A new triterpenoid from the fruits of Gardenia jasminoides var. radicans Makino

A novel triterpenoid 3α,16β,23,24-tetrahydroxy-28-nor-ursane-12,17,19,21-tetraen (1) was isolated from the fruits of Gardenia jasminoides var. radicans Makino. The structure of the new compounds was elucidated on the basis of spectroscopic analysis including MS and NMR data. Compound 1 was in vitro tested for cytostatic activity on human throat cancer (Hep-2) cell line by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide method and showed mild anticancer activity with the IC₅₀ of 31.2 μM.     

Geissoschizine methyl ether N-oxide,a new alkaloid with antiacetylcholinesterase activity from Uncaria rhynchophylla

Geissoschizine methyl ether N-oxide, a new oxindole alkaloid, along with 14 known alkaloids, was isolated from the aerial part of Uncaria rhynchophylla. Their structures were identified by comprehensive spectral methods, including 2D NMR experiments, and confirmed by comparing with the literature data. In vitro acetylcholinesterase (AChE) inhibitory activity assay showed that the new compound exhibited anti-AChE activity with IC₅₀ value of 23.4 μM.     

Guaiane-type sesquiterpenoid glucosides from Gardenia jasminoides Ellis

Two new guaiane-type sesquiterpenoid glucosides (1 and 2) were isolated from the fruit of Gardenia jasminoides Ellis. Their structures were elucidated to be (1R,7R,10S)-11-O-β-D-glucopyranosyl-4-guaien-3-one (1) and (1R,7R,10S)-7-hydroxy-11-O-β-D-glucopyranosyl-4-guaien-3-one (2) by one- and two-dimensional NMR techniques ((1)H NMR, (13)C NMR, HSQC, HMBC and NOESY), MS, CD spectrometry and chemical methods.     

HPTLC–densitometric and HPTLC–MS methods for analysis of flavonoids

HPTLC silica gel plates without and with fluorescence indicator F₂₅₄ in combination with n-hexane–ethyl acetate–formic acid (20:19:1, v/v/v) as a developing solvent were explored for the HPTLC–densitometric and HPTLC–MS/(MSⁿ) analyses of flavonoids. Pre-development of the plates with chloroform–methanol (1:1, v/v) was needed for reliable HPTLC–densitometric analyses of flavonoid aglycones in the whole R_F range, while 2-step pre-development (1^st methanol–formic acid (10:1, v/v), 2^nd methanol), that decreased background signals of formic acid adducts, was required for HPTLC–MS analyses. Optimization with conditioning of the adsorbent layer with water before development and saturation of the twin trough chamber resulted in required decrease of the R_F values of studied flavonoids (flavone, apigenin, luteolin, chrysin, quercetin dihydrate, myricetin, kaempferide, kaempferol, naringenin, pinocembrin).

Detection was performed based on fluorescence quenching (on the plates with F₂₅₄), natural fluorescence and after post-chromatographic derivatization with natural product reagent without or with further enhancement and stabilization of fluorescent zones with polyethylene glycol (PEG 400 or PEG 4000) or paraffin–n-hexane reagents. For all three reagents, drying temperature and time passed after drying influenced the intensity, which was increasing the first 20?min, and the stability (less than 2?h for PEGs and at least 24?h for paraffin–n-hexane) of the standards’ zones.

Optimal wavelengths for densitometric evaluation were selected based on in-situ absorption spectra scanned before and after derivatization and after stabilization. The developed method was tested via analyses of propolis, roasted coffee, rose hip, hibiscus, rosemary and sage crude extracts. To further increase the reliability of the obtained densitometric results HPTLC–MS/(MSⁿ) analyses of all crude extracts were performed. Several phenolic and non-phenolic compounds were tentatively identified.

Some possible interferences with phenolic acids (chlorogenic acid, rosmarinic acid, protocatechuic acid, gallic acid, syringic acid, ellagic acid, trans-cinnamic acid, o-coumaric acid, m-coumaric acid, p-coumaric acid, caffeic acid, ferulic acid, sinapic acid) that are often present in the extracts together with flavonoids were also examined.     

Three new 3,4-seco-cycloartane triterpenes from Gardenia sootepensis

The plants in the genus Gardenia (Rubiaceae) have long been used as traditional medicines in China. In this study, two new 3,4-seco-cycloartane triterpenes, sootepin J (1) and sootepin K (2), and a novel nor-3,4-seco-cycloartane triterpenes, sootepin L (3), together with two known compounds (4–5), were isolated from the methanolic extract of the leaves and twigs of Gardenia sootepensis. The structures of the new compounds were elucidated by combinations of 1D, 2D NMR experiments and HR-MS data, while the known compounds were identified by comparison of the NMR data with previously published data.     

Two new simple iridoids from the ant-plant Myrmecodia tuberosa and their antimicrobial effects

Six iridoid derivatives (1–6), including two new compounds myrmecodoides A and B (1 and 2), were isolated from the ant-plant Myrmecodia tuberosa. Their structures were determined on the basis of spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, NOESY and HR-ESI-MS) and by comparison with the literature values. Among isolates, 3 and 4 exhibit weak antibacterial effect against Staphylococcus aureus subsp. aureus with MIC value of 100.0 μg/mL.     

水线草的化学成分

采用硅胶柱色谱、凝胶柱色谱、重结晶等方法对水线草的化学成分进行了分离和纯化,并根据其理化性质和波谱数据鉴定了化合物的结构,结果显示,从水线草中可分离得到7个化合物,分别鉴定为：5,6,7,4’-四甲氧基黄酮（I）,7-羟基-5,6,4’-三甲氧基黄酮（Ⅱ）,3’,4’,5,6,7-五甲氧基黄酮（Ⅲ）,5,7,4’-三羟基-6-甲氧基黄酮（IV）,5,4’-二羟基-6,7-二甲氧基黄酮（V）,α-香树精（Ⅵ）,β-谷甾醇（Ⅶ）,这些化合物是首次从该种植物中分离得到的．     

六月雪化学成分研究

从六月雪中分离得到5个化合物,利用波谱等方法鉴定为5-乙酰基-6-羟基-2-异丙烯苯并呋喃(5-Acetyl-6-hydroxy-2-isopropenylbenzofuran,1);5-乙酰基-0-羟基-2-丙酮苯并呋喃(5-Acetyl-6-hydroxy-2-acetonepenylbenzofuran,2);邻苯二甲酸二乙酯(Diethyl Phthalate,3);β-谷甾醇(β-sitosterol,4);豆甾醇(Stigmasterol,5),其中化合物(1),(2),(3)为首次从该植物中分得.     

High‐performance liquid chromatographic method for the quantification of Mitragyna inermis alkaloids in order to perform pharmacokinetic studies

In Africa, Mitragyna inermis (Willd.) O. Kuntze (Rubiaceae) is commonly used in traditional medicine to treat malaria. Antimalarial activity is mostly due to the hydromethanolic extract of M. inermis leaves and especially to the main alkaloids, uncarine D and isorhynchophilline. In the present study, we describe for the first time an HPLC method for the simultaneous quantification of uncarine D and isorhynchophylline in biological matrices. SPE was used to extract the components and the internal standard naphthalene from human and pig plasma samples. Chromatographic separation was performed on a C‐18 reversed column at a flow rate of 1 mL/min, using methanol–phosphate buffer (10:90, pH 7), as a mobile phase. Good linearity was observed over the concentration ranges of 0.0662–3.31 μg/mL for uncarine D and 0.0476–2.38 μg/mL for isorynchophylline. The precision was less than 12% and the accuracy was from 86 to 107% without any discrepancy between the two species. Uncarine D and isorhynchophylline recoveries were over 80%. These results allowed the quantification of both uncarine D and isorhynchophylline in pig plasma after intravenous administration of M. inermis extract.     

Constituents of Leaves of Uncaria Hirsuta Haviland

Nine compounds, ursolic acid (1), β-sitosteryl glucoside (2), umbelliferone (3), uncarine-A (4), chlorogenic acid (5), rutin (6), neohesperidin (7), quercitrin (8)and afzelin (9) were isolated and characterized from fresh leaves of Uncaria hirsuta. Their structures were elucidated by spectral methods. Among them, uroslic acid (I) exhibited a cytotoxic principle of this plant.