Chemistry of pyrrocorphins: methylative opening of the macrocycle between rings A and D, a side reaction in the peripheral C-methylation of a 20-methyl-pyrrocorphinate

One of the minor products from the previously described peripheral -methylation of a magnesium()-20-methyl--pyrrocorphinate is a C-19-methylated 19,20-seco-corphinoid derivative which, on complexation with nickel() acetate, recyclizes to a nickel()-tetradehydro-corrinate.

Chemistry of pyrrocorphins: synthesis of isobacteriochlorins and pyrrocorphins bearing a methyl group at the meso position between rings A and D

A sigmatropic methyl shift from the angular position C-1 in ring to the position C-20 between rings and constitutes the crucial step in syntheses leading to a 20-methyl-isobacteriochlorin and to 20-methyl-pyrrocorphins which served as substrates in the investigation presented in the accompanying communication.

Role of Methyl Salicylate on Oviposition Deterrence in Arabidopsis thaliana

Plants attacked by herbivores have evolved different strategies that fend off their enemies. Insect eggs deposited on leaves have been shown to inhibit further oviposition through visual or chemical cues. In some plant species, the volatile methyl salicylate (MeSA) repels gravid insects but whether it plays the same role in the model species Arabidopsis thaliana is currently unknown. Here we showed that Pieris brassicae butterflies laid fewer eggs on Arabidopsis plants that were next to a MeSA dispenser or on plants with constitutively high MeSA emission than on control plants. Surprisingly, the MeSA biosynthesis mutant bsmt1-1 treated with egg extract was still repellent to butterflies when compared to untreated bsmt1-1. Moreover, the expression of BSMT1 was not enhanced by egg extract treatment but was induced by herbivory. Altogether, these results provide evidence that the deterring activity of eggs on gravid butterflies is independent of MeSA emission in Arabidopsis, and that MeSA might rather serve as a deterrent in plants challenged by feeding larvae.

Multiple programmed cell death pathways are involved in N-methyl-N-nitrosourea-induced photoreceptor degeneration.

PURPOSE: To identify programmed cell death (PCD) pathways involved in N-methyl-N-nitrosourea (MNU)-induced photoreceptor (PR) degeneration. METHODS: Adult C57BL/6 mice received a single MNU i.p. injection (60 mg/kg bodyweight), and were observed over a period of 7 days. Degeneration was visualized by H&E overview staining and electron microscopy. PR cell death was measured by quantifying TUNEL-positive cells in the outer nuclear layer (ONL). Activity measurements of key PCD enzymes (calpain, caspases) were used to identify the involved cell death pathways. Furthermore, the expression level of C/EBP homologous protein (CHOP) and glucose-regulated protein 78 (GRP78), key players in endoplasmic reticulum (ER) stress-induced apoptosis, was analyzed using quantitative real-time PCR. RESULTS: A decrease in ONL thickness and the appearance of apoptotic PR nuclei could be detected beginning 3 days post-injection (PI). This was accompanied by an increase of TUNEL-positive cells. Significant upregulation of activated caspases (3, 9, 12) was found at different time periods after MNU injection. Additionally, several other players of nonconventional PCD pathways were also upregulated. Consequently, calpain activity increased in the ONL, with a maximum on day 7 PI and an upregulation of CHOP and GRP78 expression beginning on day 1 PI was found. CONCLUSIONS: The data indicate that regular apoptosis is the major cause of MNU-induced PR cell death. However, alternative PCD pathways, including ER stress and calpain activation, are also involved. Knowledge about the mechanisms involved in this mouse model of PR degeneration could facilitate the design of putative combinatory therapeutic approaches.

Total Synthesis of Aignopsanes, A Class of Sesquiterpenes: (+)-Aignopsanoic Acid A, (−)-Methyl Aignopsanoate A, and (−)-Isoaignopsanoic A

A general strategy for the synthesis of aignopsanes, a new family of sesquiterpene natural products of marine origin, is presented. The total synthesis of (+)-aignopsanoic acid A (1), (−)-methyl aignopsanoate A (2), and (−)-isoaignopsanoic A (3) has been achieved and their absolute configuration confirmed. (+)-Microcionin-1 (4), a structurally related furanosesquiterpene isolated in both enantiomeric forms from marine sponges, was also synthesized and its absolute configuration established in an unambiguous way. Interestingly, we report that (+)-microcionin-1 (4), can be converted by a simple oxidation process to aignopsanoic acid A (1). This transformation supports the hypothesis that (+)-microcionin-1 (4) may be an intermediate in the biosynthesis of aignopsanes.

Practical approach to the use of daylight photodynamic therapy with topical methyl aminolevulinate for actinic keratosis: a European consensus

INTRODUCTION Daylight-mediated photodynamic therapy has been shown to be an effective therapy for actinic keratoses (AKs) and a simple and tolerable treatment procedure in three randomized Scandinavian studies and two recent Phase III randomized controlled studies in Australia and Europe. OBJECTIVES To establish consensus recommendations for the use of daylight photodynamic therapy (DL-PDT) using topical methyl aminolaevulinate (MAL) in European patients with AKs. METHODS The DL-PDT consensus recommendations were developed on behalf of the European Society for Photodynamic Therapy in Dermatology and comprised of 10 dermatologists from different European countries with experience in how to treat AK patients with PDT. Consensus was developed based on literature review and experience of the experts in the treatment of AK using DL-PDT. RESULTS The recommendations arising from this panel of experts provide general guidance on the use of DL-PDT as a dermatological procedure with specific guidance regarding patient selection, therapeutic indications, when to treat, pre-treatment skin preparation, MAL application and daylight exposure for patients with AK in different countries of Europe. CONCLUSIONS This consensus recommendation provides a framework for physicians to perform DL-PDT with MAL cream while ensuring efficiency and safety in the treatment of patients with AK in different European countries.