Radical scavenging, antioxidant and cytotoxic activity of Brazilian Caatinga plants

Extracts of 32 plants from the Brazilian northeastern semi-arid region called Caatinga were evaluated through DPPH radical scavenging assay, beta-carotene bleaching, and brine shrimp lethality tests (BST). Among the extracts studied Byrsonima cf. gardneriana, Mascagnia coriacea, Cordia globosa, Diodia apiculata and Hypenia salzmannii showed the highest activities in DPPH radical scavenging test. In the beta-carotene bleaching test the highest activities were observed for Passiflora cincinnata, Chamaecrista repens, B. cf. gardneriana, Rollinia leptopetala, Serjania glabrata, Diospyros gaultheriifolia, C. globosa, Mimosa ophtalmocentra, M. coriacea and Lippia cf. microphylla. In contrast, R. leptopetala, Zornia cf. brasiliensis and Leonotis nepetifolia were the most active species in the BST.     

球磨-酶解法制备纳米竹纤维的结构表征

采用机械球磨对竹纤维进行预处理,再经纤维素酶水解制备纳米竹纤维。通过光学显微镜(OM)、透射电子显微镜(TEM)、傅立叶红外光谱仪(FTIR)和X射线衍射仪(XRD)对竹纤维的形貌、组成、光谱学性能以及晶体特性进行了表征。实验结果表明:球磨法和酶解法在一定程度上都可以细化竹纤维;球磨预处理有助于竹纤维的酶解过程,且球磨-酶解法制备的纳米竹纤维粒径在100 nm左右;所制备的纳米竹纤维仍然保持竹纤维的基本化学结构,但球磨处理破坏了纤维素的结晶结构,其结晶度由64.15%降低到了38.55%。     

中山陵景区异龄复层混交林群落抑菌功能测定

在南京中山陵景区对构建的9种异龄复层混交林群落抑菌功能测定表明,不同混交林群落都有明显的抑菌作用。上午10:00时,含有秃杉、香樟和阔瓣含笑的混交林抑菌率达到80%以上;9种不同混交林空气中细菌菌落数减少1 328~1 817个/m3,抑菌率为64.4%~88.3%。下午15:00时,含有阔瓣含笑、乳源木莲、香樟、深山含笑和秃杉的混交林抑菌率也达到80%以上;9种不同混交林空气菌落数减少1 398~1 975个/m3,抑菌率达65.5%~92.7%。     

Antioxidant and enzyme inhibition activities and chemical profiles of Polygonum sachalinensis F.Schmidt ex Maxim (Polygonaceae)

Polygonum sachalinensis is a widespread invasive plant in Europe. Chemical profiles of its different organs were studied by HPLC-UV-ESI/MS. Seven major constituents quercetin-3-O-β-D-galactopyranoside, quercetin-3-O-arabinopyranoside, lapathoside D, N-trans-feruloyltyramine, lapathoside C, hydropiperoside, and vanicoside B were isolated and identified. The free radical-scavenging, α/β-glucosidase, and acetylcholinesterase inhibitory activities of crude MeOH extracts and isolated compounds were studied. The structure–activity relationships were discussed. The chemical profiles revealed flavonoids and phenylpropanoids are the major compounds of all the organs of this plant. Quercetin-3-O-arabinopyranoside, lapathoside D, N-trans-feruloyltyramine, lapathoside C and hydropiperoside were isolated from this species for the first time. In the α-glucosidase bioassay, quercetin-3-O-β-D-galactopyranoside, lapathoside D and N-trans-feruloyltyramine demonstrated stronger activities than the positive reference acarbose. The trend in scavenging power showed no relation to enzyme inhibition in the test models.     

Protective enzyme activity and physiological properties of four mulberry varieties affected by drought stress in the Panxi Region of Sichuan Province, China

In order to identify the effects of drought stress on protective enzyme activity and physiological properties, four mulberry varieties, i.e.,‘Nanye-1’, ‘Yunsang-1’, ‘Xinyizhilai’ and ‘Husang-32’ in the Panxi Region of Sichuan Province, China, were selected. The activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in four mulberry varieties was determined. Soluble protein, soluble sugar, proline, net photosynthetic rate and transpiration rate of mulberry leaves were analyzed. The resul...