An oligosaccharide-marker approach to quantify specific polysaccharides in herbal formula by LC-qTOF-MS: Danggui Buxue Tang, a case study.

Polysaccharides have broad bioactivities and are major components of water decoction of herb formulae. However, the quality control of polysaccharides remains a challenge. Oligosaccharide-fragment approach has been considered in elucidating chemical structures of polysaccharides, but never been used for quantitation. Using reference chemicals and a real sample Danggui Buxue Tang (DBT) in this study, an oligosaccharide-marker approach was established to quantify specific polysaccharides. Firstly, linear relationships between parent polysaccharides and hydrolysis-produced daughter oligosaccharides were verified using reference polysaccharides. Then in case of DBT, two fluorescence-labeled oligosaccharides with high specificity to individual parent polysaccharides were selected as markers. They were easily isolated and identified. Their potential in quantification of parent polysaccharides were satisfactorily validated in terms of linearity (r≥0.99), repeatability (RSD ≤ 8.4 %), and spike recovery (≥80 %). This method could be a promising approach for quality assessment of polysaccharides in herbal formulae.

Oligosaccharide-marker approach for qualitative and quantitative analysis of specific polysaccharide in herb formula by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry: Dendrobium officinale, a case study.

Qualitative and quantitative analysis of polysaccharides in herb formula remain challenge due to the limited choices of analytical methods concerning the intrinsic characteristics of large molecular mass. Herein, an oligosaccharide-marker approach was newly developed for quality assessment of polysaccharides in herbal materials, using Dendrobium officinale as a case study. This method involved partial acid hydrolysis of D. officinale polysaccharide (DOP) followed by p-aminobenzoic ethyl ester (ABEE) derivatization. Two ABEE-labeled oligosaccharides namely, Te-Man-ABEE and Pen-Man-ABEE, were selected as chemical markers due to their high specificity in herb formula. The linear relationship between the content of these two markers and the content of DOP was then successfully established respectively. The linear relationship was further transformed to that between peak area of chemical markers and DOP content so that chemical markers were not necessary to be isolated for analysis. This linear relationship was systemically validated in terms of precision and accuracy. The results showed that these two oligosaccharide-markers presented a good linear relationship with DOP (R2 ≥ 0.997) in the range of 0.68-16.02 µg. These markers also demonstrated satisfactory precision (RSD < 7.0%), and recovery (91.41%-118.30%) in real sample determination. Additionally, there was no significant difference between the results given by the two chemical markers as the RSD values were not more than 7.0%. While concerning the results given by the oligosaccharide-markers and the previously-published polysaccharide marker, the RSD value was not more than 6.4%. These suggest that the oligosaccharide-marker approach is a simple, quick, and reliable method to qualitatively and quantitatively determine of specific polysaccharide in herb formula.

Antidepressant-like and anti-oxidative efficacy of Campsis grandiflora flower.

OBJECTIVES: Our study aimed to investigate the antidepressant-like effect of ethyl acetate extract of the flowers of Campsis grandiflora (EFCG) in a mice model of chronic unpredictable mild stress (CUMS). METHODS: HPLC-Q-TOF-MS was used to identify the chemical constituents of EFCG. The DPPH assay and ABTS radical-scavenging assay were performed to measure the antioxidant properties. The protective properties of EFCG against H2 O2 -induced oxidative damage were analysed in PC12 cells. The changes of behaviour profiles were investigated by using open-field test, sucrose preference test, forced swimming test (FST) and tail suspension test (TST). Brain tissue samples of mice were collected, and antioxidative measure levels were measured. KEY FINDINGS: The result showed that EFCG had the most active anti-oxidative effect and the protective effect against H2 O2 oxidative injury in PC12 cells. Treatment with the EFCG significantly reduced the depressant-like severity and immobility period as compared with untreated CUMS mice in FST and TST. Moreover, EFCG significantly elevated the contents of superoxide dismutase, Glutathione Peroxidase and decreased the contents of Malonaldehyde (MDA) in mice brain. CONCLUSIONS: Our study found first the antidepressant activity of the EFCG. The results suggested the therapeutic potential of EFCG for depressive disorder.

Chemical constituents of Isodon nervosus and their cytotoxicity.

Two new ent-kaurane diterpenoids, 6,20,15alpha-trihydroxy-6,7-seco-1alpha,7-olide-ent-kaur-16-ene (1) and 7beta,12alpha-dihydroxy-6beta,15beta-diacetoxy-7alpha,20-epoxy-ent-kaur-2,16-dien-1-one (2), together with the six known compounds, were isolated from the aerial part of Isodon nervosus. The structures of the new compounds were determined by spectral methods (1D, 2D NMR, and MS). Six compounds were assayed for their cytotoxicity against HL60, SMMC-7721, and HeLa human cell lines. Compounds 5, 7, and 8 showed significant cytotoxicity.

Cytotoxic ent-kaurane diterpenoids from Isodon macrophyllus.

Two new ent-kaurane diterpenoids, dayecrystals D-E (1-2), together with nine known compounds, isojaponin A (3), rabdosin A (4), lushanrubescensin J (5), wikstroemioidin B (6), maoyecrystal C (7), rabdosin B (8), isodonal (9), shikokianin (10), and effusanin A (11), were isolated from the leaves of Isodon macrophyllus. The structures of the new compounds were elucidated using 1D and 2D NMR spectroscopy. The (13)C-NMR spectral data of compound 4 are reported for the first time. All of the compounds were tested for their cytotoxicities against DU145 and LoVo human tumor cells. Compounds 4, 10, and 11 showed inhibitory effects on DU145 cells with IC(50) values 5.90, 4.24, and 3.16 microM, and LoVo cells with IC(50) values 14.20, 17.55, and 3.02 microM, respectively.

[Chemical constituents of Isodon macrophyllus (II)].

OBJECTIVE: To study the chemical constituents of Isodon macrophyllus. METHODS: Compounds were spearated and purified by silica gel column chromatography and their structures were elucidated on the basis of spectral data and chemical evidences. RESULTS: Six compounds were obtained from EtOAc extract of leaves of Isodon macroplhllus and identified as rabdophyllin H(I), lushan-ruhescensins F(II), maovecrystal J(III), Taibaijap onicain A(IV), rabdosinate(V), dancostero(VI). CONCLUSION: Co mpounds II-IV were isolated from this plant for the first time.

Cytotoxic constituents of Isodon rubescens var. lushiensis.

Five new ent-kaurane diterpenoids, ludongnins F-J (1-5), along with 10 known compounds, guidongnins A-C (6-8), angustifolin (9), 6-epiangustifolin (10), sculponeatin J (11), gardenin D, 5,3',4'-trihydroxy-6,7,8-trimethoxyflavone, pedalitin, and quercetin, were isolated from the leaves of Isodon rubescens var. lushiensis. The structures of 1-5 were determined by spectroscopic analysis, as well as X-ray crystallographic analysis of 1. Compounds 1-11 were evaluated against K562 leukemia cells for their cytotoxic effects.

Diterpenoids from Isodon japonica.

A new ent-kaurane diterpenoid maoyecrystal F (1) and its acetonide derivative (2), together with seven known compounds, lasiodonin, maoyerabdosin, odonicin, enmenin, oridonin, beta-sitosterol and daucosterol, were isolated from the leaves of Isodon japonica.