Stefan Schulz

Stefan Schulz
Technische Universität Braunschweig · Institute of Organic Chemistry

Professor Dr.

About

409
Publications
73,739
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
10,438
Citations
Introduction
Stefan Schulz currently works at the Institute of Organic Chemistry, Technische Universität Braunschweig. Stefan does research in Organic Chemistry, Chemical Ecology, Natural Products and Medicinal Chemistry. Their current project is 'Chemistry of communication.'
Additional affiliations
January 1998 - present
Technische Universität Braunschweig
Position
  • Director of Institute of Organic Chemistry
January 1988 - December 1997
University of Hamburg

Publications

Publications (409)
Article
Full-text available
During courtship, male butterflies of many species produce androconial secretions containing male sex pheromones (MSPs) that communicate species identity and affect female choice. MSPs are thus likely candidates as reproductive barriers, yet their role in speciation remains poorly studied. Although Heliconius butterflies are a model system in speci...
Article
Full-text available
Clostridioides difficile (previously Clostridium difficile ) causes life-threatening gut infections. The central metabolism of the bacterium is strongly influencing toxin production and consequently the infection progress. In this context, the composition and potential origin of the volatile metabolome was investigated, showing a large number of su...
Article
Investigation of the contents of the scent glands of the heliconiine butterfly Heliconius erato phyllis via gas chromatography/electroantennography revealed an unprecedented active compound. The males transfer this compound to females during mating. The structure of (2R,6E,10R)-2,6-dimethyl-6-undecen-10-olide, a derivative of geranylacetone, was pr...
Article
Heliconius erato is a neotropical butterfly species that is part of a complex mimicry ring, with colorful wing patterns. For intraspecific communication, males use pheromones that are released from two different scent-emitting structures. Scent glands located near the abdominal claspers of males, containing antiaphrodisiac pheromones, release a hig...
Article
Insect repellents are important means of personal protection against bites from mosquitoes carrying various pathogens. Odorant-dependent behaviours are triggered by odor ligands bound to odorant receptors. Insect odorant receptors are heterotetrameric ligand-gated cation channels composed of an obligatory subunit, ORco, and one of many variable sub...
Article
Full-text available
Emerging evidence shows that the cuticular and silk lipids of spiders are structurally more diverse than those of insects, although only a relatively low number of species have been investigated so far. As in insects, such lipids might play a role as signals in various contexts. The wasp spider Argiope bruennichi has probably the best investigated...
Article
Full-text available
Unser Mitglied Prof. Dr. Dr. h.c. mult. Wittko Francke verstarb völlig unerwartet am 27.12.2020 in Hamburg im Alter von 80 Jahren an einer SARS-Cov-2-Infektion. Noch aus dem Krankenhaus gab er Korrekturanweisungen für Manuskripte, obwohl er bereits mit dem Tode kämpfte. Wer war diese außergewöhnliche Persönlichkeit?
Article
Full-text available
Chemical communication plays a fundamental role in many aspects of an animal's life from assessing habitat quality to finding mating partners. Behavioural observations show that chemical communication likewise plays an important role in spiders, but the contexts and the substances involved are little explored. Here, we investigate the chemical comm...
Article
Am 27. Dezember 2020 starb Wittko Francke, Professor für Organische Chemie. Sein zentrales Forschungsgebiet war die chemische Ökologie.
Article
Full-text available
The butterfly Heliconius erato occurs in various mimetic morphs. The male clasper scent gland releases an anti‐aphrodisiac pheromone and additionally contains a complex mixture of up to 350 components, varying between individuals. In 114 samples of five different mimicry groups and their hybrids 750 different compounds were detected by gas chromato...
Preprint
Full-text available
Emerging evidence shows that the cuticular and silk lipids of spiders are structurally more diverse than those of insects, although only a relatively low number of species have been investigated so far. As in insects, such lipids might play a role as signals in various context. The wasp spider Argiope bruennichi has probably the best investigated c...
Article
P. inhibens 2.10 is an effective biofilm former on marine surfaces and has the ability to outcompete other microorganisms, possibly due to the production of the plasmid-encoded, secondary metabolite tropodithietic acid (TDA). P. inhibens 2.10 biofilms produce phenotypic variants with reduced competitiveness compared to the wild-type. In the present...
Article
Full-text available
Secondary metabolites are key components in microbial ecology by mediating interactions between bacteria and their environment, neighboring species or host organisms. Bioactivities can be beneficial for both interaction partners or provide a competitive advantage only for the producer. Colonizers of confined habitats such as biofilms are known as p...
Article
Full-text available
In eusocial insects, chemical communication is crucial for mediating many aspects of social activities, especially the regulation of reproduction. Though queen signals are known to decrease ovarian activation of workers in highly eusocial species, little is known about their evolution. In contrast, some primitively eusocial species are thought to c...
Article
Full-text available
The esteemed member of the German Society for General and Applied Entomology (DGaaE), Prof. Dr. Dr. h. c. mult. Wittko Francke, died unexpectedly on 27 December 2020 in Hamburg at the age of 80 from a SARS-Cov-2 infection. Even from the hospital, he gave corrective instructions for manuscripts, although he was already struggling with death. Who was...
Article
Bacteria have evolved a diverse array of signaling pathways that enable them to quickly respond to environmental changes. Understanding how these pathways reflect environmental conditions and produce an orchestrated response is an ongoing challenge. Herein, we present a role for collective modifications of environmental pH carried out by microbial...
Article
The uncommon jasmone derivatives dehydrojasmone, isojasmol, and isojasmyl acetate, floral scent compounds from night-blooming Araceae, were synthesized in a scalable synthesis employing conjugate addition with a selenoacetal as the key step. The stereoselective strategy with subsequent enzymatic kinetic resolution allowed determining the absolute c...
Article
For a long time, frogs were believed to communicate primarily via the acoustic channel, but during the last decades it became obvious that various lineages also use chemical communication. In this Account we present our research on the identification of volatile lactones from Madagascan Mantellidae and African Hyperoliidae frogs. Both possess male...
Article
Microorganisms produce and excrete a versatile array of metabolites with different physico-chemical properties and biological activities. However, the ability of microorganisms to release volatile compounds has only attracted research attention in the past decade. Recent research has revealed that microbial volatiles are chemically very diverse and...
Article
Full-text available
Plants and insects often use the same compounds for chemical communication, but not much is known about the genetics of convergent evolution of chemical signals. The terpene ( E )-β-ocimene is a common component of floral scent and is also used by the butterfly Heliconius melpomene as an anti-aphrodisiac pheromone. While the biosynthesis of terpene...
Article
Full-text available
Male ithomiine butterflies (Nymphalidae: Danainae) have hairpencils on the forewings (i.e., androconia) that disseminate semio-chemicals during courtship. While most ithomiines are known to contain derivatives of pyrrolizidine alkaloids, dihydropyrrolizines, or γ-lactones in these androconia, here we report on a new class of fatty acid esters ident...
Article
Full-text available
The genus Pseudooceanicola from the alphaproteobacterial Roseobacter group currently includes ten validated species. We herein describe strain Lw-13eT, the first Pseudooceanicola species from marine macroalgae, isolated from the brown alga Fucus spiralis abundant at European and North American coasts. Physiological and pangenome analyses of Lw-13eT...
Article
Full-text available
Much of our knowledge regarding the role of chemicals in species recognition in arthropods is based on a few taxonomic groups, predominantly insect pest species. To investigate the chemical underpinnings of species recognition cues in other arthropods, we conducted mate choice experiments and analyzed the chemical profiles of two species in the lon...
Article
Full-text available
The degree to which loci promoting reproductive isolation cluster in the genome—that is, the genetic architecture of reproductive isolation—can influence the tempo and mode of speciation. Tight linkage between these loci can facilitate speciation in the face of gene flow. Pheromones play a role in reproductive isolation in many Lepidoptera species,...
Article
Full-text available
Odorant-dependent behaviors in insects are triggered by the binding of odorant ligands to the variable subunits of heteromeric olfactory receptors. Previous studies have shown, however, that specific odor binding to ORco, the common subunit of odorant receptor heteromers, may allosterically alter olfactory receptor function and profoundly affect su...
Article
Cell-cell fusion is crucial for the development and propagation of most eukaryotic organisms. Despite this importance, the molecular mechanisms mediating this process are only poorly understood in any biological system. In particular, the step of plasma membrane merger and the contributing proteins and physicochemical factors remain mostly unknown....
Chapter
Bacterial volatile organic compounds (VOCs) represent a structurally very broad mixture of compounds, likely not less diverse than plant or animal volatiles. Within this diversity individual compounds might be commonly found in many, often unrelated strains, while others are restricted to a certain group of strains. In addition, strain specific com...
Preprint
Full-text available
Male ithomiine butterflies (Nymphalidae: Danainae) have hairpencils on the forewings (i.e. androconia) that disseminate semiochemicals during courtship. While most ithomiines are known to contain derivatives of pyrrolizidine alkaloids, dihydropyrrolizines or g-lactones in these androconia, here we report on a new class of fatty acid esters identifi...
Article
The marine alphaproteobacterium Phaeobacter inhibens DSM 17395, a member of the Roseobacter group, was recently shown to markedly enhance growth upon deletion of its 262-kb chromid encoding biosynthesis of tropodithietic acid (TDA). To scrutinize the metabolic/regulatory adaptations that underlie enhanced growth of the Δ262 mutant, its transcriptom...
Article
The male produced sex pheromone of the stink bug Edessa meditabunda was previously identified as a mixture of the esters methyl 4,8,12-trimethylpentadecanoate (1) and methyl 4,8,12-trimethyltetradecanoate (2), produced in a ratio of 92:8, respectively. Bioassays showed that the synthetic major compound alone is sufficient to elicit a response from...
Preprint
Full-text available
The degree to which loci promoting reproductive isolation cluster in the genome - i.e. the genetic architecture of reproductive isolation - can influence the tempo and mode of speciation. Tight linkage between these loci can facilitate speciation in the face of gene flow. Pheromones play a role in reproductive isolation in many Lepidoptera species,...
Article
Covering: up to the end of 2019 The application of coupled gas chromatography/direct deposition Fourier transform infrared (GC/DD-FTIR) spectroscopy in the field of volatile natural product identification yields orthogonal information to GC/MS analysis about functional groups and C–C double bonds. This underused method facilitates structure elucida...
Article
Full-text available
Mouse lemurs are small, nocturnal, arboreal solitary foragers and are endemic primates of Madagascar. This lifestyle and their high predation risk can explain why mouse lemurs rely heavily on olfaction for intraspecific communication. As they often use urine for this purpose, we investigated dichloromethane extracts of the urine of two mouse lemur...
Article
Full-text available
Colour pattern is the main trait that drives mate recognition between Heliconius species that are phylogenetically close. However, when this cue is compromised such as in cases of mimetic, sympatric and closely related species, alternative mating signals must evolve to ensure reproductive isolation and species integrity. The closely related species...
Preprint
Full-text available
Odorant-dependent behaviors in insects are triggered by the binding of odorant ligands to the variable subunits of heteromeric olfactory receptors. Previous studies have shown, however, that specific odor binding to ORco, the common subunit of odorant receptor heteromers, may alter allosterically olfactory receptor function and affect profoundly su...
Article
Males of the parasitoid wasp Urolepis rufipes use 2,6-dimethyl-7-octene-1,6-diol as a sex pheromone to attract virgin females. Herein, we determine the absolute configuration of the pheromone to be (2S,6S)-2,6-dimethyl-7-octene-1,6-diol (2S,6S-6)...
Article
Brassicadiene, a novel tricyclic diterpene hydrocarbon, was identified by a combination of mass spectrometry, mi-crochemical tests, and analysis of NMR spectra. The compound constitutes >90% of the volatile organic compounds (VOCs) produced by cauliflower seedlings, Brassica oleracea var. botrytis. The invasive stink bug Bagrada hilaris is strongly...
Article
Full-text available
In many animals, mate choice is important for the maintenance of reproductive isolation between species. Traits important for mate choice and behavioral isolation are predicted to be under strong stabilizing selection within species; however, such traits can also exhibit variation at the population level driven by neutral and adaptive evolutionary...
Article
Full-text available
The plantation area of sea buckthorn (Hippophae rhamnoides L.) is expanding in many European countries due to increasing demand for berries, thus creating suitable conditions for the rapid expansion of the fruit fly Rhagoletis batava, a pest of economic importance. To decrease insecticide use, effective means for pest population monitoring are requ...
Article
Sigillins are highly chlorinated natural products from the springtail Ceratophysella sigillata (Collembola) that are used to deter arthropod predators. We report here the isolation and structure elucidation of sigillin F, a hydrogenated benzopyranone compound bearing two trichloromethyl groups, and the synthesis of trideoxysigillin (8), a non-natur...
Article
Full-text available
Five new members of the salinilactone family, salinilactones D‐H, are reported. These bicyclic lactones are produced by Salinispora bacteria and display extended or shortened alkyl side chains compared to the recently reported salinilactones A‐C. They were identified by GC/MS, gas chromatographic retention index and comparison with synthetic sample...
Article
Full-text available
Understanding the production, response, and genetics of signals used in mate choice can inform our understanding of the evolution of both intraspecific mate choice and reproductive isolation. Sex pheromones are important for courtship and mate choice in many insects, but we know relatively little of their role in butterflies. The butterfly Heliconi...
Article
Full-text available
Floral scents are important pollinator attractants, but there is limited knowledge about the importance of single components in plant–pollinator interactions. This especially is true in crop pollination systems. The aim of this study is to identify floral volatiles of several European pear cultivars (Pyrus communis L.), and to determine their poten...
Preprint
Full-text available
Colour pattern has been long recognised as the trait that drives mate recognition between Heliconius species that are phylogenetically close. However, when this cue is compromised such as in cases of mimetic, sympatric and closely related species, alternative mating signals must evolve to ensure reproductive isolation and species integrity. The clo...
Article
Full-text available
The bacterial communities colonizing amphibian skin have been intensively studied due to their interactions with pathogenic chytrid fungi that are causing drastic amphibian population declines. Bacteria of the family Alcaligenaceae, and more specifically of the genus Pigmentiphaga, have been found to be associated specifically to arboreal frogs. He...
Preprint
Full-text available
Terpenes, a group of structurally diverse compounds, are the biggest class of secondary metabolites. While the biosynthesis of terpenes by enzymes known as terpene synthases (TPSs) has been described in plants and microorganisms, few TPSs have been identified in insects, despite the presence of terpenes in multiple insect species. Indeed, in many i...
Article
Full-text available
In the anuran family Dendrobatidae, aposematic species obtain their toxic or unpalatable alkaloids from dietary sources, a process known as sequestering. To understand how toxicity evolved in this family, it is paramount to elucidate the pathways of alkaloid processing (absorption, metabolism, and sequestering). Here, we used an exploratory skin ge...
Article
Full-text available
Ithomiine butterflies use pyrrolizidine alkaloids (PAs) as precursors for male pheromones, such as dihydropyrrolizines or lactones. In contrast to most other ithomiine genera, none of these compounds have ever been detected in Oleria species. The absence of these compounds is thought to be the result of limited access to PA-containing plants. Here...
Preprint
Full-text available
Pheromones are important for courtship and mate choice in many insects, but we know relatively little of their role in butterflies. The butterfly Heliconius melpomene uses a complex blend of wing androconial compounds during courtship. Electroantennography in H. melpomene and its close relative H. cydno showed that responses to androconial extracts...
Article
Full-text available
The plant genus Ficus is a keystone resource in tropical ecoystems. One of the unique features of figs is the diversity of fruit traits, which in many cases match their various dispersers, the so-called fruit syndromes. The classic example of this is the strong phenotypic differences found between figs with bat and bird dispersers (color, size, pre...
Article
Full-text available
Identifying the traits causing reproductive isolation and the order in which they evolve is fundamental to understanding speciation. Here, we quantify prezygotic and intrinsic postzygotic isolation between allopatric, parapatric and sympatric populations of the butterflies Heliconius elevatus and Heliconius pardalinus. Sympatric populations from th...
Article
Full-text available
In specialized pollination systems, floral scents are crucial for flower–pollinator communication, but key volatiles that attract pollinators are unknown for most systems. Deceptive Ceropegia trap flowers are famous for their elaborate mechanisms to trap flies. Recent studies revealed species-specific floral chemistry suggesting highly specialized...
Article
Full-text available
Fire salamanders ( Salamandra salamandra) are conspicuously colored amphibians secreting a skin poison that contains unique steroid alkaloids such as samandarine (1) and samadarone (2), exhibiting toxic as well as antimicrobial activities. Because of their antipredatory and anti-infectious functions, alkaloids from Salamandra poison are of interest...
Article
Parent-offspring relationships take many forms. One particular form of parental behavior is egg care when parents brood their eggs after laying them. Parents of many oviparous vertebrates and terrestrial arthropods brood their eggs. Spiders present a particular interesting form of parental behavior, enclosing their eggs in a silk sac (or egg-sac) a...
Article
Luteolide is a 10-membered aliphatic macrolactone, (4R,8S,9S)-4,8-dimethylundecan-9-olide ((-)-17), released by the femoral gland of males of the mantellid frog Gephyromantis luteus. Its structure was established using NMR, MS, and chiral GC and confirmed by stereoselective synthesis of different stereoisomers. Among the approximately 20 current ma...