A NEW TRITERPENE SAPONIN FROM THE STEMS AND LEAVES OF PANAX GINSENG

a new triterpene compound was isolated from the stems and leaves of Panax ginseng C. A. Meyer and established as 3β, 6α, 12β-trihydroxy-dammar-20(21), 24-diene-6-0-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside on the basis of spectral analysis and chemical evidence.

Panax notoginseng saponins influence on transplantation of neural stem cell-derived dopaminergic neurons in a rat model of Parkinson’s disease

BACKGROUND： Dopaminergic neurons differentiated from neural stem cells have been successfully used in the treatment of rat models of Parkinson＇s disease; however, the survival rate of transplanted cells has been low. Most cells die by apoptosis as a result of overloaded intracellular calcium and the formation of oxygen free radicals. OBJECTIVE： To observe whether survival of transplanted cells, transplantation efficacy, and dopaminergic differentiation from neural stem cells is altered by Panax notoginseng saponins （PNS） in a rat model of Parkinson＇s disease. DESIGN, TIME AND SETTING： Cellular and molecular biology experiments with randomized group design. The experiment was performed at the Animal Experimental Center, First Hospital of Sun Yat-sen University from April to October 2007. MATERIALS： Thirty-two adult, healthy, male Sprague Dawley rats, and four healthy Sprague Dawley rat embryos at gestational days 14-15 were selected. The right ventral mesencephalon was injected with 6-hydroxydopamine to establish a model of Parkinson＇s disease. 6-hydroxydopamine and apomorphine were purchased from Sigma, USA. METHODS： Neural stem cells derived from the mesencephalon of embryonic rats were cultivated and passaged in serum-free culture medium. Lesioned animals were randomly divided into four groups （n = 8）： dopaminergic neuron, dopaminergic neuron ＋ PNS, PNS, and control. The dopaminergic neuron group was injected with 3 μL cell suspension containing dopaminergic neurons differentiated from neural stem cells. The dopaminergic neurons ＋ PNS group received 3 μ L dopaminergic cell suspension combined with PNS （250 mg/L）. The PNS group received 3 μL PNS （250 mg/L）, and the control group received 3 μL DMEM/F12 culture medium. MAIN OUTCOME MEASURES： The rats were transcardially perfused with 4% paraformaldehyde at 60 days post-grafting for immunohistochemistry. The rats were intraperitoneally injected with apomorphine （0.5 mg/kg） to induce rotational behavior. RESULTS： Cell counts of tyrosine hydroxylase-positive neurons in the dopaminergic neuron ＋ PNS group were （732±82.6） cells/400-fold field. This was significantly greater than the dopaminergic neuron group [（326 ± 34.8） cells/400-fold field, P 〈 0.01]. Compared to the control group, the rotational asymmetry of rats that received dopaminergic neuron transplants was significantly decreased, beginning at 20 days after operation （P 〈 0.01）. Rotational asymmetry was further reduced between 10-60 days post-surgery in the dopaminergic neuron ＋ PNS group, compared to the dopaminergic neuron group （P 〈 0.01）. CONCLUSION： Panax notoginseng saponins can increase survival and effectiveness of dopaminergic neurons differentiated from neural stem cells for transplantation in a rat model of Parkinson＇s disease.

Dammarane-type saponins from steamed leaves of Panax notoginseng

Four new dammarane-type triterpenoid saponins,namely notoginsenosides SFt1-SFt4(1-4)were isolated from the steamed leaves of Panax notoginseng(Burk.)F.H.Chen(Araliaceae),together with 17 known saponins.Their structures were established on the basis of detailed spectroscopic analyses and acidic hydrolysis.The known ginsenosides Rk2 and Rh3 were obtained from P.notoginseng for the first time.All of these new saponins showed no in vitro cytotoxicity against five human cancer cell lines(HL-60,SMMC-7712,A-549,MCF-7,and SW480).

Ginsenoside-Rg_6, a Novel Triterpenoid Saponin from the Stem-Leaves of Panax ginseng C. A. Mey.

A novel dammarane-type triterpene oligoglycoside, named ginsenoside-Rg6 3, was isolated from the stem-leaves of Panax ginseng C. A. Mey., together with two known ones, 20(S)-ginsenoside-Rg2 1 and 20(R)-ginsenoside-Rg2 2. On the basis of chemical and physicochemical evidence , the structure of ginsenoside-Rg6 have been elucidated as 6-O-(-L-rhamnosyl-(1?2)-(-D-glucopyranosyl-dammarane-(E)-20(22), 24-diene-3(, 6(, 12(-triol.

Chinese preparation Xuesaitong promotes the mobilization of bone marrow mesenchymal stem cells in rats with cerebral infarction

After cerebral ischemia, bone marrow mesenchymal stem cells are mobilized and travel from the bone marrow through peripheral circulation to the focal point of ischemia to initiate tissue regeneration. However, the number of bone marrow mesenchymal stem cells mobilized into peripheral circulation is not enough to exert therapeutic effects, and the method by which blood circulation is promoted to remove blood stasis influences stem cell homing. The main ingredient of Xuesaitong capsules is Panax notoginseng saponins, and Xuesaitong is one of the main drugs used for promoting blood circulation and removing blood stasis. We established rat models of cerebral infarction by occlusion of the middle cerebral artery and then intragastrically administered Xuesaitong capsules（20, 40 and 60 mg/kg per day） for 28 successive days. Enzyme-linked immunosorbent assay showed that in rats with cerebral infarction, middle- and high-dose Xuesaitong significantly increased the level of stem cell factors and the number of CD117-positive cells in plasma and bone marrow and significantly decreased the number of CD54-and CD106-positive cells in plasma and bone marrow. The effect of low-dose Xuesaitong on these factors was not obvious. These findings demonstrate that middle- and high-dose Xuesaitong and hence Panax notoginseng saponins promote and increase the level and mobilization of bone marrow mesenchymal stem cells in peripheral blood.

免疫增强剂三七茎叶皂苷口服液的质量控制研究

本研究从性状、pH、相对密度、装量差异、微生物限度、鉴别、含量测定等方面对三七茎叶皂苷口服液(Oral liquid of saponins of stems and leaves of Panax notoginseng,LSPN)进行质量控制研究。利用薄层色谱(thin layer chromatography,TLC)法,鉴定其主要成分;利用高效液相色谱-蒸发光散射(high-performance liquid chromatography with evaporative light scattering detector,HPLC-ELSD)法,建立LSPN中人参皂苷Rb1和Rb3含量的同步分析方法。HPLC-ELSD的色谱条件:色谱柱为GL,InertSustain C18柱(5μm,250×4.6 mm Column);流动相为乙腈(A)-水(B),采用梯度洗脱;进样量:10 L;人参皂苷Rb1和Rb3保留时间分别为13.264 min和15.415 min。ELSD运行参数:氮气流速为1.64 slpm,气化温度为48℃,蒸发温度为80℃。结果表明,LSPN为黄绿色的澄清液体,味苦,pH、相对密度和微生物限度均符合标准要求。人参皂苷Rb1和Rb3的检出限(limit of detection,LOD)均为10 g/mL,定量限(limit of quantitation,LOQ)均为20 g/mL,均在20~500 g/mL内线性关系良好;回归方程分别为Y=1.58X+1.72(r=0.999904)和Y=1.60X+1.64(r=0.999628)。人参皂苷Rb1和Rb3的平均加样回收率分别为101.25%和100.42%,RSD分别为2.71%和1.12%。该法准确,精密度、重现性好,可用于LSPN中人参皂苷Rb1和Rb3的含量测定。

三七茎叶提取物对断奶仔猪生长性能、血清生化指标和肠道健康的影响

试验旨在研究三七茎叶提取物对断奶仔猪生长性能、血清生化指标和肠道健康的影响。选取26日龄断奶仔猪24头随机分为3组,每组8个重复,每个重复1头仔猪。对照组饲喂基础饲粮,低剂量组、高剂量组分别在基础饲粮中添加0.2%和0.4%的三七茎叶提取物。试验期21 d。结果显示,与对照组相比,高剂量组断奶仔猪平均日增重显著升高(P<0.05),低剂量组和高剂量组血清乳酸脱氢酶活性、谷草转氨酶活性和谷草/谷丙的比值显著降低(P<0.05);高剂量组断奶仔猪十二指肠、空肠、回肠的绒毛高度显著增加(P<0.05),十二指肠和回肠的绒隐比显著升高(P<0.05);低剂量组和高剂量组结肠白细胞介素-12 p35(IL-12 p35)、白细胞介素-12 p40(IL-12 p40)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和干扰素-γ(IFN-γ)的mRNA表达量显著降低(P<0.05)。研究表明,在饲粮中添加三七茎叶提取物可以改善断奶仔猪生长性能、肠道健康,添加0.4%三七茎叶提取物较为适宜。

FGF-2和三七总皂苷诱导骨髓间充质干细胞向心肌样细胞分化

目的探究碱性成纤维细胞生长因子(basic fibro-blast growth factor,FGF-2)和三七总皂苷(Panax notoginseng saponins,PNS)单独或联合诱导对骨髓间充质干细胞(bone mesenchymal stem cells,BMSCs)向心肌细胞(cardiomyocytes,CMs)分化的影响以及PNS和FGF-2促分化的作用机制。方法全骨髓贴壁法分离20~30 g 3周龄SD大鼠的骨髓间充质干细胞,通过流式细胞术鉴定骨髓间充质干细胞的纯度。鉴定纯度合格后通过PNS和FGF-2单独或联合诱导以及PNS和FGF-2分别与LY294002(phosphatidylinositol 3 kinase抑制剂)联用诱导骨髓间充质干细胞向心肌细胞分化。根据培养的相应时间点,分为对照组、三七总皂苷组(PNS组)、碱性成纤维细胞生长因子组(FGF-2组)、三七总皂苷+碱性成纤维细胞生长因子组(PNS+FGF-2组)。通过免疫组织化学检测诱导后Desmin和Cx43的表达水平;Western blot检测心肌特异性蛋白、有关通路蛋白及细胞凋亡有关蛋白的表达水平;采用RT-qPCR检测心肌转录因子表达水平。结果各单独诱导组(FGF-2组、PNS组)或联合诱导组(PNS+FGF-2组)均提高心肌特异性蛋白和基因表达水平(P<0.05),且最高表达水平出现在联合组。PNS和FGF-2分别与LY294002联用,相较于两单独诱导组降低了心肌特异性蛋白和基因的表达水平,降低通路相关蛋白Akt的磷酸化水平,且Bcl-2水平降低,Bax水平升高,Bcl-2/Bax比值减小(P<0.05)。结论PNS和FGF-2均可使骨髓间充质干细胞诱导后向心肌细胞定向分化,且二者的联合诱导是一种更高效的诱导方法。PI3K/Akt信号通路参与了PNS和FGF-2促进骨髓间充质干细胞向心肌细胞分化的过程,且PNS和FGF-2起到减少细胞凋亡的作用。

林下三七茎叶采收机设计及往复式割刀仿真试验

三七属于长茎秆类作物,茎叶采收是三七收获的重要环节之一。针对林下三七茎叶采收劳动强度大、缺乏成熟的采收装置等问题,结合林下三七农艺要求和茎秆力学参数,设计了一种林下三七茎叶采收装置,主要由控制箱、机架和剪叶装置组成,确定了整机尺寸、切割行程、前进速度和割幅宽度等参数。对往复式切割器关键结构参数的设计主要包括动刀片、定刀片、曲柄连杆机构、护刃器等,能够满足三七茎叶不伤苗、不漏割的技术要求。对切割器进行了运动学分析,在切割速度为0.4~0.8 m·s^(-1)时,能够在保证切割效果的同时,还保证整机的稳定性及安全性。构建了三七茎秆和切割刀片的刚柔耦合仿真模型,开展切割刀片仿真分析,将最大切割力作为评价指标,通过三因素三水平试验可知,影响切割的因素由大到小依次为切割倾角、切割速度、刀具构型,确定了刀型对三七茎秆切割力的降低效果为三角形刀片>梯形刀片>矩形刀片,三七茎秆-切割刀片的最优参数组合为切割倾角为90.5°、刀型为三角形刀片和切割速度为0.52 m·s^(-1),此时最大切割力为7.46 N,满足切割要求。

基于配体垂钓技术筛选三七叶中环氧合酶-2抑制剂

市售环氧合酶-2(COX-2)抑制剂如美洛昔康、塞来昔布等与传统的非甾体抗炎药相比虽能够有效治疗炎症,但是也存在着引起肝毒性、心血管疾病的风险。中药三七、人参等被证实具有良好的抗炎作用且毒副作用小,因此从中药中筛选潜在的COX-2抑制剂对于开发安全有效的新型抗炎药具有重要意义。本研究以磁性纳米材料作为高效载体,采用配体垂钓法替代传统低效筛选手段,结合固定化金属亲和技术,解决了传统酶固定方法带来的酶活性降低或酶分子堆积等问题。首先合成了聚多巴胺(PDA)包覆的Fe_(3)O_(4),在PDA表面螯合Ni^(2+),利用金属离子亲和作用固定COX-2,制备了一种绿色环保、特异性好的垂钓工具。采用扫描电子显微镜、透射电子显微镜、X射线光电子能谱仪、热重分析仪、振动样品磁强计等方法对其结构进行了表征,结果显示磁性纳米材料为核壳结构,粒径为250~300 nm,具有较大的比表面积,且磁性强、稳定性好。以COX-2抑制剂塞来昔布为垂钓目标物对COX-2的固定条件及垂钓条件进行了优化。该法成功应用于三七叶中潜在COX-2抑制剂的筛选,最终得到了13种能与COX-2相互作用的成分,经液相色谱-质谱联用技术鉴定均为20(S)-原人参二醇型皂苷。与传统的筛选方法相比,本方法简便快速,酶活性高,能够实现对特定目标物的捕获与富集。该研究对新型抗炎药的合成与开发具有指导意义,为高效地从中药复杂体系中发现抗炎药物或先导化合物提供了借鉴,同时也为三七叶的资源化合理应用提供了新的思路。

施用烟杆炭对三七连作土壤酶活性和微生物群落结构的影响

采用室内培养法研究了烟杆炭对土壤脲酶、蛋白酶、酸性磷酸酶活性和微生物群落结构(磷脂脂肪酸,PLFA)的影响.结果表明:施烟杆炭可显著提高三七连作土壤脲酶、蛋白酶活性和土壤微生物量,缓解连作障碍.

基于网络药理学探究三七叶对糖尿病大鼠的治疗机制

目的 利用网络药理学和动物实验,研究三七叶抗糖尿病的主要活性成分和潜在作用机制。方法 基于Pubchem、PharmMapper、OMIM等数据库筛选三七叶与糖尿病共同的潜在靶点之后,再利用STRING数据库和Cytoscape软件构建蛋白相互作用网络图,对其进行拓扑学分析和聚类分析获得核心靶点,并进行GO和KEGG富集分析筛选药物作用于疾病的可能机制。随后进行动物实验验证三七叶的抗糖尿病作用。结果 预测结果共获得三七叶与糖尿病的共同靶点50个,核心靶点有3个:ANXA5、CFB、GSTP1,共涉及生物过程986种,细胞组成15种,分子功能74种,信号通路101条。动物实验表明三七叶可降低糖尿病大鼠的血糖,减少与糖尿病肾病相关的p38 MAPK和TGF-β1 mRNA的表达,同时也可以调节氧化应激和血脂水平,减少动脉粥样硬化。结论 三七叶是通过多途径多靶点共同发挥抗糖尿病的作用,其作用机制可能与减少氧化应激、调节细胞因子、减少动脉粥样硬化和抗糖尿病肾病肾纤维化等有关。

UPLC-MS/MS测定心悦胶囊中6个皂苷类成分的含量

目的:采用超高效液相色谱-质谱法(UPLC-MS/MS)建立心悦胶囊中主要成分人参皂苷Rg_(1)、人参皂苷Re、人参皂苷Rb_(1)、拟人参皂苷F_(11)、人参皂苷Rd和20(S)-人参皂苷F1的含量测定方法。方法:使用Waters ACQUITY BEH C_(18)色谱柱(100 mm×2.1 mm,1.7μm),以乙腈-水为流动相,梯度洗脱,流速为0.5 mL·min^(–1),柱温为40℃,电喷雾电离源,多反应离子监测扫描方式进行检测。结果:6个成分分别在质量浓度为9.638~963.800、9.839~983.900、9.951~995.100、5.270~1054.000、9.608~960.800、4.905~981.000 ng·mL^(–1)时与峰面积线性关系良好(r>0.998),平均加样回收率(RSD)分别为96.9%(2.2%)、100.1%(1.5%)、97.2%(1.8%)、98.5%(2.3%)、96.6%(2.8%)、100.2%(3.5%)。结论:所建立的方法快速、准确、灵敏度高,可用于心悦胶囊中西洋参茎叶总皂苷的质量控制。

三七茎叶采收机仿生切割刀片设计与试验

针对传统三七茎叶采收机切割刀片在滑切减阻、刀片刃口锋利性等方面存在明显不足,以切叶蚁上颚结构特征为仿生原型,运用逆向工程技术,提取切叶蚁上颚轮廓曲线,分别基于切叶蚁的切齿齿顶尖锐端和上颚轮廓曲线设计了A、B两种不同的仿生切割刀片;开展了EDEM仿真与台架对比试验,仿真试验结果表明,仿生刀片A、B相较于传统刀片的平均最大剪切力分别降低7.74%和3.07%;台架试验结果表明,仿生刀片A、B相较于传统刀片的平均最大剪切力分别降低8.84%和2.53%,并且仿生刀片A、B在提高三七茎秆横切面平整度方面效果显著;3种刀片仿真试验与台架试验所测得的最大剪切力误差均不大于3.64%,仿真试验结果与实际试验结果基本一致。以刀型、切割倾角、切割速度为试验因素,开展正交试验,确定了较优参数组合为仿生刀片A、切割倾角0°、切割速度400 mm/min。基于较优参数组合开展田间试验,结果显示其对三七茎叶采收平均完整率为97.37%,较传统刀片提升2.01个百分点,平均漏割率为2.64%,较传统刀片降低1.46个百分点,表明以切叶蚁上颚切齿齿顶尖锐端为特征点设计的仿生刀片能够有效提升三七采收机作业性能。

基于麻雀搜索算法优化的四种神经网络模型在三七茎粗预测中的效果评估

以1年生三七(Panax notoginseng)为研究对象,通过正交试验考察光、水、营养物质对三七茎粗的影响,利用麻雀搜索算法(Sparrow search algorithm,SSA)优化4种模型,分别为反向传播神经网络(Back propagation neural network,BPNN)、长短期记忆神经网络(Long short term memory,LSTM)、随机森林(Random forest,RF)和广义回归神经网络(General regression neural network,GRNN),并应用这4种模型对三七茎粗进行预测。结果表明,光照、水肥等非生物因素对三七茎粗具有明显影响,各因素对三七茎粗的影响程度依次为遮光层数>土壤含水量>矿源黄腐酸钾含量>光照时长。SSA-GRNN模型的决定系数最高,为0.865 6,其次为SSA-RF模型、SSA-BPNN模型、SA-LSTM模型;SSA-GRNN模型的MAE和MSE分别为0.064 1、0.008 7,均低于SSA-BPNN模型、SSA-LSTM模型、SSA-RF模型;SSA-RF模型和SSA-LSTM模型的适应度较大,且陷入了局部最优的情况,从而无法达到全局最优解,SSA-GRNN模型的适应度最小且以最少的迭代次数达到了最佳的适应度。

Transformation of Compound K from Saponins in Leaves of Panax notoginseng by Immobilized β-Glucanase

Objective To prepare an active anti-tumor component,compound K(C-K),from saponins in leaves of Panax notoginseng(SLPN) using immobilized β-glucanase.Methods Two entrapments,alginate gel-1(Alg 1) and alginate gel-2(Alg 2),were evaluated for their ability to immobilize β-glucanase.The amount and purity of C-K obtained from the transformation process were analyzed by HPLC,and the immobilizing parameters were optimized.Results β-Glucanase can be immobilized and reused with either of the entrapment.However,using Alg 1 resulted in higher enzyme activity than Alg 2.The optimal concentration of the immobilized enzyme was 10%;The optimal crosslinking time was 4–6 h;and the optimal concentration of the crosslinking agent was 6%– 7%.Conclusion Immobilized β-glucanase shows sustained enzyme activity,good ethanol tolerance,and was reusable for the preparation of C-K from SLPN.

Effects of Panax Notoginseng Saponins on Homing of C-kit^+ Bone Mesenchymal Stem Cells to the Infarction Heart in Rats

Objective:To investigate the effects of panax notoginseng saponins(PNS) on homing of C-kit+ bone mesenchymal stem cells(BMSCs) to the infarction heart.Methods:The acute myocardial infraction(AMI) model was established in 140 Wistar rats,105 model rats survived after operation,and the model rats were randomly divided into five groups,21 rats in each group:Western medicine group mobilized by subcutaneous injection of human granuloctye colony stimulating factor(G-CSF) 50 μg·kg-1·d-1;sham operation group and a model group treated by subcutaneous injection of normal saline 50 μg·kg-1·d-1;Chinese medicine group mobilized by intraperitoneal injection of Xuesaitong(血塞通)(ingredients of PNS) 150 mg·kg-1·d-1;integrative medicine group mobilized by subcutaneous injection of G-CSF 50 μg·kg-1·d-1 and intraperitoneal injection of Xuesaitong 150 mg·kg-1·d-1.Except for the sham-operated group,each group was divided into three sub-groups by three time points of 1 d,7 d and 14 d.G-CSF was injected once a day for 7 d.Xuesaitong was injected once a day until the rats were killed.The flow cytometry was used for detection of C-kit + cells in the peripheral blood in different time points,and immunohistochemical method was used for detection of the changes of C-kit + cell and Ki-67+ cell numbers in the marginal zone of AMI.Results:Twenty-four hours after the operation,C-kit + cells had a slight increase in the model group compared with the sham operation group(P>0.05).The peripheral blood C-kit+ cells in the integrative group increased significantly compared with the other groups on 7 d and 14 d(all P<0.05).Meanwhile the expression of C-kit + cells and Ki-67+ cells in the marginal zone of AMI in the integrative group increased significantly compared with the Chinese medicine group,the western medicine group and the model group on 1 d,7 d and 14 d(all P<0.05),and the cells in the integrative group decreased significantly on 14 d compared with that on 7 d(P<0.05).Conclusion:PNS can cooperate with G-CSF to mobilize C-kit+ BMSCs from the marrow into the peripheral blood and promote them "homing" to the infarction heart.

4种真菌发酵对三七叶化学成分及药理活性的影响

以三七叶为原料,选择米根霉、粗糙脉孢菌、红曲霉和鲁氏毛霉4种真菌对其进行发酵,测定发酵过程中三七叶总皂苷、总多糖、总酚和总黄酮的含量变化,评估其体外抗氧化活性和α-葡萄糖苷酶抑制活性的变化,并采用超高效液相色谱-质谱对发酵前后三七叶的代谢谱进行分析。结果表明:4种真菌均可使三七叶中总皂苷和总多糖含量显著降低,但米根霉、粗糙脉孢菌和红曲霉可提高总酚含量,而米根霉和鲁氏毛霉可提高总黄酮含量。真菌发酵3~5 d后,三七叶的抗氧化活性明显增强,其中红曲霉发酵3 d的增强效果最好,可使三七叶的1,1-二苯基-2-三硝基苯肼自由基、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除能力以及铁离子还原能力分别提高14.30%、5.13%、18.40%。此外,真菌发酵可先降低后提高三七叶的α-葡萄糖苷酶抑制活性,其中红曲霉在发酵6 d后可使其提高16.03%。进一步的非靶向代谢组学分析,从三七叶中共鉴定出573种代谢物,经红曲霉发酵3 d后,其上调代谢物明显少于下调代谢物,主要为氨基酸、生物碱、碳水化合物、脂类、酚类、类黄酮以及萜类化合物等;对其中的21种皂苷类化合物进行进一步分析,发现其中只有人参皂苷F2显著上调,另有8种皂苷显著下调;对差异代谢物进行京都基因与基因组百科全书富集分析发现,嘌呤代谢、嘧啶代谢、类黄酮生物合成、辅助因子的生物合成等是三七叶在发酵过程中最可能的代谢通路。综上,真菌发酵尤其是红曲霉发酵是改善三七功能活性的绿色有效手段,其可通过多个作用途径使三七叶的代谢物变化,影响其功能活性,本研究可为三七叶的绿色加工提供科学参考。

三七茎秆离散元参数标定与试验

针对利用离散元法进行三七联合收获、茎秆杀秧等关键作业过程仿真分析时,三七茎秆本征参数、三七茎秆及作业装备间接触参数缺乏问题,以三七茎秆为对象,利用EDEM软件建立三七茎秆离散元Hertz-Mindlin/Hertz-Mindlin with bonding模型,通过堆积角试验和虚拟仿真试验对三七茎秆离散元参数进行标定,并建立三七茎秆杀秧装置模型。通过力学特性试验确定三七茎秆本征参数;采用圆筒提升法进行三七茎秆堆积角试验,使用Origin软件对堆积角图像进行轮廓拟合得到三七茎秆堆积角为44.53°;设计Placktt-Burman试验、最陡爬坡试验和Central-Composite试验确定三七茎秆及作业装备间接触参数,并利用堆积角试验和剪切试验验证模型的可靠性。结果表明:三七茎秆与作业装备间碰撞恢复系数、静摩擦因数、滚动摩擦因数分别为0.319、0.25、0.029;三七茎秆间的碰撞恢复系数、静摩擦因数、滚动摩擦因数最优值分别为0.4、0.29、0.032;Hertz-Mindlin with bonding模型法向刚度Kn为3.26×10^(8)N/m^(3)、切向刚度Ks为2.17×10^(8)N/m^(3)、法向临界应力σ为2.27 MPa、切向临界应力γ为9.65 MPa、粘结半径Rd为0.1 mm;堆积角验证试验中相对误差为0.29%;剪切验证试验中相对误差为1.52%,误差较小。三七茎秆离散元模型与实际情况基本一致,三七茎秆模型和标定离散元仿真参数可靠,可为三七茎秆离散元仿真研究提供参考。

三七茎叶-滇黄精速溶粉提取工艺及抗氧化活性分析

为探索三七茎叶-滇黄精复合产品的开发工艺,该研究分析了三七茎叶-滇黄精速溶粉中可溶性总糖、皂苷、多酚化合物的组成及含量,并测定其抗氧化活性。以单因素-响应面实验考察三七茎叶-滇黄精在乙醇添加量、料液比(g∶mL)、浸提时间3种变量条件下的最佳浸提条件,进一步以喷雾干燥的方法获取三七茎叶-滇黄精速溶粉,以蒽酮比色法测定速溶粉中可溶性总糖的含量,高效液相色谱法测定速溶粉中皂苷、多酚含量,进一步测定其抗氧化活性,并进行感官审评。喷雾干燥优化出三七茎叶与滇黄精的最佳质量比为6∶4,最佳浸提工艺为三七茎叶-滇黄精的料液比(g∶mL)为1∶21,29%(体积分数)乙醇,浸提37 h,重复浸提2次,每1 kg复合物可得到速溶粉374.23 g,得粉率37.42%,该速溶粉溶解性好,香甜回甘。速溶粉中可溶性总糖含量为(55.44±3.21)mg/g,活性成分以三七皂苷Fa、Fd、Fc、人参皂苷Rb1等7种皂苷及咖啡酸(caffeic acid,CA)、表儿茶素没食子酸酯(epicatechin-3-gallate,ECG)、表没食子儿茶素没食子酸酯(epigallocahechin-3-gallate,EGCG)等5种酚类化合物为主。抗氧化活性结果表明,三七茎叶-滇黄精速溶粉对ABTS阳离子自由基、DPPH自由基、超氧阴离子自由基、羟自由基具有较好的清除能力,其IC 50值分别为0.30、0.63、0.49、1.67 mg/mL。该研究优化了三七茎叶-滇黄精浸提工艺,所得速溶粉富含皂苷、多酚、可溶性糖等成分,为三七茎叶和滇黄精在食品开发领域提供基础研究数据,为云南特色食品及药食同源产品的开发利用提供科学支撑。