[Quality standard of Lobeliae Chinensis Herba].

In light of related methods in Chinese Pharmacopoeia(2020 edition), this study established the quality standard for Lobeliae Chinensis Herba. The TLC identification method was established with silica gel GF_(254) thin layer plate, diosmin standard, linarin standard, and the reference material of Lobeliae Chinensis Herba. The loss on drying, total ash, acid-insoluble ash, and ethanol-soluble extracts of 18 batches of Lobeliae Chinensis Herba samples were determined according to the general principles in Chinese Pharmacopoeia. Then, HPLC was adopted in the establishment of characteristic chromatogram and content determination. The results showed that the established method can achieve good separation for diosmin, linarin, and lobetyolin. Based on the results of detection for 18 batches of Lobeliae Chinensis Herba samples, the draft quality standard was established, which was expected to provide reference for the revision of this medicinal herb in Chinese Pharmacopoeia.

Alkaloids with acetylcholinesterase inhibitory activity from Corydalis racemosa (Thunb.) Pers.

Two new isoquinoline alkaloids (1 and 2) along with fourteen known alkaloids (3-16) were isolated from Corydalis racemosa (Thunb.) Pers. Their structures were elucidated by analyzing spectroscopic and spectrometric data (NMR, UV, IR, and MS) and comparing their spectroscopic, spectrometric and physicochemical data with the values archived in the literature. The absolute configurations of new compounds were determined via X-ray crystallographic assay and electronic circular dichroism calculations. Acetylcholinesterase (AChE) inhibitory activity of all compounds was evaluated. Compounds 5, 6, 9, 11, and 12 exhibited inhibitory activity against AChE with IC50 values ranged from 10.2 to 63.4 µM.

[Two new phenylpropanoid amide glycosides from whole plants of Corydalis racemosa].

Two new phenylpropanoid amide glycosides and ten analogues were isolated from the CH_2Cl_2 layer of 95% ethanol extract of the whole plants of Corydalis racemosa by using various chromatographic techniques, including silica gel, Sephadex LH-20, ODS column chromatographies, and semi-preparative HPLC. Their structures were identified on the basis of physicochemical properties, MS, NMR, and IR spectroscopic data as N-cis-sinapoyltyramine-4'-O-ß-glucoside(1), N-cis-sinapoyl-3-methoxytyramine-4'-O-ß-glucoside(2), N-cis-sinapoyltyramine(3), N-cis-feruloyltyramine(4), N-trans-cinnamoyltyramine(5), N-trans-feruloylphenethylamine(6), N-trans-p-methoxycinnamoyl-3-hydoxyoctopamine(7), N-cis-feruloyl-3-methoxytyramine(8), N-trans-feruloyltyramine(9), N-trans-feruloyl-3-methoxytyramine(10), N-trans-sinapoyltyramine(11), and N-trans-p-coumaroyltyramine(12). Compounds 1 and 2 are new compounds. Compounds 3-7 are obtained from the plants of Papaveraceae for the first time, and compounds 8-12 are firstly isolated from C. racemosa.

Benzophenone glycosides from the pericarps of Aquilaria yunnanensis S. C. Huang.

Two new benzophenone glycosides, aquilarisides A (1) and B (2), together with six known analogues (3-8) were isolated from the pericarps of Aquilaria yunnanensis S. C. Huang. Their structures were elucidated on the basis of 1D and 2D NMR and mass spectroscopic analyses, and the absolute configuration of compound 1 was determined by experimental and calculated electronic circular dichroism (ECD) spectra. Anti-inflammatory activities of all compounds 1-8 were evaluated for their inhibitory activities against lipopolysaccharide (LPS)-stimulated induced nitric oxide (NO) production in RAW 264.7 cells using the Griess assay. Compound 2 indicated a weak inhibition of NO production.

Two new polyketides from the fungus Penicillium oxalicum MHZ153.

Two new polyketides, penicilloxalones A (1) and B (2), together with 13 known compounds (3-15), were isolated from the ethyl acetate extract of the solid substrate fermentation cultures of the fungus Penicillium oxalicum MHZ153. The structures of the isolates were determined by spectroscopic analysis and comparison of their spectroscopic and physicochemical data with the literature values. Compounds 7 and 11 showed inhibition of nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells with IC50 values of 0.9 ± 0.2 µM and 87.9 ± 0.7 µM, respectively.

Homoisoflavonoid derivatives from the red resin of Dracaena cochinchinensis.

Five new homoisoflavonoid derivatives, including three meta-homoisoflavanes (1-3), one homoisoflavanone (4), and one homoisoflavan (5), along with five known analogues (6-10), were isolated from the red resin of Dracaena cochinchinensis (Chinese dragon's blood). Their structures were elucidated by analysis of spectroscopic data (1D and 2D NMR, IR, and HRESIMS). The absolute configuration of compound 1 was determined by single-crystal X-ray crystallographic analysis, and those of 2-5 were established on the basis of experimental and computed ECD data. Compounds 4, 6, and 9 exhibited moderate inhibition of nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells with IC50 values of 60.4-75.6 µM.

[Phenylpropanoid amides from whole plants of Corydalis edulis].

Ten phenylpropanoid amides were isolated from the whole plants of Corydalis edulis Maxim. by various of column chromatographies including silica gel, Sephadex LH-20, and ODS. Their structures were identified on the basis of physicochemical properties, MS, NMR, and IR spectroscopic data. These compounds were identified as N-trans-sinapoyl-3-methoxytyramine-4'-O-ß-glucoside(1), N-trans-sinapoyl-3-methoxytyramine(2), N-trans-sinapoyltyramine(3), N-trans-p-coumaroyltyramine(4), N-trans-sinapoyl-7-hydroxytyramine(5), N-cis-feruloyltyramine(6), N-cis-p-coumaroyltyramine(7), N-trans-feruloyltyramine(8), N-trans-feruloyl-3-methoxytyramine(9), and N-trans-feruloyl-7-hydroxytyramine(10). Compound 1 is a new compound. Compounds 2-7 are obtained from the plants of Papaveraceae for the first time, while compounds 8-10 are firstly isolated from C. edulis.

Identification of glutathione and related cysteine conjugates derived from reactive metabolites of methyleugenol in rats.

Methyleugenol (ME), an alkenylbenzene compound, is a constituent of many foods and is used as flavoring agent in foodstuffs and as fragrance in cosmetics. It has been reported that exposure to ME can cause carcinogenicity, cytotoxicity, and genotoxicity. Metabolic activation is suggested to play an important role in ME-induced toxicities. Electrophilic metabolites of ME have been reported to covalently bind to proteins and nucleic acids. The objective of this study was to identify GSH and related cysteine conjugates derived from these reactive metabolites in vivo. Five biliary GSH (M1-M5) and four urinary cysteine conjugates (M6-M9) were detected in rats given ME. M1 and M2 were GSH conjugates derived from the epoxide of ME. M3, M4, and M5 were GSH conjugates possibly generated from the corresponding α,ß-unsaturated aldehyde, carbonium ion, and quinone methide, respectively. The structures of the GSH conjugates were verified by chemical synthesis. Cysteine conjugates M6, M7, M8, and M9 were found to correspond to the respective M1/M2, M3, M4, and M5. The data obtained from the present in vivo work facilitate the understanding of mechanism action of ME toxicities and may provide information suitable for use as biomarkers of exposure to ME.