A new sesquiterpene lactone from yacon leaves

Discovery of indole analogues from Periplaneta americana extract and their activities on cell proliferation and recovery of ulcerative colitis in mice

Background: As an important medicinal insect, Periplaneta americana (PA) has been applied for the treatment of wounds, burns, and ulcers with fewer side effects and a reduced recurrence rate, which provides great potential for developing new drugs based on its active constituents. Materials and methods: The main chromatographic peaks determined by high performance liquid chromatography (HPLC) in the PA concentrated ethanol-extract liquid (PACEL) were separated, purified, and identified by semi-preparative LC, mass spectrum, and 1H NMR spectroscopic analysis. The biological activities of the identified compounds were investigated by methylthiazolyldiphenyl-tetrazolium bromide (MTT) method based on in vitro human skin fibroblasts (HSF) and in vivo experiments based on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mouse model. Furthermore, RT-qPCR of six genes related to inflammation or intestinal epithelial cell proliferation was employed to investigate the molecular mechanism of the indole analogues recovering UC in mice. Results: Five indole analogues were purified and identified from PACEL, including tryptophan (Trp), tryptamine (pa01), 1,2,3,4-tetrahydrogen-β-carboline-3-carboxylic acid (pa02), (1S, 3S)-1-methyl-1,2,3,4-tetrahydrogen-β-carboline-3-carboxylic acid (pa03), and (1R, 3S)-1-methyl-1,2,3,4-tetrahydrogen-β-carboline-3-carboxylic acid (pa04), among which the pa02 and pa04 were reported in PA for the first time. In vitro and in vivo experiments showed that PACEL, Trp, and pa02 had promoting HSF proliferation activity and intragastric administration of them could alleviate symptoms of weight loss and colon length shortening in the UC mice. Although recovery activity of the compound pa01 on the colon length was not as obvious as other compounds, it showed anti-inflammatory activity in histological analysis. In addition, The RT-qPCR results indicated that the three indole analogues could alleviate DSS-induced intestinal inflammation in mice by inhibiting pro-inflammatory cytokines (MMP7, IL1α) and down-regulating BMP8B expression. Conclusion: This study reported the isolation, purification, structure identification, and biological activity of the active indole analogues in PACEL. It was found for the first time that the PA extract contained many indole analogues and Trp, which exhibited good proliferation activity on HSF fibroblasts as well as anti-UC activity in mice. These indole analogues probably are important components related to the pharmacological activity in PA.

Aromatic glycosides from the aerial part of Bupleurum chinense

A new aromatic glycoside (1) and twelve (2-13) known aromatic glycosides were isolated from the n-butyl alcohol of the 70% EtOH extract of the aerial part of Bupleurum chinense. Among them, compounds 4-7, 9, 11-13 were isolated from Umbelliferae plants for the first time. Their structures were elucidated by NMR and MS spectroscopy, and the absolute configuration of compound 1 was elucidated by single-crystal X-ray diffraction. Compounds 6 and 10 showed moderate cytotoxic activities on MGC-803 cell lines with IC₅₀ values of 8.63 ± 0.08 and 13.65 ± 1.73 μM, respectively.

A new coumarin isolated from the roots of Heracleum dissectum Ledeb

A new coumarin named (9 R, 10 R)-9, 10-dihydro-10-hydroxy-9-methoxy-bergapten (1) and 13 known compounds (2-14) were isolated from the roots of Heracleum dissectum Ledeb., in which compounds (2-13) were obtained from H. dissectum for the first time. Their structures were illuminated by HR-ESI MS, 1 D and 2 D NMR, optical rotation and comparison with literatures. All compounds were evaluated against hepatocellular carcinoma HepG2 cell lines and the results showed that candinol C (8) had moderate cytotoxic activity against HepG2 cells with IC₅₀ value at 57.6 ± 1.1 µM.

Investigation of chemical constituents of safflower and their tyrosinase inhibitory activity

Investigation on bioactive chemical constituents of safflower led to the isolation of 10 compounds from the aqueous extract, including a new alkaloid (1), a new glucopyranoside (2), and 8 known compounds (3-10). The structures of two new compounds were elucidated on the basis of extensive spectral analyses, including 1D, 2D-NMR and HRESIMS. Biological research on the isolates indicated that compounds 3, 4 and 9 remarkably inhibited tyrosinase with IC₅₀ at 0.11, 0.20 and 0.11 mM, respectively, compared with the positive control arbutin (0.26 mM). To investigate the interaction between enzyme and isolated compounds, an in silico docking study was carried out. The research provided valuable experience for phytochemistry and biological investigation on safflower.

Synthetic Esterification of Yacon Sesquiterpene Lactone, Sonchifolinic Acid led to Cytotoxic SARs Study

Cytotoxicity on sonchifolinic acid (1) isolated from Samallunthus leaf and synthetic compounds related to compound 1 were comparatively studied for the first time. Derivatives of 1 such as propyl (1a), butyl (1b), pentyl (1c) and 2-methoxy ethyl (1d) sonchifolate were prepared and their cytotoxic activity on HeLa cells were compared with sonchifolin (2), a structurally related natural compound. Alkylation of the carboxylic acid group at C-14 position in 1 enhanced the cytotoxic activity 2–5 times (1a - 1d and 2, IC50 5.29 - 21.07 μM) compared with that of sonchifolinic acid (1) (IC50 47.12 μM). Higher lipophilicity and moderate bulkiness of the inserted alkyl group contributed to the increased SL cytotoxicity in vitro. This result shows sonchifolinic acid (1) could be a valuable leading compound for semi-synthetic derivatives in order to develop new potent anticancer drugs.

Two new sesquiterpene lactones from leaves of yacon, Smallanthus sonchifolius

The chemical constituents of 95% EtOH extract of yacon leaves were separated to yield two new sesquiterpene lactones, together with three known compounds. The two new compounds were characterized to be 8β-angeloyloxy-13-methoxyl-11, 13-dihydromelampolid-14-oic acid methyl ester (1) and 8β-(3-methylbut-2-enoyl) oxy-13-methoxyl-11, 13-dihydromelampolid-14-oic acid methyl ester (2) on the basis of NMR spectra, HR-MS and other spectroscopic methods. The cytotoxicity of compounds 1-5 were evaluated on human hepatoma cell Bel-7402 and all the compounds showed moderate cytotoxicity.

Constituents of the Fruits of Citrus medica L. var. sarcodactylis and the Effect of 6,7-Dimethoxy-coumarin on Superoxide Anion Formation and Elastase Release

Investigation of the chemical constituents from the fruits of Citrus medica L. var. sarcodactylis Swingle has led to the characterization of a new sesquiterpene 1 along with thirty-two known compounds. The structure of 1 was established on the basis of 2D NMR spectroscopic and mass spectrometric analyses, and the known compounds were identified by comparison of their physical and spectroscopic data with those reported in the literature. In addition, most of the isolated compounds were evaluated for the activity assayed by the in vitro inhibition of superoxide anion generation and elastase release by human neutrophils. The results showed that only 6,7-dimethoxycoumarin (5) exhibited significant inhibition of superoxide anion generation, with IC₅₀ value of 3.8 ± 1.4 μM.

Two new sesquiterpene lactone glycosides from Cnicus benedictus

Two new sesquiterpene lactone glycosides, namely melitensin 15-O-β-D-glucoside (1) and 11β,13-dihydrosalonitenolide 15-O-β-D-glucoside (2), along with eight known compounds (3-10) were isolated from the aerial part of Cnicus benedictus L. Their structures were elucidated from analyses of extensive spectroscopic data. Compounds 1-6 all possessed an α-methyl-γ-lactone moiety. Moreover, compound 5 exhibited moderate activity against the growth of Aspergillus fumigatus, with IC₅₀ values of 17.67 μg mL^-1.