Extraordinary preservation of gene collinearity over three hundred million years revealed in homosporous lycophytes.

Homosporous lycophytes (Lycopodiaceae) are a deeply diverged lineage in the plant tree of life, having split from heterosporous lycophytes (Selaginella and Isoetes) ~400 Mya. Compared to the heterosporous lineage, Lycopodiaceae has markedly larger genome sizes and remains the last major plant clade for which no chromosome-level assembly has been available. Here, we present chromosomal genome assemblies for two homosporous lycophyte species, the allotetraploid Huperzia asiatica and the diploid Diphasiastrum complanatum. Remarkably, despite that the two species diverged ~350 Mya, around 30% of the genes are still in syntenic blocks. Furthermore, both genomes had undergone independent whole genome duplications, and the resulting intragenomic syntenies have likewise been preserved relatively well. Such slow genome evolution over deep time is in stark contrast to heterosporous lycophytes and is correlated with a decelerated rate of nucleotide substitution. Together, the genomes of H. asiatica and D. complanatum not only fill a crucial gap in the plant genomic landscape but also highlight a potentially meaningful genomic contrast between homosporous and heterosporous species.

The haplotype-resolved genome of diploid Chrysanthemum indicum unveils new acacetin synthases genes and their evolutionary history.

Acacetin, a flavonoid compound, possesses a wide range of pharmacological effects, including antimicrobial, immune regulation, and anticancer effects. Some key steps in its biosynthetic pathway were largely unknown in flowering plants. Here, we present the first haplotype-resolved genome of Chrysanthemum indicum, whose dried flowers contain abundant flavonoids and have been utilized as traditional Chinese medicine. Various phylogenetic analyses revealed almost equal proportion of three tree topologies among three Chrysanthemum species (C. indicum, C. nankingense, and C. lavandulifolium), indicating that frequent gene flow among Chrysanthemum species or incomplete lineage sorting due to rapid speciation might contribute to conflict topologies. The expanded gene families in C. indicum were associated with oxidative functions. Through comprehensive candidate gene screening, we identified five flavonoid O-methyltransferase (FOMT) candidates, which were highly expressed in flowers and whose expressional levels were significantly correlated with the content of acacetin. Further experiments validated two FOMTs (CI02A009970 and CI03A006662) were capable of catalyzing the conversion of apigenin into acacetin, and these two genes are possibly responsible acacetin accumulation in disc florets and young leaves, respectively. Furthermore, combined analyses of ancestral chromosome reconstruction and phylogenetic trees revealed the distinct evolutionary fates of the two validated FOMT genes. Our study provides new insights into the biosynthetic pathway of flavonoid compounds in the Asteraceae family and offers a model for tracing the origin and evolutionary routes of single genes. These findings will facilitate in vitro biosynthetic production of flavonoid compounds through cellular and metabolic engineering and expedite molecular breeding of C. indicum cultivars.

Prevalence and genotype distribution of HPV infections among women in Chengdu,China.

BACKGROUND: Human papilloma virus (HPV) infection among female is the cause of cervical cancer and genital warts. In China, the HPV vaccination rate and the target population screening rate among females are low, and the aims of this study on the genotype distribution and prevalence of HPV infection were to provide more targeted strategies for the prevention and treatment of cervical cancer and HPV-related diseases. METHODS: Polymerase chain reaction-reverse dot blot (PCR-RDB) was adopted for HPV genotyping test, the prevalence and 23 genotypes distribution of HPV infections among 181,705 women in Chengdu from 2013 to 2020 were analysed. RESULTS: The overall prevalence rate of HPV infection among 181,705 cases was 23.28%, the prevalence of HR-HPV at the age group < 20 years, 60-69 years and ≥ 70 years were higher than the overall prevalence.The prevalence of HPV showed a bimodal U-shaped curve with age; the first and second peak common occurred among females < 20 years old (42.97%) and 60-69 years old (37.56%), respectively.The top five genotypes of HPV infection among females in Chengdu were HPV52/16/58/81/53. Single infection (73.26%) was the main HPV infection pattern, followed by double infection (19.17%) and multiple infection (7.57%), the infection rate of HPV showed a gradual declined as the patterns of HPV coinfections increased, low-risk and high-risk coinfection was higher in low-risk HPV infection (43.68%) and lower in high-risk HPV infection (13.59%). The prevalence of genotypes - 6 and - 81 infection was the second highest at the age group of 20 and 40-59, respectively, while the prevalence of HPV16 was the highest at the age group of ≥ 70 among 23 genotypes among the 181,705 women. CONCLUSIONS: The prevalence of HPV infections among women in Chengdu is higher than domestic certain developed citys, among the five vaccines available, nonavalent vaccine is more suitable for Chengdu females. For young females prioritizing vaccination is essential in the current context.Double screening for HPV DNA is important in middle-aged women (30-49 years), and screening should not be lacking in older women (> 65 years). Additionally,for patients with genital warts, it is necessary to screen for high-risk HPV infection and provide appropriate management and treatment. Given the limitations of this study, future HPV research should aim to achieve full coverage of the target population, and our studies should also include cellular or pathological data of HPV-positive cases, vaccination rates, and various lifestyle details.

The Discovery of Weddellamycin, a Tricyclic Polyene Macrolactam Antibiotic from an Antarctic Deep-Sea-Derived Streptomyces sp. DSS69, by Heterologous Expression.

Polyene macrolactams are a special group of natural products with great diversity, unique structural features, and a wide range of biological activities. Herein, a cryptic gene cluster for the biosynthesis of putative macrolactams was disclosed from a sponge-associated bacterium, Streptomyces sp. DSS69, by genome mining. Cloning and heterologous expression of the whole biosynthetic gene cluster led to the discovery of weddellamycin, a polyene macrolactam bearing a 23/5/6 ring skeleton. A negative regulator, WdlO, and two positive regulators, WdlA and WdlB, involved in the regulation of weddellamycin production were unraveled. The fermentation titer of weddellamycin was significantly improved by overexpression of wdlA and wdlB and deletion of wdlO. Notably, weddellamycin showed remarkable antibacterial activity against various Gram-positive bacteria including MRSA, with MIC values of 0.10-0.83 µg/mL, and antifungal activity against Candida albicans, with an MIC value of 3.33 µg/mL. Weddellamycin also displayed cytotoxicity against several cancer cell lines, with IC50 values ranging from 2.07 to 11.50 µM.

Development of multidimensional water poverty in the Yangtze River Economic Belt, China.

As a basic natural and strategic resource, water is of great significance to the sustainable development of economies and societies. Owing to population growth, industrialization, the acceleration of urbanization, and global warming, water poverty is gradually increasing in some parts of the world. Effectively assessing water poverty from different dimensions is still a serious challenge for global water resources planning. This paper establishes a framework of multidimensional water poverty (MWP) from six dimensions: water management, water technology, water assets, water welfare, water resources, and water environment. The measurement model of MWP is built based on the Back Propagation Neural Network (BPNN), and the Spatial Correlation Analysis tool is used to visualize the spatial effects of MWP. The Yangtze River Economic Belt (YREB) was used as a case study and the main factors affecting the MWP of the YREB were determined by the Geodetector. When analyzing the results the following observations were made: (1) In terms of time distribution, the level of MWP in the YREB has gradually increased, and the poverty gap between the upper reaches, as well as the middle and lower reaches, shows an increasing trend. (2) With respect to spatial distribution, there is a continuously increasing agglomeration effect that shows a gradient-increasing distribution pattern of "West-Central-East." (3) The MWP in the YREB is mainly affected by these indicators in the three dimensions consisting of water resources, water technology, and water management. Specifically, R&D expenditure as a percentage of GDP, the proportion of water-saving irrigation area in the cultivable land area, the urban daily wastewater treatment capacity, the land surface water resources per capita, and the groundwater resources per capita play an important role in the MWP. Based on the above findings, targeted policy recommendations are proposed to alleviate the MWP in the YREB.

Modeling the power system resilience in China under different natural disasters.

A good understanding of the power system resilience is necessary for optimizing the investment strategies and supporting the emergency rescue, but the existing quantitative estimation results based on real outage events are still lacked due to the data limitations. Therefore, this study first establishes a unified framework to measure the power system resilience under different natural disasters, by integrating the electricity performance curve with the dynamic inoperability input-output model. Then, a database of 285 Chinese historical big power outage events caused by natural disasters is established, and the city-level power system resilience values are estimated. Finally, a benefit analysis is conducted for improving the power system resilience. Our major findings are that: (1) Electricity system recoveries quickest from hail (23.05 h), while restores slowest from snowstorm (117.31 h). (2) China's city electricity system is the most resilient to the thunderstorm, while is the least resilient to the earthquake. (3) Enhancing the power system resilience will significantly reduce the requirements for rescue resources, and the saved emergency rescue cost ranges from 0.57 million yuan to 12.08 million yuan with 1% reduction of initial inoperability.

Spatial-temporal variation and driving factors decomposition of agricultural grey water footprint in China.

The management of agricultural water pollution is crucial to alleviate the water crisis and promote regional sustainable development. Therefore, it is necessary to clarify the spatial-temporal variation characteristics of the agricultural grey water footprint (GWF) and accurately identify its main influencing factors, aiming at formulating differentiated regional management strategies. Based on this, the agricultural GWFs of 31 provincial regions in China from 2011 to 2019 were firstly calculated, and then the spatial-temporal variation characteristics of agricultural GWF were analyzed using the ArcGIS software and Standard Deviational Ellipse (SDE) method. Finally, the Generalized Divisia Index Method (GDIM) was creatively introduced to decompose the factors of agricultural GWF change and their respective contributions at the national and provincial levels. The main results are as follow: (1) Agricultural GWF in China decreased on the whole and showed significant provincial differences. Among them, the agricultural GWF of Henan Province was the largest while that of Shanghai City was the smallest. Compared with 2011, most provinces saw a decrease in agricultural GWF in 2019 while Yunnan, Tibet, Qinghai, Ningxia and Xinjiang Provinces achieved growth. (2) Areas with higher agricultural GDP generally had higher agricultural GWF. The spatial distribution of agricultural GWF and breeding GWF generally tended to be consistent, with the lower value in northwest and southeast of China and higher value in the northeast and southwest of China. Meanwhile, the mean center of SDE of agricultural GWF was located in Henan Province from 2011 to 2018, and shifted to Shaanxi Province in 2019, showing a slight northwest shift. (3) Agricultural GWF intensity and agricultural GDP had the largest restraining effect and driving effect on agricultural GWF growth, respectively. Additionally, China has achieved decoupling between agricultural GWF and agricultural GDP, reflecting that the patterns of agricultural production and consumption have become more sustainable. The findings of this study can provide important decision-making insights for agricultural water pollution management and industry adjustment.

Leaf functional traits differentiation in relation to covering materials of urban tree pits.

BACKGROUND: Understanding the ecological strategies of urban trees to the urban environment is crucial to the selection and management of urban trees. However, it is still unclear whether urban tree pit cover will affect plant functional traits. Here, we study the response of urban trees to different tree pit covers, analyzed the effects of different cover types on soil properties and their trade-off strategies based on leaf functional traits. RESULTS: We found that there were obvious differences in the physical properties of the soil in different tree pit covers. Under the different tree pit cover types, soil bulk density and soil porosity reached the maximum under cement cover and turf cover, respectively. We found that tree pit cover significantly affected the leaf properties of urban trees. Leaf thickness, chlorophyll content index and stomatal density were mainly affected by soil bulk density and non-capillary porosity in a positive direction, and were affected by soil total porosity and capillary porosity in a negative direction. Leaf dry matter content and stomata area were mainly negatively affected by soil bulk density and non-capillary porosity, and positively affected by soil total porosity and capillary porosity. Covering materials of tree pits promoted the functional adjustment of plants and form the best combination of functions. CONCLUSION: Under the influence of tree pit cover, plant have low specific leaf area, stomata density, high leaf thickness, chlorophyll content index, leaf dry matter content, leaf tissue density and stomata area, which belong to "quick investment-return" type in the leaf economics spectrum.

Distribution and evolution of H1N1 influenza A viruses with adamantanes-resistant mutations worldwide from 1918 to 2019.

H1N1 influenza is a kind of acute respiratory infectious disease that has a high socioeconomic and medical burden each year around the world. In the past decades, H1N1 influenza viruses have exhibited high resistance to adamantanes, which has become a serious issue. To understand the up-to-date distribution and evolution of H1N1 influenza viruses with adamantanes-resistant mutations, we conducted a deep analysis of 15875 M2 protein and 8351 MP nucleotides sequences. Results of the distribution analyses showed that 77.32% of H1N1 influenza viruses harbored-resistance mutations of which 73.52% were S31N, And the mutant variants mainly appeared in North America and Europe and H1N1 influenza viruses with S31N mutation became the circulating strains since 2009 all over the world. In addition, 80.65% of human H1N1 influenza viruses and 74.61% of swine H1N1 influenza viruses exhibited adamantanes resistance, while the frequency was only 1.86% in avian H1N1 influenza viruses. Studies from evolutionary analyses indicated that the avian-origin swine H1N1 influenza viruses replaced the classical human H1N1 influenza viruses and became the circulating strains after 2009; The interspecies transmission among avian, swine, and human strains over the past 20 years contributed to the 2009 swine influenza pandemic. Results of our study clearly clarify the historical drug resistance level of H1N1 influenza viruses around the world and demonstrated the evolution of adamantanes-resistant mutations in H1N1 influenza viruses. Our findings emphasize the necessity for monitoring the adamantanes susceptibility of H1N1 influenza viruses and draw attention to analyses of the evolution of drug-resistant H1N1 influenza variants.

Study on the Value of Blood Biomarkers NLR and PLR in the Clinical Diagnosis of Influenza a Virus Infection in Children.

BACKGROUND: The aim is to explore the value and significance of changes in neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) in the diagnosis and treatment of patients with influenza virus infection. METHODS: A total of 1,330 cases of influenza A diagnosed with the nucleic acid testing were collected according to the 2019 version of the influenza diagnosis and treatment regimen in our hospital from September 2020 to December 2020. During the same period, 1,330 cases of healthy subjects were used as controls. The colloidal gold method and fluorescent PCR were used to detect influenza A virus. The sysmex800i was used for routine blood test, and statistical analysis was then performed. RESULTS: Comparing the relevant indicators between the research group and the healthy control group showed that the differences in NLR, PLR, PLT, absolute lymphocyte values, etc. were all statistically significant (p < 0.001). Among them, the average results of NLR and PLR of the research group were all larger than those of the control group; the mean values of the absolute value of lymphocytes (x 109) and PLT (x 109) in the research group were all smaller than those of the control group. The NLR, PLR, LMR, age, and other parameters of the research group and the healthy control group were analyzed to determine whether there was influenza infection according to a binary logistic regression model. The results showed that the differences were not statistically significant except for age and LMR (p > 0.05) and did not enter the regression model. The differences in other parameters such as NLR and PLR were all statistically significant (all p < 0.001), which were all entered into the regression model. They were very significant for predictive diagnosis of influenza A. The areas under the ROC curve of NLR and PLR were 0.961 (95% CI: 0.953-0.968) and 0.749 (95% CI: 0.730-0.769), respectively; the sensitivity and specificity of NLR were 88.4% and 93.1%, respectively, and Youden's index was 0.815, the optimal diagnostic cutoff value was 1.478; the sensitivity and specificity of PLR were 56.70% and 89.60%, respectively; the Youden's index was 0.463, and the optimal diagnostic cutoff value was 124. CONCLUSIONS: NLR and PLR had a certain degree of accuracy in the diagnosis of viral infections in children with influenza A. The diagnostic effect of NLR was particularly good. In the early stage of the disease, cheap and easily available blood biomarkers can be used to diagnose influenza A. However, LMR had no diagnostic value for influenza A because the area under the curve was too small.

A performance analysis framework for carbon emission quota allocation schemes in China: Perspectives from economics and energy conservation.

Carbon emission quota allocation plays a critical role in carbon emission reduction in an efficient and economic manner. However, the scientific assessment of carbon quota allocation schemes and thus making a reasonable decision depending on preference still confuses relevant decision makers. This study proposes a performance analysis framework for carbon quota allocation schemes by using a nonparametric frontier analysis approach from the perspectives of economic growth and energy conservation. Then, we apply this approach to evaluate the relative economic and energy conservation performances of 15 allocation schemes by reallocating the 2015 Chinese provincial carbon emission quotas, each of which is constructed via a combination of equity, grandfathering, efficiency and ability to pay principles. The results show that the proposed allocation scheme that integrates efficiency and the ability to pay principles is the best option, realizing approximately 6.78% outputs increase and 3.01% energy conservation relative to the actual 2015 emission scenario. We also show that the best scheme is linked to total quotas; the scheme considering only the equity principle is superior to others, while the total quotas are reduced by 10%. The study provides not only a theoretical tool, but also empirical evidence for the construction of China's carbon quota allocation scheme.

Identifying the critical transmission sectors with energy-water nexus pressures in China's supply chain networks.

Energy and water resources are drawing increasing attention in China as indispensable elements of economic development and social stability. Energy and water are interconnected in economic systems. Although the nexus between them has been widely studied, few insights can be acquired by the intermediate transmission pressures across supply chains. Combing betweenness-based method and multi-regional input-output (MRIO) analysis, we, in this study, identified critical transmission sectors and main driving factors resulting from the usage structure. In details, we found that Metallurgy (S14) in Shandong, Henan, Jiangxi, Anhui, Sichuan, Zhejiang, Hunan, and Jiangsu, Electricity and hot water production and supply (S22) in Beijing and Guizhou, and Nonmetal production (S13) in Henan are the most critical transmission sectors bearing energy-water nexus pressures, ranking at the top 100 in China's supply chain networks. Roughly, the usage structure was mainly dominated by fixed capital formation, urban household consumption and trade export, and therefore should be given priority to mitigate environmental pressures. Our study provides a novel perspective of sector-specific and province-typical policy recommendations for mitigating energy-water nexus pressures in China's supply chain networks.

RedH and PigC Catalyze the Biosynthesis of Hybrubins via Phosphorylation of 4'-Methoxy-2,2'-Bipyrrole-5'-Carbaldehyde.

Hybrubins are "unnatural" alkaloids with the same 4'-methoxy-2,2'-bipyrrole-5'-methine moiety found in prodiginines and a different ring derived from tetramic acids. Here, we demonstrated that RedH, a homologue of prodigiosin synthetase PigC, was responsible for the biosynthesis of hybrubins A and B in Streptomyces lividansIn vitro reactions indicated that RedH and PigC catalyzed the intermolecular condensation between 4'-methoxy-2,2'-bipyrrole-5'-carbaldehyde (MBC) and (Z)-5-ethylidenetetramic acid (ETA) to produce hybrubin B. Moreover, we demonstrated that RedH and PigC activated MBC via phosphorylation of the aldehyde group to form an intermediate Pi-MBC and that the subsequent condensation between Pi-MBC and (Z)-5-ethylidenetetramic acid occurs in a nonenzymatic way.IMPORTANCE Hybrubins are an emerging class of prodiginines possessing a new C ring derived from 5'-substituted tetramic acids and the methylene bridge connecting the C ring at a different position. We have supposed that condensation between 4'-methoxy-2,2'-bipyrrole-5'-carbaldehyde (MBC) and 5-ethylidenetetramic acid (ETA) yields the hybrid natural products hybrubins, which was proposed to be catalyzed by the undecylprodigiosin synthetase RedH. However, it is doubted whether RedH is able to catalyze another type of condensation between MBC and tetramic acids. In this study, we have demonstrated that the MBC-ETA condensation proceeds through RedH/PigC-catalyzed enzymatic activation of MBC via phosphorylation and a nonenzymatic condensation of Pi-MBC with ETA. Since MBC analogues have been shown to be accepted by PigC, more hybrubin analogues might be produced by using combinations of MBC analogues and other tetramic acids in future studies.

The evolution and molecular characteristics of H9N2 avian influenza viruses in Jiangxi of China.

To understand the evolution and molecular characteristics of Jiangxi H9N2 viruses, we isolated 17 viruses in 2011 and analyzed their characteristics. Phylogenetic analyses revealed that their hemagglutinin genes originate from JS/1/00-like sublineage, neuraminidase genes originate from BJ/94-like sublineage, PB1, PA, NP, and NS genes all come from SH/F/98-like sublineage, PB2 genes originate from ST/163/04-like sublineage, while M genes come from G1-like sublineage. Genotype analysis showed that our isolates were classified as genotype 57. Molecular analyses indicated that our strains contained specific sites characteristic of low-pathogenic viruses. The current study once again highlights the necessity for continued surveillance of novel H9N2 viruses.

An evolutionary game analysis of governments' decision-making behaviors and factors influencing watershed ecological compensation in China.

As a way to coordinate the interests of multi-government and solve the problem of transboundary water pollution, watershed ecological compensation system has been promoted in China. It is necessary to understand the influencing factors of watershed ecological compensation from the perspective of how interactions occur between different governments. This paper analyses the interaction among upstream governments, downstream governments and the central government in the Eastern Route of South-to-North Water Transfer Project, using evolutionary game theory. In particular, how ecological benefits are distributed between upstream and downstream governments is analyzed. Simultaneously, numerical simulation is used to analyze the effects of influencing factors on governments' behaviors. The results show that: (1) the initial willingness of governments to corporate affect their final behaviors; (2) upstream and downstream governments cannot spontaneously cooperate to implement watershed ecological compensation system without supervision of the central government; (3) opportunity costs only have a significant impact on upstream governments; (4) punishment on downstream governments can effectively influence the behaviors of governments at all levels; (5) high ecological compensation fee improve downstream governments' willness not to pay; (6) upstream governments get about 78% of ecological benefits due to the implementation of watershed ecological compensation system.

Will regional economic integration influence carbon dioxide marginal abatement costs? Evidence from Chinese panel data.

With frequent trade and technology diffusion, the barriers between regions are gradually weakening, and regions have become more integrated over recent years. Regional economic integration not only stimulates labour mobility, but also achieve scale economy, both of which may also influence carbon dioxide (CO2) marginal abatement costs through affecting energy consumption, CO2 emissions, productivity growth, and technical progress. Nevertheless, to the best of our knowledge, none of the studies has currently concerned the influence of regional economic integration on CO2 marginal abatement costs. To fill this research gap, this study first theoretically clarifies the influence mechanism of regional economic integration on CO2 marginal abatement cost, and then empirically attempts to investigate their relationship in the context of China, with panel data models. To serve this purpose, the provincial CO2 marginal abatement cost and regional economic integration are estimated by parametric directional distance function and price-based approach, respectively. The results show that China's regional economic integration level indeed gradually improved over 2002-2011 except in 2003-04 and 2006-09 due to the spread of Severe Acute Respiratory Syndrome (SARS) and the sub-prime loan crisis. Moreover, evolution of regional economic integration indeed contributes to the increase of CO2 marginal abatement cost at 5% significance level. Using robust tests, it can be found that the results are also reliable and robust to sub-samples.

Historical Accountability for Equitable, Efficient, and Sustainable Allocation of the Right to Emit Wastewater in China.

Establishing policies for controlling water pollution through discharge permits creates the basis for emission permit trading. Allocating wastewater discharge permits is a prerequisite to initiating the market. Past research has focused on designing schemes to allocate discharge permits efficiently, but these schemes have ignored differences among regions in terms of emission history. This is unfortunate, as fairness may dictate that areas that have been allowed to pollute in the past will receive fewer permits in the future. Furthermore, the spatial scales of previously proposed schemes are not practical. In this article, we proposed an information entropy improved proportional allocation method, which considers differences in GDP, population, water resources, and emission history at province spatial resolution as a new way to allocate waste water emission permits. The allocation of chemical oxygen demand (COD) among 30 provinces in China is used to illustrate the proposed discharge permit distribution mechanism. In addition, we compared the pollution distribution permits obtained from the proposed allocation scheme with allocation techniques that do not consider historical pollution and with the already established country plan. Our results showed that taking into account emission history as a factor when allocating wastewater discharge permits results in a fair distribution of economic benefits.

Ochracenes A-I, Humulane-Derived Sesquiterpenoids from the Antarctic Fungus Aspergillus ochraceopetaliformis.

Nine new humulane-derived sesquiterpenoids, ochracenes A-I (1-9), were isolated from the Antarctic fungus Aspergillus ochraceopetaliformis SCSIO 05702. Their structures including absolute configurations were elucidated on the basis of spectroscopic analysis, Mosher's method, and electronic circular dichroism analysis. Compared with previous humulane-type sesquiterpenoids, ochracenes A-I (1-9) featured novel carbon skeletons with corresponding methyl migration, ring cleavage, and carbon loss. Two unprecedented 8,9-secocyclic sesquiterpenoids (2 and 3) exhibited inhibitory effects on lipopolysaccharide-induced NO release in RAW 264.7 mouse macrophage cell lines with IC50 values of 14.6 ± 0.5 and 18.3 ± 1.7 µM, respectively.

Antitubercular and cytotoxic tigliane-type diterpenoids from Croton tiglium.

Five new tigliane diterpene esters (1-5), highly oxygenated tetracyclic diterpenoid carbon skeleton, together with three known analogues (6-8) were isolated from the leaves of Croton tiglium. Extensive NMR and mass spectroscopic analysis were used to elucidate their structures. Most of the isolated compounds were tested for their cytotoxic and antitubercular activities. Among them, the cytotoxic activities of these tigliane-type diterpenes strongly depend on the species of the tumor cells. Especially, these bioactivity compounds showed strong cytotoxic activities against the K562 cell line, and their inhibition effects were close to the positive control Taxol. Furthermore, compounds 1, 2, 6, and 7 showed potent antitubercular activities with MIC values of 19.5, 20.9, 20.5, and 13.4µM, respectively.

Dicarabrol, a new dimeric sesquiterpene from Carpesium abrotanoides L.

A new dimeric sesquiterpene, dicarabrol (1), together with three known sesquiterpenes, carabrol (2), 11(13)-dehydroivaxillin (3), and 2-desoxy-4-epi-pulchellin (4), were isolated from the whole plant of Carpesium abrotanoides L. Their structures were elucidated on the basis of spectroscopic analysis, and single crystal X-ray diffraction analysis. Compound 1 possessed a dimeric sesquiterpene core featured with a cyclopentane ring connecting two sesquiterpene lactone units rarely discovered in nature. Dicarabrol (1), as well as three known sesquiterpenes (2-4), had potent in vitro cytotoxicities against the K562, MCF-7, Hela, DU145, U937, H1975, SGC-7901, A549, MOLT-4, and HL60 cell lines with IC50 values ranging from 0.10 to 46.7 µM, while they showed significant antiviral (H1N1 and H3N2) activities. Furthermore, compounds 1, 3 and 4 displayed significant antimycobacterial activity (IC50 3.7, 6.0, and 7.6 µM, respectively).