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Two new triterpene saponins, namely notoginsenoside Ng5 (1) and notoginsenoside Ng6 (2) were isolated from the leaves of Panax notoginseng, along with five known ones. Their structures were determined by chemical methods, NMR and X-ray experiments. The absolute configuration of compound 3 with four sugar units was confirmed by single crystal X-ray analysis. Compounds 2–4 and 6 inhibited PC12 cell damage induced by serum deprivation, and increased cell viability from 58.7 ± 6.7% to 66.7 ± 4.5%, 76.1 ± 6.1%, 64.7 ± 5.2% and 67.2 ± 5.0% at 10 μM, respectively.

Two new triterpenoid saponins named notoginsenoside-Ng3 (1) and notoginsenoside-Ng4 (2) along with three known saponins (3–5), were isolated from a water extract of the leaves of Panax notoginseng. Their structures were elucidated by HRESIMS, NMR, X-ray techniques and acid hydrolysis. Moreover, compound 2 was characterized with the conjugated double bonds side-chain, which was rarely found in this plant. The absolute configuration of notoginsenoside Fa (3) with five sugars was confirmed by the single-crystal X-ray diffraction for the first time. Acetylcholinesterase inhibitory activity experiments were also conducted, all the isolated saponins showed weak inhibitory activities in the final concentration of 0.16 mmol/L.

Eight new alkaloids, including three pairs of enantiomers (+)-(2′S,3′R)-clauselansine A (1a) and (−)-(2′R,3′S)-clauselansine A (1b); (+)-(2′S,3′R)-clauselansine B (2a) and (−)-(2′R,3′S)-clauselansine B (2b); (+)-(3S,4R,5S,6S)-clauselansine C (3a) and (−)-(3R,4S,5R,6R)-clauselansine C (3b), (+)-(1′R,2′R,6′R)-claulansine B (4a), and (+)-(1′R,2′R)-claulansine D (5a), together with twelve known alkaloids (4b, 5b, 6a, 6b, 7a, 7b and 8–13) were isolated from the stems of Clausena lansium. Their structural elucidation and stereochemistry determination were achieved by spectroscopic and chemical methods including 1D and 2D NMR experiments, especially the employment of electronic circular dichroism calculation spectra, Mosher's method, and Snatzke's method expressed by the induced circular dichroism spectrum. Compounds 1b, 2a, 3b, 5a, and 5b inhibited PC12 cell damage induced by Okadaic Acid, and increased cell viability from 70.5 ± 5.4% to 83.4 ± 4.1%, 91.2 ± 10.1%, 83.5 ± 7.8%, 89.7 ± 4.8%, 83.3 ± 5.9% at 10 μM, respectively.

Two new triterpene saponins, namely notoginsenoside Ng5 (

In view of the significant neuroprotective effect of Clausena lansium, we continued to separate the n-butanol and the water extracts from the stems of C. lansium in order to find the leading compounds with significant activity. Two new phenolic glycosides, Clausenolside A-B (1-2), one new pair of phenolic enantiomers (3a, 3b), and two new monoterpenoids, clausenapene A-B (4-5), together with twelve known analogues (6-17) were isolated from the stems of C. lansium. Compounds 1-17 were obtained from C. lansium for the first time. Compounds 3a, 3b, 4, 16, and 17 showed strong or moderate potential neuroprotective effects on inhibited PC12 cell injury induced by okadaic acid, and compound 9 exhibited strong potential hepatoprotective activities. Their structures were elucidated on the basis of spectroscopic analyses, including UV, IR, NMR experiments, and electronic circular dichroism (ECD) spectra.

Two new carbazole alkaloids, claulansine S (1) and claulansine T (2), and one new amide alkaloid, clauamide A (3), together with four known analogues (4-7) were isolated from the stems of Clausena lansium. Their structures were elucidated on the basis of spectroscopic analyses, including UV, IR, and NMR experiments (HSQC, HMBC, and NOE experiments). Compounds 4 and 6 showed moderate hepatoprotective activities.

Seven new carbazole alkaloids, claulansines L-R ( 1 – 7 ), and six known analogues ( 8 – 13 ) were isolated from the stems of Clausena lansium . Their structures were elucidated on the basis of spectroscopic analyses, including UV, IR, and NMR experiments (HSQC, HMBC, and NOE experiment). Compound 7 showed moderate anti-inflammatory activities. Compounds 3 , 5 , 6 , 8 , and 12 exhibited moderate hepatoprotective activities.