using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-ESI-Q/TOF-MS/MS) for comprehensive characterization of lycodine-type alkaloids for the first time. The lycodine-type alkaloids were detected successfully from Lycopodiastrum casuarinoides, Huperzia serrata and Phlegmarirus carinatus in seven plants of the Lycopodiaceae and Huperziaceae families, based on the established characteristic MS fragmentation of five known alkaloids. Furthermore, a total of 13 lycodine-type alkaloids were identified, of which three pairs of isomers were structurally characterized and differentiated. This study further improves mass analysis of lycodine-type alkaloids and demonstrates the superiority of UPLC with a high-resolution mass spectrometer for the rapid and sensitive structural elucidation of other trace active compounds. Copyright © 2016 John Wiley & Sons, Ltd.

Further C-15-acyl phragmalin derivatives from Chukrasia tabularis A. Juss.

Relying on characteristic double UV absorptions (210 and 270 nm), sixteen phragmalins with three types of enolic acyl substituents at C-15 were isolated directly from EtOH extracts of the seeds of Chukrasia tabularis A. Juss. Eight of these compounds possessed a C-15-acetyl phragmalin skeleton, and the basic carbon skeleton and absolute configuration of one of these was determined by NMR and X-ray diffraction analysis, while the structures of the other phragmalins were determined via NMR, HR-MS, and CD spectra. Additionally, all of the isolates were tested for inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 macrophages and cytotoxicity in SMMC-7721, MCF-7 and U2OS tumor cells.

New cassane-type diterpenoids from Caesalpinia bonduc.

Six new cassane diterpenoids, named caesalls H-M (1-6), were isolated from the seed kernels of Caesalpinia bonduc. Their structures were elucidated on the basis of spectroscopic analysis, mainly NMR and MS. The absolute configurations of compounds 1 and 3 were determined by a single-crystal X-ray study using a mirror CuKα radiation and circular dichroism (CD) spectra, respectively. None of the compounds were cytotoxic against HepG-2, MCF-7 and MG-63 cells.

A new acorane sesquiterpene from the aerial parts of Psychotria yunnanensis.

Psycacoraone A (1), a new acorane-type sesquiterpene possessing rare spirobicyclic carbon skeleton, was isolated from the aerial parts of Psychotria yunnanensis. Its structure was elucidated on the basis of spectroscopic methods including HR-ESI-MS, 1D and 2D NMR. The absolute configuration of 1 was determined by calculation of electronic circular dichroism using density functional theory.

Teucvisins A-E, five new neo-clerodane diterpenes from Teucrium viscidum.

Two new neo-clerodane diterpenoids, teucvisins A and B (1, 2), and three new 19-nor-neoclerodane diterpenoids, teucvisins C-E (3-5), together with ten known constituents (6-15) were isolated from the whole plants of Teucrium viscidum. All the isolates were evaluated for their inhibitory activities of lipopolysaccharide (LPS)-induced nitric oxide production in RAW264.7 macrophages. The results indicated that compounds 11 and 15 showed moderate inhibition with an IC50 value of 21.9 and 22.4 µM, respectively.

Withanolides from Physalis minima and their inhibitory effects on nitric oxide production.

Six new withanolides (1-6), including two uncommon 1,10-seco withanolides (1 and 2), together with five known withanolides (7-11), were isolated from the whole plants of Physalis minima Linn.. The structures of new compounds were elucidated through spectroscopic methods, including (1)H, (13)C NMR, 2D-NMR, HRESIMS and circular dichroism (CD). Inhibitory effects of the isolates on nitric oxide (NO) production in lipopolysaccaride-activated RAW264.7 macrophages were evaluated. Compounds 2 and 5 showed strong inhibitory activities with IC50 values of 8.04 and 10.01 µM, respectively. Compounds 1, 9 and 10 exhibited moderate inhibitory activities with IC50 values from 25.54 to 43.58 µM.

Chemical characteristics combined with bioactivity for comprehensive evaluation of Panax ginseng C.A. Meyer in different ages and seasons based on HPLC-DAD and chemometric methods.

Panax ginseng C.A. Meyer has been known as a valuable traditional Chinese medicines for thousands years of history. Ginsenosides, the main active constituents, exhibit prominent immunoregulation effect. The present study first describes a holistic method based on chemical characteristic and lymphocyte proliferative capacity to evaluate systematically the quality of P. ginseng in thirty samples from different seasons during 2-6 years. The HPLC fingerprints were evaluated using principle component analysis (PCA) and hierarchical clustering analysis (HCA). The spectrum-efficacy model between HPLC fingerprints and T-lymphocyte proliferative activities was investigated by principal component regression (PCR) and partial least squares (PLS). The results indicated that the growth of the ginsenosides could be grouped into three periods and from August of the fifth year, P. ginseng appeared significant lymphocyte proliferative capacity. Close correlation existed between the spectrum-efficacy relationship and ginsenosides Rb1, Ro, Rc, Rb2 and Re were the main contributive components to the lymphocyte proliferative capacity. This comprehensive strategy, providing reliable and adequate scientific evidence, could be applied to other TCMs to ameliorate their quality control.

Chemical constituents from Trichilia connaroides and their nitric oxide production and α-glucosidase inhibitory activities.

Phytochemical investigation of the stem and bark of Trichilia connaroides led to the isolation of eight new nortriterpenoids (1-8), along with fifteen known compounds (9-23). Their structures were established based on extensive spectroscopic analysis. The absolute configuration of 2 was confirmed by X-ray crystallographic study. The nitric oxide production and α-glucosidase inhibitory effects for these isolates were evaluated: moderate to strong nitric oxide production inhibitory activities were found for 5, 6, and 11-15, with IC50 values ranging from 7.5 to 26.3 µM; marked α-glucosidase inhibitory effects were observed for 22 and 23, with IC50 values of 2.3 and 0.4 µM, respectively.

Bioactive benzofuran neolignans from Aristolochia fordiana.

Six new benzofuran neolignans (1-6) were isolated from the EtOAc-soluble fraction of the aerial part of Aristolochia fordiana, together with twelve known analogues (7-18). The structures of the isolated compounds were elucidated by spectroscopic methods. All isolates were evaluated for their inhibitory effects on nitric oxide production in lipopolysaccaride-activated RAW264.7 macrophages and for their cytotoxic activities on three human cancer cell lines. Compound 2 showed significant nitric oxide production inhibitory activity with an IC50 value of 10.00 µM, while compound 16 exhibited cytotoxic activity with an IC50 value of 11.9 µM against MG-63 and compound 18 of 9.15 µM against HepG2 cell lines, respectively.

Aphanamenes A and B, two new acyclic diterpene [4 + 2]-cycloaddition adducts from Aphanamixis grandifolia.

Aphanamenes A (1) and B (2), two unprecedented acyclic diterpene dimers formed via a [4 + 2]-cycloaddition, were isolated from the root bark of Aphanamixis grandifolia. Their structures were elucidated by spectroscopic analyses, and the absolute configuration of 1 was determined by ECD calculations. Both 1 and 2 showed significant inhibition on NO production on lipopolysaccharide-induced RAW264.7 macrophages.

Amomaxins A and B, two unprecedented rearranged labdane norditerpenoids with a nine-membered ring from Amomum maximum.

Amomaxins A (1) and B (2), featuring an unprecedented rearranged labdane norditerpene skeleton with a nine-membered ring, along with their biosynthetic related known compound isocoronarin D (3) were isolated from the roots of Amomum maximum. Their structures with absolute configurations were determined by spectroscopic data, CD experimentation, and single-crystal X-ray diffraction. Compound 2 showed an inhibitory effect on nitric oxide (NO) production in lipopolysaccharide-induced RAW264.7 macrophages.