Exploring the pharmacognostical and phytochemical profiles of aqueous extracts of Kalanchoe

The use of plants for medicinal purposes has a long history, however it is desirable a continuous evaluation seeking for complementary scientific evidences for their safe application. Species within the Kalanchoe genus are often referred to as "miracle leaf" due to their remarkable healing properties. Traditionally, these plants have been used to treat infections, inflammation, and cancer. Despite their widespread use, the identification of their active components remains incomplete. This study aimed to differentiate K. crenata (KC), K. marmorata (KM), and K. pinnata (KP) by conducting detailed histochemical and phytochemical analyses, and to assess their antioxidant capabilities. The investigation revealed significant differences between the species, highlighting the variability in phenolic (PC) and flavonoid contents (FC) and their distinct antioxidant effects. The KM demonstrated the greatest results (PC: 59.26 ± 1.53 mgEqGA/g; FC: 12.63 ± 0.91 mgEqCQ/g; DPPH• (IC50): 110.66 ug/ml; ABTS•+ (IC50): 26.81 ug/ml; ORAC: 9.65 ± 0.75 mmolTE) when compared to KC and KP. These findings underscore a new reference for research within the Kalanchoe genus.

Do phylogenetic community metrics reveal the South African quartz fields as terrestrial-habitat islands?

BACKGROUND AND AIMS

The quartz fields of the Greater Cape Floristic Region (GCFR) are arid and island-like special habitats, hosting ~142 habitat-specialized plant species, of which 81 % are local endemics, characterized by a rapid turnover of species between and among sites. We use several phylogenetic community metrics: (1) to examine species diversity and phylogenetic structure within and among quartz fields; (2) to investigate whether quartz field specialists are evolutionarily drawn from local species pools, whereas the alternative hypothesis posits that there is no significant evolutionary connection between quartz field specialists and the local species pools; and (3) to determine whether there is an association between certain traits and the presence of species in quartz fields.

METHODS

We sampled and developed dated phylogenies for six species-rich angiosperm families (Aizoaceae, Asteraceae, Crassulaceae, Cyperaceae, Fabaceae and Santalaceae) represented in the quartz field floras of southern Africa. Specifically, we focused on the flora of three quartz field regions in South Africa (Knersvlakte, Little Karoo and Overberg) and their surrounding species pools to address our research questions by scoring traits associated with harsh environments.

KEY RESULTS

We found that the Overberg and Little Karoo had the highest level of species overlap for families Aizoaceae and Fabaceae, whereas the Knersvlakte and the Overberg had the highest species overlap for families Asteraceae, Crassulaceae and Santalaceae. Although our phylogenetic community structure and trait analyses showed no clear patterns, relatively low pairwise phylogenetic distances between specialists and their local species pools for Aizoaceae suggest that quartz species could be drawn evolutionarily from their surrounding areas. We also found that families Aizoaceae and Crassulaceae in Knersvlakte and Little Karoo were phylogenetically even.

CONCLUSIONS

Despite their proximity to one another within the GCFR, the studied areas differ in their species pools and the phylogenetic structure of their specialists. Our work provides further justification for increased conservation focus on these unique habitats under future scenarios of global change.

Phylogenomics and plastomics offer new evolutionary perspectives on Kalanchoideae (Crassulaceae)

BACKGROUND AND AIMS

Kalanchoideae is one of three subfamilies within Crassulaceae and contains four genera. Despite previous efforts, the phylogeny of Kalanchoideae remains inadequately resolved with persistent issues including low support, unstructured topologies and polytomies. This study aimed to address two central objectives: (1) resolving the pending phylogenetic questions within Kalanchoideae by using organelle-scale 'barcodes' (plastomes) and nuclear data; and (2) investigating interspecific diversity patterns among Kalanchoideae plastomes.

METHODS

To explore the plastome evolution in Kalanchoideae, we newly sequenced 38 plastomes representing all four constituent genera (Adromischus, Cotyledon, Kalanchoe and Tylecodon). We performed comparative analyses of plastomic features, including GC and gene contents, gene distributions at the IR (inverted repeat) boundaries, nucleotide divergence, plastomic tRNA (pttRNA) structures and codon aversions. Additionally, phylogenetic inferences were inferred using both the plastomic dataset (79 genes) and nuclear dataset (1054 genes).

KEY RESULTS

Significant heterogeneities were observed in plastome lengths among Kalanchoideae, strongly correlated with LSC (large single copy) lengths. Informative diversities existed in the gene content at SSC/IRa (small single copy/inverted repeat a), with unique patterns individually identified in Adromischus leucophyllus and one major Kalanchoe clade. The ycf1 gene was assessed as a shared hypervariable region among all four genera, containing nine lineage-specific indels. Three pttRNAs exhibited unique structures specific to Kalanchoideae and the genera Adromischus and Kalanchoe. Moreover, 24 coding sequences revealed a total of 41 lineage-specific unused codons across all four constituent genera. The phyloplastomic inferences clearly depicted internal branching patterns in Kalanchoideae. Most notably, by both plastid- and nuclear-based phylogenies, our research offers the first evidence that Kalanchoe section Eukalanchoe is not monophyletic.

CONCLUSIONS

This study conducted comprehensive analyses on 38 newly reported Kalanchoideae plastomes. Importantly, our results not only reconstructed well-resolved phylogenies within Kalanchoideae, but also identified highly informative unique markers at the subfamily, genus and species levels. These findings significantly enhance our understanding of the evolutionary history of Kalanchoideae.

Exploring Plastomic Resources in Sempervivum (Crassulaceae): Implications for Phylogenetics

The plastid organelle is vital for photosynthesis and energy production. Advances in sequencing technology have enabled the exploration of plastomic resources, offering insights into plant evolution, diversity, and conservation. As an important group of horticultural ornamentals in the Crassulaceae family, Sempervivum plants are known for their unique rosette-like structures and reproduction through offsets. Despite their popularity, the classification status of Sempervivum remains uncertain, with only a single plastome sequence currently available. Furthermore, codon usage bias (CUB) is a widespread phenomenon of the unbalanced usage of synonymous codons in the coding sequence (CDS). However, due to the limited available plastid data, there has been no research that focused on the CUB analysis among Sempervivum until now. To address these gaps, we sequenced and released the plastomes of seven species and one subspecies from Sempervivum, revealing several consistent patterns. These included a shared 110 bp extension of the rps19 gene, 14 hypervariable regions (HVRs) with distinct nucleotide diversity (π: 0.01173 to 0.02702), and evidence of selective pressures shaping codon usage. Notably, phylogenetic analysis robustly divided the monophyletic clade into two sections: Jovibarba and Sempervivum. In conclusion, this comprehensive plastomic resource provides valuable insights into Sempervivum evolution and offers potential molecular markers for DNA barcoding.

First Report of Root and Collar Rot caused by Phytophthora nicotianae on ⨯Graptoveria 'Silver Star' in Korea

⨯Graptoveria 'Silver Star' (a cross between Graptopetalum filiferum and Echeveria agavoides) from the Crassulaceae family, are an evergreen succulent with lotus constellation-shaped flowers, making it consumer favorite ornamental plant in Korea. In 2019, Korea's ornamental production was estimated at KRW 517.4 billion (EUR 382 million), from 4,244 ha of farming area according to the Ministry of Agriculture, Food and Rural Affairs of Korea. In July 2023, ⨯Graptoveria 'Silver Star' plants with chlorotic leaves, root and collar rot were observed in a greenhouse in Yongin (37°14'27.9"N, 127°10'39.19"E), Korea. To isolate the causal agent, small pieces (1 mm2) of symptomatic tissues were surface-sterilized using 1% NaOCl for 1 min, then put onto a water agar (WA) plate and incubated in the dark at 25℃ for five days. Two isolates (FD00202, FD00203) were obtained from diseased leaves, stem and roots by isolating single sporangium. To investigate the morphological characteristics of the isolates, the mycelium from potato dextrose agar (PDA) were transferred to V8 agar (V8A) followed by incubation at 25°C in the dark for 7 days. The isolates produced dense cottony mycelium, with slightly petaloid and light rossette pattern, with coralloid edges measuring 70 to 83 mm diameter. Sporangium were spheroid (30.0-48.0 µm long, 25.0-35.0 µm wide) with globose chlamydospores (17.0-50.0 µm long, 18.0-38.0 µm wide). Oogonia were not observed. Morphological and cultural characteristics of these isolates were phenotypically similar to that of Phytophthora nicotianae (Faedda et al. 2013; Abad et al. 2023). For molecular identification, genomic DNA was extracted from 5 days old cultures using the Maxwell® RSC PureFood GMO and Authentication Kit (Promega). Two gene regions, the rDNA-ITS, COX I were amplified and sequenced using primers ITS1/ITS4 and FM83/FM84, respectively (White et al. 1990; Martin and Tooley 2003). The resulting sequences were deposited in GenBank with accession no. LC783858 to LC783861. A BLASTn search of the DNA sequences from ITS, COX I showed 99.81 and 98.94% identity to P. nicotianae isolate IMI 398853, respectively. Maximum likelihood phylogenetic analyses were performed for the combined data set with ITS, COX I using MEGA7 under the Tamura-Nei model (Kumar et al. 2016). The isolates formed a monophyletic group with P. nicotianae isolate IMI 398853, CPHST BL162, and CPHST BL 44. Based on morphological characteristics and molecular analysis, the isolates were identified as P. nicotianae. T confirm their pathogenicity, inoculum was prepared in accordance with Ann (2000). Artificially wounded healthy plant roots were dipped in zoospore suspension (3.0 × 106 zoospore/ml) for 24 hours, with mock-treated plants (control) dipped in sterile distilled water (Ann. 2000). Thereafter, the plants were transplanted into new medium and kept under high humidity. Symptoms were observed after 10 days of incubation. The plants inoculated with P. nicotianae showed similar symptoms of chlorotic leaves with root and collar rot, while control remained symptomless. The pathogen was re-isolated from all inoculated plants and confirmed as P. nicotianae by morphological and molecular analysis. but not from controls, fulfilling Koch's postulates. Phytophthora nicotianae was previously report on Echeveria derenbergii and Kalanchoe blossfeldiana causing brown spot on stems and roots in California and Korea, respectively (French 1989; Oh and Son 2008). To best of our knowledge, this is the first report of P. nicotianae causing root and collar rot on ⨯Graptoveria 'Silver Star' plants in the Korea.

Comprehensive evaluation of morphological and physiological responses of seventeen Crassulaceae species to waterlogging and drainage under temperate monsoon climate

Unpredictable rainfall frequently results in excess moisture, which is detrimental to the landscape because it interferes with the genetic, morphological, and physiological processes of plants, even though the majority of urban landscapes frequently experience moisture shortages. A study was conducted to analyze the effects of a 36-day waterlogging phase and a subsequent 12-day recovery period on the morpho-physiological responses of 17 Crassulaceae species with the goal of identifying those which were more tolerant of the conditions. Results revealed that waterlogging stress has an impact on all morpho-physiological parameters. Sensitive materials (S7, Hylotelephium telephium 'Purple Emperor' and S15, S. sexangulare) showed severe ornamental quality damage, mortality, decreases in total dry biomass, root-shoot ratio, and chlorophyll content, as well as higher MDA concentrations. Lower reductions in these parameters, along with improved antioxidant enzyme activities and greater recovery capabilities after drainage, were observed in the most tolerant materials S2 (H. spectabile 'Brilliant'), S3 (H. spectabile 'Carl'), and S5 (H. telephium 'Autumn Joy'). Furthermore, with the exception of early death materials (S7 and S15), all materials showed varying intensities of adventitious root formation in response to waterlogging. The 17 species were divided into 4 clusters based on the comprehensive evaluation value. The first group included S1-S3, S5-S6, S8-S12, which were waterlogged tolerant with the highest values (0.63-0.82). S14 belongs to the intermediate waterlogging tolerant. S4, S13, S16, and S17 were clustered into the low waterlogging-tolerant group. S7 and S15 were the most susceptible to waterlogging. The survival and success of Crassulaceae species (especially, the first and second cluster), throughout this prolonged period of waterlogging (36 days) and recovery were attributed to a combination of physiological and morphological responses, indicating that they are an appealing species for the creation of rain gardens or obstructed drainage locations.

Medicinal Plants Used for Eye Conditions in Mexico-A Review

Medicinal plants have been historically significant for treating common human diseases in Mexico. Although some ethnobotanical research exists, limited ethnomedicinal data has documented medicinal plants employed for eye health. This review focuses on ethnomedicinal information and preclinical and clinical studies regarding medicinal plants used in Mexico for treating symptoms associated with eye conditions. An electronic database search was conducted by consulting scientific articles, books about Mexican herbal medicine, and academic theses. This work recorded 69 plant species belonging to 26 plant families, especially plants from the Crassulaceae family, which are used as remedies for irritation and infections in the eye. Eight of these medicinal plants have been the subject of preclinical studies using ocular models, and one medicinal plant has been tested in clinical trials. The evidence of pharmacological effects indicates the promising therapeutic potential of these medicinal plants for developing new treatments for eye conditions. However, toxicological studies are necessary to ensure safe application to the eye, particularly as traditional medicine continues to be relied upon worldwide. In addition, this review highlights the need to perform ethnobotanical and phytochemical studies in Mexico regarding the medicinal flora used as remedies for eye conditions.

A Review of the Popular Uses, Anatomical, Chemical, and Biological Aspects of Kalanchoe (Crassulaceae): A Genus of Plants Known as "Miracle Leaf"

Species of the genus Kalanchoe have a long history of therapeutic use in ethnomedicine linked to their remarkable healing properties. Several species have chemical and anatomical similarities, often leading to confusion when they are used in folk medicine. This review aims to provide an overview and discussion of the reported traditional uses, botanical aspects, chemical constituents, and pharmacological potential of the Kalanchoe species. Published scientific materials were collected from the PubMed and SciFinder databases without restriction regarding the year of publication through April 2023. Ethnopharmacological knowledge suggests that these species have been used to treat infections, inflammation, injuries, and other disorders. Typically, all parts of the plant are used for medicinal purposes either as crude extract or juice. Botanical evaluation can clarify species differentiation and can enable correct identification and validation of the scientific data. Flavonoids are the most common classes of secondary metabolites identified from Kalanchoe species and can be correlated with some biological studies (antioxidant, anti-inflammatory, and antimicrobial potential). This review summarizes several topics related to the Kalanchoe genus, supporting future studies regarding other unexplored research areas. The need to conduct further studies to confirm the popular uses and biological activities of bioactive compounds is also highlighted.

Biological Activities and Chemical Profiles of Kalanchoe fedtschenkoi Extracts

In this study, the leaves of Kalanchoe fedtschenkoi were consecutively macerated with hexane, chloroform, and methanol. These extracts were used to assess the bioactivities of the plant. The antimicrobial activity was tested against a panel of Gram-positive and -negative pathogenic bacterial and fungal strains using the microdilution method. The cytotoxicity of K. fedtschenkoi extracts was investigated using human-derived macrophage THP-1 cells through the MTT assay. Finally, the anti-inflammatory activity of extracts was studied using the same cell line by measuring the secretion of IL-10 and IL-6. The phytoconstituents of hexane and chloroform extracts were evaluated using gas chromatography-mass spectrometry (GC/MS). In addition, high-performance liquid chromatography (HPLC) was used to study the phytochemical content of methanol extract. The total flavonoid content (TFC) of methanol extract is also reported. The chemical composition of K. fedtschenkoi extracts was evaluated using Fourier-transform infrared spectroscopy (FTIR). Results revealed that the chloroform extract inhibited the growth of Pseudomonas aeruginosa at 150 μg/mL. At the same concentration, methanol extract inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA). Regarding their cytotoxicity, the three extracts were highly cytotoxic against the tested cell line at IC50 < 3 μg/mL. In addition, the chloroform extract significantly stimulated the secretion of IL-10 at 50 μg/mL (p < 0.01). GC/MS analyses revealed that hexane and chloroform extracts contain fatty acids, sterols, vitamin E, and triterpenes. The HPLC analysis demonstrated that methanol extract was constituted by quercetin and kaempferol derivatives. This is the first report in which the bioactivities and chemical profiles of K. fedtschenkoi are assessed for non-polar and polar extracts.

Phytochemical profile and anti-inflammatory activity of a commercially available Rhodiola rosea root extract

Rhodiola rosea roots and rhizomes hold an important place in the folk medicines of Russia, Scandinavia, Mongolia, and China as a health supplement for stimulating the nervous system, enhancing physical and mental performances, and nowadays they constitute the active ingredient in many popular commercial preparations sold worldwide as food additives, pharmaceutical remedies, and drinks. This study was aimed at providing a detailed phytochemical characterization of the Rhodiola 5%, a commercially available extract of R. rosea roots, and resulted in the characterization of 18 secondary metabolites, including 13 polyphenols and 6 terpenoids, and in the discovery of the new rhodiosidin (5), the first R. rosea metabolite to show both terpenoid and cinnamoyl moieties. The 5-lipoxygenase inhibiting activity of the main components was characterized and disclosed that rosiridin (6), kenposide A and rosavins are mainly responsible for this activity of the extract.

Gel formulated with Bryophyllum pinnatum leaf extract promotes skin wound healing in vivo by increasing VEGF expression: A novel potential active ingredient for pharmaceuticals

Bryophyllum pinnatum (Crassulaceae) is used in traditional medicine for treating skin wounds. In our previous study, a topical gel containing B. pinnatum aqueous leaf extract showed a preclinical anti-inflammatory effect in in vivo acute edema models. In continuation, the present study aims to evaluate the phytochemical content and the stability of a formulation in gel containing B. pinnatum aqueous leaf extract and its healing properties and mechanism of action through an experimental model of induction of skin wounds in rats and in vitro assays. The animals were treated topically for 7 or 14 days with a formulation in gel containing extract at 5% or a placebo or Fibrinase^® in cream. In addition, to establish some quality control parameters, the total phenolic content (TPC), total flavonoid content (TFC), and a study focusing on the phytochemical and biological stability of a gel for 30 days at two different conditions (room temperature and 40°C/75% RH) were performed. Gel formulation containing extract showed a TPC and TFC of 2.77 ± 0.06 mg of gallic acid/g and 1.58 ± 0.03 mg of quercetin/g, respectively. Regarding the stability study, the formulation in gel showed no significant change in the following parameters: pH, water activity, chromatographic profile, and the content of the major compound identified in the extract. The gel formulation containing extract stimulated skin wound healing while reducing the wound area, as well as decreasing the inflammatory infiltrate, reducing the levels of IL-1β and TNF-α, and stimulating angiogenesis with increased expression of VEGF, an effect similar to Fibrinase. In conclusion, the gel formulation containing extract exhibited relevant skin wound healing properties and, therefore, has the potential to be applied as a novel active ingredient for developing wound healing pharmaceuticals.

Antitrypanosomal, Antitopoisomerase-I, and Cytotoxic Biological Evaluation of Some African Plants Belonging to Crassulaceae; Chemical Profiling of Extract Using UHPLC/QTOF-MS/MS

In our continuous study for some African plants as a source for antitrypanosomally and cytotoxic active drugs, nine different plants belonging to the Crassulaceae family have been selected for the present study. Sedum sieboldii leaves extract showed an antitrypanosomal activity against Trypanosoma brucei with an IC₅₀ value of 8.5 µg/mL. In addition, they have cytotoxic activities against (HCT-116), (HEPG-2) and (MCF-7), with IC₅₀ values of 28.18 ± 0.24, 22.05 ± 0.66, and 26.47 ± 0.85 µg/mL, respectively. Furthermore, the extract displayed inhibition against Topoisomerase-1 with an IC₅₀ value of 1.31 µg/mL. It showed the highest phenolics and flavonoids content among the other plants' extracts. In order to identify the secondary metabolites which may be responsible for such activities, profiling of the polar secondary metabolites of S. sieboldii extract via Ultra-Performance Liquid Chromatography coupled to High-Resolution QTOF-MS operated in negative and positive ionization modes, which revealed the presence of 46 metabolites, including flavonoids, phenolic acids, anthocyanidins, coumarin, and other metabolites.

Ten Plastomes of Crassula (Crassulaceae) and Phylogenetic Implications

The genus Crassula is the second-largest genus in the family Crassulaceae, with about 200 species. As an acknowledged super-barcode, plastomes have been extensively utilized for plant evolutionary studies. Here, we first report 10 new plastomes of Crassula. We further focused on the structural characterizations, codon usage, aversion patterns, and evolutionary rates of plastomes. The IR junction patterns-IRb had 110 bp expansion to rps19-were conservative among Crassula species. Interestingly, we found the codon usage patterns of matK gene in Crassula species are unique among Crassulaceae species with elevated ENC values. Furthermore, subgenus Crassula species have specific GC-biases in the matK gene. In addition, the codon aversion motifs from matK, pafI, and rpl22 contained phylogenetic implications within Crassula. The evolutionary rates analyses indicated all plastid genes of Crassulaceae were under the purifying selection. Among plastid genes, ycf1 and ycf2 were the most rapidly evolving genes, whereas psaC was the most conserved gene. Additionally, our phylogenetic analyses strongly supported that Crassula is sister to all other Crassulaceae species. Our findings will be useful for further evolutionary studies within the Crassula and Crassulaceae.

Plant growth forms dictate adaptations to the local climate

Adaptive radiation is a significant driver of biodiversity. Primarily studied in animal systems, mechanisms that trigger adaptive radiations remain poorly understood in plants. A frequently claimed indicator of adaptive radiation in plants is growth form diversity when tied to the occupation of different habitats. However, it remains obscure whether morphological adaptations manifest as growth form diversity per se or as its constituent traits. We use the classic Aeonium radiation from the Canary Islands to ask whether adaptation across climatic space is structured by growth form evolution. Using morphological sampling with site-associated climate in a phylogenetic context, we find that growth forms dictate adaptations to the local environment. Furthermore, we demonstrate that the response of specific traits to analogous environments is antagonistic when growth forms are different. This finding suggests for the first time that growth forms represent particular ecological functions, allowing the co-occurrence of closely related species, being a product of divergent selection during evolution in sympatry.

Polyketides with anti-inflammatory activity from Rhodiola tibetica endophytic fungus Alternaria sp. HJT-Y7

Seven undescribed polyketides with particular ortho-trisubstituted benzo[c]furan and benzo[c]oxepin spiro structures were isolated from Rhodiola tibetica endophytic fungus Alternaria sp. HJT-Y7. Structural elucidations of these compounds were determined mainly by NMR and HR-ESI-MS analysis. An assumed polyketide biosynthetic pathway of these isolates was proposed. Two undescribed compounds and four known compounds showed significant inhibitory effects on LPS-induced NO production in RAW 264.7 cells without cytotoxicity at their effective concentrations.

The complete chloroplast genome sequence of Orostachys minuta (Crassulaceae)

The chloroplast (cp) genome sequence is determined and analyzed for Orostachys minuta for the first time. The cp genome was 150,369 bp in length, containing a large single-copy (LSC) of 82,795 bp and a small single-copy (SSC) of 16,854 bp, which were separated by a pair of 25,360 bp inverted repeats (IRs). The overall G + C content of the O. minuta cp genome amounted to 37.7%. In total, 113 unique genes were annotated, consisting of 79 protein-coding genes (PCGs), 30 transfer RNAs (tRNAs), and four ribosomal RNAs (rRNAs). Among these genes, 18 contained one or two introns. A maximum-likelihood (ML) phylogenetic analysis based on 33 taxa showed that O. minuta formed a clade with O. japonica. This study will provide a baseline as well as valuable molecular phylogenomic information for various future studies to determine the taxonomic position and phylogenetic relationships of the genus Orostachys.

Anther Wall Formation in Aeonium balsamiferum and A. ciliatum (Crassulaceae)

Similarities (features of the family Crassulaceae) and differences in anther development and structure were observed between Aeonium balsamiferum and A. ciliatum. Microsporangia are rounded in A. ciliatum and elongate oval in A. balsamiferum. The septum between microsporangia is consequently longer in A. ciliatum and extremely short in A. balsamiferum. In the latter, pollen can spill out through both the stomium and the apical pore (the phenomenon first discovered in the family Crassulaceae), and both modes of theca opening occur simultaneously, suggesting a greater specialization for pollination for the A. balsamiferum anther. The outer tapetum is single-layered in both species, but its cells are mononuclear in A. ciliatum and binuclear in A. balsamiferum. The inner tapetum is usually single-layered and irregularly two-layered in rare cases; its cells increase in size by a factor of 2 in A. ciliatum and 3-4 in A. balsamiferum (resembling papilloid cells in structure in the latter). Similarities in anther structure were observed between the genera Aeonium and Sedum. In both genera, the anther was isobilateral (on a transverse section) and had an epiconnective, a four-beamed connective, and an annular fibrous layer on the inner side of the connective in the lower region, where there is no fusion of the anther and filament; pollen grains were of the same structural type: tricolporate with a striated surface. The findings were consistent with the cladistic reconstructions that put species of the polyphyletic genus Sedum in the tribes Aeonieae, Semperviveae, and Sedeae. Aeonium balsamiferum and A. ciliatum fall into the Aeonium clade and occupy an intermediate position between the Telephium clade (Sedum kamtschaticum) and the Acre clade (S. palmeri).

Comparative transcriptome and tissue-specific expression analysis of genes reveal tissue-cultured plants as an alternative source for phenylethanoids and phenylpropanoids in Rhodiola imbricata (Edgew.)

Rhodiola imbricata (Crassulaceae) is a traditional trans-Himalayan endangered medicinal herb with immense therapeutic applications. Over the years, over-exploitation, un-managed harvesting, and lack of captive cultivation procedures persuaded threat to its wild habitat. Plant tissue culture and RNA-Seq-based molecular bioprospection of key regulatory genes aid the understanding of molecular dynamics involved in specialized metabolites (phenylethanoids and phenylpropanoids) biosynthesis and its sustainable production. Hence, comparative transcriptomic analysis was performed using leaf and root tissues from the wild and tissue-cultured plants, revealing tissue-specific production of salidroside and rosavin. The transcriptome profiling resulted in 345 million high-quality reads yielding 92,380 unique transcripts with an N₅₀ of 1260 bp. Tissue-specific gene expression analysis revealed that both phenylethanoids and phenylpropanoids biosynthesis are predominantly associated with the shikimate pathway. In addition to RNA-Seq data, the downstream biosynthesis pathways genes viz., phospho-2-dehydro-3-deoxyheptonate aldolase (DAHPS), 3-dehydroquinate synthase (DHQS), shikimate kinase (SK), chorismate mutase (CM), arogenate dehydrogenase (TYRAAT), aromatic-L-amino-acid decarboxylase (TDC), phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4-CL), cinnamoyl-CoA reductase (CCR), and cinnamyl alcohol dehydrogenase (CAD) showed higher expression pattern in wild plant tissues compared to tissue-cultured plants. The transcript fold expression determined by RT-qPCR results followed similar patterns as those observed in RNA-seq and targeted metabolite profiling data. Salidroside and rosavin content in wild plants exhibited 2.40 fold and 1.77 fold increase accumulation compared to the tissue-cultured plant. The present investigation explained the tissue and condition-specific significant differences between the expression of proposed biosynthetic pathway genes and salidroside and rosavin content. Additionally, NAC, bHLH, and ARF were the most abundant transcription factor families found in the transcriptomic analysis of R. imbricata. The generated transcriptome dataset provides a valuable gene(s)/transcription factors hub that can be used for the sustainable production of salidroside and rosavin in R. imbricata under tissue culture conditions.

Evidence linking life-form to a major shift in diversification rate in Crassula

PREMISE

Plants have evolved different ecological strategies in response to environmental challenges, and a higher lability of such strategies is more common in plant groups that adapt to various niches. Crassula (Crassulaceae), occurring in varied mesic to xeric habitats, exhibits a remarkable diversity of life-forms. However, whether any particular life-form trait has shaped species diversification in Crassula has remained unexplored. This study aims to investigate diversification patterns within Crassula and identify potential links to its life-form evolution.

METHODS

A phylogenetic tree of 140 Crassula taxa was reconstructed using plastid and nuclear loci and dated based on the nuclear DNA information only. We reconstructed ancestral life-form characters to estimate the evolutionary trends of ecophysiological change, and subsequently estimated net diversification rates. Multiple diversification models were applied to examine the association between certain life-forms and net diversification rates.

RESULTS

Our findings confirm a radiation within Crassula in the last 10 million years. A configuration of net diversification rate shifts was detected, which coincides with the emergence of a speciose lineage during the late Miocene. The results of ancestral state reconstruction demonstrate a high lability of life-forms in Crassula, and the trait-dependent diversification analyses revealed that the increased diversification is strongly associated with a compact growth form.

CONCLUSIONS

Transitions between life-forms in Crassula seem to have driven adaptation and shaped diversification of this genus across various habitats. The diversification patterns we inferred are similar to those observed in other major succulent lineages, with the most-speciose clades originating in the late Miocene.

The Conservation of Chloroplast Genome Structure and Improved Resolution of Infrafamilial Relationships of Crassulaceae

Crassulaceae are the largest family in the angiosperm order Saxifragales. Species of this family are characterized by succulent leaves and a unique photosynthetic pathway known as Crassulacean acid metabolism (CAM). Although the inter- and intrageneric relationships have been extensively studied over the last few decades, the infrafamilial relationships of Crassulaceae remain partially obscured. Here, we report nine newly sequenced chloroplast genomes, which comprise several key lineages of Crassulaceae. Our comparative analyses and positive selection analyses of Crassulaceae species indicate that the overall gene organization and function of the chloroplast genome are highly conserved across the family. No positively selected gene was statistically supported in Crassulaceae lineage using likelihood ratio test (LRT) based on branch-site models. Among the three subfamilies of Crassulaceae, our phylogenetic analyses of chloroplast protein-coding genes support Crassuloideae as sister to Kalanchoideae plus Sempervivoideae. Furthermore, within Sempervivoideae, our analyses unambiguously resolved five clades that are successively sister lineages, i.e., Telephium clade, Sempervivum clade, Aeonium clade, Leucosedum clade, and Acre clade. Overall, this study enhances our understanding of the infrafamilial relationships and the conservation of chloroplast genomes within Crassulaceae.

Wound healing cream formulated with Kalanchoe pinnata major flavonoid is as effective as the aqueous leaf extract cream in a rat model of excisional wound

Leaves of Kalanchoe pinnata are used worldwide for healing skin wounds. This study aimed to develop and compare two creams containing a leaf aqueous extract of K. pinnata (KP; 6%) and its major flavonoid [quercetin 3-O-α-L-arabinopyranosyl-(1→2)-α-L-rhamnopyranoside] (0.15%). Both creams were topically evaluated in a rat excision model for 15 days. On the 12^th day, groups treated with KP leaf-extract and KP major flavonoid creams exhibited 95.3 ± 1.2% and 97.5 ± 0.8% of healing, respectively (positive control = 96.7 ± 0.8%; negative control = 76.1 ± 3.8%). Both resulted in better re-epithelialization and denser collagen fibres. Flavonol glycosides are the main phenolics in KP leaf-extract according to HPLC-ESI-MS/MS analysis. KP major flavonoid plays a fundamental role in the wound healing. The similar results found for both creams indicate that the use of KP crude extract should be more profitable than the isolated compound.

Plastid genome of stonecrop Hylotelephium verticillatum (Sedoideae; Crassulaceae): insight into structure and phylogenetic position

The first complete chloroplast genome sequence of Hylotelephium verticillatum, was reported in this study. The plastome size was 151,398 bp in total length, with one large single copy (LSC; 82,951 bp), one small single copy (SSC; 16,839 bp), and two inverted repeat (IR) regions (IRa and IRb, each with 25,804 bp). The overall GC content was 37.8% and the genome contained 128 genes, including 85 protein-coding, 37 transfer RNA, and 6 ribosomal RNA genes. Phylogenetic analysis of 15 representative plastomes within the family Crassulaceae suggests that H. verticillatum is sister to congeneric H. ewersii.

Next-Generation Genome Sequencing of Sedum plumbizincicola Sheds Light on the Structural Evolution of Plastid rRNA Operon and Phylogenetic Implications within Saxifragales

The genus Sedum, with about 470 recognized species, is classified in the family Crassulaceae of the order Saxifragales. Phylogenetic relationships within the Saxifragales are still unresolved and controversial. In this study, the plastome of S. plumbizincicola was firstly presented, with a focus on the structural analysis of rrn operon and phylogenetic implications within the order Saxifragaceae. The assembled complete plastome of S. plumbizincicola is 149,397 bp in size, with a typical circular, double-stranded, and quadripartite structure of angiosperms. It contains 133 genes, including 85 protein-coding genes (PCGs), 36 tRNA genes, 8 rRNA genes, and four pseudogenes (one ycf1, one rps19, and two ycf15). The predicted secondary structure of S. plumbizincicola 16S rRNA includes three main domains organized in 74 helices. Further, our results confirm that 4.5S rRNA of higher plants is associated with fragmentation of 23S rRNA progenitor. Notably, we also found the sequence of putative rrn5 promoter has some evolutionary implications within the order Saxifragales. Moreover, our phylogenetic analyses suggested that S. plumbizincicola had a closer relationship with S. sarmentosum than S. oryzifolium, and supported the taxonomic revision of Phedimus. Our findings of the present study will be useful for further investigation of the evolution of plastid rRNA operon and phylogenetic relationships within Saxifragales.

Local anti-inflammatory activity: Topical formulation containing Kalanchoe brasiliensis and Kalanchoe pinnata leaf aqueous extract

Kalanchoe brasiliensis and Kalanchoe pinnata are used interchangeably in traditional medicine in the treatment of wound healing. In this context, the objective of the present study was to evaluate the local anti-inflammatory activity of a topical formulation containing aqueous extract of both species. The in vivo model used was ear edema induced by croton oil and paw edema induced by carrageenan. The Swiss mice treatments use formulations containing aqueous extract at different concentrations (1.25%, 2.5%, and 5%) or dexamethasone (1 mg/g), all administered topically and immediately after edema induction. The treatment with formulations containing aqueous extract of both species reduced ear and paw edema, besides that, the decrease in edema was evidenced by reduction of myeloperoxidase activity, IL-1β, and TNF-α levels and increase IL-10 levels. In conclusion, the two species showed local anti-inflammatory activity; however K. brasiliensis showed a better result in both edematogenic models since it had activity in the lowest concentration.

Chemical composition, antioxidant and gastrointestinal properties of Sedum dendroideum Moc & Sessé ex DC leaves tea infusion

ETHNOPHARMACOLOGICAL RELEVANCE

Sedum dendroideum Moc & Sessé ex DC (Crassulaceae) is a medicinal plant employed in Mexican and Brasilian folk medicine as juice or infusion, as remedy for the treatment of different diseases, including gastric disorders.

AIM OF THE STUDY

Although some studies carried out with Sedum dendroideum have demonstrated its gastroprotective effect, the purpose of this study was to elucidate the chemical constituents, antioxidant, cytotoxic and mechanisms underlying the gastrointestinal properties of Sedum dendroideum accordingly its traditional use, as fresh leaves tea infusion (SDI).

MATERIALS AND METHODS

Chemical constituents were analyzed using high performance liquid chromatography and mass spectrometry (HPLC-MS). Antioxidant and cytotoxicity were evaluated in in vitro assays. The efficacy of the SDI on macroscopic ulcer appearance, mucus and GSH maintenance on ethanol- and indomethacin-induced ulcer models, gastric acid secretion and gastrointestinal motility were investigated.

RESULTS

Phytochemical analysis by HPLC-MS revealed the presence of different flavonol glycosides, containing myricetin and quercetin, along with the kaempferol as aglycones. In vitro pharmacological investigation of SDI demonstrated potent antioxidant activity in DPPH assay (IC50: 13.25 ± 3.37 µg/mL) and absence of cytotoxicity in Caco-2 cells by MTT method. Oral administration of SDI (ED₅₀ of 191.00 ± 0.08 mg/kg) in rats promoted gastroprotection against ethanol or indomethacin in rats through reinforcement of gastric wall mucus, GSH content and nitric oxide release, without present antisecretory properties. The gastroprotective effect was maintained when SDI (19 mg/kg) was administrated by intraperitoneal route. Furthermore, SDI (150 mg/kg) unchanged the gastric emptying but increase small bowel transit in mice through cholinergic pathways.

CONCLUSIONS

Collectively, this study confirmed that Sedum dendroideum promotes gastroprotection through preventing of endogenous defense mechanisms, represented by mucus and GSH without changes gastric acid secretion. Sedum dendroideum tea infusion features a chemical profile that contributes to the antioxidant and gastric health-promoting effects, supporting the use in folk medicine for the treatment of gastrointestinal disorders.

Antibacterial Activity of Kalanchoe mortagei and K. fedtschenkoi Against ESKAPE Pathogens

Plants in the genus Kalanchoe (Family: Crassulaceae) are used in traditional medicine throughout the tropics for treating a variety of conditions. Two species, Kalanchoe mortagei and K. fedtschenkoi, have established ethnobotanical usage but have been neglected in previous research concerning their potential bioactivity. Here, we provide a thorough review of the reported antimicrobial activities of Kalanchoe genus and evaluate the in vitro antibacterial effects of two previously unexplored species against a panel of multidrug-resistant bacteria, the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae). Plant specimens were collected and voucher specimens deposited in the Emory University Herbarium. Dried plant material was ground into a powder and extracted as ethanolic macerations or as aqueous decoctions. Extracts were tested against the ESKAPE pathogens for growth inhibitory activity. Cytotoxicity to human cells was assessed via a lactate dehydrogenase assay of treated human keratinocytes (HaCaTs). K. fedtschenkoi extracts demonstrated growth inhibitory effects against two Gram-negative species, A. baumannii (strain CDC-33) and P. aeruginosa (AH-71), as well as S. aureus (UAMS-1). In these cases, growth inhibition greater than 50% (IC50) was generally observed at concentrations of 256 μg mL-1, though one K. fedtschenkoi extract (1465, prepared from stems) exhibited an IC50 against A. baumannii at 128 μg mL-1. All extracts were well tolerated by HaCaTs (LD50 ≥ 256 μg mL-1). Chemical characterization using HPLC and chemical standards established the presence of caffeic acid and quercetin in both plant species, as well as kaempferol in K. fedtschenkoi. These results reveal K. fedtschenkoi to be a plant of medicinal interest, and future research should aim to characterize the bioactivity of this species and its active constituents through bioassay-guide fractionation. Effects on bacterial biofilm formation and quorum-sensing are also research topics of interest for this genus.

Crassula, insights into an old, arid-adapted group of southern African leaf-succulents

The Crassulaceae is an important family in the Greater Cape Floristic Region of southern Africa and is the seventh largest family in the arid Succulent Karoo Biome. After the Aizoaceae it is the largest group of leaf-succulents in southern Africa. This is the first investigation of a broad selection (68%) of the ±170 species of Crassula. We used data from three chloroplast and two nuclear gene-regions, which yielded many informative characters and provided good resolution among the species. We show that only five of the 20 sections in Crassula are monophyletic. However, the clades recovered show close correlation with the two subgenera that were once recognized. Crassula contains more than 25 succulent annual species which are not closely related to each other but form early-diverging branches in each of the three major clades. One of these major clades contains far more perennial species than the others and is the greatest diversification within Crassula. This diversification mostly arose within the last 10 million years (my) and spread across much of southern Africa. Members of the smaller two major clades are often soft- and flat-leaved perennials (many with basic chromosome number x = 8, with high levels of polyploidy). Those in the largest diversification (where a basic chromosome number of x = 7 predominates) show other arid-adaptations (more highly succulent leaves with a dense covering of hairs or papillae or a smooth xeromorphic epidermis). Their flowers are also more variable in shape and bee-, moth- and butterfly-pollinated species are known among them. We establish that Crassula arose in the Greater Cape Floristic Region of southern Africa. While much of its diversity has evolved in the last 10 my, Crassula nevertheless contains species that are much older and itself arose ±46 my ago. Since all its species are succulent it is possible that they are part of an early arid-adapted flora that contributed to the Succulent Karoo Biome in the western part of southern Africa. Consequently this Biome may not be assembled only from 'young lineages' as is usually thought to be the case.

Optimization of Aqueous Extraction from Kalanchoe pinnata Leaves to Obtain the Highest Content of an Anti-inflammatory Flavonoid using a Response Surface Model

INTRODUCTION

The medicinal plant Kalanchoe pinnata is a phenolic-rich species used worldwide. The reports on its pharmacological uses have increased by 70% in the last 10 years. The leaves of this plant are the main source of an unusual quercetin-diglycosyl flavonoid (QAR, quercetin arabinopyranosyl rhamnopyranoside), which can be easily extracted using water. QAR possess a strong in vivo anti-inflammatory activity.

OBJECTIVE

To optimize the aqueous extraction of QAR from K. pinnata leaves using a three-level full factorial design.

MATERIAL AND METHODS

After a previous screening design, time (x₁ ) and temperature (x₂ ) were chosen as the two independent variables for optimization. Freeze-dried leaves were extracted with water (20% w/v), at 30°C, 40°C or 50°C for 5, 18 or 30 min. QAR content (determined by HPLC-DAD) and yield of extracts were analyzed. The optimized extracts were also evaluated for cytotoxicity.

RESULTS

The optimal heating times for extract yield and QAR content were similar in two-dimensional (2D) surface responses (between 12.8 and 30 min), but their optimal extraction temperatures were ranged between 40°C and 50°C for QAR content and 30°C and 38°C for extract yield. A compromise region for both parameters was at the mean points that were 40°C for the extraction temperature and 18 min for the total time.

CONCLUSION

The optimized process is faster and spends less energy than the previous one (water; 30 min at 55°C); therefore is greener and more attractive for industrial purposes. This is the first report of extraction optimization of this bioactive flavonoid. Copyright © 2018 John Wiley & Sons, Ltd.

Gastroprotective and Antioxidant Activity of Kalanchoe brasiliensis and Kalanchoe pinnata Leaf Juices against Indomethacin and Ethanol-Induced Gastric Lesions in Rats

Kalanchoe brasiliensis and Kalanchoe pinnata are used interchangeably in traditional medicine for treating peptic ulcers and inflammatory problems. In this context, this study aims to characterize the chemical constituents and evaluate the gastroprotective activity of the leaf juices of the two species in acute gastric lesions models. Thin Layer Chromatography (TLC) and Ultra High Performance Liquid Chromatography coupled to Mass Spectrometer (UHPLC-MS) were performed for chemical characterization. Wistar rats were pre-treated orally with leaf juices (125, 250 and 500 mg/kg) or ranitidine (50 mg/kg). The peaks observed in the chromatogram of K. brasiliensis showed similar mass spectra to flavonoid glycosides derived from patuletin and eupafolin, while K. pinnata showed mass spectra similar to compounds derived from quercetin, patuletin, eupafolin and kaempferol. K. brasiliensis at all doses and K. pinnata at doses of 250 mg/kg and 500 mg/kg significantly reduced the lesions in the ethanol induction model. In the indomethacin induction model, both species showed significant results at doses of 250 and 500 mg/kg. Also, the pre-treatment with leaf juices increased the antioxidant defense system, glutathione (GSH), whereas malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) levels were significantly decreased. Treatment with leaf juices led to the upregulation of zone occludes-1 (ZO-1) and the downregulation of inducible nitric oxide synthase (iNOS) and factor nuclear-κβ transcription (NF-κB-p65), while also showing a cytoprotective effect and maintaining mucus production. These findings show that the leaf juices of the two species showed gastroprotective effects on ethanol and gastric indomethacin injury which were a consequence of gastric inflammation suppression, antioxidant activity and the maintenance of cytoprotective defenses and mucosal structure architecture.

Climate Is Not All: Evidence From Phylogeography of Rhodiola fastigiata (Crassulaceae) and Comparison to Its Closest Relatives

How geological events and climate oscillations in the Pleistocene glaciation shaped the geographic distribution of genetic variation of species on the Qinghai-Tibetan Plateau (QTP) and its adjacent areas has been extensively studied. However, little studies have investigated whether closely related species in the same genus with similar physiological and life history traits responded similarly to the glacial climatic oscillations. If this is not the case, we would expect that the population histories of studied species were not driven by extrinsic environmental changes alone. Here we conducted a phylogeographic study of a succulent alpine plant Rhodiola fastigiata, using sequences from chloroplast genome and nrITS region, as well as ecological niche modeling. The results of R. fastigiata were compared to other congeneric species that have been studied, especially to R. alsia and R. crenulata. We found that for both markers, two geographic groups could be revealed, corresponding to the QTP plateau and the Hengduan Mountains, respectively, indicating isolated refugia in those two areas. The two groups diverged 1.23 Mya during the Pleistocene. We detected no significant population expansion by mismatch distribution analysis and Bayesian Skyline Plot. We found that even these similar species with similar physiological and life history traits have had different demographic histories in the Quaternary glacial periods. Our comparative phylogeographic study sheds new lights into phylogeographic research that extrinsic environmental changes are not the only factor that can drive population demography, and other factors, such as coevolved interactions between plants and their specialized pathogens, that probably played a role need to be examined with more case studies.

The complete chloroplast genome sequence of Phedimus Kamtschaticus (Crassulaceae) in Korea

The complete chloroplast genome sequence of Phedimus kamtschaticus, which commonly occurs in northeastern Asia was determined. The genome size was 151,652 bp, composed of one pair of inverted repeats (IRs) of 25,977 bp, which were separated by one large single-copy (LSC; 83,010 bp) and one small single-copy (SSC; 16,688 bp) region. The chloroplast genome contained 132 genes, including 88 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. The overall GC content was 37.8%. Phylogenetic analysis of the complete chloroplast genome suggested that P. kamtschaticus was most closely related to Ulleung Island insular endemic P. takesimensis.

The influence of habitat on the evolution of plants: a case study across Saxifragales

BACKGROUND AND AIMS

Organismal evolution tends to be closely associated with ecological conditions. However, the extent to which this association constrains adaptation or diversification into new habitats remains unclear. We studied habitat evolution in the hyper-diverse angiosperm clade Saxifragales.

METHODS

We used species-level phylogenies for approx. 950 species to analyse the evolution of habitat shifts as well as their influence on plant diversification. We combined habitat characterization based on floristic assignments and state-of-the art phylogenetic comparative methods to estimate within- and across-habitat diversification patterns.

KEY RESULTS

Our analyses showed that Saxifragales diversified into multiple habitats from a forest-inhabiting ancestor and that this diversification is governed by relatively rare habitat shifts. Lineages are likely to stay within inferred ancestral ecological conditions. Adaptation to some habitat types (e.g. aquatic, desert) may be canalizing events that lineages do not escape. Although associations between increased diversification rates and shifts in habitat preferences are occasionally observed, extreme macroevolutionary rates are closely associated with specific habitats. Lineages occurring in shrubland, and especially tundra and rock cliffs, exhibit comparatively high diversification, whereas forest, grassland, desert and aquatic habitats are associated with low diversification.

CONCLUSIONS

The likelihood of occupation of new habitats appears to be asymmetric. Shifts to aquatic and desert habitats may be canalizing events. Other habitats, such as tundra, might act as evolutionary sources, while forests provide the only habitat seemingly colonized easily by lineages originating elsewhere. However, habitat shifts are very rare, and any major environmental alteration is expected to have dramatic evolutionary consequences.

(-)-Epicatechin derivate from Orostachys japonicus as potential inhibitor of the human butyrylcholinesterase

Cholinesterase inhibitors block the bioconversion of neurotransmitters by cholinesterase in the nervous system. Epicatechin derivatives (1, 3 and 5), polyphenols (6 and 7) from Orostachys japonicus, and catechin derivatives (2 and 4) from our in-house library were evaluated for their inhibitory activity on cholinesterase. Compound 5 exhibited IC50 values of 58.3±2.4 and 17.8±3.8μg/mL on AChE and BuChE, respectively. Compound 5 inhibited BuChE more strongly than AChE through a competitive behavior. In silico binding positions of 5 in the active site were predicted using Autodock 4.2 and processed in a 10000-ps molecular dynamics simulation to assess the stability of compound 5 binding.

Potential Health Risks Posed by Plant-Derived Cumulative Neurotoxic Bufadienolides in South Africa

Bufadienolide-type cardiac glycosides have a worldwide distribution and are mainly synthesized by plants, but there are also animal sources. In South Africa, members of three genera of the Crassulaceae (Cotyledon, Tylecodon and Kalanchoe) cause a unique chronic form of cardiac glycoside poisoning, predominantly in small stock. This paretic/paralytic condition is referred to as “krimpsiekte”, cotyledonosis or “nenta”. “Krimpsiekte” is a plant poisoning only reported from South Africa and is regarded as the most important plant poisoning of small stock in the semi-arid Little Karoo and southern fringes of the Great Karoo. The toxicosis is caused by cumulative bufadienolides which have neurotoxic properties. Four types of cumulative neurotoxic bufadienolides, namely cotyledoside, and the tyledosides, orbicusides and lanceotoxins, have been isolated. Based on the structure activity relationships and certain toxicokinetic parameters possible reasons for their accumulation are presented. Consumption of edible tissues from animals that have ingested these plants poses a potential risk to humans.

New Bufadienolides Isolated from the Roots of Kalanchoe daigremontiana (Crassulaceae)

An aqueous extract from the roots of Kalanchoe daigremontiana turned out to be a rich source of bufadienolides. The existing literature data relate mainly to the aerial parts of Kalanchoe but there is no information about the metabolic profile of the roots, which are also used in traditional medicine. Our investigation concerning the roots of K. daigremontiana led to the isolation and characterization of eight new bufadienolides, namely 1β,3β,5β,14β,19-pentahydroxybufa-20,22-dienolide (1), 19-(acetyloxy)-1β,3β,5β,14β-tetrahydroxybufa-20,22-dienolide (2), 3β-O-α-l-rhamno-pyranosyl-5β,11α,14β,19-tetrahydroxybufa-20,22-dienolide (3), 19-(acetyloxy)-3β,5β,11α,14β-tetrahydroxybufa-20,22-dienolide (4), 3β,5β,11α,14β,19-pentahydroxy-12-oxo-bufa-20,22-dienolide (5), 19-(acetyloxy)-3β,5β,11α,14β-tetrahydroxy-12-oxo-bufa-20,22-dienolide (6), 19-(acetyloxy)-1β,3β,5β,11α,14β-pentahydroxy-12-oxo-bufa-20,22-dienolide (7) and 1β-(acetyloxy)-3β,5β,11α,14β,19-pentahydroxy-12-oxo-bufa-20,22-dienolide (8), together with seven known compounds: 11α,19-dihydroxytelocinobufagin (9), bersaldegenin-1-acetate (10), daigredorigenin-3-acetate (11), bersaldegenin-1,3,5-orthoacetate (12), bryotoxin B (13), bryophyllin B (14) and bersaldegenin (15). The structures were established applying extensive 1D- and 2D-NMR and MS spectroscopic analyses.

Application of succulent plant leaves for Agrobacterium infiltration-mediated protein production

When expressing plant cell wall degrading enzymes in the widely used tobacco (Nicotiana benthamiana) after Agrobacterium infiltration, difficulties arise due to the thin leaf structure. Thick leaved succulents, Kalanchoe blossfeldiana and Hylotelephium telephium, were tested as alternatives. A xyloglucanase, as well as a xyloglucanase inhibitor protein was successfully produced.

Induction of wound-periderm-like tissue in Kalanchoe pinnata (Lam.) Pers. (Crassulaceae) leaves as a defence response to high UV-B radiation levels

BACKGROUND AND AIMS

UV-B radiation can be stressful for plants and cause morphological and biochemical changes. Kalanchoe pinnata is a CAM leaf-succulent species distributed in hot and dry regions, and is rich in flavonoids, which are considered to be protective against UV-B radiation. This study aims to verify if K. pinnata has morphological or anatomical responses as a strategy in response to high UV-B levels.

METHODS

Kalanchoe pinnata plants of the same age were grown under white light (control) or white light plus supplemental UV-B radiation (5 h d(-1)). The plants were treated with the same photoperiod, photosynthetically active radiation, temperature and daily watering system. Fragments of the middle third of the leaf blade and petiole were dehydrated and then embedded in historesin and sectioned in a rotary microtome. Sections were stained with toluidine blue O and mounted in Entellan®. Microchemical analyses by optical microscopy were performed on fresh material with Sudan III, Sudan IV and phloroglucinol, and analysed using fluorescence microscopy.

KEY RESULTS

Supplemental UV-B radiation caused leaf curling and the formation of brown areas on the leaves. These brown areas developed into a protective tissue on the adaxial side of the leaf, but only in directly exposed regions. Anatomically, this protective tissue was similar to a wound-periderm, with outer layer cell walls impregnated with suberin and lignin.

CONCLUSIONS

This is the first report of wound-periderm formation in leaves in response to UV-B radiation. This protective tissue could be important for the survival of the species in desert regions under high UV-B stress conditions.

Anti-inflammatory effects of Bryophyllum pinnatum (Lam.) Oken ethanol extract in acute and chronic cutaneous inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Bryophyllum pinnatum (Lam.) Oken (Crassulaceae), popularly known in Brazil as "folha-da-fortuna", is a plant species used in folk medicine for the external and internal treatment of inflammation, infection, wound, burn, boil, ulcers and gastritis, and several other diseases. The present study aimed to perform the chemical characterization and the evaluation of the topical anti-inflammatory effect of the ethanol extract of Bryophyllum pinnatum leaves (EEBP) in acute and chronic mice ear edema models induced by different irritant agents.

MATERIALS AND METHODS

The EEBP chemical characterization was performed by HPLC-UV DAD. Ear edema on Swiss mice was induced by the topical application of Croton oil (single and multiple applications), arachidonic acid, phenol, capsaicin and ethyl phenylpropiolate (EPP). The topical anti-inflammatory effect of EEBP was evaluated by measuring the ear weight (acute inflammation models) and thickness (chronic inflammation model). Histopathological analyses of ear tissue samples sensitized with Croton oil (single and multiple applications) were also performed.

RESULTS

The flavonoids rutin, quercetin, luteolin and luteolin7-O-β-d-glucoside were detected in EEBP. Topical application of EEBP significantly (P<0.001) inhibited the ear edema induced by Croton oil single application (inhibition of 57%), arachidonic acid (inhibition of 67%), phenol (inhibition of 80%), capsaicin (inhibition of 72%), EPP (inhibition of 75%) and Croton oil multiple application (55% after 9 days). Histopathological analyses confirmed the topical anti-inflammatory effect of EEBP since it was observed reduction of edema, epidermal hyperplasia, inflammatory cells infiltration and vasodilation.

CONCLUSIONS

The results suggest that EEBP is effective as a topical anti-inflammatory agent in acute and chronic inflammatory processes possibly due to inhibition of arachidonic acid pathway, which justify the traditional use of Bryophyllum pinnatum as a remedy for skin disorders.

Comparative genetic structure between Sedum ussuriense and S. kamtschaticum (Crassulaceae), two stonecrops co-occurring on rocky cliffs

• Premise of the study: Geographic isolation due to discontinuities of suitable habitat may have significant effects on the genetic structure of plant populations. Even within a few kilometers, physical barriers to gene flow may lead to considerable genetic differentiation among populations.• Methods: Sedum ussuriense is a boreal species that in Korea occurs only in four valleys separated by mountain ranges in Juwangsan National Park and its vicinity (a range of ∼15 km). Its congener S. kamtschaticum, by contrast, co-occurs in the four valleys but also on the intervening mountains. Using 12 allozyme loci, we comparatively assessed genetic variability and structure in 12 population pairs of the two stonecrops.• Key results: While we found high and comparable levels of within-population genetic variation for the two species, among-population divergence was significantly higher in S. ussuriense (F_ST = 0.261 vs. F_ST = 0.165). Sedum ussuriense also showed a much higher percentage of among-valley variation (19%) than S. kamtschaticum (4%).• Conclusions: High levels of genetic diversity in the two Sedum species are consistent with the previous hypothesis that mountains of the Korean Peninsula served as glacial refugia for many boreal species. Given that the two congeners have similar life-history traits, the lower among-population differentiation in S. kamtschaticum is attributable to its higher abundance and more continuous distribution in the study area. This study confirms the central role of geographic isolation in the genetic structure of plant species even at very small scales.

How succulent leaves of Aizoaceae avoid mesophyll conductance limitations of photosynthesis and survive drought

In several taxa, increasing leaf succulence has been associated with decreasing mesophyll conductance (g M) and an increasing dependence on Crassulacean acid metabolism (CAM). However, in succulent Aizoaceae, the photosynthetic tissues are adjacent to the leaf surfaces with an internal achlorophyllous hydrenchyma. It was hypothesized that this arrangement increases g M, obviating a strong dependence on CAM, while the hydrenchyma stores water and nutrients, both of which would only be sporadically available in highly episodic environments. These predictions were tested with species from the Aizoaceae with a 5-fold variation in leaf succulence. It was shown that g M values, derived from the response of photosynthesis to intercellular CO2 concentration (A:C i), were independent of succulence, and that foliar photosynthate δ(13)C values were typical of C3, but not CAM photosynthesis. Under water stress, the degree of leaf succulence was positively correlated with an increasing ability to buffer photosynthetic capacity over several hours and to maintain light reaction integrity over several days. This was associated with decreased rates of water loss, rather than tolerance of lower leaf water contents. Additionally, the hydrenchyma contained ~26% of the leaf nitrogen content, possibly providing a nutrient reservoir. Thus the intermittent use of C3 photosynthesis interspersed with periods of no positive carbon assimilation is an alternative strategy to CAM for succulent taxa (Crassulaceae and Aizoaceae) which occur sympatrically in the Cape Floristic Region of South Africa.

Sedum tarokoense (Crassulaceae), a new species from a limestone area in Taiwan

BACKGROUND

An unknown Sedum was found from the limestone region in Taiwan. After a detailed comparison with other congeners in Taiwan and neighboring countries, we identified this plant as a new species.

RESULTS

This new taxon resembles S. nokoense Yamamoto, S. alfredii Hance, and S. uniflorum Hook. & Arn. subsp. oryzifolium (Makino) H. Ohba, but differs in leaf shape, sepal morphology, and seed testa micro-morphology. Ecologically, this new taxon occurs exclusively on limestone, while S. nokoense and S. alfredii grow in non-limestone areas and S. uniflorum subsp. oryzifolium is only found on sandy seashores.

CONCLUSIONS

Sedum tarokoense H.W. Lin & J.C. Wang is described as a new species. We provide a description, line drawing, and distribution map, as well as photograph, a key and a table to distinguish S. tarokoense from its related species.

Microsatellite markers in Rhodiola (Crassulaceae), a medicinal herb genus widely used in traditional Chinese medicine

PREMISE OF THE STUDY

Microsatellite loci are described for Rhodiola, a medicinal herb genus widely used in traditional Chinese medicine. •

METHODS AND RESULTS

A total of 17 polymorphic microsatellite primer pairs were developed using the combined biotin capture method. The number of alleles per locus ranged from one to 12 across 192 individuals from R. bupleuroides, R. crenulata, R. fastigiata, and R. sacra, and the mean observed and expected heterozygosities ranged from 0.177 to 0.412 and from 0.363 to 0.578, respectively. •

CONCLUSIONS

The results demonstrate the potential use of this new set of microsatellite markers for genotyping individuals and estimating genetic diversity in Rhodiola.

Molecular phylogenetic position of podostemaceae, a marvelous aquatic flowering plant family

Podostemaceae are aquatic herbs and are famous for their anomalous vegetative morphology, occurring only in rapids. Because of its peculiar morphology, there were no established theory nor accepted opinion on the phylogenetic position. Especially, Cusset and Cusset (1988) proposed the new class, Podostemopsida beside the Magnollopsida and Liliopsida. We, therefore, consequences extensive and detailled analyses using nucleotide sequences ofrbcL genes for two genera and three species of the family together with many representatives of the families of flowering plants to determine the closest ally. The conclusion was that the Crassulaceae is a sister group to the Podostemaceae.