Functional Crosstalk between Discrete Indole Terpenoid Gene Clusters in Tolypocladium album

Indole terpenoids make up a large group of secondary metabolites that display an enticing array of bioactivities. While indole diterpene (IDT) and rarely indole sesquiterpene (IST) pathways have been found individually in filamentous fungi, here we show that both cluster types are encoded within the genome of Tolypocladium album. Through heterologous reconstruction, we demonstrate the SES cluster encodes for IST biosynthesis and can tailor IDT substrates produced by the TER cluster.

Generation of Alternate Indole Diterpene Architectures in Two Species of Aspergilli

The significant structural diversity and potent bioactivity of the fungal indole diterpenes (IDTs) has attracted considerable interest in their biosynthesis. Although substantial skeletal diversity is generated by the action of noncanonical terpene cyclases, comparatively little is known about these enzymes, particularly those involved in the generation of the subgroup containing emindole SA and DA, which show alternate terpenoid skeletons. Here, we describe the IDT biosynthetic machinery generating these unusual IDT architectures from Aspergillus striatus and Aspergillus desertorum. The function of four putative cyclases was interrogated via heterologous expression. Two specific cyclases were identified that catalyze the formation of epimers emindole SA and DA from A. striatus and A. desertorum, respectively. These cyclases are both clustered along with all the elements required for basic IDT biosynthesis yet catalyze an unusual Markovnikov-like cyclization cascade with alternate stereochemical control. Their identification reveals that these alternate architectures are not generated by mechanistically sloppy or promiscuous enzymes, but by cyclases capable of delivering precise regio- and stereospecificities.

Biosynthesis of Nodulisporic Acids: A Multifunctional Monooxygenase Delivers a Complex and Highly Branched Array

Nodulisporic acids (NAs) are structurally complex potent antiinsectan indole diterpenes. We previously reported the biosynthetic gene cluster for these metabolites in Hypoxylon pulicicidum and functionally characterised the first five steps of the biosynthetic pathway. Here we reveal a highly complex biosynthetic array, furnishing multiple end products through expression of cluster components in Penicillium paxilli. We show that seven additional cluster-encoded gene products comprise the biosynthetic machinery that elaborate precursor NAF in this highly branched pathway. The combined action of these enzymes delivers 37 NA congeners including four major end products, NAA, NAA₁ , NAA₂ and NAA₄ . The plethora of intermediates arises due to modification of the carboxylated prenyl tail by a single promiscuous P450 monooxygenase, NodJ, a pivotal branchpoint enzyme which produces four distinct biosynthetic products giving rise to the complex metabolic grid that characterises NA biosynthesis.

2-O-β-d-Glucopyranosyl l-Ascorbic Acid, a Stable Form of Vitamin C, Is Widespread in Crop Plants

2-O-β-d-Glucopyranosyl l-ascorbic acid (AA-2βG) is a stable, bioavailable vitamin C (AA) derivative. We report the distribution and seasonal variation of AA-2βG in apples and its occurrence in other domesticated crops and in wild harvested Ma̅ori foods. Liquid chromatography-mass spectrometry analyses showed high AA-2βG concentrations in crab apples (Malus sylvestris) but low concentrations in domesticated apples. Leaves of crab and domesticated apple cultivars contained similar intermediate AA-2βG concentrations. Fruits and leaves of other crops were analyzed: mainly Rosaceae but also Actinidiaceae and Ericaceae. AA-2βG was detected in all leaves (0.5-6.1 mg/100 g fr. wt.) but was at lower concentrations in most fruits (0.0-0.5 mg/100 g fr. wt.) except for crab apples (79.4 mg/100 g fr. wt.). Ma̅ori foods from Solanaceae, Piperaceae, Asteraceae, and a fern of Aspleniaceae also contained AA-2βG. This extensive occurrence suggests a general role in AA metabolism for AA-2βG.

Discovery of a stable vitamin C glycoside in crab apples (Malus sylvestris)

Non-targeted LC-MS metabolomics on fruit of three wild and domesticated apple species (Malus sylvestris, M. sieversii and M. domestica) showed that two crab apple (M. sylvestris) accessions were distinguished by high concentrations of an ascorbic acid glycoside (AAG). This was partly purified, but key NMR signals were masked by inseparable sucrose. Reference samples of 2-O-β-D-glucopyranosyl L-ascorbic acid and 2-O-β-D-galactopyranosyl L-ascorbic acid were synthesised, but both coincided with the crab apple AAG on LC-MS. Peracetylation of the crab apple extract allowed both purification and characterisation, and the AAG was proven to be 2-O-β-D-glucopyranosyl L-ascorbic acid by comparison of ¹H NMR, HRMS and HPLC data with synthesised peracetylated ascorbyl glycoside standards. The stability of the natural AA 2-β-glycoside was similar to synthetic 2-O-α-D-glucopyranosyl L-ascorbic acid, used widely in cosmetic and pharmaceutical products. This discovery in crab apples (Rosaceae) is only the fourth reported occurrence of any ascorbyl glycoside from plants, the others being from Cucurbitaceae, Solanaceae and Brassicaceae. It is hypothesised that AAGs may be more widespread in plants than currently realised.

Immunocytology of synovial fluid cells may be of diagnostic and prognostic value in arthritis

Cells of the synovial fluid (SF) have been examined by immunocytochemical methods. Samples were aspirated from four groups of patients with knee effusions: (a) seropositive inflammatory arthritis (n = 9); (b) seronegative inflammatory arthritis (n = 9); (c) osteoarthritic patients (n = 5); and (d) patients with traumatised knees (n = 4). The proportions of lymphocyte and macrophage subsets within the SF were determined with a panel of monoclonal antibodies. Patients with inflammatory arthritis had significantly larger proportions of activated T cells (RFT2+) and macrophages with the phenotype of interdigitating cells (RFD1+). No significant difference between groups could be found on differential count or when T4+/T8+ subset ratios were calculated. No significant difference in proportions of lymphocyte or macrophage subsets was found between the groups with seropositive and seronegative inflammatory arthritis. In two of three patients, where immunocytochemical analysis was performed before and after intra-articular steroids, reductions in the proportions of RFT2+ T cells and RFD1+ macrophage like cells were seen. It is suggested that such analysis may be of diagnostic or prognostic value.

Ulcerative vulvitis in Reiter's syndrome. A case report

In a case of acute Reiter's syndrome with severe vulvitis the diagnosis was based on the presence of a vaginal discharge and dysuria, arthritis, conjunctivitis, buccal ulceration, keratodermia blenorrhagica, and HLA B27 tissue-typing antigen. The vulval lesions were similar in appearance to those of circinate vulvitis. The acute histological change were confined to shallow ulceration with an inflammatory infiltration of the subjacent dermis. Coincidential lichen sclerosus et atrophicus was present, which could have been masked by the acute lesions.

Arthritic causes of chest pain

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