Metabolic profiles of Fufang Xiling Jiedu capsule in rats by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry.

Fufang Xiling Jiedu capsule (FXJC), a traditional Chinese medicine that evolved from "Yinqiao Powder", is widely used for the treatment of cold and influenza. However, due to a lack of in vivo metabolism research, the chemical components responsible for the therapeutic effects still remain unclear. Hence, this study aimed to describe the metabolic profiles of the FXJC in rat plasma, urine, and feces. A combined data mining strategy based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was employed and 201 xenobiotics, including 117 prototype components and 84 metabolites were detected. Phenolic acids, flavonoids, triterpenes, and lignans were prominent ingredients absorbed in vivo, and the major metabolic pathways of the detected metabolites were glucuronidation, sulfation, methylation, and oxidation. This is the first systematic study on the metabolism of the FXJC in vivo, providing valuable information for future studies on the efficacy, toxicity, and mechanism of the FXJC.

Muscone suppresses myocardial ischemia damage by regulating PI3K/Akt signaling pathway.

Muscone is the main active compound of Moschus. In this paper, the cardioprotective effect of Muscone on acute myocardial ischemia (AMI) rats and its potential mechanisms were investigated. AMI rat models were established to evaluate the protective effect and antioxidative function of Muscone on the hearts. Moreover, Western blot analysis was conducted to quantify the phosphorylated PI3K and AKT levels in PI3K/Akt pathway for further investigating the mechanism of Muscone. Results showed that Muscone could markedly lessen the infarct size and myocardial injury, improve cardiac function, inhibit cardiomyocyte apoptosis and down-regulate serum reactive oxygen species level as indicated by the decreased MDA, BNP and c-TnI activities and the increased SOD, GSH-px, CAT activities and the expression of Bax protein. In addition, it was revealed that Muscone notably promoted the phosphorylation of PI3K and AKT. These findings denote that Muscone exerts a protective effect in heart via inhibition of oxidative stress and apoptosis, offering new insights into the treatment of CHD and the clinical application of Muscone.

Anti-pandemic influenza A (H1N1) virus potential of Xilingjiedu capsule in vitro.

This study is aimed to investigate the effect of Xilingjiedu capsule (XLC), one of a preparation of traditional Chinese medicine, on influenza A (H1N1) virus as well as its preliminary mechanism. The median cell mortality (TC50) to A549 cells and half effective inhibition concentration (IC50) of influenza A (H1N1) virus of XLC were determined by MTT assay. Reed-Muench method was used to calculated the 50% tissue culture infective dose (TCID50) of H1N1 virus to A549 cells. In mechanism research, the mRNA expression levels of MyD88, TLR4, TLR7 and TRAF6 and the protein expression level of MyD88 were detected by using RT-PCR and Western blot, respectively. The results suggested that XLC showed good anti influenza A (H1N1) virus activity. The antiviral mechanism of XLC was related to the Toll-like signaling pathway. It could drown regulate the mRNA expression level of MyD88 and TLR4 and the protein level of MyD88. This research provides reference for the application of XLC in anti influenza virus.

Investigating the Pharmacological Mechanisms of SheXiang XinTongNing Against Coronary Heart Disease Based on Network Pharmacology and Experimental Evaluation.

SheXiang XinTongNing (XTN), which is composed of six traditional Chinese herbs, is a commercially available Chinese patent medicine that has been widely used as the treatment of coronary heart disease (CHD). Its mechanisms against coronary heart disease, however, remain largely unknown. This study aimed to investigate the pharmacological mechanisms of XTN against CHD via network pharmacology and experimental evaluation. In this study, GO enrichment and KEGG pathway enrichment were firstly performed for acquiring the potentially active constituents of XTN, the candidate targets related to coronary heart disease, the drug-components-targets network as well as the protein-protein interaction network and further predicting the mechanisms of XTN against coronary heart disease. Subsequently, a series of in vitro experiments, specifically MTT assay, flow cytometry and Real-time quantitative polymerase chain reaction analysis, and a succession of in vivo experiments, including Tunel staining and immunohistochemical staining were conducted for further verification. Results showed that Bcl-2, IGF1, CASP3 were the key candidate targets which significantly associated with multiple pathways, namely PI3K-Akt signaling pathway and MAPK signaling pathway. It indicated that the potential mechanism of XTN against CHD may be predominantly associated with cell apoptosis. The in vitro experimental results showed that XTN treatment remarkably decreased the apoptotic rate and Bax/Bcl-2 ratio of H9c2 cells. Histological results confirmed that XTN not only effectively alleviated oxidative damage caused by myocardial ischemia but inhibited cell apoptosis. Given the above, through the combined utilization of virtual screening and experimental verification, the findings suggest that XTN makes a significant contribution in protecting the heart from oxidative stress via regulating apoptosis pathways, which lays the foundations and offers an innovative idea for future research.

Screen of anti-migraine active compounds from Duijinsan by spectrum-effect relationship analysis and molecular docking.

ETHNOPHARMACOLOGICAL RELEVANCE: Duijinsan (DJS) is a famous Chinese medicine prescription composed of Radix scutellariae (RS) and Rhei Radix (RRR), which has been mainly used for treating migraine. AIM OF THE STUDY: This study aimed to uncover the anti-migraine active compounds from DJS and preliminary predicted the pharmacological mechanism by evaluating the spectrum-effect relationship between high-performance liquid chromatography (HPLC) fingerprints and anti-migraine effects of Duijinsan (DJS) extract combined with molecular docking. MATERIALS AND METHODS: HPLC and LC-MS were applied for chemical analyses of DJS extracts in different proportions. Inhibition of DJS extracts on trigeminal nerve cell releasing calcitonin gene related peptide (CGRP) experiment was performed. The active compounds were screened by spectrum-effect relationship analysis and confirmed by molecular docking and the activities of major predicted compounds were validated in vitro. RESULTS: Twenty-six common peaks were assigned and identified from the fingerprints of different proportions DJS extracts. In vitro experimental results showed that DJS extracts inhibited inflammation and release of CGRP from trigeminal nerve cells. Five predicted active compounds, Chrysin 6-C-arabinoside 8-C-glucoside, Chrysin 6-C-glucoside 8-C-arabinoside, baicalin, Chrysin-7-O-Beta-D-glucoronide and Oroxylin A 7-O-glucuronide were sorted out according to spectrum-effect relationship analysis and molecular docking comprehensively. In vitro validation experiments showed that all the predicted compounds inhibited the CGRP releasing and the activation of TRPV1 channel. Baicalin, chrysin-7-O-ß-D-glucuronide and Oroxylin A-7-glucoronide significantly inhibited the activation of TRPV1 channel. CONCLUSION: Chrysin 6-C-arabinoside 8-C-glucoside, Chrysin 6-C-glucoside 8-C-arabinoside, baicalin, Chrysin-7-O-Beta-D-glucoronide and Oroxylin A 7-O-glucuronide which can inhibit the CGRP releasing and the activation of TRPV1 channel were screened as the anti-migraine active compounds by spectrum-effect relationship analysis and molecular docking.

The rapid identification of chemical constituents in Fufang Xiling Jiedu capsule, a modern Chinese medicine, by ultra-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry and data mining strategy.

Fufang Xiling Jiedu capsule is an effective Chinese medicine widely used for the treatment of cold and influenza. However, its chemical constituents had not been determined, which entailed a huge obstacle to further pharmacological studies, clinical-safe medication administration, and quality evaluation. To identify the chemical constituents in Fufang Xiling Jiedu capsule, an efficient and systematic approach using ultra-high-performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry in conjunction with a data mining strategy was adopted in this study. As a result, 145 compounds were qualitatively identified, including 26 phenolic acids, 46 flavonoids, 39 triterpenes, and 34 other compounds, among which 6 were potentially new and 144 were being reported from Fufang Xiling Jiedu capsule for the first time. This research not only provides useful information for quality control of Fufang Xiling Jiedu capsule and its involved single herbs but also serve as basis data for further study of Fufang Xiling Jiedu capsule in vivo. Moreover, it provides a reference for the characterization of the chemical constituents of other Chinese medicine preparations.

Chinese Medicine She-Xiang-Xin-Tong-Ning, Containing Moschus, Corydalis and Ginseng, Protects from Myocardial Ischemia Injury via Angiogenesis.

The Chinese patent medicine She-Xiang-Xin-Tong-Ning (SXXTN) is a clinical medication for coronary heart disease (CHD) and angina pectoris. This study aimed to investigate pharmacological effects of SXXTN and elucidate the role in angiogenesis on human umbilical vein endothelial cells (HUVECs) and acute myocardial ischemia (AMI) rats. We prepared SXXTN to treat the cells to reveal their effects on oxidative stress-damaged cell viability, as well as cell proliferation, migration, and tube formation processes. SXXTN was also used to treat coronary artery ligation-induced acute myocardial ischemia rats to confirm whether it had positive effect on myocardial issues by hematoxylin and eosin (HE), 2,3,5-triphenyltetrazolium chloride (TTC) staining and immunohistochemical staining. We measured the levels of peroxidative damage-related enzymes in cytoplasm and serum by biochemical kits and detected vascular endothelial growth factor (VEGF), angiotensin II (Ang II), thromboxane B2 (TXB2), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1α) levels in cells and rats by enzyme-linked immunosorbent assay (ELISA) kits. The results showed that SXXTN protects HUVECs against oxidative stress damage and reversed the decrease of superoxide dismutase (SOD), glutathione (GSH) and increase of creatine kinase (CK), lactate dehydrogenase (LDH) caused by oxidative stress. SXXTN promoted angiogenesis through stimulating cell migration, tube formation, and activating VEGF/VEGFR2 and ERK1/2 pathways. Furthermore, SXXTN reduced infarct size and inhibited PGI2/TXA2 imbalance, preventing atherosclerosis plaque rupture leading to worsening coronary heart disease. Taken together, we report the first in vivo and in vitro evidence that SXXTN reduced oxidative stress-mediated damage and enhanced angiogenesis, which might be useful in treatment of myocardial infarction.

Jinbei Oral Liquid ameliorates bleomycin-induced idiopathic pulmonary fibrosis in rats via reversion of Th1/Th2 shift.

Objective: Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal interstitial lung disease with high mortality. The pivotal role of Th1/Th2 immunological balance in the development and progression of IPF has been demonstrated previously. This study aimed to evaluate the effect of Jinbei Oral Liquid (JBOL) on IPF and its relationship with Th1/Th2 shift. Methods: Rats were divided into six groups: control group, model group (bleomycin), pirfenidone group (positive group, 54 mg/kg, i.g.) and JBOL (5.4, 10.8 and 21.6 mL/kg, i.g.) groups. The rat model was established by an intratracheal instillation of bleomycin (BLM, 5 mg/kg). One day after injection of BLM, pirfenidone or JBOL was given to rats once daily within 28 consecutive days, respectively. Positron emission tomography/computed tomography (PET/CT) was performed on the treated rats. The extent of alveolitis and fibrosis was observed by H&E and Masson trichrome staining. The contents of TGF-ß1, TNF-α, IL-4 and IFN-γ were further quantified by ELISA assay. Results: PET/CT and histopathological evidence showed the ability of JBOL to attenuate bleomycin-induced alveolitis and fibrosis extent, and the alveolitis lesion score was markedly decreased compared with the model group. The increased expression of inflammatory cytokines TGF-ß1 and TNF-α induced by bleomycin was also suppressed by JBOL. The Th1 response was limited by the reduced IFN-γ after BLM administration, and the Th2 response predominated significantly marked by the increased IL-4. JBOL could increase the level of IFN-γ and markedly increased the ratio of IFN-γ/IL-4. Conclusion: These findings suggested that JBOL may attenuate BLM-induced idiopathic pulmonary fibrosis via reducing inflammatory cell infiltration, pro-inflammatory cytokine release and excessive collagen deposition in rats. One of the mechanisms is the reversion of Th1/Th2 shift caused by BLM.

[A new aurone with anti-inflammatory activity from Cleistocalyx operculatus flower buds].

A new compound(Z)-6-hydroxy-4-methoxy-5,7-dimethylaurone was isolated from Cleistocalyx operculatus flower buds. Its structure was identified by spectroscopic data including MS, ¹H-NMR, ¹³C-NMR HSQC and HMBC. A known compound, 2',4'-dihydroxy-6'-methoxy-3'5'-dimethylchalcone (DMC), was also isolated and identified,and used as material to synthesize (Z)-6-hydroxy-4-methoxy-5,7-dimethylaurone.Anti-inflammatory activities of the two compounds were tested in vitro. The results showed that (Z)-6-hydroxy-4-methoxy-5,7-dimethylaurone possesses much stronger PGE2 inhibitory activity (IC50 6.12 nmol·L⁻¹) than the positive control ibuprofen （68.66 nmol·L⁻¹ï¼‰.

[Simultaneous determination of thirteen components in Tong'an injection by LC-MS/MS].

The aim of this study was to develop a simple, sensitive ultra performance liquid chromatography mass spectrometry (UPLC-MS/MS) method for the determination of syringaresinol, N-trans-feruloyltyramine, chelerythrine chloride, sinomenine, coptisine chloride, sanguinarine, chelidonine, magnolflorine, allocryptopine, protopine, farrerol, stylopine and dihydrosanguin-arine in Tong'an injection (TAI), which could be used for the quality control of TAI. The UPLC analysis was performed on Agilent Zorbax SB-Aq column (2.1 mm×150 mm,3.5 µm), with 0.1% formic acid solution (A) -acetonitrile (B) as the mobile phase for gradient elution (0.01-2 min, 5%B; 2-8 min, 5%-30%B; 8-11 min, 30%-95%B; 11-13 min, 95%B; 13-13.1 min, 95%-5%B; 13.1-14 min, 5%B). The flow rate was 0.5 mL•min⁻¹, and the column temperature was 25 ℃; multiple reaction monitoring (MRM) was performed in electrospray ion source positive ion mode for quantitative determination. The calibration curves for the above thirteen compounds showed good linear relationship in corresponding mass concentration range (r>0.999 0). The average recovery rate of the compounds ranged from 95.70% to 104.8%, with RSD of less than 1.9%. The contents of thirteen active components in 10 batches of TAI were 0.021 2-0.029 0, 0.001 7-0.002 3, 0.000 9-0.001 3, 5.952-6.205 2, 0.195 4-0.240 5, 0.002 0-0.002 9, 0.693-0.798 2, 0.069 3-0.078 2, 0.089 29-0.102 9, 0.386 5-0.420 1, 0.014 3-0.015 9, 0.755 3-0.842 1, and 0.008 2-0.011 2 g•L⁻¹ respectively. Methodology validation proved that this method was simple, rapid, sensitive and accurate, which can be used to provide reference for the comprehensive evaluation of TAI quality. The determination results of 10 batches of TAI showed the content of each batch had no significant difference. The results may provide a basis for the quality control of TAI.

[Simultaneous determination of eleven components in Ginkgo biloba leaves by high performance liquid chromatography method].

To study Ginkgo biloba leaves in different producing area, we establish an HPLC method for the simultaneously determination of seven flavonoids glycosides and four biflavonoids in G. biloba leaves. The analysis was performed on an Agilent ZORBAX SB-C18 column(4.6 mm×250 mm, 5 µm) wich acetonitrile, and 0.4% phosphoric acid as mobile phase at flow rate of 1 mL•min⁻¹ in a gradient edution, and the detection was carried out at 254 nm.The calibration curves of the seven flavonoids glycosides and four biflavonoids had a good linearitiy with good recoveries. The established HPLC method is simple, rapid, accurate, reliable, and sensitive, and can be applied to the identification and quality control of G. biloba leaves.

A new hetero dimeric terpenoid derivative, japonicaside C, from the flower buds of Lonicera japonica.

A rare hetero dimeric terpenoid derivative, named japonicaside C, together with five known secoiridoid gloucosides were isolated from the flower buds of Lonicera japonica. The structures of these compounds were established on the basis of spectroscopic analyses. Japonicaside C is the first representative of a novel type of hetero dimeric terpenoid, biogenetically originated from a guaiane-type sesquiterpenoid and a secoiridoid glucoside. Anti-virus activity of the isolated compounds was evaluated in vitro.

[Research on Chinese medicine pairs effects of Panax notoginseng and Bletilla striata before and after compatibility on contents of notoginsenosides].

To discuss the synergistic mechanism of compatible use of two medicinal herbs,Panax notoginseng and Bletilla striata, an HPLC was established to determine two ginseng saponins (20S)-ginseng saponin Rg3 and ginseng saponin Rh4 contained in single decoction of Panax notoginseng as well as in compound decoction of Panax notoginseng and Bletillastriata in different compatibility ratio (1∶0.5, 1∶1, 1∶2), followed by analyzing the impact of amount of notoginsenosides after compatibility. As a result, compared with the single decoction of Panax notoginseng, the contents of ginseng saponin Rg3 and ginseng saponin Rh4 in the compound decoction of Panax notoginseng and Bletillastriata were on the rise as the increasement of the amount of Bletillastriata. The contents of the notoginsengsaponin R1, ginseng saponin Rg1 and ginseng saponin Rb1 of Panax notoginseng single decoction were significantly decreased after compatibility. Therefore, after compatibility, it was more easy to produce (20S)-ginseng saponin Rg3 and ginseng saponin Rh4.This study can extend to a method of preparation of (20S)-ginseng saponin Rg3 and ginseng saponin Rh4. Furthermore, after compatibility, two ginseng saponins which had lipase inhibitory effect were both increased significantly, indicating that the compatibility of these two herb medicines may have effect on losing weight.

[Effect of rat intestinal flora in vitro on metabolites of acteoside].

Acteoside was used for anaerobic incubation with rat intestinal flora in vitro. HPLC was used to detect the changes of acteoside at different incubation time points and HPLC-Q-TOF-MS was used to identify the metabolites of acteoside. The results showed that acteoside could be metabolized by rat intestinal flora in vitro and the metabolites were 3,4-dihydroxyphenyl acid, caffeic acid and 3-(3'-hydroxyphenyl) propionic acid.

[Effect of rat intestinal flora on in vitro metabolic transformation of pumiloside].

To study the metabolic transformation of pumiloside by rat intestinal flora in vitro and identify its metabolites. Pumiloside was incubated in the rat intestinal flora in vitro. HPLC was used to monitor the metabolic process, and HPLC-Q-TOF-MS was used to identify the structures of biotransformation products. In vitro, pumiloside was easily metabolized by rat intestinal flora, and with the prolongation of metabolic time, pumiloside was transformed into several metabolites. Three metabolites were initially identified in this experiment. The study indicated that pumiloside could be extensively metabolized in the rat intestinal flora in vitro.

[Study on chemical constituents from seed of Oroxylum indicum].

Oroxylum indicum was a traditional Chinese medicine. In order to study the chemical constituents from the seed of O. indicum, the chemical constituents of 80% methanol extract of seeds of O. indicum were subjected to chromatography on silica gel, Sephadex LH-20, and preparative HPLC, leading to the isolation of eleven compounds. The structures were identified by various spectroscopic data including ESI-MS, 1H-NMR and 13C-NMR data as oroxin B (1), chrysin (2), baicalein (3), neglectein (4), quercetin-3-O-ß-D-galactopy ranoside (5), quercetin-7-O-ß-D-glucopyranoside (6), 2α,3ß-dihydroxylluPeol (7), lupeol (8), rengyol (9), ß-sitostero (10), and stigmasterol (11). Among them, compound 5 were firstly obtained from O. indicum.

[Traditional Chinese medicine pairs (III)--effect of extract of Ginseng Radix et Rhizoma and Puerariae Lobatae Radix on intestinal absorption in rats].

This study focused on the intestinal absorption of traditional Chinese medicines (TCM) to reveal the scientific connotation of the compatibility of TCM pairs. The single pass intestinal perfusion (SPIP) was used in rats to compare the absorption of single extracts from Puerariae Lobatae Radix, single extracts from Ginseng Radix et Rhizoma, combined extracts from Puerariae Lobatae Radix and Ginseng Radix et Rhizoma and Puerariae Lobatae Radix and Ginseng Radix et Rhizoma mixture in rats. The content of puerarin, ginsenoside Rg1, ginsenoside Re and ginsenoside Rb1 in liquid were tested by HPLC. The speed constant (Ka) and apparent permeability coefficients (Papp) were calculated and compared. Specifically, the order of puerarin Ka and Papp values from high to low was Ginseng Radix et Rhizoma and Puerariae Lobatae Radix mixture > single extracts from Puerariae Lobatae Radix > combined extracts from Ginseng Radix et Rhizoma and Puerariae Lobatae Radix; the order of ginsenosides Ka and Papp values from high to low was Ginseng Radix et Rhizoma and Puerariae Lobatae Radix mixture > single extracts from Ginseng Radix et Rhizoma > combined extracts from Ginseng Radix et Rhizoma and Puerariae Lobatae Radix. The combined administration of Ginseng Radix et Rhizoma and Puerariae Lobatae Radix may improve the absorption in the intestinal tract.

Study on the anti-gout activity of chlorogenic acid: improvement on hyperuricemia and gouty inflammation.

Gout is a metabolic disorder associated with hyperuricemia resulting in the deposition of monosodium urate (MSU) crystals in joints and tissues. Lowering serum uric acid (Sur) levels and anti-inflammation are highly essential in treating gout. Chlorogenic acid (CA), as one of the most abundant polyphenols in the Chinese medicines, has been rarely reported to have an anti-gout effect. The model of potassium oxonate (PO)-induced hyperuricemia in mice and MSU crystal-induced inflammation in rats has been established in this study. The potential beneficial effects and mechanisms of CA on hyperuricemia and gouty arthritis were elucidated. The results demonstrated that CA significantly decreased the Sur level by inhibiting the xanthine oxidase (XOD) activity but not increasing the urinary uric acid (Uur) level. In addition, CA also exhibited the effect of suppressing paw swelling. Further investigation indicated that CA improved the symptoms of inflammation induced by MSU crystals by inhibiting the production of proinflammatory cytokines including interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). The present study suggests that CA may have a considerable potential for development as an anti-gouty arthritis agent for clinical application.

In vivo anti-inflammatory and analgesic activities of strictosamide from Nauclea officinalis.

CONTEXT: Strictosamide is the main representative constituent of Nauclea officinalis Pierre ex Pitard (Rubiaceae), which has been used for a long time in China to treat diseases related to infection and inflammation, but its pharmacological activities are not well studied. OBJECTIVE: This work evaluates the anti-inflammatory and analgesic activities of strictosamide by in vivo experiments. MATERIALS AND METHODS: The anti-inflammatory activity was assessed in mice by models of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema, acetic acid-elevated vascular permeability, and carboxymethylcellulose sodium (CMC-Na)-induced leukocyte migration. The analgesic activity was estimated in mice using acetic acid-induced writhing and hot-plate tests. Compound was injected to mice twice a day for 3 d at doses of 10, 20, and 40 mg/kg. RESULTS: At 20 and 40 mg/kg, strictosamide obviously decreased the TPA-induced mice ear edema (24.7 and 28.1% inhibition, respectively), and significantly inhibited acetic acid-stimulated peritoneal vascular permeability in mice (23.3 and 33.4% inhibition, respectively). It also significantly decreased the leukocytes in the mice peritoneal cavity induced by CMC-Na at all the tested doses (46.0, 49.1, and 58.7% inhibition, respectively). To acetic acid-induced writhing test in mice, strictosamide markedly prolonged the pain latency at 20 and 40 mg/kg and decreased the writhing counts at 40 mg/kg (49.7% inhibition). However, it did not obviously improve the pain threshold of mice in hot-plate test. DISCUSSION AND CONCLUSION: Strictosamide may have important effects on inflammation and inflammatory pain. The results provide scientific support for the role of strictosamide in the use of N. officinalis to treat inflammatory diseases.

Transformation of strictosamide to vincoside lactam by acid catalysis.

AIM: To identify the structure of the acid-catalyzed product of strictosamide and explore the reaction mechanism. METHODS: The acid-catalyzed reaction process of strictosamide was monitored by HPLC, and a macroporous resin was used to purify the reaction solution. The structure of the product was confirmed by MS, NMR, and ROESY spectra. RESULTS: The acid-catalyzed transformation yield from strictosamide to vincoside lactam was 52%. CONCLUSION: The reaction mechanism of the transformation from strictosamide to vincoside lactam may be related to the stability of the three-dimensional configuration of the compound. These results offer a new way to obtain vincoside lactam from the widely distributed indole alkaloid strictosamide by acid-catalysis.