Extraction optimization and adsorption isotherm kinetics of polyphenols from blossoms of Citrus aurantium L. var. amara Engl

ABSTRACT

Crude extracts were extracted from blossoms of Citrus aurantium L. var. amara Engl. with 50% ethanol (CAVAP-E), 50% methanol (CAVAP-M), and hot water (CAVAP-W). CAVAP-W had the highest polyphenol yield of 3.7%. The optimum values of liquid/solid ratio, ultrasonic time, and ultrasonic power were 34.06 mL/g, 1 h, and 81.04 W, respectively. The adsorption characteristics of polyphenols were investigated using different macroporous resins. AB-8 and HP-20 resins offered higher adsorption and desorption capacities. Langmuir equation was more suitable to predict the adsorption of polyphenols. The pseudo second-order model was satisfactory to describe the kinetic data of polyphenols onto AB-8 and HP-20.     

合欢皮提取物对黑曲霉抑菌活性的研究

采用滤纸片法和生长速率法,测定了合欢皮乙醇提取物对4种常见菌种的抑菌活性;结果表明:合欢皮乙醇提取物对金黄色葡萄球菌的最低抑制浓度(MIC)为20mg/mL,对黑曲霉的抑制中浓度(EC50)为12.43mg/mL,即对黑曲霉抑菌效果较好。再进一步采用生长速率法,测定了合欢皮4种萃取物对黑曲霉(Aspergillus niger)的抑菌活性。4种萃取物中,正丁醇相对黑曲霉抑菌效果最好,其EC50为7.68mg/mL。结论:合欢皮乙醇提取物对黑曲霉的有效抑菌成分主要集中于正丁醇相,对于开发天然食品防腐剂有很大价值与潜力。      

Decomposition and nutrient release from pruning residues of two indigenous agroforestry species during the wet and dry seasons

The decomposition of leaves from Cordia africana Lam. and Albizia gummifera G. F.Gmel was investigated during the wet and dry seasons at Wondo Genet (Ethiopia). Litterbags of leaves were buried in soils under farmland and shaded-coffee agroforestry systems. Residual matter was recovered after 4, 8, 12, and 16 weeks and analysed for nitrogen (N), phosphorus (P), potassium (K), cellulose, lignin, soluble polyphenol and condensed tannin content. Mass-loss and release of N, polyphenols and condensed tannins were greater from Albizia leaves than from Cordia leaves, suggesting that a high polyphenol content does not necessarily retard decomposition. The rates of mass loss and release of the majority of leaf constituents were considerably faster during the wet season than during the dry season. Lignin decomposition, however, proceeded more rapidly during the dry season, and no significant seasonal differences were observed for polyphenol decomposition. The decomposition kinetics of most leaf components during the wet season were best described by a single-exponential model, but a quadratic model provided the best fit during the dry season. Initial leaf chemistry and season were important decomposition factors, while land-use effects were negligible. However, land-use effects showed distinct seasonal differences, with leaf litter decomposing more rapidly in soil under shaded-coffee than under farmland management, especially during the wet season. This study also demonstrated that polyphenol content does not show the predictive effects it has been attributed to have and that other constituents, such as condensed tannins, would be better suited for this purpose.     

Comparative GC/MS analysis of essential oils extracted by 3 methods from the bud of Citrus aurantium L. var. amara Engl

A comparative study of steam distillation extraction (SDE), reflux extraction (RE), and ultrasound-assisted extraction (USE) was conducted for the extraction of essential oils from the bud of Citrus aurantium L. var. amara Engl. Each method was evaluated in terms of qualitative and quantitative composition of the isolated essential oil by gas chromatography/mass spectrometry (GC/MS). The extract yields of essential oil were 0.16%, 2.18%, and 2.34%, respectively. A total of 82 compounds were identified by GC/MS. The main components obtained by SDE were terpinen-4-ol (20.98%), dipentene (11.67%), terpinene (9.24%), those by RE were palmitic acid (20.61%), 2-chloroethyl linoleate (14.54%), tetracosane (12.26%), and α-linolenic acid (11.24%), and those by USE were tetracosane (11.32%), heneicosane (11.06%), and palmitic acid (8.76%). Comparative analysis indicated that SDE was favorable for the extraction of monoterpene hydrocarbons, sesquiterpene hydrocarbons, alcohols, and carbonyl compounds, RE and USE had certain advantages in the extraction of aliphatic saturated hydrocarbons, organic acids, and esters. It is concluded that different extraction methods may lead to different yields of essential oils; the choice of appropriate method is very important to obtain more desired components with higher physiological activities. PRACTICAL APPLICATION: C. aurantium oils from different plant parts have great economic, medicinal, and nutritional values because of their wide-spectrum biological activities. The essential oil from C. aurantium L. var amara is one of the best C. aurantium oils. The data presented in this article will help us understand the relationship between essential oils and its extraction methods and know more about the aromatic components of Citrus aurantium bud. The methods established in this study will provide useful reference information for further studies, and offer essential oil industries with helpful guidance in practice.     

不同方法提取代代花中挥发油成分的GC-MS分析

分别采用水蒸汽蒸馏法、回流法和超声法提取代代花中的挥发油成分,提取率分别为0.16%、2.18%和2.34%。再用气相色谱-质谱法（GC-MS）对挥发油成分进行分析,峰面积归一法确定各组分的相对含量。三种方法分别鉴定出55、34、29种化学成分,其中水蒸气蒸馏法以萜品醇（20.98%）、柠檬烯（11.67%）主,回流法以棕榈酸（20.61%）、9,12-十八碳二烯酸-2-氯乙胺（14.54%）为主,超声法以正二十四烷（11.32%）、正二十一烷（11.06%）、棕榈酸（8.76%）为主。结果表明：不同方法提取的挥发油的组成及含量存在差异,针对目标产物需要选择合适的提取方法,水蒸汽蒸馏法对无极性和弱极性的萜烯和萜醇类化合物提取效果较好,超声法和回流法对极性稍强的脂肪酸和酯类有明显的提取优势。     

中国产玳玳叶油的化学成份研究

用挥发油提取器提取玳玳树枝和树叶中的挥发油,利用气相色谱-质谱(GC-MS)分析其中的化学成份,采用GC峰面积归一法定量,鉴定出54种化学物,占挥发油总量的98.9%以上,主要成份为芳樟醇、乙酸芳樟酯、乙酸香叶酯等.     

Tolerance ofAlbizia zygia (DC) Macbride,a Shade Tree for Cocoa,to Soil Acidity and Water Stresses

This paper reports the results of the study carried out to assess the tolerance to soil acidity and drought of Albizia zygia (DC) Macbride, which is one of the West African native tree species growing wild and used to provide shade for cocoa, with a high potential for amelioration of degraded cocoa soils. The results of the present study indicate that A zygia is tolerant to soil acidity. The species also exhibited characteristics of drought avoidance. Stomatal control was found to serve as a protective mechanism against excessive water loss when the seedlings were exposed to drought. The relationship between leaf water content and xylem pressure potential also indicated an ability of the species to maintain a given level of water tension throughout a certain degree of tissue dehydration. The high root:shoot ratio obtained for A zygia in this experiment suggests that the species is adapted to a resource limited environment. The increased magnitude of instantaneous relative growth rate in well-watered plants compared to water-stressed plants also indicates the overriding effect of changes in the instantaneous unit leaf rate on growth in A zygia subjected to different watering regimes.     

正交试验法优化屈曲花总黄酮的超声波辅助提取工艺

本文采用正交实验设计法优化了超声波辅助提取屈曲花总黄酮的工艺条件。首先,通过单因素实验研究乙醇浓度、提取时间、料液比和超声波功率对总黄酮得率的影响。然后,利用正交实验设计法优化最佳提取工艺。实验结果表明,乙醇浓度对屈曲花总黄酮得率的影响最大,其次依次为提取时间、料液比、超声波功率。最佳的提取条件为乙醇浓度85%、料液比1∶70、提取时间15 min、超声波功率100 W。在该条件下,总黄酮得率为2.456%。本文为工业化应用提供了参考标准,也为广泛开发利用屈曲花药物资源提供了良好的参考价值。      

Separation and Purification of Two Isomeric Saponins from Albiziae Cortex by High-Speed Counter-Current Chromatography and Preparative High-Performance Liquid Chromatography

Following constituents’ enrichment steps with the AB-8 macroporous resin, silica gel, and ODS columns, high-speed counter-current chromatography (HSCCC) and preparative HPLC were successfully used for the isolation and purification of two complex isomeric saponins including a new one from albiziae cortex. The two-phase solvent system used for separation was composed of n -hexane/ n -butanol/water (1:10:5, v/v/v ). A total of 8.2 mg julibroside J _{5 a} and 11.6 mg julibroside J ₅ with purity of higher than 98%, respectively, as determined by HPLC-ELSD were obtained from the constituents enriched fraction (475.4 mg) of albiziae cortex. Their structures were identified by HR-MS, ¹ H NMR ¹³ C NMR, and 2D NMR. This is the first ever report on the separation of complex isomeric saponins from albiziae cortex by HSCCC.     

药食同源代代花药理作用及应用研究进展

代代花是药食同源目录公布的第一批中药材,含有挥发油类、黄酮类、多糖类、生物碱类、香豆素类等化学成分,具有抗氧化、抗炎、抗菌、抗病毒、抗肿瘤、降血脂等药理作用,在食品、医药、日化等行业有一定应用。作为保健产品组分或中药配方组分,其可起调节机体功能或治疗病症的作用,在大健康领域彰显独特的价值。近年来,代代花的关注度进一步提升,针对其药理作用及应用方面的研究逐渐增加。该研究系统梳理国内外相关研究,从代代花的药理作用以及应用现状等方面进行分析和总结,期望推进深入研究和开发代代花的发展进程,为未来研究和综合开发利用代代花提供理论依据。