Youyi Zhao

The first chlorogenic acid ester saponin from Lonicera macranthoides

An original triterpenoid saponin, named lonimacranthoide I, was isolated from the flower buds of Lonicera macranthoides (Caprifoliaceae). It has hederagenin as aglycone. Lonimacranthoide I is a rare chlorogenic acid ester acylated at C-23 of hederagenin. The structure of the saponin was established based on chemical and spectral methods.

2-phenoxychromone flavonoid glycoside from artemisia rupestris

A new 2-phenoxychromone glycoside was isolated from the n-butanol extract of Artemisia rupestris. Its structure was established as 6-demethoxy-4′-O-methylcapillarisin-7-O-β-glucoside based on spectral data.

A New Lupane-Type Triterpenoid Saponin from Lonicera macranthoides

A new lupane-type triterpenoid saponin, named lonimacranthoside A1, was isolated from the flower buds of Lonicera macranthoides. The structure of lonimacranthoside A1 was elucidated as 3β-O-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl-23-hydroxy-lup-20(29)-en-28-oic acid 28-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl ester (1) on the basis of spectral data and chemical evidence. This is the first reported occurrence of a lupane-type saponin in the plant.

Chemical Constituents of Suaeda salsa and their Cytotoxic Activity

Suaeda salsa (L.) Pall. (Chenopodiaceae) is represented by 20 species in China [1]. It also one of the most important halophyte and has important economic value because its seeds contain approximately 40% oil, rich in unsaturated fatty acids, which can be easily converted to chemical compounds for industrial and pharmaceutical use [2]. It has been used as a nutrient vegetable by local residents and received growing attention due to its pharmaceutical importance in recent years [3]. Studies on modern pharmacology show that it has been used to treat hyperglycemia, hypertension, cardiovascular diseases, and so on. However, no phytochemical investigations have been reported on this plant. This paper describes the isolation and structural elucidation of ten known metabolites, three lignans: (–)-syringaresinol (1), (–)-syringaresinol-4-O-D-glucopyranoside (2), and syringin (3); two phenolic acids: syringic acid (4), and syringic acid-D-glucopyranosyl ester (5); and others: adenosine (6), adenine (7), -daucosterol (8), uracil (9), and -sitosterol (10). The structures of compounds were established based on chemical and spectral methods. All compounds were isolated from this plant for the first time. Compounds 1–3 were evaluated for their in vitro cytotoxicity determined by the MTT colorimetric method. Compound 2 showed moderate activity against four cell lines, HL-60 (promyelocytic leukemia), MCF-7 (breast carcinoma), HepG2 (liver carcinoma), and A549 (lung carcinoma), with IC50 values of 36.18, 51.87, ~100, and > 100 M, respectively. General Comments. Melting points were measured using a XT-4 Boetius micro melting point apparatus and were uncorrected. IR spectra were detected on a Nexus 870 FT-IR spectrometer. HR-ESI-MS spectra were measured on an Agilent 6520 UPLC/Q-TOF/MS spectrometer. NMR data were acquired on a Bruker DRX500 or 300 NMR spectrometer with 1H and 13C NMR observed at 500 or 300 and 125 or 75 MHz, and all chemical shifts ( ) are given in ppm with reference to the solvent. Silica gel (200–300 mesh) for column chromatography was obtained from Qingdao Marine Chemical Factory, Qingdao, China. Sephadex LH-20 was purchased from Pharmacia Biotech, Sweden. HPLC analyses were performed with a column of Allsphere ODS-2.5 m (250 4.6 mm), Agilent pump 1100, and ELSD detector Alltech 500. All other chemicals used in this study were of analytical grade. TLC analyses were carried out on silica gel 60 F254 (Merck) plates. The compounds were monitored by spraying 1% vanillin-H2SO4 reagent, followed by heating at 105 C for 1–2 min. The spectral data of the purified compounds are reported below.

Two new linear furanocoumarin glycosides from Angelica dahurica

Two new linear furanocoumarin glycosides, tert-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranosyl-oxypeucedanin hydrate (1) and sec-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranosyl-oxypeucedanin hydrate (2), were isolated from the fresh roots of Angelica dahurica. The structures of new compounds were elucidated on the basis of spectral analysis.

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)-β-d-glucuropyranosyl-23-aldehyde-30-norolean-12, 20 (29)-dien-28-oic acid-28-O-β-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.

Induction of apoptosis by Bigelovii A through inhibition of NF‑κB activity

Bigelovii A is a 30-nortriterpenoid glycoside, isolated from Salicornia bigelovii Torr. Until now, the effect of Bigelovii A on breast cancer treatment was unknown. The present research indicated that Bigelovii A significantly inhibited the proliferation of human breast cancer cells (MCF-7, MDA-MB-231 and MDA-MB-468) in a concentration-dependent manner. It was particularly effective in MCF7 cells, with an IC50 value of 4.10±1.19 µM. The anti-proliferative effect of Bigelovii A was ascribed to the induction of apoptosis, which was characterized by chromatin condensation, externalization of phosphatidylserine on the plasma membrane, hypodiploid DNA, activation of caspases and poly (ADP-ribose) polymerase cleavage. Furthermore, Bigelovii A reduced B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl) expression and caused disruption of mitochondrial membrane potential, which are indicative features of mitochondria-dependent apoptotic signals. It was also identified that Bigelovii A downregulated the constitutive activation of nuclear factor (NF)-κB, as indicated by the electrophoretic mobility gel shift assay and immunocytochemistry. Furthermore, Bigelovii A suppressed constitutive IκBα phosphorylation via inhibition of IκB kinase activity. In addition to the effects on Bcl-2 and Bcl-xl, Bigelovii A also downregulated the expression of the NF-κB-regulated gene products, Cyclin D1 and cyclooxygenase-2. This led to the induction of apoptosis and arrest of cells at the G1 phase of the cell cycle.