16-nor Limonoids from Harrisonia perforata as promising selective 11ß-HSD1 inhibitors.

Two new 16-nor limonoids, harperspinoids A and B (1 and 2), with a unique 7/5/5/6/5 ring system, have been isolated from the plant Harrisonia perforate together with a known one, Harperforin G (3). Their structures were elucidated by NMR spectroscopy, X-ray diffraction analysis and computational modelling. Compound 1 exists as polymorphic crystals. Conformations of 1 in solution were further discussed based on the computational results. These compounds exhibited notable inhibitory activity against the 11ß-HSD1 enzyme. Compound 3 had potencies for the inhibition of human 11ß-HSD1 with high selectivity against 11ß-HSD2 (IC50 0.58 µM, SI > 174). Molecular docking and quantitative structure-activity relationship studies revealed a mixed regulatory mechanism.

[Research on certified reference material of emodin in rhubarb and its alcohol extract, water extract].

The certified reference materials (CRMs) of emodin in rhubarb and its alcohol extract, water extract were developed by using quantity transfer technology from single chemical composition to the complex systems. The CRM of emodin was used for quantity transfer, and high performance liquid chromatography (HPLC) method was used to determine the contents of emodin in different matrix composition. By establishing mathematical model and calculating the parts of uncertainty, the uncertainty values were finally gotten. CRMs of emodin in rhubarb, alcohol extract and water extract were accomplished. The content values of emodin were 0.40% ±0.03%, 1.15%±0.18%, 0.16%±0.08% (k=2,P=0.95), respectively. The established method for quantity transfer has successfully solved the technical problems that the value of active ingredient of traditional Chinese medicine can't be traced to SI units. The series of CRMs are assigned as grade primary reference materials, which are useful for quality control of the emodin content, also provide the accurate and reliable CRM, materials standard and standard methods.

Chemical constituents from fruits of Harrisonia perforata.

Eight limonoids (1-8) including three A, B and D-seco-16-nor-type ones, 5,6-dehydrodesepoxyharperforin C2 (1), harrpernoid B (2), and its C-9S epimer, harrpernoid C (3), along with six known compounds (9-14), were isolated from fruits of Harrisonia perforata. Extensive spectroscopic analysis was used to elucidate their structures and stereochemistries. Further confirmation of structures of 1 and 2 were obtained by single-crystal X-ray diffraction. Limonoids (1-8) were evaluated for their anti-tobacco mosaic virus activity and in vitro cytotoxicity against A549 and HL60 cell lines; only compound 2 showed weak activity.

Chemical constituents from the leaves and stems of Schisandra rubriflora.

Six new nortriterpenoids, schirubridilactones A-F (1-6), as well as 14 known compounds, were isolated from the leaves and stems of Schisandra rubriflora. The structures of 1-6 were elucidated on the basis of spectroscopic methods including HSQC, HMBC, (1)H-(1)H COSY, and ROESY NMR experiments. The relative stereochemistry of 1 was confirmed through single-crystal X-ray analysis. In addition, compounds 1-6 showed anti-HIV-1 activity with EC(50) values in the range 14.3-80.8 microg/mL and selectivity indices in the range 2.2-9.0.