Leaf and stem micromorphology of Byrsonima sericea DC. by light and scanning electron microscopy

Micromorphological studies were carried out using multiple microscopic techniques on the leaves and stem bark of Byrsonima sericea DC. (Malpighiaceae), a species popularly known as “murici” and used medicinally, in order to identify both qualitative and quantitative features of leaf and stem anatomy and histochemistry as differential parameters to support both the quality control of its ethnodrugs and the taxonomy of the genus. The study was conducted using traditional techniques of plant anatomy, histochemical tests, and the stomatal index (SI). Byrsonima sericea has hypostomatic leaves, anomocytic stomata, and its epidermal walls are anticlinal and straight on the adaxial and curved on the abaxial faces. T‐shaped trichomes were observed mainly on the abaxial surface. The leaf epidermis showed waxes syntopism on both surfaces, with the occurrence of different crystalloid forms on a single phylloplane. The mesophyll is dorsiventral, with 3‐4 collateral vascular bundles. Phenolic compounds, starch, and proteins were identified in the petiole and stem. The SI was 14.5 ± 0.53% (p < .05), but did not showed significant variations. A set of characters were found to be distinctive for the studied species, however, constituting parameters that could be used to separate B. sericea from other species of the genus.     

Mechanochemically assisted fabrication of ultrafine Pd nanoparticles on natural waste-derived nitrogen-doped porous carbon for the efficient formic acid decomposition

Utilizing natural waste as carbon source to prepare porous carbon with ultrahigh surface area and developing a facile protocol to synthesize supported metal nanoparticles toward an efficient formic acid (FA) decomposition are vital but remains challenging. Here, discarded ginkgo leaves were utilized as carbon source to prepare ginkgo leaf-derived porous carbon (GLPC) with an ultrahigh surface area of 3851 m²/g. Based on the as-prepared nitrogen-doped GLPC (N-GLPC) after “soft” nitriding, a facile solid-state reduction strategy with mortar-pestle grinding and without the use of any organic solvent and stabilizing ligand was developed to synthesize ultrafine and well-distributed Pd nanoparticles (NPs) with a diameter of 2.7 ± 0.7 nm. The “soft” nitriding temperature and addition of base during preparation played vital roles in the activity of the fabricated catalysts. The Pd/N-GLPC-350 exhibited the highest catalytic activity toward decomposing FA, achieving a high turnover frequency of 2952 h^?1 at 333 K. The Pd/N-GLPC-350 was quite stable and could be reused at least five times without evident activity loss. This study provides a facile solid-state reduction protocol with mortar-pestle grinding to synthesize metal NPs by using natural waste-derived porous carbon as support toward efficient FA decomposition.     

Ethanolic Noni (Morinda citrifolia L.) leaf extract dechlorophyllised using sedimentation process: Antioxidant,antibacterial properties and efficacy in extending the shelf-life of striped catfish slices

Antioxidant and antimicrobial activities of ethanolic noni leaf extract (ENLE) without and with chlorophyll removal by sedimentation method were comparatively investigated. Total chlorophyll content was reduced by 82% in the top fraction (CR-ENLE) collected after 24 h at 4 °C as compared to that of ENLE. Antioxidant and antimicrobial activities were lower in the bottom fraction rich in chlorophyll (Chlo-ENLE) than others (P < 0.05). Based on the microbiological limit, the shelf-life of striped catfish slices pre-treated with 400 mg kg⁻¹ C-R-ENLE was extended to 9 days as compared to the 3 days recorded for the control (without pre-treatment). Slices treated with CR-ENLE had lower lipid oxidation than those treated with ENLE during refrigerated storage (P < 0.05). The sedimentation process was therefore a potential green method for producing ENLE having improved antioxidant and antimicrobial activities without green colour. It can be used as a natural additive for shelf-life extension of fish slices.     

草莓（Fragaria × ananassa）叶水提物对UVB致 皮肤损伤的保护作用

在草莓叶水提物（Strawberry leaf water extract，SLWE）制备基础上，测定SLWE成分，抗氧化活性、抑制非酶糖基化（NEG）能力，及SLWE对正常生长人皮肤成纤维细胞（HFF-1）细胞活率、透明质酸（HA）、人I型胶原蛋白（COL I）、羟脯氨酸（HYP）、基质金属蛋白酶1（MMP-1）、基质金属蛋白酶9（MMP-9）含量，评价SLWE延缓皮肤衰老功效。在中波紫外线（UVB）致HFF-1损伤模型基础上，测定SLWE对保护组活性氧（ROS）、丙二醛（MDA）、MMP-1和超氧化物歧化酶（SOD）的影响，探讨SLWE对UVB致HFF-1损伤保护机制。结果表明：SLWE富含Vc、槲皮素、绿原酸、没食子酸及儿茶素类物质，其中槲皮素含量12.86 mg/L，表儿茶素含量10.13 mg/L。SLWE自由基清除能力良好，清除不同自由基能力依次为O2-?＞DPPH＞ABTS＞亚铁离子螯和＞?OH；水溶液体积分数为1%的SLWE非酶糖基化抑制率为87.17%；体积分数大于3%的SLWE可提高HFF-1中HA、COL I和HYP含量（p＜0.05），体积分数为6%的SLWE可降低MMP-1含量（p＜0.01），说明SLWE具有提升皮肤含水量，增加胶原含量，抑制胶原降解，实现延缓衰老的功效；在SLWE对UVB致HFF-1损伤保护模型中，SLWE可有效降低因UVB刺激而产生的ROS，体积分数6%的SLWE可显著降MDA，抑制MMP-1表达，提高SOD活力，说明SLWE有助于缓解氧化应激造成的细胞损伤。     

Spray Drying of Green Corn Pulp

Maize (Zea mays) is a cereal grown in Brazil, and its availability is limited to the harvest season. An alternative processing route is based on the production of green corn powder, which has a longer shelf-life and increased versatility. This study aimed to evaluate the influence of drying conditions on the physical characteristics, size, and morphology of green corn powder. Drying experiments were performed on a spray dryer according to a central composite rotational design to evaluate inlet air temperature, feed flow rate, and pulp concentration. The yield of dried pulp corn had an average value of 36.19%. The following mean values for the physical properties of the powder were measured: solubility of 94.37 g/100 g, wettability of 128.05 seconds, moisture content of 1.97%, water activity of 0.13, density of 0.79 g/mL, and a particle diameter of 31.02 µm. The powder was also yellow with less intensity, and the particle surface was smooth at higher temperatures and had a tendency to form agglomerates. The estimated optimal conditions for spray drying were 48% (w/w) pulp concentration, 172°C inlet air temperature, and feed flow rate of 0.56 L/h.     

大孔树脂对桃金娘叶总黄酮的静态吸附性能研究

分别研究了X-5和AB-8两种不同树脂对桃金娘叶总黄酮的静态吸附和解吸性能。结果表明,X-5树脂具有较好的吸附和解吸参数,是一种分离纯化桃金娘叶总黄酮较好的树脂,其最佳条件为温度为25℃、吸附时间为6 h、黄酮原液pH=6时,吸附率最大,为66.07%,此时选用95%的乙醇做解吸剂,于30℃温度下解吸12 h时,解吸效果最佳。