Study on characterization of Bupleurum chinense polysaccharides with antioxidant mechanisms focus on ROS relative signaling pathways and anti-aging evaluation in vivo model.

This study explored the structures of three polysaccharides from Bupleurum chinense DC. (BCPRs), and evaluated their antioxidant and anti-aging properties. The HPGPC and ion chromatography analyses revealed that the molecular weights of the BCPRs ranged from 12.05 to 21.20 kDa, and were primarily composed of rhamnose, arabinose, xylose, galactose, glucose and galacturonic acid. Methylation and NMR studies identified 10 PMAAs, establishing the various backbones of BCPRs 1-3. BCPR-3 demonstrated potent antioxidant activities, including DPPH, ABTS, hydroxy, and superoxide radicals scavenging in vitro. At concentrations between 125 and 500 µg/mL, BCPR-3 increased T-AOC, SOD and GSH-Px activities, while decreasing MDA levels in H2O2-induced SH-SY5Y cells. In addition, RNA-seq results indicated that BCPR-3 considerably downregulated the expression of 49 genes and upregulated five genes compared with the control group. KEGG analysis suggested that these differentially expressed genes (DEGs) were predominantly involved in the TNF and PI3K/Akt signaling pathways. Furthermore, in vivo experiment with Drosophila melanogaster showed that BCPR-3 could extend the average lifespan of flies. In conclusion, polysaccharides from B. chinense exhibited potential antioxidant and anti-aging activities, which could be developed as new ingredients to combat oxidative stress damage and slow the aging process.

Caffeoylquinic acids protect against alcoholic liver injury and rare C10 acetylenic acids from Erigeron breviscapus.

Three new compounds (1-2, 4) along with ten known ones (3, 5-13), were isolated from the whole plant of Erigeron breviscapus. Compounds 1 and 2, two novel C10 acetylenic acids and compound 4, a jasmone glucoside were elucidated by the detailed analysis of 1D and 2D NMR, HRESIMS spectra, and experimental and calculated electronic circular dichroism (ECD). Compounds 1-3 represent the first example of acetylenic acids incorporating C10 skeleton from E. breviscapus. In addition, the antioxidant effects of all compounds were evaluated by ferric reducing power, 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate acid) (ABTS) and 2.2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. Our results indicated the significant antioxidant activity of caffeoylquinic acids. Additionally, compounds 10-11 and 13 played protective role on alcoholic liver injury cells in a dose-dependent manner.

Prenylated flavonoids with significant anti-hepatoma activity from Daphne giraldii and effects on Fibroblast Growth Factor Receptor 1 (FGFR1).

We report here the orchestration of molecular ion networking (MoIN) and a set of computational and informatics assisted structural elucidation approaches in the discovery of 23 new prenyl-flavonoids and 13 known molecules from Daphne giraldii Nitsche (Thymelaeaceae), some of which possess significant bioactivity against hepatoma carcinoma. Daphnegiratriprenylone A (DPTP-A) represents the class of polyprenyl-flavonoids possessing a triprenyl substitution, and was identified with the guidance of mass spectrometry and nuclear magnetic resonance combined with computational approaches. This approach illustrates a paradigm shift in the application of computational tools for the direct assignment of new natural product structures and it was demonstrated to be reliable compared to conventional 2D-NMR techniques. Seventeen compounds exhibited potent and selective activity against Hep3B cells (IC50 ranging from 0.42 to 7.08 µM). Tyrosine kinase FGFR1 has emerged as a potential target of polyprenyl-flavonoids by a reverse pharmacophore mapping approach. We validated that the prenyl-flavonoids effectively inhibit FGFR1 using the Mobility Shift Assay, Western blot and molecular dynamics simulations, and the results suggest significant potency of the compounds towards FGFR1. These findings provide a new chemical class with strong links to traditional medicines, possessing reasonable safety for developing potential therapeutic agents for FGFR1-related diseases.

Network pharmacology-based approach to investigate the mechanisms of Zingiber officinale Roscoe in the treatment of neurodegenerative diseases.

Neurodegenerative diseases (NDDs) are chronic neurological disorders associated with cognitive or motor dysfunction. As a common spice, Zingiber officinale Roscoe has been used as a medicine to treat a variety of NDDs. However, at the molecular level, the mechanisms of Z. officinale in treating of NDDs have not been deeply investigated. In this study, network pharmacology method, molecular docking, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were used to predict the mechanisms of Z. officinale in the treatment of NDDs. After a series of biological information analyses, five core targets were obtained, including heme oxygenase 1 (HMOX1), acetylcholinesterase (AChE), nitric oxide synthase (NOS), catechol-O-methyl-transferase (COMT), and metabotropic glutamate receptor 5 (mGluR5). Compounds 75, 68, 46, 67, 69, 49, 66, 50, 34, and 64 were identified as the main components of Z. officinale in the treatment of NDDs. The crucial pathways mainly include neuroactive ligand-receptor signaling pathways, cyclic adenosine monophosphate signaling pathways, dopamine synaptic signaling pathways, and so on. Besides, in vitro experiments by AChE inhibitory activities assay and neuroprotective activities against H2 O2 -induced injury in human neuroblastoma SH-SY5Y cells validated the reliability of the results of network analysis. PRACTICAL APPLICATIONS: Zingiber officinale Roscoe is widely used as a traditional spice and herbal medicine. It contains a number of active ingredients, which have shown activities on anti-neurodegenerative diseases (NDDs). In this paper, the potential mechanism of Z. officinale in the treatment of NDDs is explored through network pharmacology, and it was verified by in vitro experiments. The mechanism was not only clarified at the system level but also proved to be effective at the biological level. The results can be used as a reference for Z. officinale in the treating of NDDs.

Isolation of triterpenoid saponins from Medicago sativa L. with neuroprotective activities.

Three new pentacyclic triterpenoid saponins (1-3), together with medicagenic acid (4) were isolated and purified from 70% EtOH extract of Medicago sativa L. by different column chromatographic and semi-preparative HPLC. Their structures were established by direct interpretation of their spectral data, mainly HR-ESI-MS, 1D-NMR, 2D-NMR, and chemical methods, as well as comparison with literature data. Additionally, all isolates were evaluated for their neuroprotective activities against H2O2-induced damage in human neuroblastoma SHSY5Y cells. As a results, compounds 1 and 2 (67.14% and 73.05%) exhibited potent neuroprotective activities. These findings provide new insights into developing better treatment of neurodegenerative diseases for M. sativa in the future.

Structural features, selenization modification, antioxidant and anti-tumor effects of polysaccharides from alfalfa roots.

Hot water extraction and chromatographic purification methods were used to extract and purify two polysaccharides (RAPS-1 and RAPS-2) from the roots of alfalfa. Subsequently, RAPS-2 was modified using the HNO3/Na2SeO3 method to obtain Se-RAPS-2. The structural features, antioxidant and in vitro anti-tumor activities of the three polysaccharides were evaluated. The structural analysis revealed that RAPS-1 (Mw = 10.0 kDa) was composed of rhamnose, xylose, arabinose, galacturonic acid, mannose and glucose, whereas RAPS-2 (Mw = 15.8 kDa) consisted of rhamnose, xylose, galacturonic acid, mannose, glucose and galactose. RAPS-1 contained 1 â†’ 2, 1 â†’ 4, 1 â†’ 3, and 1 â†’ 6 or 1 â†’ glycosidic bonds; however, while RAPS-2 lacked 1 â†’ 4 glycosidic linkages. The molecular weight of Se-RAPS-2 was 11.0 kDa less than that of RAPS-2. The results of activities demonstrated that Se-RAPS-2 displayed superior antioxidant activity and inhibitory effect in HepG2 cells than RAPS-1 and RAPS-2.

Structural characteristics of Medicago Sativa L. Polysaccharides and Se-modified polysaccharides as well as their antioxidant and neuroprotective activities.

Medicago Sativa L., a nutrient-rich plant used as feed for cattle and sheep, is widely planted globally. This study investigated the structural characteristics and activities of three kinds of novel polysaccharides (APS1, APS2 and APS3) isolated from the stems of M. sativa as well as its two selenium modified products (Se-APS2 and Se-APS3). APS1 (Mw = 13.4 KDa) and APS2 (Mw = 11.2 KDa) were composed of rhamnose, arabinose, mannose and galactose with different molar ratio, APS3 (Mw = 18.6 KDa) was composed of rhamnose, arabinose, fructose, mannose and galactose. All APS1-3 contained 1 â†’ 3 : 1 â†’ 6 : 1 â†’ 4 : 1 â†’ 2 glycosidic bonds in a ratio of 0.74:0.09:0.05:0.12, 0.34:0.20:0.36:0.10 and 0.63:0.17:0.06:0.14, respectively. The selenium content of Se-APS2 (Mw = 9.0 KDa) and Se-APS3 (Mw = 10.2 KDa) were 1.05 and 2.57 µg/mg, respectively. Their surface morphology and thermal stability were determined by scanning electron microscope (SEM) and thermal analysis (TGA), respectively. Further, the antioxidant and neuroprotective activities of the three natural polysaccharides and two Se-polysaccharides were studied. Interestingly, Se-polysaccharides not only exhibited higher antioxidant activity, but also higher neuroprotective activity compared to natural polysaccharides.

Neogenkwanine I from the flower buds of Daphne genkwa with its stereostructure confirmation using quantum calculation profiles and antitumor evaluation.

Neogenkwanine I (1), a new daphnane-type diterpene with 4,7-ether group, along with four known ones (2-5), were isolated from Daphne genkwa. The structure including absolute configurations of 1 was established on the basis of NMR, 13C-NMR and ECD calculations and CD exciton chirality analysis. 13C-NMR and ECD calculations of daphnane-type diterpenes were reported here for the first time. All of the diterpenes were screened for their cytotoxic activities against MCF-7 and Hep3B cell lines. The cytotoxicity structure- activity relationship of compounds was illustrated with the absence of ortho-ester group of daphnane-type diterpenes.

A network pharmacology study on the triterpene saponins from Medicago sativa L. for the treatment of Neurodegenerative diseases.

Neurodegenerative diseases (NDDs) are characterized by progressive and irreversible, is a kind of complex illnesses, and the long-term therapy which is frequently associated with adverse side effects. Medicago sativa L., widely consumed as a vegetable, has the effects of improving memory and relieving central nervous system diseases. However, there are less studies on its specific mechanism for NDDs. In this investigation, we applied a method of network pharmacology, which combined molecular docking and network analysis to decipher the mechanisms of M. sativa in NDDs. The pharmacological system generated 55 triterpene saponins from M. sativa, and predicted 27 potential targets with 100 pathways in the treatment of NDDs. As a result, 13 compounds, 10 target proteins, and 6 signaling pathways were found to play important roles in the treatment of NDDs. In addition, in vitro experiments of isolates confirmed activities for NDDs, which were consistent with the results of network pharmacology prediction. PRACTICAL APPLICATIONS: Medicago sativa L. has been widely consumed as a vegetable, which possesses many nutritional components. As a functional food stuff, M. sativa can improve human health, such as memory improving activities, relieving central nervous system diseases, immunomodulatory, antioxidant, anticancer, and anti-inflammatory. In this article, the mechanism of triterpene saponins from M. sativa against NDDs was successfully predicted by network pharmacology method. The results will serve as a reference of M. sativa against NDDs.

Sesquiterpenoids and γ-pyranone derivatives from the whole plant of Erigeron breviscapus and their neuroprotective effects.

Four new sesquiterpenes (1-2, 6-7), a new pyranone glycoside (10) along with six known compounds, were isolated from the whole plant of Erigeron breviscapus. Their planar structures were elucidated using extensive spectroscopic analyses. Brevisterpene A (1) and brevisterpene B (2) were proved to be a pair of diastereomer followed by mixtures resolution using chiral HPLC. Their absolute configurations were determined by ECD calculation. The relative configuration of brevisnoside B (7) was elucidated by a combined analysis of NOESY spectrum and computation of 13C NMR chemical shifts, and determination of the absolute configurations of 6 and 7 assisted by optical rotation calculations. Compounds 1 and 2 displayed moderate neuroprotective effects against H2O2-induced damage in SH-SY5Y cells.

Daturanolide A-C, Three New Withanolides from Datura metel L. and Their Cytotoxic Activities.

Three new withanolides (1-3), named as daturanolide A-C, along with six known withanolides (4-9) were isolated from the flowers of Datura metel L. Their structures with absolute configurations were elucidated by a series of spectroscopic methods, electronic circular dichroism (ECD) analyses, and X-ray crystallography. All the isolates were evaluated for cytotoxicity against five human cancer cell lines (HCT116, U87-MG, NCI-H460, BGC823, and HepG2), and 6 exhibited marked cytotoxicity.

Antiplatelet aggregation and antithrombotic benefits of terpenes and flavones from hawthorn leaf extract isolated using the activity-guided method.

Hawthorn is a well-known functional food; at present, increasing attention has been given to hawthorn leaf due to its numerous functional and nutritional properties. In this study, the antithrombotic properties of hawthorn leaves were evaluated using the activity-guided isolation process and high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS). A crude extract prepared in 75% ethanol was fractionated using macroporous resin D101 and polyamide chromatography to obtain three active fractions (Fr.C, Fr.C-1 and Fr.C-2). Thereafter, the inhibitory activities of these fractions were examined by platelet aggregation and antithrombus assays using a zebrafish model. Using the HPLC-QTOF-MS technique, we identified 25 compounds in the active fraction (Fr.C). The structures of these compounds were identified by comparing the retention time (tR) and mass spectral data from the previous reports and 19 reference compounds. Based on the analysis, 21 peaks were detected in the mass spectrum of Fr.C-1 and 8 peaks were detected in Fr.C-2, we found that 11 compounds in Fr.C-1 exhibited potent inhibitory effects on platelet aggregation, including nine monoterpenoids, one diterpenoid and one flavanone. Accordingly, monoterpenoids are suggested as the main anti-platelet aggregation constituents from hawthorn leaves. Particularly, compounds 10 and 24 inhibited ADP-induced platelet aggregation and delayed FeCl3-induced thrombus in zebrafish. Furthermore, interactions between compounds 10 and 24 with two ADP receptors P2Y1 and P2Y12, serving as the target for key regulators of antiplatelet aggregative activity, were investigated via molecular modeling. In addition, five flavones were obtained from the active fraction (Fr.C-2). These results indicated that monoterpenoid glycosides and some flavones were responsible for the antithrombotic activity of hawthorn leaves. Moreover, this study shows that the activity-guided isolation is a fast, efficient and systematic separation method for the identification of active compounds in natural products.

Network pharmacology and RNA sequencing studies on triterpenoid saponins from Bupleurum chinense for the treatment of breast cancer.

Breast cancer remains the most commonly diagnosed malignancy among women, which is frequently associated with adverse side-effects and high metastasis. Bupleurum chinense DC. has been empirically and extensively used as the core prescription for more than half of Chinese formulations for the adjuvant therapy of breast cancer, and its biological activity against breast cancer has been proven by both in vitro and in vivo experiments. Saikosaponin compounds are the characteristic constituent of B. chinense, which exhibit significant cytotoxicity toward several cancer cells. However, the specific mechanisms of these compounds in the treatment of breast cancer have not been comprehensively understood. Therefore, we aimed to determine more potentially therapeutic targets and investigate the biological mechanisms of B. chinense. In the present study, we adopted network pharmacology and bioinformatics analysis to facilitate this requirement. Consequently, the network analysis revealed that saikosaponin-f (39), saikosaponin-d (14), saikosaponin-c (26), saikosaponin-h (54), saikosaponin-g (41), 3'',6''-O-diacetylsaikosaponin-d (20), 11α-methoxy-saikosaponin-f (40), and 6''-O-acetylsaikosaponin-b1 (48) might play important roles in the treatment of breast cancer. In addition, the apoptosis regulator Bcl-2 (BCL-2), C-X-C chemokine receptor type 4 (CXCR4), probable ATP-dependent RNA helicase DDX5 (DDX5), protein kinase C alpha (PRKCA), and proto-oncogene tyrosine-protein kinase Src (SRC) were the potential therapeutic targets that exhibited intense interactions. Mechanistically, a gene enrichment analysis revealed that the action of B. chinense against breast cancer was achieved by the regulation of several biological signaling pathways, such as pathways in cancer, PI3K-Akt signaling pathway, EGFR tyrosine kinase inhibitor resistance, microRNAs in cancer, etc. More importantly, we verified that the predictions involving saikosaponin-d by the cytotoxicity assay, apoptosis analysis, and RNA sequencing methods were partly consistent with those obtained from the network pharmacology prediction.

Neuroprotective effects of triterpenoid saponins from Medicago sativa L. against H2O2-induced oxidative stress in SH-SY5Y cells.

Medicago sativa L. is a forage legume plant widely distributed in all continents. Six new triterpenoid saponins, Medicagosides A-F (1-6) and five known ones (7-11) were isolated from M. sativa. Their structures were determined via HRESIMS, 1D and 2D NMR analysis. Biologically, all the isolates displayed neuroprotective activities against H2O2-induced damage in SH-SY5Y cells. Among them, compounds 1, 3-5 and 10 exhibited striking neuroprotective activities at 100 µM, restoring cell viability range from 79.66% to 89.03%, relative to 79.46% (100 µM) of Trolox used as the positive control.

Unusual cadinane-type sesquiterpene glycosides with α-glucosidase inhibitory activities from the fruit of Cornus officinalis Sieb. et Zuuc.

Five novel and rare cadinane-type sesquiterpene glycosides, cornucadinoside A-E (1-5) were isolated from water extract of the fruit of Cornus officinalis Sieb. et Zuuc.. The new chemical structures, together with their absolute configurations, were elucidated on the basis of extensive spectroscopic analysis, including a comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. Their structures, which possess a naphthalene skeleton, are the first report on the occurrence of cadinane sesquiterpene glycosides in Cornus. Additionally, all the compounds exhibited marked α-glucosidase inhibitory activity except for 3in vitro.

Novel sarsasapogenin-triazolyl hybrids as potential anti-Alzheimer's agents: Design, synthesis and biological evaluation.

Sarsasapogenin, an active ingredient in Rhizoma anemarrhenae, is a promising bioactive lead compound in the treatment of Alzheimer's disease. To search for more efficient anti-Alzheimer agents, a series of novel sarsasapogenin-triazolyl hybrids were designed, synthesized, and evaluated for their Aß1-42 aggregation inhibitory activities. Most of these new hybrids displayed potent Aß1-42 aggregation inhibition. In particular, the promising compounds 6j and 6o displayed a better ability to interrupt the formation of Aß1-42 fibrils than curcumin. Moreover, 6j and 6o exhibited moderate neuroprotective effects against H2O2-induced neurotoxicity in SH-SY5Y cells. To investigate whether 6j and 6o could improve cognitive deficits, we performed behavioral tests to examine the learning and memory impairments induced by intracerebroventricular injection of Aß1-42 (ICV-Aß1-42) in mice and TUNEL staining to observe neuronal apoptosis in the hippocampus. The results obtained indicated that oral treatment with 6j and 6o significantly ameliorated cognitive impairments in behavioral tests and TUNEL staining showed that 6j and 6o attenuated neuronal loss in the brain. Taken together, the results we obtained showed that the sarsasapogenin skeleton could be a promising structural template for the development of new anti-Alzheimer drug candidates, and compounds 6j and 6o have the potential to be important lead compounds for further research.

The neuroprotective and antioxidant profiles of selenium-containing polysaccharides from the fruit of Rosa laevigata.

Rosa laevigata fruit has been known as a functional foodstuff for a long time. Recently, increasing attention has been given to polysaccharides from R. laevigata fruit due to their numerous medicinal and nutritional properties. In this study, a rapid and effective approach for the extraction and separation of polysaccharides from the title fruit was developed using microwave-assisted aqueous two-phase extraction (MA-ATPE) with a PEG/ammonium sulfate system. After analysis of the response surface methodology (RSM) data based on a Box-Behnken design (BBD), a model was proposed and was found to predict an optimum yield value of 258.99 mg g-1 which is in good agreement with the experimental value (258.59 mg g-1). Two selenium (Se)-containing polysaccharides, Se-RLFP-1 and Se-RLFP-2, were isolated from R. laevigata fruit. Their chemical structures were elucidated by acid hydrolysis, weight-average molecular mass and Se-content analysis, along with UV, FT-IR, 1H and 13C NMR spectroscopy. As a result, Se-RLFP-1 was found to be mainly composed of mannose, glucose, galactose and xylose in a molar ratio of 1.4 : 7.9 : 1.0 : 1.5, while Se-RLFP-2 was composed of mannose, rhamnose, glucose, galactose and xylose (12.6 : 1.0 : 38.3 : 5.6 : 19.6). Furthermore, the antioxidant properties of the polysaccharides were investigated on the basis of FRAP, ABTS and DPPH radical scavenging assays. The results showed that the two polysaccharides had a noticeable effect on the radical scavenging of ABTS and DPPH, especially at high concentrations. In addition, the neuroprotective effect of Se-RLFP-1 and Se-RLFP-2 against oxidative stress induced by H2O2 in SH-SY5Y neuroblastoma cells was also investigated. In particular, Se-RLFP-1 exhibited obvious neuroprotective activity at a concentration of 100 µg mL-1.

Extraction and isolation of polyhydroxy triterpenoids from Rosa laevigata Michx. fruit with anti-acetylcholinesterase and neuroprotection properties.

Rosa laevigata fruit, at present, is becoming increasingly popular as a functional foodstuff with several nutritional and medicinal properties. To explore the acetylcholinesterase (AChE) inhibitory activity of extracts from the Rosa laevigata Michx. fruit (RLMF), a simple and efficient enrichment purification technology based on microwave-assisted extraction (MAE) and multi vacuum extraction columns (VEC) was applied to screen and identify triterpenoids (TTs) in the RLMF extracts. The MAE conditions were optimized using the Box-Behnken design (BBD) with a quadratic regression model and the response surface method (RSM). The optimum conditions were as follows: ethanol concentration, 69%; extraction time, 12 min; ratio of liquid to raw material, 26 : 1 mL g-1; and microwave power, 528 W. Under these conditions, the maximum content of triterpenoids reached 62.48 ± 0.25 mg g-1, which was close to the predicted value of 62.69 mg g-1. In addition, two pure polyhydroxy triterpenoids: 2α,3ß,19α,23-tetrahydroxyurs-12-en-28-oic acid (1) and 2α,3ß,19α,23-tetrahydroxyurs-12-en-28-oic acid-28-O-ß-d-glucopyrannoside (2) were isolated and enriched to more than 500 mg by a multi VEC method. Furthermore, the quantities of compounds 1 and 2 from RLMF were 5.36 and 10.37 mg g-1, respectively, as determined using HPLC. These compounds were further assessed for acetylcholinesterase inhibitory and neuroprotection properties. The results showed that 1 and 2 showed potent AChE inhibitory activities with IC50 values of 29.22 and 45.47 µg mL-1, respectively. At high concentration, compounds 1 and 2 produced a 92% and 89% inhibition on the target enzyme, which was consistent with docking results between AChE and each isolate. Moreover, both 1 and 2 exhibited potential neuroprotective activities against H2O2-induced SHSY5Y cell death.

Coumarins from the bark of Juglans mandshurica exhibited anti-hepatoma activities via inducing apoptosis.

Hepatocellular carcinoma (HCC), the most common type of liver cancer, has high morbidity and mortality rates, and its prognosis is poor. The treatment options of HCC are limited by the lack of effective chemotherapy. Therefore, looking for effective drugs with little toxicity is very urgent. The aim of this study was to search for small molecule targeting on liver cancer from Juglans mandshurica, which has been used to treat cancers for a long time in China. Under the guide of anti-hepatoma activity, a new coumarin (1), together with eight reported analogs (2‒9), was isolated from the 75% EtOH extract. The structures of these compounds were determined by 1D and 2D NMR experiments. The absolute configuration of 1 was established by comparison of experimental and calculated electronic circular dichroism (ECD) spectra. The in vitro cytotoxicity experiments on two liver cancer cell lines (HepG2 and Hep3B) showed that compounds 2 and 5 had moderate antitumor activities on both cell lines. And further studies of antitumor mechanisms by the observation of morphological changes and Western blot analyses exhibited that induction of apoptosis might be a possible way that inhibited cell growth.

Cytotoxic clerodane diterpenoids from Croton crassifolius.

Hepatocellular carcinoma (HCC) is the most common type of liver cancer, and treatment options for HCC are limited. In addition, the discovery of new natural compounds with anti-hepatocarcinoma activity is attracting increasing attention. For this reason, phytochemical investigation of Croton crassifolius led to the isolation of 17 diterpenoids, including three new clerodane diterpenoids, named crassifolius A-C (1-3), along with 14 known ones (4-17). Their structures were established by 1D, 2D NMR, HR-ESI-MS, detailed calculated electronic circular dichroism (ECD) spectra and the assistance of quantum chemical predictions (QCP) of 13C NMR chemical shifts. The cytotoxicities of all these compounds against human liver cancer lines (HepG2 and Hep3B) were determined. Among them, compound 1 exhibited good cytotoxicity with IC50 value of 17.91µM against human liver tumor cells Hep3B. Following further studies of the anti-tumor mechanism of compound 1-induced cell growth inhibition, we found that compound 1 caused apoptotic cell death in Hep3B cells by detecting morphologic changes and Western blotting analysis.