Neolignans of Virola carinata bark

Four neolignans, dehydrodieugenol, its monomethylether, carinatone and carinatin have been isolated from the hexane fraction of the bark of Virola carinata. Three new neolignans were separated from the chloroform fraction and examined by spectroscopy and chemical reactions. Their structures were determined as (2S, 3S)-5-allyl- 7-methoxy-3-hydroxymethyl-2-(3′,4′-dimethoxyphenyl)-2,3-dihydrobenzofuran, (2S)- 1-(3′,4′-dimethoxyphenyl)-2-(3″-allyl-5″-methoxy-6″-hydroxyphenyl)propanone(1) ol(3), (1S,2S)-1-(3′,4′-dimethoxyphenyl)-2-(3″-allyl-5″-methoxy-6″-hydroxyphenyl) propanol(1) and called dihydrocarinatinol, carinatonol and carinatol, respectively.     

Comparative phylogenetic analyses of Chinese Horsfieldia (Myristicaceae) using complete chloroplast genome sequences

The biologist's ruler for biodiversity is the species; accurate species identification is fundamental to the conservation of endangered species and in-depth biological scientific exploration. However, the delimitation and affinities of Horsfieldia in China has been controversial, owing in part to very low levels of molecular divergence within the family Myristicaceae. Because species boundaries and phylogenetic relationships within Horsfieldia are also unclear, 13 samples were collected across its distribution in China and their genomes were subjected to shotgun sequencing using Illumina platforms. A total of 40 487 994–84 801 416 pair-end clean reads were obtained and, after assembly, the complete chloroplast genome was recovered for all samples. Annotation analysis revealed a total of 112 genes, including 78 protein-coding genes, 30 transfer RNA, and 4 ribosomal RNA genes. Six variable loci (petN-psbM, trnH-psbA, ndhC-trnV, psbJ-psbL, ndhF, and rrn5-rrn23) were identified. Phylogenetic analyses strongly support the presence of four distinct species of Horsfieldia in China. In addition, samples that had been identified previously as Horsfieldia kingii (Hook. f.) Warb. were indistinguishable from those of H. prainii (King) Warb., suggesting that if H. kingii does occur in China, it was not collected in this study. Similarly, the chloroplast genome of one H. hainanensis Merr. sample from Guangxi province was identical to H. tetratepala C. Y. Wu, suggesting that the distribution range of H. hainanensis might be narrower than assumed previously. The phylogenetic relationships between the Chinese Horsfieldia species based on the whole chloroplast genomes was supported strongly, indicating the potential for using entire chloroplast genomes as super-barcodes for further resolution of the phylogeny of the genus Horsfieldia.     

滇南风吹楠花粉形态观察

采用光镜、扫描电镜和透射电镜对滇南风吹楠的花粉形态进行观察.滇南风吹楠的花粉粒呈单粒存在,远极面观为椭圆形,近极面观大体为三角形,为不等极,两侧对称.花粉粒具一条远极单萌发沟;花粉大小为(15)19.90(21) μm×(20)22.50(25) μm.花粉粒外壁纹饰为网状,网脊平均宽度为0.29 μm;网眼形状不规则...     

A new chromane derivative from the stem bark of Scyphocephalium ochocoa

A new chromane, 5,8-dihydroxy-2-(10′-phenyldecyl)chroman-4-one (1) was isolated from the stem bark of Scyphocephalium ochocoa, along with three known compounds (2–4). The structure of compound 1 was determined with help of spectroscopic data including IR, UV, HREIMS, 1D and 2D NMR (COSY, HMQC and HMBC) experiments. Furthermore, the chemotaxonomic significance of these compounds along with other compounds previously isolated from Scyphocephalium ochocoa was discussed.     

Diarylpropanoids from Iryanthera polyneura

The trunk wood of Iryanthera polyneura Ducke (Myristicaceae) contains pinocembrin, 1-(2′,4′-dihydroxyphenyl)-3-(3″,4″-methylenedioxyphenyl)-propane, 1-(2′,4′-dihydroxy-3′-methylphenyl)-3-(2″-methoxy-4″, 5″-methylenedioxyphenyl)-propane and 4,2′,4′-trihydroxy-3-methoxydihydrochalcone.     

Constitutions of diarylpropanoids from Virola multinervia

The wood of Virola multinervia Ducke (Myristicaceae) contains sitosterol, stigmasterol and two novel diarylpropanoids virolane [1-(2-hydroxy-4-methoxyphenyl)-3-(3,4-methylenedioxyphenyl)-propane] and virolanol [2-hydroxy-1-(2-hydroxy-4-methoxyphenyl)-3-(3,4-methylenedioxyphenyl)-propane].     

(−)-di-de-o-methylgrandisin, a lignan from Virola pavonis leaves

Leaves of Virola pavonis yielded a (7,7′β,8β,8′)-4,4′-dihydroxy-3,3′5,5′-tetramethoxy-7,7′-epoxyligna (−)-di-de-O-methylgrandisin.     

Implications of collection patterns of botanical specimens on their usefulness for conservation planning: an example of two neotropical plant families (Moraceae and Myristicaceae) in Peru

We evaluated the usefulness of herbarium collection databases for assessing patterns of species diversity and distribution based on a dataset from the flowering plant families Moraceae and Myristicaceae from the Peruvian Amazon. For Moraceae, a total of 3523 collections were used representing 134 species. The Myristicaceae were represented by 2113 collections of 46 species. We evaluated the distribution of collections based on 252 grid cells (0.5° size) covering all lowland rainforest in the Peruvian Amazon. We found that collections were concentrated in a few cells and that species diversity clearly increases in relation to collection density. Moraceae were collected in only 45% and Myristicaceae in only 31% of the 252 grid cells. Fifty percent of the collections came from just six and three cells, respectively. Most species were represented by only a small number of collections and collected only in a few grid cells, meaning a few widespread common species tend to dominate the collection records. Not surprisingly, most collections were made close to towns and transport routes. We evaluated the usefulness of rarefaction curves and diversity estimators for comparing diversity between regions. These techniques seem to be of little use for botanical collections due to violations of underlying assumptions. Problems such as accuracy of geographic and taxonomic data and strong bias in the spatial representation of the whole dataset are important to consider when basing conservation analysis, planning, and decision-making on seemingly large databases of biodiversity collections and are discussed in detail.