Alpha-glucosidase inhibitor from Chinese aloes

Activity-guided fractionation of the methanol extract of Chinese aloes led to the isolation of aloeresin A, which demonstrated significant dose dependent alpha-glucosidase inhibitory activities, with IC(50) values of 11.94 and 2.16 mM, against rat intestinal sucrase and maltase, respectively.     

减压耦合超声法提取桑叶脱氧野尻霉素及降血糖活性研究

[目的]为高效制备桑叶中的一种多羟基生物碱—脱氧野尻霉素(Deoxynojirimycin,DNJ),以期为建立桑叶DNJ提取新技术及其营养价值的开发提供参照.[方法]以桑叶为原料,采用响应面优化法建立基于减压耦合超声法提取桑叶DNJ的工艺条件优化,并以其对α-葡萄糖苷酶与蔗糖酶的综合抑制率为指标,考察其与降血糖活性间...     

鸡卵白蛋白⁃桑葚酒渣花色苷纳米颗粒特性

桑葚酒渣作为桑葚酒酿造过程中的废弃物,富含多酚类生物活性成分,尤其是桑葚花色苷,具有较大的开发利用价值。以桑葚酒渣花色苷为研究对象,考察鸡卵白蛋白(OVA)?桑葚酒渣花色苷纳米颗粒的包埋率、外观形态、粒径和电势分布和抗氧化活性,以及在模拟胃肠消化体系中的稳定性。结果表明,当桑葚酒渣花色苷与OVA摩尔比为3∶1时,OVA能包埋最多的桑葚酒渣花色苷。桑葚酒渣花色苷与OVA在磷酸盐缓冲液中能相互作用形成纳米颗粒,其粒径约为40~45 nm。OVA?桑葚酒渣花色苷纳米颗粒较未包埋桑葚酒渣花色苷清除1,1?二苯基?2?三硝基苯肼(DPPH)自由基和2,2′?连氮基?双?(3?乙基苯并二氢噻唑啉?6?磺酸)二铵盐(ABTS)自由基能力明显增强。在模拟胃消化模型中,包埋前后的桑葚酒渣花色苷稳定性没有显著性差异;在模拟肠消化模型中,包埋后的桑葚酒渣花色苷稳定性显著提高,未包埋的花色苷在4.0 h后含量降低83.00%左右,而有OVA包埋的桑葚酒渣花色苷含量只降低45.00%左右,表明OVA与桑葚酒渣花色苷结合对花色苷的抗氧化稳定性有较好的保护作用。研究结果为桑葚酒渣花色苷的开发利用提供理论依据。     

<Emphasis Type="Italic">Broussonetia papyrifera</Emphasis> (paper mulberry): its growth,yield and potential as a fallow crop in slash-and-burn upland rice system of northern Laos

In northern Laos, shortened fallows in the slash-and-burn upland rice system are not sustainable either from a production or economic standpoint. This paper evaluates the potential for using the indigenous fast-growing tree, Broussonetia papyrifera L. Vent. (paper mulberry) as an economic fallow crop. The objectives of this study are to assess the inner bark yield of paper mulberry, and to evaluate rice productivity following paper mulberry cultivation. In addition, allometric models for estimating the inner bark yield of paper mulberry are developed. Inner bark yield of paper mulberry stands ranging in age from 9 to 48 months ranged from 10 to 208 g m⁻², and increased with age. The models using diameter at breast height and stem height, or diameter at breast height only as independent variables explained well the variation in inner bark yield. When paper mulberry was completely removed during the rice growing season, rice yields in these areas were similar to those following weedy bush fallow. When paper mulberry was allowed to grow, rice yields were negatively correlated to paper mulberry stem density. When paper mulberry lateral branches were pruned back, rice yields could be maintained if the paper mulberry stem density was <0.22 stems m⁻², suggesting that if paper mulberry is managed properly, rice yields can be maintained at current levels. The paper mulberry-upland rice rotation system improves the productivity of a traditional slash-and-burn system through harvesting paper mulberry inner bark; however the long-term sustainability of such a system remains unclear and warrants further investigation.     

吉安市应大力发展桑、果、茶

全文以列表形式记述吉安市5年中桑果茶生产特征,并对县域分布格局提出开拓建议。     

桑叶茶元素分析及其保健功能分析

用微波消解技术对样品进行消解,用火焰原子吸收法测定了浙江桐乡桑叶茶中8种矿物元素的含量,结果表明,桑叶茶中的矿物元素含量较高,其中含量最高的是K、Ca、Mg,比茶叶高出3 ～ 6倍,且其比例有利于人体吸收,有较高的营养保健价值,适合各类人群饮用.     

Laboratory and field evaluation of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> for controlling Mulberry whitefly <Emphasis Type="Italic">Pealius mori</Emphasis> Takahashi (Homoptera: Aleyrodidae) in mulberry (<Emphasis Type="Italic">Morus alba</Emphasis> Linn)

In a laboratory screening of 12 isolates of entomopathogenic fungi against nymphs of the mulberry whitefly (Pealius mori Takahashi), Beauveria bassiana (Balsamo-Crivelli) Vuillemin CKB-048 was the most virulent, causing 87 ± 3% mortality at 1 × 10⁶ conidia/ml. Infection was confirmed by growth of the fungus from cadavers and by scanning electron microscopy of treated nymphs. Beauveria bassiana CKB-048 was formulated as a wettable powder (1 × 10⁹ conidia/g) and tested in two mulberry (Morus alba Linn) plantations in central and northeastern Thailand. In both locations, two spray applications of B. bassiana CKB-048 at 3.75 × 10¹² to 6.25 × 10¹² conidia/ha and at 14 day intervals provided good control of whitefly nymphs; control with B. bassiana CKB-048 was comparable to that with the pesticide buprofezin at 250 g of active ingredient/ha. In addition, no mortality of silkworm larvae occurred when the larvae were fed with mulberry leaves sprayed with B. bassiana CKB-048 7, 14, or 21 days earlier.     

Antimutagenic, antioxidant and antimicrobial properties of Maytenus krukovii bark

The hydroalcoholic extract of Maytenus krukovii bark was investigated for its in vitro mutageno-protective activities by means of the Ames Salmonella/microsome assay. The extract showed an inhibitory effect in both T98 and T100 strains against the mutagenic activity of promutagen 2-aminoanthracene but was not protective against directly acting mutagens sodium azide and 2-nitrofluorene. When tested as a radical scavenger and antioxidant it produced a dose-dependent inhibition. The extract did not show significant antibacterial properties, and was weakly active against dermatophyte and phytopathogenic fungi, but inhibited the growth of phytopathogen Pithyum ultimum.     

A major facilitator superfamily transporter in Colletotrichum fructicola (CfMfs1) is required for sugar transport,appressorial turgor pressure,conidiation and pathogenicity

The major facilitator superfamily (MFS) is one of the largest membrane‐protein families. To investigate the role of MFS proteins in the fungal plant anthracnose pathogen Colletotrichum fructicola, the CfMFS1 gene was deleted. This resulted in reduced mycelial growth, conidial yield and decreased virulence on tea oil camellia leaves. In addition, ?Cfmfs1 showed increased sensitivity to osmotic stress and to a cell‐wall stressor. Further analysis revealed that CfMfs1 is required for conidial penetration and appressorial turgor pressure, both important for fungal pathogen invasion. Confocal fluorescence microscopy showed that CfMfs1 is localized to membranes of both hyphae and conidia, suggesting that it may be a membrane transporter. Our study provides evidence that CfMfs1 has a role in conidiation, sugar transport, stress response, conidial penetration, appressorial turgor pressure and virulence against tea oil camellia.     

青钱柳叶提取物对Caco-2细胞二糖酶活性的抑制作用

采用Caco-2细胞模型,分析了青钱柳Cyclocarya paliurus叶水提物、醇提后的水提物、95%醇提物、乙酸乙酯萃取物和正丁醇萃取物5种不同提取物对Caco-2细胞活力的影响及对Caco-2细胞上麦芽糖酶、蔗糖酶、乳糖酶3种二糖酶活性的抑制作用。结果表明,5种不同提取物中除95%醇提物对Caco-2细胞活力产生一定影响外,其余4种提取物对Caco-2细胞基本无毒性,在200 mg·L^-1浓度提取物范围内培养24～72 h后细胞仍能保持较高活力;对3种二糖酶活性抑制作用效果最好的为醇提后的水提物,尤其是对蔗糖酶和乳糖酶的抑制作用更为明显,最高的抑制率分别达到76.35%和60.13%,其次为乙酸乙酯萃取物,对乳糖酶的抑制率最高达54.41%。从青钱柳叶不同方法提取物的制备流程说明多糖类或中等极性的黄酮甙类有可能是青钱柳叶中抑制二糖酶活性的主要组成成分。     

Antimicrobial activity of 2-arylbenzofurans from Morus species against methicillin-resistant Staphylococcus aureus

Nine 2-arylbenzofurans isolated from Morus species were tested for their antimicrobial activities against methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Micrococcus luteus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Among these compounds, chalcomoracin (a leaf phytoalexine of mulberry tree) exhibited considerable antibacterial activity against MRSAs (MICs 0.78 μg/ml).     

Synergetic deodorant effect and antibacterial activity of composite paper containing waste tea leaves

Composite paper containing waste tea leaves was prepared to investigate the effective utilization of waste tea leaves as deodorant material. Paper containing waste green tea leaves did not have increased deodorizing ability compared with controls either against acidic odors such as hydrogen sulfide and acetic acid gases or against neutral odors such as formaldehyde and acetaldehyde gases. In contrast, the paper had excellent deodorizing ability against basic odors such as ammonia and trimethylamine gases. It was observed during additional tests conducted on paper samples containing 60 wt% waste leaves of oolong tea, black tea, pu-erh tea, or hojicha, that all the samples reduced the ammonia concentration to below 1 ppm, which is the threshold concentration for olfactory recognition, within 30 min. Further, paper containing waste green tea leaves was found to decrease the odor residual rate to 5.1% in 30 min even for a waste tea leaf content of 10 wt%. The excellent deodorizing ability of the paper could be attributed to the chemical reactions between odorous substances and the catechins found in tea leaves. After the deodorization of ammonia, paper containing waste green tea leaves was found to have increased antibacterial activity against Staphylococcus aureus.     

竹叶提取物活性成分分析及其对酵母菌生长的影响

对宜宾市当地佯黄竹等10种竹的竹叶进行活性成分提取，分析其60%乙醇提取物中黄酮、多酚、总糖、还原糖、多糖含量，并探究不同竹种竹叶提取物对酵母菌生长的影响，以期筛选适宜作为酿酒辅料的竹种。结果表明：除佯黄竹对酵母菌出现明显抑菌圈外，其余竹种均无明显抑菌圈，说明其对酵母菌生长无抑制作用，竹叶作为白酒酿造辅料具有可行性。     

Inhibition of Trypanosoma cruzi by plant extracts used in Chinese medicine

In this work, we assessed the effect of extracts obtained from 17 plants used in traditional Chinese medicine. These extracts were tested in vitro with the epimastigote form of Trypanosoma cruzi, clone Bra C(15) C(2), at 27 degrees C in F-29 medium at a concentration of 100 microg/ml in axenic cultures. Allopurinol was used as reference drug. Seven plant extracts showed inhibitory activities lower than 25%. Pueraria lobata, Mahonia beaei, Dictamus dasycarpus, Kochia scoparia, Sophora flavescens and Ligustrum lucidum showed effects with inhibition values between 25% and 60%, whereas Lithospermum erythrorhizon, Saussurea lappa, Melia toosendan and Cinnamomum cassia showed the greatest inhibitory activity of 100%. The IC(50) of these extracts were: 0.4, 2.4, 1.8 and 3.9 microg/ml, respectively. The MTT assay was made and did not show cytotoxic activity. These results allowed us to suggest that L. erythrorhizon, S. lappa, M. toosendan and C. cassia could be a source of new compounds against T. cruzi.     

不同整地方式对果桑生长及结实的影响

利用引入的“大10”果桑品种于开远市果桑基地进行不同整地方式的种植试验,试验结果表明：不同的整地方式对果桑的生长及结实产生显著的影响。经撩壕沟整地定植的果桑其树体长势旺,单株结实量和产叶量最高,其次为全垦整地挖穴定植的果桑,直接挖穴定植的果桑结实极差,长势也不好。     

Comparison of the growth traits of a commercial pioneer tree species,paper mulberry (Broussonetia papyrifera L. Vent.), with those of shade-tolerant tree species: investigation of the ecophysiological mechanisms underlying shade-intolerance

In rural areas of northern Laos, a commercially valuable pioneer tree species, paper mulberry (Broussonetia papyrifera L. Vent.) has been recommended for intercropping under plantations of commercial trees. However, less is understood about the growth of this pioneer tree species in the understorey and the mechanism underlying the shade intolerance. We measured growth characteristics for seedlings of paper mulberry under four light intensities. We compared the relative growth rates in aboveground biomass and standing leaf area (RGR_mass and RGR_leaf), light-capture efficiency, and seeding-level mass-based daily photosynthetic rates (A _mass) with those of field-grown seedlings of eight shade-tolerant species to identify factors potentially responsible for shade-intolerance. Most growth traits of the paper mulberry seedlings did not differ consistently from those of the shade tolerant species. The ecophysiological–architectural model software showed higher A _mass and RGR_mass capacity in paper mulberry than in shade-tolerant species. Despite their higher RGR_mass, paper mulberry seedlings had negative RGR_leaf under shaded conditions due to short leaf lifespan. The linear RGR_mass–RGR_leaf relationship for paper mulberry had a high RGR_mass intercept, indicating that a high RGR_mass was required to provide positive RGR_leaf. Progressive decreases in standing leaf area with time, and possibly photosynthesis, appear to be responsible for the shade-intolerance of paper mulberry. Although intercropping of paper mulberry has been suggested in the species’ native region, understorey cultivation of paper mulberry would only be possible with relatively open canopies.     

Inhibitory effects of <Emphasis Type="SmallCaps">l</Emphasis>-pipecolic acid from the edible mushroom, <Emphasis Type="Italic">Sarcodon aspratus</Emphasis>, on angiotensin I-converting enzyme

The aqueous extract of the edible mushroom Sarcodon aspratus showed inhibitory effects against angiotensin I-converting enzyme (ACE). l-Pipecolic acid (l-piperidine-2-carboxylic acid) was isolated from a hot-water extract in a 0.02% yield as an active principle. The mode of inhibition of l-pipecolic acid was found to be competitive, whereas its d-isomer showed no significant inhibitory effects against ACE, suggesting that the configuration of the carboxyl group in the molecule plays an important role in the enzyme inhibition.     

饲料桑树在水库消落带开发利用与生态修复中的种植试验

通过在水库消落带种植饲料桑树的试验,观察饲料桑树的生长过程,总结饲料桑树在水库消落带的开发利用与生态修复中的成果及应该注意的关键性问题。     

Nitrogen application and intercropping change microbial community diversity and physicochemical characteristics in mulberry and alfalfa rhizosphere soil

Intercropping of mulberry(Morus alba L.)and alfalfa(Medicago sativa L.) is a new forestry-grass compound model in China,which can provide high forage yields with high protein.Nitrogen application is one of the important factors determining the production and quality of this system.To elucidate the advantages of intercropping and nitrogen application,we analyzed the changes of physicochemical properties,enzyme activities,and microbial communities in the rhizosphere soil.We used principal components analysis(PCA) and redundancy discriminators analysis to clarify the relationships among treatments and between treatments and environmental factors,respectively.The results showed that nitrogen application significantly increased pH value,available nitrogen content,soil water content(SWC),and urea(URE) activity in rhizosphere soil of monoculture mulberry.In contrast,intercropping and intercropping+N significantly decreased pH and SWC in mulberry treatments.Nitrogen,intercropping and intercropping+N sharply reduced soil organic matter content and SWC in alfalfa treatments.Nitrogen,intercropping,and intercropping+N increased the values of McIntosh diversity(U),Simpson diversity(D),and Shannon-Weaver diversity(H') in mulberry treatments.However,PC A scatter plots showed clustering of monoculture mulberry with nitrogen(MNE) and intercropping mulberry without nitrogen(M0).Intercropping reduced both H' and D but nitrogen application showed no effect on diversity of microbial communities in alfalfa.There were obvious differences in using the six types of carbon sources between mulberry and alfalfa treatments.Nitrogen and intercropping increased the numbers of sole carbon substrate in mulberry treatments where the relative use rate exceeded 4%.While the numbers declined in alfalfa with nitrogen and intercropping.RDA indicated that URE was positive when intercropping mulberry was treated with nitrogen,but was negative in monoculture alfalfa treated with nitrogen.Soil pH and SWC were positive with mulberry treatments but were negative with alfalfa treatments.Intercropping with alfalfa benefited mulberry in the absence of nitrogen application.Intercropping with alfalfa and nitrogen application could improve the microbial community function and diversity in rhizosphere soil of mulberry.The microbial community in rhizosphere soil of mulberry and alfalfa is strategically complementary in terms of using carbon sources.