深海来源真菌Penicillium sp. F00120代谢产物的研究

利用硅胶柱色谱、凝胶柱、反向柱色谱和高效液相色谱等手段对深海来源的真菌Penicillium sp.F00120在高盐培养基中的代谢产物进行分离纯化,从中分离得到了9个化合物。通过理化性质、波谱分析方法结合文献对照,鉴定了化合物的结构分别为:麦角甾醇(1)、4-methyl-5,6-dihydro-2-pyranone(2)、citreohybridonol(3)、1-linoleoylglycerol(4)、5α,6α-Epoxy-(22E,24R)-ergosta-8(14),22-diene-3β,7β-diol(5)、macrophorin(6)、purpurogemutantin(7)、3-(2S,4S-dihydroxypentyl)-6,8-dihydroxyisocoumarin(8)、5-hydroxy-7-(2'-hydroxypropyl)-2-methylchromone(9)。化合物2~4、6~9均为首次从深海沉积物真菌中分离得到。     

碱蓬内生真菌GMF19次级代谢产物的研究

以碱蓬根茎中分离得到的内生真菌Talaromyces pinophilus GMF19为研究对象,研究其代谢产物结构及生物活性多样性。对其发酵产物综合运用硅胶、凝胶、反相硅胶柱色谱及制备高效液相色谱法分离得到11个化合物,通过波谱学方法并与相关文献进行数据比对鉴定其结构,分别为:trichodermamides A(1)、ergosterol(2)、adenosine(3)、kojic acid(4)、5-hydroxy-4-oxo-4H-pyran-2-ethyl formate(5)、kojic acid monomethyl ether(6)、5-n-heneicosylresorcinol(7)、caffeic acid methyl ester(8)、(E)-caffeamide(9)、2,3,4-trihydroxy-6-(hydroxymethyl)-5-methylbenzylalcohol(10)与Nbacetyltryptamine(11)。除化合物2之外,其余10个化合物均为首次从该属真菌中分离得到。化合物2、3、5与7对至少2种供试植物病原真菌具有抑制活性;而化合物1及4～6具有卤虫致死活性,其中4的LD50值仅为7. 4μg/m L。     

春砂仁内生真菌Letendraea helminthicola A696的次级代谢产物研究

研究春砂仁内生真菌Letendraea helminthicola A696的次级代谢产物,采用硅胶柱色谱、ODS反相柱色谱、凝胶柱色谱及高效液相色谱等方法从该菌株的发酵液中分离得到8个化合物,通过理化性质及谱学数据分析,分别鉴定为11-hydroxyl tricinonoic acid(1)、3-(3,5-二叔丁基-4-羟基苯基)丙酸甲酯(2)、gibepyrone F(3)、gibepyrone D(4)、对羟基苯甲醛(5)、对甲氧基苯乙酸(6)、间羟基苯乙酸(7)、麦角甾醇(8),其中化合物1为新化合物,化合物2～8均为首次从Letendraea属真菌中分离得到。选取化合物1～5进行了抗菌和抗肿瘤活性试验,结果表明化合物1～5在100μg/mL浓度下均无抗菌和抗肿瘤活性。     

源自海洋裸孢壳属真菌Emericella sp. TJ414JZ-21的次级代谢产物

采用硅胶柱层析、中压反相柱层析、Sephadex LH-20凝胶柱层析以及半制备高效液相色谱等分离技术,从真菌Emericella sp.的大米发酵产物中分离得到了8个单体化合物,并利用波谱学方法结合文献数据对其结构进行了鉴定,分别为：asteltoxin (1)、asteltoxin B (2)、penicillide (3)、purpactin A (4)、tajixanthone hydrate (5)、mycophenolic acid (6)、trans-dehydrodiferulate dimethyl ester (7)、2,8-dihydroxy-1,3-dimethoxy-6-methylanthraquinone (8)。其中,化合物3和4均为首次从该属真菌中分离得到。     

红树植物老鼠簕内生真菌Aspergillus flavipes AIL8化学成分的研究

利用硅胶柱层析、Sephadex LH-20凝胶柱层析及半制备高效液相色谱等分离手段对红树林老鼠簕内生真菌Aspergillus flavipes AIL8的提取物进行分离纯化,并利用各种波谱方法,结合文献对照,确定化合物结构。从提取物中分离得到6个化合物,经鉴定为4-羟基-3-甲氧基-5-[(2E,6E)-3,7,11-三甲基十二烷-2,6,10-三烯-1-基]苯甲酸(1)、芳香类内酯化合物(2)、一癸酸甘油酯(3)、菜子甾醇(4)、7,22(E)-麦角二烯-3β,5α,6β-三醇(5)和麦角甾-6,22-二烯-5α,8α-环二氧-3β-醇(6)。6个化合物均为首次从红树林老鼠簕内生真菌A.flavipes AIL8中分离得到,其中化合物1为新天然产物。     

海洋真菌Penicillium sclerotiorum FS50的化学成分研究

采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、半制备HPLC等方法从海洋真菌菌核青霉Penicillium sclerotiorum FS50中分离纯化了9个化学成分,通过化合物波谱学数据及理化性质确定它们的结构分别为penicilazaphilone B(1)、sclerotioramine(2)、紫檀醇(3)、亚油酸甘油酯(4)、(3β,5α,6β,22E)-6-methoxyergosta-7,22-diene-3,5-diol(5)、啤酒甾醇(6)、对羟基苯乙酮(7)、酪醇(8)、邻苯二甲酸二(2-乙基)己酯(9)。其中化合物3为首次从青霉属中分离得到,化合物2、4、5、6、8、9为首次从菌核青霉中分离得到。     

海洋真菌菌核青霉FS50固体发酵代谢产物

采用硅胶柱、反相硅胶柱、凝胶柱、薄层制备和HPLC等色谱技术对1株分离自南海沉积物的海洋真菌菌核青霉Penicillium sclerotiorum FS50的大米发酵提取物进行分离纯化,从中分离得到7个化合物。通过波谱数据分析,化合物1-7分别被鉴定为:6,8‐dihydroxyisocoumarin‐3‐butyl formate(1),6,8‐dihydroxyisocoumarin‐3‐carboxylic acid(2),6‐methoxy‐8‐hydroxyisocoumarin‐3‐carboxylic acid(3),(+)‐sclerotiorin(4),4‐methyl‐5,6‐dihydropyren‐2‐one(5),5‐羟甲基糠醛(6),胡萝卜甙(7)。化合物1为新化合物,化合物2,3,6为首次从青霉属中分离得到。     

深海真菌Penicillium herquei FS83次生代谢产物研究

利用正相硅胶柱、反相硅胶柱、凝胶柱、薄层层析以及高效液相色谱法等色谱技术从深海真菌Penicillium herquei FS83的液体发酵产物中分离得到5个化合物,通过波谱数据分析结合文献对照,分别鉴定为peniherin A(1)、sclerodin(2)、对羟基苯乙酸甲酯(3)、对羟基苯乙酮(4)、(R)-甲羟戊酸内酯(5)。其中化合物1为新化合物,化合物2为首次从该属真菌中分离得到。生物活性实验显示,化合物1无明显细胞毒活性及抑菌活性。     

海洋真菌Arthrinium sp. UJNMF0008代谢产物的研究

为丰富海洋真菌的化学多样性,发现海洋真菌活性代谢产物,对海洋沉积物来源真菌Arthriniumsp.UJNMF0008的化学成分及其生物活性进行研究,采用硅胶柱色谱、凝胶柱色谱、反向柱色谱和高效液相色谱等方法从海洋沉积物来源真菌Arthriniumsp.UJNMF0008的发酵提取物中分离到5个化合物,通过核磁共振、质谱等方法,结合文献对照,鉴定了化合物的结构分别为arthoneF(1)、arthoneG(2)、sydoxanthoneC(3)、(3R,4R)-cis-4-hydroxymellein(4)和2-(2′S-hydroxypropyl)-5-methyl-7-hydroxychromone(5),其中化合物1和2是新化合物,化合物3首次从该属真菌中分离到。活性测试显示,化合物1~5在50μmoL/L的测试浓度下均没有表现出明显的抗氧自由基活性、抗菌活性以及NO释放抑制活性。     

味噌异黄酮类化学成分

对味噌中异黄酮类化学成分进行了研究。通过硅胶柱色谱、Sephadex LH-20凝胶柱色谱、反相C18硅胶柱色谱以及制备HPLC等方法,对味噌正丁醇萃取部位进行分离纯化,根据化合物的理化性质和波谱数据(1H NMR、13C NMR、HMBC、MS)鉴定单体化合物的化学结构。总共分离得到6个异黄酮类化合物(图1),分别鉴定为:染料木素(1)、大豆素(2)、黄豆黄素(3)、4',5,7,8-四羟基异黄酮(4)、4',7,8-三羟基异黄酮(5)、4',7,8-三羟基-6-甲氧基异黄酮(6)。以上化合物均为首次从味噌中分离得到。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Composition and diversity of bird communities in Swedish farmland–forest mosaic landscapes

CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.