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Marine algae are the source of a plethora of halogenated compounds, in particular brominated phenols, possessing various bioactivities. Since these natural products are typically unavailable commercially, isolation is usually indispensable for biological activity testing. However, targeted isolation may be challenging due to difficulties in identifying desired compounds via high-resolution LC–MS in crude extracts or fractions. While bromophenols have been extensively reviewed regarding their bioactivities, less attention has been given to their distribution and chemotaxonomic relevance among marine algae. Knowledge of the distribution of bromophenols may aid species identification and also point to species containing potentially novel compounds. To facilitate targeted and untargeted isolation of bromophenols from marine algae, an overview of the distribution and chemotaxonomic relevance of algal bromophenols considering recent phylogenetic findings is presented along with key analytical features of bromophenols relevant for mass spectrometric identification. Additionally, a comprehensive database listing brominated phenols from marine algae and their key analytical properties has been constructed. [ABSTRACT FROM AUTHOR]

Species of Cissampelos (Menispermaceae) are widely used in folk medicine in various cultures, for the treatment of a wide variety of diseases. Several ethnobotanical studies have reported the use of these species, which, among other benefits, instigated further researches on several pharmacological properties and biologically active compounds present in species of the genus. The objective of this review is to compile and update information about the ethnobotanical, phytochemical and biological studies of species of the Cissampelos genus. Among the officially accepted species, C. pareira, C. mucronata and C. sympodialis were the most reported in all aspects of the research. Their immunomodulatory, anti-inflammatory, antioxidant, antiallergic and antimicrobial properties have already been established. Evidently, a considerable part of these bioactivities is due to the presence of alkaloids, the main constituents of Cissampelos species. Other natural products such as essential oils, fixed oils, pectins, alcamides, polysaccharides and flavonoids have also been reported. Future investigations on Cissampelos species are necessary, especially regarding pharmacological properties, isolation of substances, mechanism of action and bioavailability in order to provide subsidies for the development of new drugs. [ABSTRACT FROM AUTHOR]

Synergistic effects of multiple plant secondary metabolites on upper trophic levels constitute an underexplored but potentially widespread component of coevolution and ecological interactions. Examples of plant secondary metabolites acting synergistically as insect deterrents are not common, and many studies focus on the pharmaceutical applications of natural products, where activity is serendipitous and not an evolved response. This review summarizes some systems that are ideal for testing synergistic plant defenses and utilizes a focused meta-analysis to examine studies that have tested effects of multiple compounds on insects. Due to a dearth of ecological synergy studies, one of the few patterns for synergy that we are able to report from the meta-analysis is that phytochemical mixtures have a larger overall effect on generalist herbivores than specialist herbivores. We recommend a focus on synergy in chemical ecology programs and suggest future hypothesis tests and methods. These approaches are not focused on techniques in molecular biology to examine mechanisms at the cellular level, rather we recommend uncovering the existence of synergy first, by combining the best methods in organic synthesis, isolation, chemical ecology, bioassays, and quantitative analyses. Data generated by our recommended methods should provide rigorous tests of important hypotheses on how intraclass and interclass compounds act synergistically to deter insects, disrupt the immune response, and ultimately contribute to diversification. Further synergy research should also contribute to determining if antiherbivore synergy is widespread among plant secondary metabolites, which would be consistent with the hypothesis that synergistic defenses are a key attribute of the evolved diverse chemical mixtures found in plants. [ABSTRACT FROM AUTHOR]

Casearia (Salicaceae sensu lato) species have been used as folk medicines in South American and Asian countries since ancient times. Previous phytochemical screenings demonstrated that the Casearia plants mainly contain clerodane diterpenoids, sesquiterpenoids, phenylpropanoids and other constituents from different chemical classes. The pharmacological studies confirmed that the crude extracts or individual compounds from the genus showed cytotoxic, hypoglycemic, antiulcer, and anti-inflammatory activities, as well as anti-snake venom property. In this review we presented a summary of the secondary metabolites isolated from Casearia species based on the published literatures through May 2013. In addition to the traditional medicinal use of Casearia plants and their taxonomic characteristics, we focused on the known biological activities of the plants and discussed them in detail here. [ABSTRACT FROM AUTHOR]

The isoprenoid family represents one of the most ancient and widespread classes of structurally and functionally rich biomolecules known to man. Although these natural products are synthesized in all organisms, the plant kingdom exhibits tremendous variation in their chemistry and roles, ranging from primary metabolism to secondary metabolism and specialized ecological interactions with the environment. Despite enormous diversity in structure and function, all isoprenoids are derived from the universal C precursor isoprene. The isoprenoid biosynthetic pathway has three major stages, viz., (1) synthesis of the isoprene building blocks, followed by their (2) assembly into flexible linear and branched hydrocarbon substrates, which then undergo (3) multistep reaction cascades to generate the vast assortment of isoprenoid end products. One of the most interesting aspects of isoprenoid biosynthesis is its being finely tuned by a multilayered and complex regulatory network, which excellently controls the machinery producing one of the most heterogeneous groups of molecules in plants. Terpene synthases, enzymes of the final stage, are key players in the generation of isoprenoid diversity, catalyzing one of the most complex reactions known to chemistry and biology. Unraveling the mechanism by which a minimal pool of substrates is thus converted into tens of thousands of regiospecific and stereospecific products, is a promising research avenue: This knowledge may be practically used for rational design of novel compounds by metabolic engineering, in order to yield plants with improved nutritional efficacy, stress resistance, bio-pharmaceutical properties etc. This review is an attempt to summarize the biochemical, molecular, physiological, structural, genomic and evolutionary aspects of isoprenoid biosynthesis, providing new insights into how these enzymes utilize various innovative strategies for creation of the so-called final terpenome. [ABSTRACT FROM AUTHOR]

There are only 15 diterpenoids known sharing the rare cubitane skeleton (1,3-diisopropyl-6,10-dimethylcyclododecane, Fig. 1) named after the natural product (+)-cubitene ((+)- 1) from the termite Cubitermes umbratus. Cubitane-type diterpenoids ('cubitanoids') have since then been isolated from gorgonian corals and there are reports that cubitene also occurs in plants. The twelve-membered ring of the cubitanoids is an interesting feature for which we have developed a novel synthesis involving bicyclic precursors. In this review, we discuss the state-of-research regarding isolation, structure elucidation, biological activity, biosynthesis, and total synthesis of cubitane-type diterpenoids.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Fungi can be found in almost all sorts of habitats competing with an even higher number of other organisms. As a consequence fungi developed a number of strategies for protection and communication with other organisms. This review focuses on the increasing number of volatile sesquiterpenes found to be produced by fungal species. The remarkable diversity of this type of volatile organic compound (VOC) within the kingdom fungi is presented and their benefits for the fungi are discussed. The majority of these compounds are hydrocarbons comprising several dozens of carbon skeletons. Together with oxygenated sesquiterpenes they include compounds unique to fungi. Only in recent years the interest shifted from a mere detection and characterization of compounds to their biological function. This review reveals highly diverse ecological functions including interactions with bacteria, other fungi, insects and plants. VOCs act as autoinducer, defend against competing species and play essential roles in attracting pollinators for spreading fungal spores. For many sesquiterpene VOCs sophisticated responses in other organisms have been identified. Some of these interactions are complex involving several partners or transformation of the emitted sesquiterpene. A detailed description of ecological functions of selected sesquiterpenes is given as well as their potential application as marker molecules for detection of mould species. Structures of all described sesquiterpenes are given in the review and the biosynthetic routes of the most common skeletons are presented. Summarizing, this article provides a detailed overview over the current knowledge on fungal sesquiterpene VOCs and gives an outlook on the future developments. [ABSTRACT FROM AUTHOR]