Phytochemicals Analysis, Antioxidant Capacities and Antimicrobial Properties of Ethyl Acetate Extract of Stem Bark of the Garlic Tree Scorodocarpus borneensis Becc.

The objective of this study was to examine the phytochemical components, antioxidant activity and antibacterial property of ethyl acetate extract of the stem bark of garlic tree （Scorodocarpus borneensis）. The dried stem bark of S. borneensis were collected and homogenized after drying at room temperature （32℃） for 30 d. The stem barks were extracted by macerated method using 95% ethanol and then fractionated with ethyl acetate. The dried ethyl acetate extract was subjected to phytoehemical screening to determine the presence of bioactive components using gas chromatography-mass spectrometry （GC-MS）. Antioxidant activity of the extract in vitro was examined by 2,2-diphenyl-l-picryl-hydrazyl （DPPH） radical scavenging assay. The antibacterial activity against gram-positive bacteria Staphylococcus aureus and gram-negative bacteria Escherichia coli was performed by disc diffusion assay. GCMS results revealed the presence of 14 different phytocompounds, viz, tetratriacontyl trifluoroacetate （41.61%）, 2-pentanone （13.65%）, oxacyclotetradecane-2,11-done （7.87%）, cinnamic acid （7.53%）, 10-octadecanoic acid （6.50%）, 1,2-benzeno dicarboxylix acid （4.99%）, octadecanoic acid （4.51%）, hexadecanoic acid （4.16%）, beta tumerone （3.01%）, 9-octadecenoic acid （1.70%）, tricosanol （1.38%）, hexadecano-phenone （1.36%）, 1-nonadecanol （0.93%） and n-nonadecanol （0.82%）. In vitro antioxidant activity （IC50） was found at 55.524 ppm as high powerful. The results of agar diffusion method showed that the ethyl acetate extracts had an antibacterial activity of 6.687 ± 0.800 mm againts S. aureus at 10% （w/v） and 7.500 ± 0.735 mm against E. coli at 10% （w/v） as moderate category. These findings suggest that S. borneensis stem bark is a valuable sources of bioactive compounds with promising as antioxidant and antibacterial sources.

Antibacterial Activity of Psidium guajava Leaf and Stem Bark Extracts on Selected Bacteria in Ugbokolo, Benue State, Nigeria

Aim: In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. The study was aimed at determining the phytochemical constituents and in vitro antibacterial activity of methanol and aqueous extracts of Psidium guajava leaves and stem bark on Escherichia coli, Salmonella typhi, Staphylococcus aureus and Proteus sp. in Ugbokolo, Nigeria. Materials and Methods: The phytochemical screening of the plant materials for various bioactive components was conducted between July and December, 2019 using standard laboratory techniques. The extracts were purified using column chromatography. The identity of the test isolates were confirmed using morphological characteristics, gram stain, motility and appropriate biochemical tests such as indole, catalase, coagulase, triple sugar iron agar. The susceptibility of the isolates to each bioactive component was determined using the agar well diffusion method. The broth dilution method was employed for the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts. Results: The result of the study showed the presence of phenol, tannins, flavonoids and saponins as bioactive compounds. The antibacterial susceptibility of the isolates to aqueous and methanol extracts of leaf and stem bark of Psidium guajava varied significantly (P Staphylococcus aureus was the most susceptible isolate at 200 mg/ml concentration with average zone of inhibition of 13.05 mm for leaf extract and 15.34 mm for stem bark extract. Proteus sp. is the least susceptible with average zone of inhibition of 8.88 mm for the leaf extract and 12.36 mm for the stem bark extract respectively. Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of aqueous and methanol extract of P. guajava leaf and stem bark showed that dilutions of various concentrations of aqueous and methanol extracts can inhibit and/or kill the isolates. Lower MIC (3.125 mg/ml) was shown by methanol extract than aqueous extract. MBC of methanol extract ranges between 6.25 - 25.0 mg/ml. Statistical analysis of the result showed methanol extract is more effective than aqueous extract while the stem bark of the plant showed higher efficacy than the leaf. Conclusion: The findings of the study imply that the extract of Psidium guajava has shown promising properties against tested microorganisms. Further study of the extract is therefore recommended.

Phytochemical Analysis of Leaf, Stem Bark, and Root Extracts of Cassia abbreviata Grown in Zambia

Background: Plants have for a long time been used as medicines to treat ailments. Cassia abbreviata (C. abbreviata) is one of the plants that has been widely used in the management of a range of ailments, including malaria, diarrhea, and abscesses. Aim: This study was conducted to investigate the phytochemical composition of crude extracts of the roots, leaves, and stem bark of C. abbreviata. Materials and Methods: This was a laboratory-based study in which the fresh leaves, stem bark, and roots of C. abbreviata were collected, thoroughly cleaned, chopped into small pieces, and kept at room temperature until fully dry. The dried plant parts were powdered separately and stored separately in airtight containers for the phytochemical investigation. Ethanol (96% v/v) or distilled water was used for the extraction of components of the coarse powder. The mixtures were separately filtered, and the filtrates were reduced to a concentrated semisolid mass by drying in a water bath at 40?C. Thereafter, phytochemical analysis for flavonoids, phenolics, tannins, saponins, alkaloids, terpenoids, glycosides, carbohydrates, and proteins was done. Results: The phytochemical analysis of the ethanolic extracts revealed the presence of high concentrations of tannins, reducing sugars, and sterols in the stem bark and roots. Flavonoids, phenolics, and proteins were present in high concentrations in the stem bark, while anthraquinone, glycosides, and alkaloids were present in the leaves and roots, respectively. Conclusion: C. abbreviata plant contains a wide range of phytochemical constituents. Depending on the solvent used for extraction, various compositions of phytochemicals are obtained in each part of the tree. However, extraction with ethanol showed a better concentration than with water for most of the phytochemicals.

Inhibition of Ehrlich ascites carcinoma by Manilkara zapota L.stem bark in Swiss albino mice

Objective:To evaluate the antitumor activity of Manilkara zapota(M.zapota) L.stem bark against Ehrlich ascites carcinoma(EAC) in Swiss albino mice.Methods:The in vivo antitumour activity of the ethyl acetate extract of stem bark of M.zapota L.(EASM) was evaluated at 50,100 and 200 mg/kg bw against EAC using mean survival time.After administration of the extract of M.zapota,viable EAC cell count and body weight in the EAC tumour hosts were observed.The animal was also observed for improvement in the haematological parameters(e.g.,heamoglobin content,red and white blood cells count and differential cell count) after EASM treatment. Results:Intraperitoneal administration of EASM reduced viable EAC cells,increased the survival lime,and restored altered haematological parameters.Significant efficacy was observed for EASM at 100 mg/kg dose(P<0.05).Conclusions:It can be concluded that the elhyl acetate extract of stem bark of M.zapota L.possesses significant antitumour activity.

Preliminary studies of acute and sub-chronic toxicity of the aqueous extract of Guibourtia tessmannii(Harms) J.Leonard stem barks (Caesalpiniaceae) in mice and rats

Objective: To investigate the toxicity of aqueous extract of Guibourtia tessmannii(Harms) J. Leonard(G. tessmannii) and evaluate its safety.Methods: NMRI mice were used to determine the acute toxicity of G. tessmannii.Increasing concentrations of the plant extracts were administered intraperitoneally or by force-feeding. General behavior and death were monitored and recorded daily for 7 days.In order to determine the sub-acute toxicity of the extract, several doses were administered by oral gavage daily for 28 days in adult Wistar rats. Different parameters were assessed including body weight, food and water intake, biochemical parameters and several vital organ weights.Results: LD50 of 328.78 mg/kg was obtained by i.p. route and more than 5 000 mg/kg was obtained in acute toxicity by oral route. In sub-acute toxicity, no significant alteration was observed in body weight or vital organs, food and water intake, and biochemical parameters.Conclusions: The results showed that the aqueous extract of G. tessmannii has low toxicity intraperitoneally and no sub-acute toxicity via oral intake.

Cytotoxic Activity of Stem Bark Extracts from Canarium odontophyllum Miq (Dabai) against Human Colorectal Carcinoma HCT 116 Cell Line

The preliminary study is aimed at evaluating the cytotoxic activity of crude extracts from the stem bark of Canarium odontophyllum against colorectal carcinoma cell HCT 116. Result of the extraction yield showed that distilled water produced the highest yield (10.58%) followed by methanol (6.55%) whereas acetone extracted the lowest yield (4.58%) from C. odontophyllum stem bark. Phytochemical screening test revealed the presence of terpenoid, flavonoid, tannin, saponin and phenolic compound in all the stem bark extracts of C. odontophyllum. Acetone extract of C. odontophyllum stem bark showed significantly higher (p < 0.05) cytotoxic effect with IC50 of 0.062 ± 1.04 mg/ml compared to methanol extract with IC50 0.122 ± 4.92 mg/ml. No cytotoxic effect was observed by the aqueous extract despite its high extraction yield. In conclusion, acetone and methanol extracts from C. odontophyllum stem bark exhibited promising cytotoxic activity against human colorectal cancer cell line HCT 116 and paves way for further investigation in view of its mode of cancer cell death.

Comparison of stem taper models for the four tropical tree species in Mount Makiling, Philippines

This study was conducted to evaluate the performance of six stem taper models on four tropical tree species, namely Celtis luzonica(Magabuyo),Diplodiscus paniculatus(Balobo), Parashorea malaanonan(Bagtikan), and Swietenia macrophylla(Mahogany) in Mount Makiling Forest Reserve(MMFR), Philippines using fit statistics and lack-of-fit statistics. Four statistical criteria were used in this study, including the standard error of estimate(SEE),coefficient of determination(R^2), mean bias( E),and absolute mean difference(AMD). For the lack-offit statistics, SEE, E and AMD were determined in different relative height classes. The results indicated that the Kozak02 stem taper model offered the best fit for the four tropical species in most statistics. The Kozak02 model also consistently provided the best performance in the lack-of-fit statistics with the best SEE, E and AMD in most of the relative height classes. These stem taper equations could help forest managers and researchers better estimate the diameter of the outside bark with any given height,merchantable stem volumes and total stem volumes of standing trees belonging to the four species of thetropical forest in MMFR.

Evaluation of Some Stem Taper Models for Camellia japonica in Mount Halla, Korea

This study was conducted to evaluate the performance of the four stem taper models on Camellia japonica in Jeju Island, Korea using fit statistics and lack-of-fit statistics. The five statistical criteria that were used in this study were standard error of estimate(SEE), mean bias( E), absolute mean difference(AMD), coefficient of determination(R2), and root mean square error(RMSE). Results showed that the Kozak model 02 stem taper had the best performance in all fit statistics(SEE: 3.4708, E : 0.0040 cm, AMD : 0.9060 cm, R2 : 0.9870, and RMSE : 1.2545). On the other hand, Max and Burkhart stem taper model had the poorest performance in each statistical criterion(SEE: 4.2121, E : 0.2520 cm, AMD : 1.1300 cm, R2 : 0.9805, and RMSE: 1.5317). For the lack-of-fit statistics, the Kozak model 02 also provided the best performance having the best AMD in most of the relative height classes for diameter outside bark prediction and in most of the DBH classes for total volume prediction while Max and Burkhart had the poorest performance. These stem taper equations could help forest managers to better estimate the diameter outside bark at any given height, merchantable stem volumes and total stem volumes of the standing trees of Camellia japonica in the forests of Jeju Island, Korea.

不同种源白桦树干氮磷化学计量特征的差异

以东北林业大学帽儿山实验林场老山人工林野外重点开放实验站(下简称帽儿山试验地)和辽宁省本溪满族自治县草河口镇辽宁省森林经营研究所实验林场(下简称草河口试验地)2个试验地的13 a种源试验林的9个白桦(Betula platyphylla)种源为研究对象,每个种源选择5株样木;在样木胸径处切割1个5 cm厚圆盘,进行树皮和树干木材样品取样;样品烘干后,用浓H 2SO 4-H 2O 2消煮,采用凯式定氮法测定树干木材和树皮的全氮(N)、采用紫外分光光度计钼锑抗比色法测定树干木材和树皮的全磷(P);应用双因素方差分析法分析种源和试验地对树皮和树干木材N、P化学计量特征的影响、冗余分析法分析种源地环境因子(经度、纬度、年均气温、7月份平均气温、8月份平均气温、6—8月份平均降水量、年均降水量)和生长性状(树高、胸径、地上生物量)对树干N、P化学计量特征的影响。结果表明:树皮和树干木材中N、P质量分数及w(N)∶w(P),受种源和试验地点的影响极显著(P<0.01);9个种源白桦的树皮、树干木材中N、P质量分数和w(N)∶w(P),均表现为帽儿山试验地的高于草河口试验地(P<0.01)。除帽儿山试验地白桦树皮的w(N)∶w(P)外,其他样木树皮和树干木材中N质量分数和w(N)∶w(P),均随种源地相对试验地点纬度的增加而先增加后降低(P<0.01);树皮和树干木材中P质量分数,均随种源地相对试验地点纬度的增加而增加(P<0.01)。种源地气温对树干N、P化学计量特征的影响,高于降水量的影响;树干木材和树皮的N质量分数与种源地降水量、气温呈负相关,树干木材和树皮的P质量分数与种源地降水量、气温呈正相关。因此,种源和试验地环境条件,均会影响白桦的N、P化学计量特征;白桦在种源地的长期适应中,种源地气温对树干N、P化学计量特征的影响高于降水量的影响。

核桃楸皮挥发油化学成分分析

采用水蒸汽蒸馏法提取核桃楸皮中的挥发油,用气相色谱/质谱联用法,鉴定了39种化合物,其中分离出烃类(26种,71.80%)、酮类(3种,10.83%)、醇类(6种,7.96%)、呋喃类(1种,5.79%)、酚类(1种,1.99%)、肟类(1种,0.95%),酯类(1种,0.71%)7大类化合物,有3类(7种,33.93%)为已知药用成分,为进一步评价其质量和开发新药提供了基础数据。

胡桃楸树皮提取物对SMMC-7721、MCF-7和A549肿瘤细胞的抑制作用及其机制

目的:观察胡桃楸树皮提取物(JMME)对SMMC-7721、MCF-7和A549 3种肿瘤细胞的生长抑制作用,确定其抑瘤的药用价值,通过检测JMME诱导肿瘤细胞凋亡、抑制端粒酶活性变化阐述其抑瘤机制。方法:分别以25、50、100、200、400和800 mg.L-1JMME作用于体外培养的SMMC-7721、MCF-7和A549肿瘤细胞72 h,采用MTT法检测生长抑制率;以200 mg.L-1JMME作用于体外培养的SMMC-7721、MCF-7和A549,于倒置显微镜下观察细胞形态学变化;琼脂糖凝胶电泳法检测细胞凋亡;PCR-ELISA法检测端粒酶活性。结果:不同浓度JMME(25、50、100、200、400和800 mg.L-1)对SMMC-7721的细胞生长抑制率(%)分别为13.06、21.77、29.88、41.74、69.82和78.08;对MCF-7的抑制率(%)为24.91、38.63、49.72、61.84、65.69和81.28;对A549的抑制率(%)为12.32、26.21、41.65、55.38、62.87和80.13;与对照组比较,JMME各浓度作用的3种肿瘤细胞的生长抑制率均升高(P<0.05),抑制率随JMME对SMMC、MCF-7和A549细胞的浓度的增加而增高(P<0.05)。JMME对SMMC、MCF-7和A549细胞的半数抑制浓度(IC50)分别为211.21、111.07和176.20 mg.L-1,对MCF-7的IC50小于其他两种瘤细胞株。经不同浓度JMME作用单位视野内细胞数量明显减少,细胞间隙增大,细胞体积明显缩小,细胞失去原有的形态,胞体皱缩变圆,出现膜发泡现象,对照组无此变化。提取DNA进行琼脂糖凝胶电泳,见DNA Ladder,表明3种肿瘤细胞经不同浓度JMME作用后出现不同程度凋亡。3种肿瘤细胞与阴性对照组比较端粒酶活性升高,而经过JMME作用后端粒酶活性均受到了抑制,抑制率分别为42.86%、73.30%和58.78%。结论:胡桃楸树皮提取物在体外有抗肿瘤活性,其机制可能与其诱导肿瘤细胞凋亡?抑制端粒酶活性有关。

祖师麻中的双黄酮类成分研究

目的 分离并鉴定祖师麻 Daphne giraldii中的黄酮类化合物。方法 利用硅胶柱色谱和 Sephadex L H- 2 0凝胶色谱分离双黄酮类成分 ,用核磁和质谱等谱学方法确定化合物的结构。结果 分离并鉴定了 4个双黄酮类化合物 daphnodorins A- D1 ( ～ )。结论 首次从祖师麻中得到化合物 daphnodorins A- D1 ,这类结构的双黄酮化合物目前仅发现于该属植物。

柞树皮对脂多糖和D-氨基半乳糖诱导败血症休克小鼠的保护作用

目的探讨柞树皮二氯甲烷提取物对脂多糖(LPS)和D-氨基半乳糖(D-GalN)诱导败血症休克小鼠的保护作用。方法 50只雄性ICR小鼠随机分为正常对照组,模型对照组,阳性对照组,高剂量给药组和低剂量给药组。两个剂量给药组分别按300,100 mg/kg腹腔注射柞树皮二氯甲烷提取物;阳性对照组按30 mg/kg腹腔注射地塞米松;正常对照组和模型对照组以等体积生理盐水灌胃,30 min后,除正常对照组外,其余各组均腹腔注射20μg/kg LPS和700 mg/kg D-GalN,比较各组血清门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)的活性和一氧化氮(NO)的含量,以及肝组织中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,同时每天观察小鼠的死亡率至第2天。结果柞树皮二氯甲烷提取物两个剂量给药组明显提高小鼠的存活率,显著抑制小鼠血清AST和ALT含量的升高(P<0.01),降低血清NO含量(P<0.01),同时明显升高小鼠肝组织SOD活性(P<0.05)、降低MDA含量(P<0.05)。结论柞树皮二氯甲烷提取物通过降低NO含量、肝保护作用,从而提高败血症性休克小鼠的存活率。

锦葵茎皮纤维增强复合材料的力学及隔声性能

为拓宽锦葵茎皮纤维的应用领域,以锦葵茎皮为原料,采用碱脱胶工艺提取锦葵茎皮纤维,并以碱处理后的锦葵茎皮纤维为增强体,聚丙烯纤维为基体,制备质量分数分别为40%、30%、20%、10%、0的锦葵茎皮纤维增强聚丙烯复合材料,探讨了纤维质量分数对锦葵茎皮纤维增强聚丙烯复合材料的拉伸、弯曲及隔声性能的影响。研究结果表明:当纤维质量分数为30%时,锦葵茎皮纤维增强复合材料的拉伸断裂强度、拉伸模量、弯曲模量均最高,弯曲强度随锦葵茎皮纤维质量分数的增加出现逐渐增大的趋势;当纤维质量分数超过10%时,锦葵茎皮纤维增强聚丙烯复合材料的电压峰值衰减率随发声频率的提高先增大后减小;当发声频率相同时,纤维质量分数越低,复合材料隔声性能越差,当纤维质量分数超过30%后,电压峰值衰减率有所下降。

锦葵茎皮果胶的提取及其对纯棉织物的应用

以锦葵茎皮为原料,酒石酸的稀释液为提取剂,采用单因素试验优化果胶的提取工艺,对果胶组成进行红外光谱分析;采用不同质量分数的果胶溶液对纯棉织物进行整理,测试了整理织物风格、拉伸性能及防紫外性能.结果表明,锦葵茎皮优化提取工艺为:pH=2,提取时间90 min,浴比1∶30;红外光谱分析表明锦葵茎皮果胶提取成功;纯棉织物经果胶溶液整理后,织物风格产生一定变化,拉伸性能有所提高,防紫外性能随着果胶浓度的增大而增强.

锦葵茎皮纤维/聚丙烯复合材料的力学与隔声性研究

采用高锰酸钾、KH-570偶联剂对锦葵茎皮纤维进行了表面处理,并以处理前后的锦葵茎皮纤维作为增强体、聚丙烯纤维为基体制备锦葵茎皮纤维含量为30%的增强复合材料,探讨了表面处理对锦葵茎皮纤维微观结构、物理机械性能的变化,讨论了表面处理前后锦葵茎皮纤维增强聚丙烯复合材料力学与隔声性能的变化。研究结果表明,锦葵茎皮纤维表面处理前后,表面的微观结构发生一定程度的变化,锦葵茎皮纤维/聚丙烯复合材料的力学性能与隔声性有一定幅度的提升,偶联剂处理后的复合材料的力学性能和隔声性能优于高锰酸钾处理后的复合材料。

黔产飞龙掌血茎皮部白屈菜红碱的含量测定

为黔产飞龙掌血药材资源的开发利用和保护提供参考依据,采用高效液相色谱（HPLC）法,以phenomenex Cemini C18（250mm×4.6mm×5μm）为色谱柱,甲醇-0.1%磷酸水溶液为流动相,梯度洗脱,在320nm波长下建立黔产飞龙掌血茎皮部的指纹图谱,并用相似度评价软件进行数据处理。结果表明：黔产飞龙掌血茎皮部药材的HPLC指纹图谱共有13个峰,与根皮部药材图谱的相似度高于0.9,初步认为飞龙掌血茎皮部的化学成分与根皮部相似,茎皮部白屈菜红碱的含量为0.06%-0.20%。

了哥王中西瑞香素对照品的制备及鉴定

目的建立从了哥王[Wikstroemia indica(L.)C.A.Mey]茎皮中制备西瑞香素对照品的方法。方法采用萃取、硅胶柱层析和重结晶方法对酶水解后了哥王茎皮的甲醇提取物进行分离纯化,通过MS、IR、1H-NMR和13C-NMR进行结构鉴定,通过TLC法和HPLC法对对照品进行纯度检测。结果从了哥王茎皮中分离纯化出西瑞香素对照品,质量分数>99.0%。结论该方法制备的西瑞香素对照品符合中药化学对照品的相关要求,可作为了哥王药材及其制剂质量控制用的化学对照品。

超声波辅助提取中国木茎皮多糖的工艺优化及抗氧化活性研究

以中国楤木(Aralia chinensis L.)茎皮为原料,研究了超声波辅助提取中国楤木茎皮多糖的最优工艺条件及体外抗氧化活性。根据Box-Behnken设计原理,在单因素实验基础上,选取液料比、提取温度、超声功率和提取时间四个因素进行四因素三水平的响应面实验,结果表明超声波辅助提取多糖的最优条件为:液料比33 m L/g、提取温度71℃、超声功率124 W、提取时间93 min,该条件下多糖提取率预测值为12.897%,验证值为12.871%±0.11%。体外抗氧化活性研究结果显示:在实验范围内,随着浓度的升高,中国楤木茎皮多糖对DPPH自由基、羟基自由基、超氧阴离子的清除能力逐渐增强,还原能力也逐渐增强。表明该响应面实验产生的回归模型用于优化中国楤木茎皮多糖的超声波提取工艺是可行的;中国楤木茎皮多糖具有一定的体外抗氧化能力,可以考虑将其开发成为一种天然抗氧化剂在医学或功能食品领域中使用。

CO_2浓度升高对红桦幼苗树皮和去皮树干特征的影响

研究了高(HD)、低(LD)两个种植密度下红桦幼苗的树皮和去皮树干特征对CO2升高的响应。结果表明,不论是否达到显著水平,树皮厚度、树皮基部横截面积和树皮体积均受到CO2升高的促进作用,但是受到种植密度升高的负作用。低密度处理中,CO2升高对去皮树干的大部分特征没有显著影响,高密度处理中,CO2升高对去皮树干特征产生了显著影响。在两个CO2处理下,所有的去皮树干的特征参数都受种植密度增加的影响而降低。此外,研究结果还发现树皮和树干对CO2升高和/或种植密度的反应程度不同,但反应方向一致。由于本实验是在控制环境生长室中对幼苗进行的,因而实验结果不宜外推到自然界生长的成年树木上。