Cyclic Peptides from the Opportunistic Pathogen Basidiobolus meristosporus.

Three new cyclic peptides, meristosporins A, B, and C (1-3), one of which features an unusual amino acid, were isolated from the opportunistic pathogen Basidiobolus meristosporus and identified by 1D, 2D NMR, MS/MS, and Marfey's analysis. The biosynthetic pathway of the hexapeptide meristosporin A (1) was deduced based on nonribosomal peptide synthetase gene clusters analysis. Compounds 1 and 2 showed cytotoxicity to RAW264.7 and 293T cells, respectively. These compounds may be involved in the fungal injury caused to human cells.

Chemical composition and antibacterial activity of 12 medicinal plant ethyl acetate extracts using LC-MS feature-based molecular networking.

INTRODUCTION: Widespread use of antibiotics has led to an increase in bacterial multiple drug resistance, thereby searching for natural antimicrobial agents from plants becomes an effective and alternative approach. In the present study, we selected six foodborne bacteria to evaluate the antibacterial activities of 12 medicinal plants ethyl acetate (EA) extracts. OBJECTIVE: This study aims to search for natural antibiotic substitutes from plant extracts. The antibacterial components were further discussed through chemometric and mass spectroscopic analyses. METHODOLOGY: Agar well diffusion and the microdilution methods were used to test the antibacterial activity. Total phenolic content (TPC) and total flavonoid content (TFC) were used to judge the active phytochemicals. To further characterise the potential antibacterial components, an ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS) coupled with Pearson correlation and feature-based molecular network (FBMN) were proposed. RESULTS: Most of the plant extracts possessed antibacterial activity against Bacillus subtilis and Salmonella typhi. Toona sinensis shoots and Firmiana simplex barks showed high inhibitory activities against Staphylococcus aureus, Shigella dysenteriae, and Escherichia coli strains with minimum inhibitory concentrations (MICs) of 1.56, 0.78, and 0.39 mg/mL, respectively. Salmonella typhi was highly sensitive to Firmiana simplex barks with an inhibitory diameter up to 21.67 ± 0.95 mm, and MIC at 0.78 mg/mL. Moreover, Toona sinensis shoots and Firmiana simplex barks had the highest TPCs. CONCLUSION: Our results indicated that Toona sinensis shoots, Koelreuteria paniculate seeds, and Firmiana simplex barks could be supplied as potential sources of antimicrobial agents. Furthermore, 36 potential bioactive compounds were identified mainly as polyphenols, glycosides, and terpenoids.

Metabolomic variation in wild and cultured cordyceps and mycelia of Isaria cicadae.

Isaria cicadae is one of the fungi used in traditional Chinese medicine with the longest tradition. It is used not only as a herbal medicine but also as a health food in Asia, together with cultured cordyceps and mycelia of the fungus used as substitute. However, the differences in their metabolite are unknown. Using a high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based metabolomic method, we found that the fungus varies in its metabolism during growth on wild insects, artificially raised insects and artificial medium. There were 109 discriminatory metabolites detected in the samples by orthogonal projection to latent structure discriminant analysis and one-way ANOVA. High level of nonribosomal peptides (NRPs) only existed in the insect portions of the wild cordyceps (WI) and cultured cordyceps (CI), revealing that immunostimulation of the host insects enhanced the synthesis of NRPs in the fungus. The finding of a significantly higher level of sphingolipids in both the insect portions (WI, CI) and the coremia of the wild cordyceps (WC) and cultured cordyceps (CC) but not in cultured mycelia (CM) of I. cicadae implies that the immunostimulation of the live insects can induce the fungus to produce more sphingolipids, and this enhanced ability is probably heritable. Apart from NRPs and sphingolipids, the insect portions also contained higher levels of bioactive compounds such as lateritin, anisomycin, streptimidone and ustiloxins. In contrast, the coremium groups (WC, CC) and CM contained 10-fold less NRP but much higher levels of sanative metabolites such as tocotrienol, 3'-deoxy-hanasanagin, γ-aminobutyric acid and phospholipids than the insect portions. The significantly higher content of antioxidants in WC, CC and CM than in WI and CI suggests that environmental oxygen has a significant effect on the metabolites. The temperature stress which the wild cordyceps encounters during growth is responsible for the relatively high content of trehalose. These findings indicate that the immunity of the host insect and growth environment have a strong impact on the metabolomic variation in Isaria cicadae. The variation in metabolites suggests differential utilization value for the insect portions, coremia and mycelia of the fungus.

Imaging mass spectrometry-guided fast identification of antifungal secondary metabolites from Penicillium polonicum.

The discovery of antibiotics from microorganisms using classic bioactivity screens suffers from heavy labor and high re-discovery rate. Recently, largely uncovered biosynthetic potentials were unveiled by new approaches, such as genetic manipulation of "silent" biosynthetic gene clusters, innovative data acquisition, and processing methods. In this work, a fast and efficient antibiotic identification pipeline based on the MALDI-TOF imaging mass spectrometry was applied to study the antifungal metabolites during the confrontation of two fungal species, Penicillium polonicum and wilt-inducing fungus Fusarium oxysporum. By visualizing the spatial distribution of metabolites directly on the microbial colony and surrounding media, we predicted the antifungal candidates before isolating pure compounds and individually testing their bioactivity, which subsequently guided the identification of target molecules using classic chromatographic methods. Via this procedure, we successfully identified two antifungal metabolites, fructigenine A and B, which belong to indole alkaloid class and were not reported for antifungal activity. Our work assigned new bioactivity to previously reported compounds and more importantly showed the efficiency of this approach towards quick discovery of bioactive compounds, which can help study the vast unexploited synthetic potential of microbial secondary metabolites.

Ethyl Rosmarinate Protects High Glucose-Induced Injury in Human Endothelial Cells.

Ethyl rosmarinate (RAE) is one of the active constituents from Clinopodium chinense (Benth.) O. Kuntze, which is used for diabetic treatment in Chinese folk medicine. In this study, we investigated the protective effect of RAE on high glucose-induced injury in endothelial cells and explored its underlying mechanisms. Our results showed that both RAE and rosmarinic acid (RA) increased cell viability, decreased the production of reactive oxygen species (ROS), and attenuated high glucose-induced endothelial cells apoptosis in a dose-dependent manner, as evidenced by Hochest staining, Annexin V⁻FITC/PI double staining, and caspase-3 activity. RAE and RA both elevated Bcl-2 expression and reduced Bax expression, according to Western blot. We also found that LY294002 (phosphatidylinositol 3-kinase, or PI3K inhibitor) weakened the protective effect of RAE. In addition, PDTC (nuclear factor-κB, or NF-κB inhibitor) and SP600125 (c-Jun N-terminal kinase, or JNK inhibitor) could inhibit the apoptosis in endothelial cells caused by high glucose. Further, we demonstrated that RAE activated Akt, and the molecular docking analysis predicted that RAE showed more affinity with Akt than RA. Moreover, we found that RAE inhibited the activation of NF-κB and JNK. These results suggested that RAE protected endothelial cells from high glucose-induced apoptosis by alleviating reactive oxygen species (ROS) generation, and regulating the PI3K/Akt/Bcl-2 pathway, the NF-κB pathway, and the JNK pathway. In general, RAE showed greater potency than RA equivalent.

Two New Oleanane-Type Saponins with Anti-Proliferative Activity from Camellia oleifera Abel. Seed Cake.

Two new oleanane-type saponins, named oleiferasaponins C4 (1) and C5 (2), were isolated from Camellia oleifera Abel. seed cake residue. Their respective structures were identified as 16α-hydroxy-22α-O-angeloyl-23α-aldehyde-28-dihydroxymethylene-olean-12-ene-3ß-O-[ß-d-galacto-pyranosyl-(1→2)]-[ß-d-glucopyranosyl-(1→2)-ß-d-galactopyranosy-(1→3)]-ß-d-glucopyranosid-uronic acid methyl ester (1) and 16α-hydroxy-22α-O-angeloyl-23α-aldehyde-28-dihydroxy-methylene-olean-12-ene-3ß-O-[ß-d-galactopyranosyl-(1→2)]-[ß-d-galactopyranosyl-(1→3)]-ß-d-glucopyranosiduronic acid methyl ester (2) through 1D- and 2D-NMR, HR-ESI-MS, and GC-MS spectroscopic methods. The two compounds exhibited potent cytotoxic activities against five human tumor cell lines (BEL-7402, BGC-823, MCF-7, HL-60 and KB).

Differential metabolic responses of Beauveria bassiana cultured in pupae extracts, root exudates and its interactions with insect and plant.

Beauveria bassiana is a kind of world-wide entomopathogenic fungus and can also colonize plant rhizosphere. Previous researches showed differential expression of genes when entomopathogenic fungi are cultured in insect or plant materials. However, so far there is no report on metabolic alterations of B. bassiana in the environments of insect or plant. The purpose of this paper is to address this problem. Herein, we first provide the metabolomic analysis of B. bassiana cultured in insect pupae extracts (derived from Euproctis pseudoconspersa and Bombyx mori, EPP and BMP), plant root exudates (derived from asparagus and carrot, ARE and CRE), distilled water and minimal media (MM), respectively. Principal components analysis (PCA) shows that mycelia cultured in pupae extracts and root exudates are evidently separated and individually separated from MM, which indicates that fungus accommodates to insect and plant environments by different metabolic regulation mechanisms. Subsequently, orthogonal projection on latent structure-discriminant analysis (OPLS-DA) identifies differential metabolites in fungus under three environments relative to MM. Hierarchical clustering analysis (HCA) is performed to cluster compounds based on biochemical relationships, showing that sphingolipids are increased in BMP but are decreased in EPP. This observation further implies that sphingolipid metabolism may be involved in the adaptation of fungus to different hosts. In the meantime, sphingolipids are significantly decreased in root exudates but they are not decreased in distilled water, suggesting that some components of the root exudates can suppress sphingolipid to down-regulate sphingolipid metabolism. Pathway analysis finds that fatty acid metabolism is maintained at high level but non-ribosomal peptides (NRP) synthesis is unaffected in mycelia cultured in pupae extracts. In contrast, fatty acid metabolism is not changed but NRP synthesis is high in mycelia cultured in root exudates and distilled water. This indicates that fungal fatty acid metabolism is enhanced when contacting insect, but when in the absence of insect hosts NRP synthesis is increased. Ornithine, arginine and GABA are decreased in mycelia cultured in pupae extracts and root exudates but remain unchanged in distilled water, which suggests that they may be associated with fungal cross-talk with insects and plants. Trehalose and mannitol are decreased while adenine is increased in three conditions, signifying carbon shortage in cells. Together, these results unveil that B. bassiana has differential metabolic responses in pupae extracts and root exudates, and metabolic similarity in root exudates and distilled water is possibly due to the lack of insect components.

TMDB: a literature-curated database for small molecular compounds found from tea.

BACKGROUND: Tea is one of the most consumed beverages worldwide. The healthy effects of tea are attributed to a wealthy of different chemical components from tea. Thousands of studies on the chemical constituents of tea had been reported. However, data from these individual reports have not been collected into a single database. The lack of a curated database of related information limits research in this field, and thus a cohesive database system should necessarily be constructed for data deposit and further application. DESCRIPTION: The Tea Metabolome database (TMDB), a manually curated and web-accessible database, was developed to provide detailed, searchable descriptions of small molecular compounds found in Camellia spp. esp. in the plant Camellia sinensis and compounds in its manufactured products (different kinds of tea infusion). TMDB is currently the most complete and comprehensive curated collection of tea compounds data in the world. It contains records for more than 1393 constituents found in tea with information gathered from 364 published books, journal articles, and electronic databases. It also contains experimental 1H NMR and 13C NMR data collected from the purified reference compounds or collected from other database resources such as HMDB. TMDB interface allows users to retrieve tea compounds entries by keyword search using compound name, formula, occurrence, and CAS register number. Each entry in the TMDB contains an average of 24 separate data fields including its original plant species, compound structure, formula, molecular weight, name, CAS registry number, compound types, compound uses including healthy benefits, reference literatures, NMR, MS data, and the corresponding ID from databases such as HMDB and Pubmed. Users can also contribute novel regulatory entries by using a web-based submission page. The TMDB database is freely accessible from the URL of http://pcsb.ahau.edu.cn:8080/TCDB/index.jsp. The TMDB is designed to address the broad needs of tea biochemists, natural products chemists, nutritionists, and members of tea related research community. CONCLUSION: The TMDB database provides a solid platform for collection, standardization, and searching of compounds information found in tea. As such this database will be a comprehensive repository for tea biochemistry and tea health research community.

Attenuation effect of a polysaccharide from large leaf yellow tea by activating autophagy.

Chemotherapy, the most common class of anticancer drugs, is considerably limited owing to its adverse side effects. In this study, we aimed to evaluate the protective effect and mechanism of action of large-leaf yellow tea polysaccharides (ULYTP-1, 1.29 × 104 Da) against chemotherapeutic 5-fluorouracil (5-Fu). Structural characterisation revealed that ULYTP-1 was a ß-galactopyranouronic acid. Furthermore, ULYTP-1 promoted autolysosome formation, activating autophagy and reducing the oxidative stress and inflammation caused by 5-Fu. Our in vivo study of 4 T1 tumour-bearing mice revealed that ULYTP-1 also attenuated 5-Fu toxicity through modulation of the gut microbiota. Moreover, ULYTP-1 effectively protected immune organs and the liver from 5-Fu toxicity, while promoting its tumour-inhibitory properties. The current findings provide a new strategy for optimising chemotherapy regimens in the clinic.

Novel Flavonol Alkaloids in Green Tea: Synthesis, Detection, and Anti-Alzheimer's Disease Effect in a Transgenic Caenorhabditis elegans CL4176 Model.

Novel N-ethy-2-pyrrolidinone-substituted flavonols, myricetin alkaloids A-C (1-3), quercetin alkaloids A-C (4a, 4b, and 5), and kaempferol alkaloids A and B (6 and 7), were prepared from thermal reaction products of myricetin, quercetin, kaempferol─l-theanine, respectively. We used HPLC-ESI-HRMS/MS to detect 1-7 in 14 cultivars of green tea and found that they were all present in "Shuchazao," "Longjing 43", "Fudingdabai", and "Zhongcha 108" green teas. The structures of 1-4 and 6 were determined by extensive 1D and 2D NMR spectroscopies. These flavonol alkaloids along with their skeletal flavonols were assessed for anti-Alzheimer's disease effect based on molecular docking, acetylcholinesterase inhibition, and the transgenic Caenorhabditis elegans CL4176 model. Compound 7 strongly binds to the protein amyloid ß (Aß1-42) through hydrogen bonds (BE: -9.5 kcal/mol, Ki: 114.3 nM). Compound 3 (100 µM) is the strongest one in significantly extending the mean lifespan (13.4 ± 0.5 d, 43.0% promotion), delaying the Aß1-42-induced paralysis (PT50: 40.7 ± 1.9 h, 17.1% promotion), enhancing the locomotion (140.0% promotion at 48 h), and alleviating glutamic acid (Glu)-induced neurotoxicity (153.5% promotion at 48 h) of CL4176 worms (p < 0.0001).

EGCG inhibit chemical reactivity of iron through forming an Ngal-EGCG-iron complex.

Accumulated evidence indicates that the interconversion of iron between ferric (Fe(3+)) and ferrous (Fe(2+)) can be realized through interaction with reactive oxygen species in the Fenton and Haber-Weiss reactions and thereby physiologically effects redox cycling. The imbalance of iron and ROS may eventually cause tissue damage such as renal proximal tubule injury and necrosis. Many approaches were exploited to ameliorate the oxidative stress caused by the imbalance. (-)-Epigallocatechin-3-gallate, the most active and most abundant catechin in tea, was found to be involved in the protection of a spectrum of renal injuries caused by oxidative stress. Most of studies suggested that EGCG works as an antioxidant. In this paper, Multivariate analysis of the LC-MS data of tea extracts and binding assays showed that the tea polyphenol EGCG can form stable complex with iron through the protein Ngal, a biomarker of acute kidney injury. UV-Vis and Luminescence spectrum methods showed that Ngal can inhibit the chemical reactivity of iron and EGCG through forming an Ngal-EGCG-iron complex. In thinking of the interaction of iron and ROS, we proposed that EGCG may work as both antioxidant and Ngal binding siderphore in protection of kidney from injuries.

Identification and production of a novel natural pigment, cordycepoid A, from Cordyceps bifusispora.

A novel yellow pigment, cordycepoid A, was isolated and identified from the entomogenous fungi Cordyceps bifusispora. Cordycepoid A exhibited no significant toxicity against Chinese hamster ovary (CHO) cells and mice, and showed high stability against food addictives, metal ions and heat. A liquid/solid double-phase cultural process for the production of the pigment was optimized as follows: 3 days aged liquid seed, 7.5 % inoculums, incubation temperature at 25 °C, 10 days of solid culture, and the last 5 days exposed to 200 Lx scattered light. The liquid seed medium and the solid culture medium were also optimized. Ethanol was selected as extracting solvent for its scale-up production. The optimal extracting conditions were determined as liquid/solid ratio at 20:1, extracting temperature at 40 °C, ultrasonic power at 400 W, and extracting time of 40 min.

New limonoids and a dihydrobenzofuran norlignan from the roots of Toona sinensis.

Two new limonoids, toonins A (1) and B (2), and one new dihydrobenzofuran norlignan, toonin C (3), were isolated from the roots of Toona sinensis together with the ten known compounds 4-methoxy-6-(2',4'-dihydroxy-6'-methylphenyl)-pyran-2-one (4), bourjotinolone A (5), proceranone (6), matairesinol (7), 4-hydroxy-3-methoxybenzene-ethanol (8), syringic acid (9), isoscopoletin (10), lyoniresinol (11), aloeemodin (12), and ß-sitosterol (13). Their structures were elucidated on the basis of one- and two-dimensional spectroscopic analysis. Isolation of compounds 4, 6-13 from this plant is reported here for the first time.

Cyclic pentapeptides with anti-inflammatory, cytotoxic or α-glucosidase inhibitory activities from Basidiobolus meristosporus.

Basidiobolus meristosporus is an opportunistic pathogen of mammals with unique habitats, but its metabolites have not been extensively studied. Through semi-preparative HPLC, nine undescribed cyclic pentapeptides were isolated from mycelia of B. meristosporus RCEF4516. The structure of the compounds 1-9 were identified with MS/MS and NMR data and designated as basidiosin D-L respectively. The absolute configurations were determined according to the advanced Marfey's method after compound hydrolysis. Bioactivity testing showed that compounds 1, 2, 3, 4 and 8 decreased NO production in LPS-activated RAW264.7 cells in a concentration-dependent manner. The nine compounds showed cytotoxicity against RAW264.7, 293 T and HepG2 cells. All the compounds except compound 7 showed stronger inhibitory effects on α-glucosidase than acarbose.

Novel Camellia sinensis O-Methyltransferase Regulated by CsMADSL1 Specifically Methylates EGCG in Cultivar "GZMe4".

Epigallocatechin-3-O-(4-O-methyl)gallate (EGCG4″Me) in Camellia sinensis possesses numerous beneficial biological activities. However, the germplasm rich in EGCG4″Me and the O-methyltransferase responsible for EGCG4″Me biosynthesis are poorly understood. Herein, the content of EGCG3″Me and EGCG4″Me in the shoots of 13 cultivars was analyzed to demonstrate that EGCG4″Me is characteristically accumulated in the "GZMe4" cultivar but not in the other 12 cultivars. A novel O-methyltransferase (CsOMTL1) was identified from "GZMe4" using RNA-Seq and correlation analysis. Using the recombinant enzyme, EGCG4″Me was synthesized in vitro. Overexpression of CsOMTL1 via Agrobacterium-mediated genetic transformation caused constitutive accumulation of EGCG4″Me in C. sinensis callus. Moreover, the transcription factor CsMADSL1 localized in the nucleus activated the transcription of CsOMTL1 and specifically interacted with its promoter. Hence, our study identified a novel O-methyltransferase that characteristically catalyzes the synthesis of EGCG4″Me and a positive regulator of EGCG4″Me synthesis in "GZMe4", which might provide a strategy for the breeding of a tea cultivar rich in EGCG4″Me.

Novel methylated flavoalkaloids from Echa 1 green tea inhibit fat accumulation and enhance stress resistance in Caenorhabditis elegans.

Methylation is a common structural modification of catechins in tea, which can improve the bioavailability of catechins. Flavoalkaloids are catechin derivatives with a nitrogen containing five-membered ring at the C-6 or C-8 position. Here we isolated three new methylated flavoalkaloids from Echa 1 green tea (Camellia sinensis cv. Echa 1) and synthesized another four new methylated flavoalkaloids. The structures of the new ester-type methylated catechins (etmc)-pyrrolidinone A-G (1-7) were elucidated by various spectroscopic techniques, including nuclear magnetic resonance (NMR), optical rotation, infrared, UV-vis, experimental and calculated circular dichroism (CD) spectra, and high-resolution mass. Among them, 6 and 7 showed the strongest α-glucosidase inhibitory activity and significantly lowered lipid content of Caenorhabditis elegans with 73.50 and 67.39% inhibition rate, respectively. Meanwhile, 6 and 7 also exhibited strong antioxidant activity in vitro and stress resistance to heat, oxidative stress, and UV irradiation in nematodes.

Improving flavor of summer Keemun black tea by solid-state fermentation using Cordyceps militaris revealed by LC/MS-based metabolomics and GC/MS analysis.

Cordyceps militaris (C. militaris) has been approved and widely used in healthy food. The present study aimed to improve the flavor of summer Keemun black tea (KBT) using C. militaris solid-state fermentation. Combined with sensory evaluation, the volatile and non-volatile components of solid-state fermentation of KBT (SSF-KBT) and KBT were analyzed. The results showed that after the solid-state fermentation, the contents of total polyphenol, total flavonoid, and total free amino acids were significantly reduced. Further non-targeted metabolomics analysis revealed that the contents of non-galloylated catechins and d-mannitol increased, while the galloylated catechins and flavonoid glycosides decreased as did the bitterness and astringency of KBT. Dihydro-ß-ionone and ß-ionone (OAV = 59321.97 and 8154.17) were the aroma-active compounds imparting woody and floral odors in SSF-KBT, respectively. Current study provides a new avenue to develop summer-autumn KBT.

Iron traffics in circulation bound to a siderocalin (Ngal)-catechol complex.

The lipocalins are secreted proteins that bind small organic molecules. Scn-Ngal (also known as neutrophil gelatinase associated lipocalin, siderocalin, lipocalin 2) sequesters bacterial iron chelators, called siderophores, and consequently blocks bacterial growth. However, Scn-Ngal is also prominently expressed in aseptic diseases, implying that it binds additional ligands and serves additional functions. Using chemical screens, crystallography and fluorescence methods, we report that Scn-Ngal binds iron together with a small metabolic product called catechol. The formation of the complex blocked the reactivity of iron and permitted its transport once introduced into circulation in vivo. Scn-Ngal then recycled its iron in endosomes by a pH-sensitive mechanism. As catechols derive from bacterial and mammalian metabolism of dietary compounds, the Scn-Ngal-catechol-Fe(III) complex represents an unforeseen microbial-host interaction, which mimics Scn-Ngal-siderophore interactions but instead traffics iron in aseptic tissues. These results identify an endogenous siderophore, which may link the disparate roles of Scn-Ngal in different diseases.

Antineoplastic agents. 587. Isolation and structure of 3-epipancratistatin from Narcissus cv. Ice Follies.

Bioassay-guided (cancer cell line) separation of an extract prepared from Narcissus cv. Ice Follies (from The Netherlands) led to the isolation of a new Amaryllidaceae isocarbostiryl, 3-epipancratistatin (1b), as well as narciclasine (2). This Narcissus cultivar was found to be a good source of narciclasine. The structure of 1b was established by high-resolution mass and high-field 2D NMR spectroscopic analyses. Against a panel of murine and human cancer cell lines, 3-epipancratistatin (1b) led to cell growth inhibition (GI(50) 2.2-0.69 µg/mL) some 100× less than that found for pancratistatin (1a) and narciclasine (2), thereby revealing an important configurational requirement in 1a for strong cancer cell growth inhibition.

A new saponin from tea seed pomace (Camellia oleifera Abel) and its protective effect on PC12 cells.

A new triterpenoid saponin, oleiferasaponin A1, was isolated from tea seed pomace (Camellia oleifera Abel). The structure of oleiferasaponin A1 was elucidated on the basis of chemical and physicochemical evidence and was found to be 22-O-cis-2-hexenoyl-A1-barrigenol 3-O-[ß-D-galactopyranosyl(1→2)] [ß-D-glucopyranosyl(1→2)-α-L-arabinopyranosyl(1→3)]-ß-D-glucopyranosiduronic acid. PC12 cells injured with H2O2 were used as the model to test the protective effects of oleiferasaponin A1. The results indicated that oleiferasaponin A1 can potentially prevent the H2O2-induced cell death of PC12 cells.