Changes of volatile organic compounds and bioactivity of Alternaria brassicae GL07 in different ages

Plant endophytes are rich in secondary metabolites and are widely used in medicine, chemical, food, agriculture, and other fields. Here, an endophytic fungus is isolated from Ginkgo biloba L. leaves and identified as Alternaria brassicae GL07 through genotypic characterizations. It can produce fruity scented volatiles. The analysis of volatile organic compounds (VOCs) was done by gas chromatography–mass spectrometry. A total of 32 components were identified; and at different culture times, the composition of VOCs was different. It had more components in the first two weeks, but a fewer components on the 21st day. More olefins, ketone, aldehyde, and alcohol were found in the growth period and more amines and esters were found in the decline period. Also, 2,5‐dihydroxyacetophenone, β‐ionone, and nonanal were found. They were the same ingredients in Ginkgo essential oils and some of them were isolated for the first time in the volatile constituents of endophytes. The antioxidant activity and whitening activities of all extracts were also evaluated. When cultured for 10 days, it had the strongest 2,2‐diphenyl‐2‐picrylhydrazyl radical (IC₅₀, 0.56 g/L), hydroxyl radical scavenging ability (IC₅₀, 0.47 g/L), reducing ability, and tyrosinase inhibition ability (IC₅₀, 5.18 g/L), which may be due to a large amount of ketones and alcohols produced during the log phase. This demonstrates the potential of A. brassicae GL07 to produce bioactive compounds and to be used for perfume and cosmetic industries.     

柳珊瑚共附生真菌Alternaria sp.(WZL003)抑菌化合物的分离及其作用机制初步研究D

目的研究1株柳珊瑚共附生真菌具有抑菌活性次级代谢产物及抑菌作用机制。方法采用活性追踪分离的方法,运用硅胶柱层析、Sephadex LH-20凝胶柱层析和半制备HPLC等手段,对采自中国南海的柳珊瑚Echinogorgia rebekka中分离获得的共附生链格孢霉属真菌Alternaria sp.(WZL003)的发酵产物进行分离和纯化,利用NMR、MS等波谱方法,并与文献对照,确定化合物的结构;以海洋病原菌和污损菌鳗弧菌Vibrio anguillarum为对象研究化合物的抑菌作用机制。结果从该菌发酵液的乙酸乙酯提取物中,分离获得1个对V.anguillarum具有较强抑菌活性的蒽醌类化合物macrosporin。结论初步的抑菌作用机制研究发现,该化合物能破坏鳗弧菌的细胞壁和细胞膜,导致细胞通透性增加,胞内大量内容物外泄,最终导致菌体死亡,从而起到抑菌作用。本研究首次报道了macrosporin对鳗弧菌的抑菌作用及其作用机制。     

Microbial transformation of asiatic acid by Alternaria longipes

Asiatic acid is a major pentacyclic triterpene isolated from Centella asiatica. It shows a variety of bioactivities. In order to obtain its derivatives, potentially useful for detailed pharmacological studies, the substrate was subjected to incubations with selected micro-organisms. In this work, asiatic acid was converted into three new compounds: 2α,3β,23,30-tetrahydroxyurs-12-ene-28-oic acid (1), 2α,3β,22β,23-tetrahydroxyurs-12-ene-28-oic acid (2), and 2α,3β,22β,23,30-pentahydroxyurs-12-ene-28-oic acid (3) by the fungus Alternaria longipes AS 3.2875. The structures of the three metabolites were determined by 1D and 2D NMR spectral data.     

Intricate isavuconazole therapy of a subcutaneous nodule caused by Alternaria infectoria in a heart transplant recipient

Invasive fungal infections have appeared to be increasingly emergent in immunocompromised patients, especially in solid organ transplant (SOT) recipients. The Alternaria genus encompasses more than 80 dematiaceus species. Among them, Alternaria alternata and Alternaria infectoria are the most frequent isolated as responsible for infection in humans.To our knowledge, we report the first case of a heart transplant recipient suffering from subcutaneous nodule caused by Alternaria infectoria and who was treated with isavuconazole. Despite all the promises of this new azole drug, one should keep in mind the potential great variability of the inter-individual responses for such complex patients. We demonstrate herein how it can be challenging to manage Alternaria infection in SOT recipients. More comprehensive studies and recommendations are expected in the context of Alternaria infections.     

Effects of γ-radiation on the fungus Alternaria alternata in artificially inoculated cereal samples

The objective of this study was to evaluate the effects of different γ-radiation doses on the growth of Alternaria alternata in artificially inoculated cereal samples. Seeds and grains were divided into four groups: Control Group (not irradiated), and Groups 1, 2 and 3, inoculated with an A. alternata spore suspension (1×10⁶ spores/mL) and exposed to 2, 5 and 10 kGy, respectively. Serial dilutions of the samples were prepared and seeded on DRBC (dichloran rose bengal chloramphenicol agar) and DCMA (dichloran chloramphenicol malt extract agar) media, after which the number of colony-forming units per gram was determined in each group. In addition, fungal morphology after irradiation was analyzed by scanning electron microscopy (SEM). The results showed that ionizing radiation at a dose of 5 kGy was effective in reducing the growth of A. alternata. However, a dose of 10 kGy was necessary to inhibit fungal growth completely. SEM made it possible to visualize structural alterations induced by the different γ-radiation doses used.     

Cutaneous infection by Alternaria infectoria in a renal transplant patient

Abstract: Skin lesions are common in renal transplant recipients (RTR) and the clinical distinction of malignancy versus infection may be difficult in this patient population, with the need for further histological and biological investigations. We report here on a 73-year-old male RTR who presented with Alternaria infectoria phaeohyphomycosis of 1 year's duration. Mycological cultures were negative, and the diagnosis was performed by real-time polymerase chain reaction assay and direct sequencing. The extension of the lesion under itraconazole treatment required its surgical excision. Alternaria are ubiquitous plant-inhabiting saprobes, which are increasingly associated with opportunistic phaeohyphomycosis in immunocompromised individuals.     

河南省食管癌高低发区粮食中互隔交链孢霉毒素的化学检测

互隔交错孢霉毒素从随机采集于食管癌高低发区粮食样品中被提取后,用化学方法纯化,再经薄层层析(TLC)检测。结果显示:高低发区粮食中毒素的阳性率有显著差异,提示高发区互隔交链孢霉毒素在粮食中的广泛存在与食管癌的发生有密切关系。     

Case Report. Cutaneous phaeohyphomycosis due to Alternaria alternata

Zusammenfassung.   Wir beschreiben eine isolierte, umschriebene Läsion einer kutanen Alternariose, die bei einer nierentransplantierten Patientin aufgetreten war. Die Histopathologie ähnelte zunächst der einer kutanen Cryptococcose, aber Alternaria alternata konnte mittels morphologischer und molekularbiologischer Methoden identifziert werden. Die chirurgische Entfernung, begleitet von einer prophylaktischen Itraconazolgabe (200 mg day⁻¹ für 4 Wochen), führte zu einer vollständigen Heilung.     

Sporotrichoid phaeohyphomycosis due to Alternaria infectoria

We describe a cardiac transplant patient who had human cutaneous alternariosis with a sporotrichoid distribution of skin lesions. In this patient identification of the causative organism Alternaria infectoria was achieved by sequencing the rDNA internal transcribed spacer domain. Treatment with itraconazole led to clinical resolution within 4 months.