Undescribed protolimonoids from the root bark of Dictamnus dasycarpus Turcz.

Nine undescribed protolimonoids, including two apotirucallane and seven tirucallane triterpenoids, as well as five known compounds, were isolated from the root bark of Dictamnus dasycarpus Turcz. Their structures were elucidated by extensive spectroscopic analysis. Compounds 4-8, with an undescribed 22,25-epoxytirucallene part, were established their absolute configuration by single-crystal X-ray diffraction of 4. Such compounds might provide evidence for the degradation of protolimonoids to limonoids, bridging an oxidative cleavage biogenetic pathway between these structurally diverse triterpenoids. None of them showed anti-inflammatory, hepatoprotective, or monoamine oxidase B inhibitory activity.

Structures and neuroprotective activities of triterpenoids from Cynomorium coccineum subsp. songaricum (Rupr.) J. Leonard.

Cynomorium coccineum subsp. songaricum (Rupr.) J. Leonard has been widely used as a Chinese herbal remedy or a functional food for treating symptoms of aging or neurodegenerative diseases. A further investigation on the finding of active constituents led to the isolation and identification of four previously undescribed triterpenoids, together with 20 known compounds. Their structures were elucidated by extensive spectroscopic analysis (IR, NMR, HRMS, and CD). Sixteen compounds showed significant neuroprotective effects against glutamate-induced or oxygen-glucose deprivation-induced SK-N-SH cell death. Our findings revealed the active constituents of C. coccineum subsp. songaricum and indicated that both oleanane-type and ursane-type triterpenes could be valuable platforms for neurodegenerative agents based on primary structure-activity relationship analysis.

A full set of 8,4'-oxy-8'-phenylneolignan stereoisomers from Sophora tonkinensis and their absolute configurations by TDDFT.

A full set of 8,4'-oxy-8'-phenylneolignans with four chiral carbons, named (+)/(-)-leptolepisols D1‒D2 and (+)/(-)-sophorols A‒F, were isolated from the roots and rhizomes of Sophora tonkinensis Gagnep., including 14 previously undescribed stereoisomers, along with 2 known leptolepisol D diastereomers. Their planar structures and relative configurations were elucidated by detailed spectroscopic analysis (HRESIMS and NMR). Based on a highly accurate conformer filtering protocol at low computational cost, the absolute configurations of full set 8,4'-oxy-8'-phenylneolignans were completely assigned by TDDFT calculations of ECD spectra for the first time. Furthermore, (+)/(-)-sophorol A, (-)-sophorol B, and (-)-sophorol E could moderately suppress the lipopolysaccharide-induced nitric oxide production in murine macrophages at 10 µM, with inhibitory ratios of 48.4-52.9%.

Antimicrobial alkaloids from the root bark of Dictamnus dasycarpus.

Two new furoquinoline alkaloids, named 1'-oxo-isoplatydesmine (1) and demethoxyacrophylline (2), as well as 11 known alkaloids (3-13) were isolated from the root bark of Dictamnus dasycarpus Turcz. The structures of 1 and 2 were established by detailed spectroscopic elucidation, such as 1 D & 2 D NMR and HRMS, etc. The unexpected autoracemization of 1 was discussed based on the stereochemistry of reported dihydrofuroquinolines. Compounds 3-5 exhibited moderate inhibitory activities against Bacillus subtilis, Candida albicans, and Pseudomonas aeruginosa with MICs 32-64 µg/ml, revealing the active principles of D. dasycarpus for treating skin diseases in its traditional usage.

[Studies on active aromatic constituents from rhizomes of Sophora tonkinensis].

Aromatic constituents from rhizomes of Sophora tonkinensis were purified by extensive chromatographic techniques including column chromatography over macroporous resin,MCI,silica gel,weak acid cation exchange resin,Sephadex LH-20,ODS,and semi-preparative HPLC. Twelve aromatic compounds were isolated and identified from the water aqueous extract of the rhizomes of S.tonkinensis. Their structures were elucidated as 4-( 3-hydroxypropyl) phenol( 1),( ±)-4-( 2-hydroxypropyl) phenol( 2),benzamide( 3),( ±)-3-( p-methoxyphenyl)-1,2-propanediol( 4),4-methoxybenzamide( 5),3-hydroxy-1-( 4-hydroxy-3-methoxyphenyl) propan-1-one( 6),tyrosol( 7),( ±)-2,3-dihydroxypropyl benzoate( 8),vanillin alcohol( 9),7,3'-dihydroxy-8,4'-dimethoxyisoflavone( 10),7,4'-dihydroxy-3'-methoxyisoflavone( 11),and 7,3'-dihydroxy-5'-methoxyisoflavone( 12). Compounds 1-9 were firstly isolated from the Sophora genus. Compounds 4,5,10 and 11 can remarkably protect Hep G2 cell against APAP-induced damage at the concentration of 10 µmol·L-1. Compounds 1-12 exhibited no significant activities on the assays of inhibition of LPS-induced NO production in RAW cell lines and NF-κB inhibition.