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1.
(+)-Marmelo Lactones A(VA) and B (VB) were synthesized from erythro-γ-methyl-l-glutamic acid (IA) and threo acid (IB), respectively. The absolute configurations of natural marmelo lactones were thus determined to be (2R, 4S) for (+)-marmelo lactone A and (2R, 4R) for ( – )-marmelo lactone B.  相似文献   

2.
Background: Prescribed burning in peatlands is controversial due to concerns over damage to their ecological functioning, particularly regarding their key genus Sphagnum. However, empirical evidence is scarce.

Aims: The aim of the article is to quantify Sphagnum recovery following prescribed burns.

Methods: We completed nine fires at a raised bog in Scotland, achieving a range of fire severities by simulating drought in some plots. We measured Sphagnum cover and chlorophyll fluorescence Fv/Fm ratio (an estimate of photosynthetic capacity) up to 36 months post-fire.

Results: Cover of dominant Sphagnum capillifolium was similar in unburnt and burnt plots, likely due to its high moisture content which prevented combustion. Burning decreased S. capillifolium Fv/Fm 5 months after fire from 0.67 in unburnt plots to 0.44 in low fire severity plots and 0.24 in higher fire severity (drought) plots. After 22 months, Fv/Fm in burnt plots showed a healthy photosynthetic capacity of 0.76 and no differences between severity treatments. Other Sphagnum species showed similar post-fire recovery though their low overall abundance precluded formal statistical analysis.

Conclusions: S. capillifolium is resilient to low–moderate fire severities and the same may be true for a number of other species. This suggests that carefully applied managed burning can be compatible with the conservation of peatland ecosystem function.  相似文献   

3.
Two new phenolic amides, grossamide (7) and N-cis-feruloyl tyramine (2), have been isolated from the roots of bell pepper (Capsicum annuum var. grossum) together with p-aminobenzaldehyde (1), N-trans-feruloyl tyramine (3), N-trans-p-coumaroyl tyramine (4), N-trans-feruloyl octopamine (5), and N-trans-p-coumaroyl octopamine (6).  相似文献   

4.
The insect antifeedant activities of pterocarpans and a sesquiterpene alcohol from the dichloromethane extract of Pterocarpus macrocarpus Kruz. (Leguminosae) were evaluated against the common cutworm, Spodoptera litura F. (Noctuidae), and the subterranean termite, Reticulitermes speratus (Kolbe)(Rhinotermitidae). Three pterocarpans, (?)-homopterocarpin (1), (?)-pterocarpin (2), and (?)-hydroxyhomopterocarpin (3) and the sesquiterpene alcohol, (+)-pterocarpol (5), were isolated from the dichloromethane extract of the heartwood of P. macrocarpus under guidance by a biological assay. Among these natural products, the most active insect antifeedant against both S. litura and R. speratus was 1. On the other hand, sesquiterpene alcohol 5 showed less insect antifeedant activity than the other pterocarpans against both insect species. While its methylated derivative, (?)-methoxyhomopterocarpin (4), showed high biological activity, 3 showed less insect antifeedant activity in this study. Interestingly, racemic 1 did not show insect antifeedant activity against S. litura. However, all of the test pterocarpans and isoflavones showed antifeedant activity against the test termites. Additionally, since these compounds were major constituents of P. macrocarpus, these antifeedant phenolics may act as chemical defense factors in this tree. In Thailand, lumber made from this tree is used to make furniture and in building construction due to its resistance to termite attack.  相似文献   

5.
Five fluorescent symmetrical dimeric bisbenzimidazoles DB(n) containing four 2,6-substituted benzimidazole cores and differing in the length of the oligomethylene linker between two bisbenzimidazole rings (n = 3, 4, 5, 7, 11) have been synthesized. The ability of the dimeric bisbenzimidazoles to form complexes with the double-stranded DNA has been shown by spectral methods. Upon binding to the double-stranded DNA, DB(n) are localized in the narrow groove. The data on the inhibition of the DNA methyltransferase Dnmt3a by DB(n) indicate that dimeric bisbenzimidazoles DB(3) and DB(11) site-specifically bind to the oligonucleotide duplex.  相似文献   

6.
【背景】粮食在生长和收储期极易受到病原真菌或产毒真菌的污染,造成严重的损失。众多实践证明木霉属(Trichoderma)可以有效防治植物病原真菌。【目的】鉴定和筛选能有效抑制粮食常见危害真菌的木霉生防菌株,开发生防菌剂,保障粮食生产安全。【方法】从粮食上分离筛选出35株木霉,通过多基因系统发育分析和形态学观察方法进行菌种鉴定,利用平板对峙试验筛选出对粮食常见危害真菌有抑制作用的菌株。【结果】35株木霉分属于8个种,分别为非洲哈茨木霉(Trichodermaafroharzianum)、类棘孢木霉(Trichodermaasperelloides)、 Trichoderma amoenum、近深绿木霉(Trichoderma paratroviride)、Trichoderma obovatum、长枝木霉(Trichoderma longibrachiatum)、东方木霉(Trichodermaorientale)和深绿木霉(Trichodermaatroviride)。对峙试验结果表明,这8种木霉对于粮食上分离到的10种危害真菌均具有较好的抑制效果。非洲哈茨木霉(T.afroharzi...  相似文献   

7.
Introduction. During a field excursion in Guizhou Province, China, we collected some interesting moss specimens with branch leaves subulate in the upper part, partially and variably bistratose laminae, and a Macromitrium-like epiphytic growth habit on tree trunks. We present morphological and phylogenetic arguments for recognising these plants as a new moss species in the genus Macromitrium Brid. (Orthotrichaceae).

Methods. We compared the morphology of the potential new species with closely related species of Macromitrium, and constructed a phylogenetic tree based on ITS2, trnL and trnG including sampling from 14 other morphologically similar species of Macromitrium.

Key results. The proposed new species belongs to the genus Macromitrium (Orthotrichaceae, Musci). It is closely related to M. gymnostomum Sull. & Lesq. in the phylogenetic tree and according to gametophytic morphological features, represents a hitherto undescribed species.

Conclusions. A new moss species, Macromitrium maolanense Zeyou Zhang, D.D.Li, Jing Yu & S.L.Guo, is described and illustrated. The new species can be distinguished from all congeners by the combination of the following features of the branch leaves: (1) oblong-lanceolate, lanceolate to linear-lanceolate, gradually narrowed to an easily broken subula; (2) rather obscure upper and medial cells, often with blackish stains among cells, densely pluripapillose; (3) variably and partially bistratose laminae in the upper 1/3 portion; (4) basal cells clear, hyaline and smooth, those near costae forming a ‘cancellina region’; and (5) with numerous brownish, clavate gemmae on upper portion. We also discuss the principal distinctive characters separating the new species from its nearest congeners.  相似文献   

8.

Casts of the foraging tunnels of eastern American moles ( Scalopus aquaticus ) show impressions from the moles' mani along the lateral walls. The number of discernable impressions ranges from one to five, each showing two or three long, flat, blunt-ended claws. The size and shape of the impressions matches the claws on the paddle-like manus of S. aquaticus . The impressions are spaced at regular intervals of about two cm, and probably represent points at which the mole pushed off from the tunnel wall with alternating laterad digging strokes. Tunnel width generally exceeds height by about 15%, reflecting the laterally compressed body of the mole. These tunnel casts help show that clear, recognizable traces can be preserved in loose, humic soils, and demonstrate the type of traces left by a “lateral-thrust” digger with fully sprawled stance, such as S. aquaticus . Identification of traces on the tunnels of living moles may be applied to the fossil record, in which fossilized burrows with similar marks could be attributed to extinct burrowing moles or mole-like locomotion.  相似文献   

9.
《Journal of bryology》2013,35(4):417-422
Abstract

The Irish plant which, following Mitten, has commonly been referred to as Plagiochila ambagiosa Mitt. is specifically different from the type of P. ambagiosa, and is therefore described as Plagiochila atlantica F. Rose, sp. nov. It is now known from very restricted areas in Western Ireland, Western Scotland and North-western France.  相似文献   

10.
11.
《Journal of bryology》2013,35(3):161-164
Abstract

The genus Lobatiriccardia Furuki is reported as new to China, from the Dulong River valley, Gaoligong Shan range, Yunnan Province and this material is described as a new species endemic to China, Lobatiriccardia yunnanensis Furuki & D.G. Long, the fifth known species in the genus. The differences between the new species and the other members of the genus are enumerated, along with a key to all known species of Lobatiriccardia.  相似文献   

12.
《Journal of bryology》2013,35(4):363-373
Abstract

Three new species of Cololejeunea, C. dianae M. Wigginton, C. sanctae-helenae M. Wigginton and C. grossestyla M. Wigginton are described and illustrated from St Helena, South Atlantic Ocean. Details of their distributions are provided, and differences between the new taxa and other species of Cololejeunea are discussed. This is also the first report of the genus Cololejeunea from St Helena.  相似文献   

13.
The structures of three new gibberellins A30, A48 and A49 and a new kaurenolide, isolated from seeds of Cucurbita pepo L., were elucidated. The structures of GA39, GA48 and GA49 were shown to be ent-3α,12β-dihydroxygibberell-16-ene-7,19,20-trioic acid (1), ent-2α,3α,10,12α-tetrahydroxy-20-norgibberell-16-ene-7,19-dioic acid 19,10-lactone (5) and the epimer at C–12 of GA48 (8), respectively. The kaurenolide was shown to have the structure: ent-6β,7α,12β-trihydroxykaur-16-en-19-oic acid 19,6-lactone (14).  相似文献   

14.
《Journal of bryology》2013,35(2):143-146
Abstract

Grimmia serrana, a new endemic species for California, is described and illustrated. The new species is readily distinguished by the presence of multi-stratose marginal bands that are rounded in cross-section. The leaf morphology displayed by Grimmia serrana is unique within the genus. The distribution of Grimmia serrana is along the western foothills of the Sierra Nevada and in the northern Coast Range.  相似文献   

15.
Three new species of Swartzieae are described and illustrated:Swartzia alternifoliolata, S. capixabensis, andZollernia cowanii. Swartzia apetala var.blanchetii and var.subcordata are considered to be synonyms ofS. apetala var.apetala, andS. grazielana a synonym ofS. macrostachya var.macrostachya. Keys to southeastern Brazil members ofSwartzia andZollernia are provided.  相似文献   

16.
《Journal of bryology》2013,35(4):677-680
Abstract

Renauldia paradoxica, a new Pterobryaceous moss from western Panama, differs from all other species of Renauldia by its long, narrowly acuminate leaves. This species fits somewhat uncomfortably in Renauldia and appears to occupy a position intermediate between Renauldia, Orthostichidium, and Pterobryopsis.  相似文献   

17.
《Journal of bryology》2013,35(1):95-97
Abstract

Key to the genera Marchesinia, Dicranolejeunea and Lopholejeunea. D. johnsoniana (Mitt.) comb.nov. from Macaronesia is figured and described in detail. The South African Marchesinia chrysophylla is transferred to Dicranolejeunea and is regarded as conspecific with D. atra (Mitt.) Vanden Berghen, syn.nov. from Central Africa.  相似文献   

18.
Six new species of Lepraria are described from North America: L. barbatica, L. cryophila, L. disjuncta, L. moroziana, L. terricola, and L. xanthonica. Lepraria torii is discussed and its range extended to include boreal eastern North America. Lepraria aurescens is reported as new to North America from Florida. Preliminary keys to the genus in North America are presented.  相似文献   

19.
The names of all 135 species-group taxa of Cerambycidae described by N. N. Plavilstshikov are listed. Types of all these taxa preserved in the Zoological Museum of the Moscow State University and in the Zoological Institute (St. Petersburg) are catalogued, with lectotypes and paralectotypes designated. New synonymies are proposed: Pseudosieversia rufa (Kraatz, 1879) = Macrorhabdium ruficollis Plavilstshikov, 1915, syn. n.; Pseudo sieversia Pic, 1902 = Macrorhabdium Plavilstshikov, 1915, syn. n.; Agapanthia angelicae Reitter, 1898 = A. jacobsoni Plavilstshikov, 1915, syn. n. Dorcadion arietinum phenax Jakovlev, 1900, stat. n. is a valid name of the taxon known before as D. arietinum strandi Plav. Alosterna tabacicolor subsp. tokatensis Pic, 1901 (= A. t. caucasica Plavilstshikov, 1936, syn. n.) is regarded as a valid name (nomen protectum), and A. chrysomeloides var. subvittata Reitter, 1885 is regarded a nomen oblitum, as well as Cortodera umbripennis var. pallidipes Pic, 1898, while C. ruthena Plavilstshikov, 1936 is nomen protectum. Vadonia bipunctata puchneri Holzschuh, 2007, stat. n. is widely distributed in southern Ukraine and southern Russia from Dnepropetrovsk to Rostov-on-Don, and in the North Caucasus; specimens of this subspecies, as also specimens of V. saucia (Mulsant et Godart, 1855), stat. rest., known from the southern Crimea, constitute a part of the type series of V. bipunctata mulsantiana (Plavilstshikov, 1936).  相似文献   

20.
Dalea acracarpica, from Chiapas, Mexico is described, illustrated, and referred to sect. Parosela ser. Lasiostomae: the var. chilensis is a yellow-flowered Chilean counterpart of purple Peruvian D. pennellii var. pennellii.  相似文献   

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