Electroantennographic and Behavioral Responses of the Melon fly, Zeugodacus cucurbitae (Coquillett), to Volatile Compounds of Ridge Gourd, Luffa acutangular L.

The melon fly, Zeugodacus cucurbitae (Coquillett), is a major invasive pest, widely distributed in the Asia-Pacific region and some parts of Africa. Melon fly attractants could improve the effectiveness of current pest management measures. Previous studies have shown that some host fruits are attractive to melon flies but few have investigated the chemical compounds responsible for their attraction. In this study, we aimed to identify the volatile compounds from Luffa acutangula L that attract Z. cucurbitae. In headspace trapping, chemical profiling identified 19 compounds from ridge gourds, with 1-pentadecene being the major component. EAG results revealed that seven compounds elicited antennal responses in Z. cucurbitae, and significant differences in antennal responses between male and female Z. cucurbitae adults were recorded to p-xylene, alpha-pinene, and 1-octadecene. Behavioral experiments demonstrated that the EAG-active compounds methyl isovalerate and methyl myristate had either attractive or repellent effects on Z. cucurbitae at different concentrations, and 1-octadecene attracted Z. cucurbitae. Our findings provide a theoretical basis producing repellents or attractants for effective Integrated Pest Management of Z. cucurbitae.

HMGB1-induced autophagy: a new pathway to maintain Treg function during chronic hepatitis B virus infection.

High-mobility group box-1 (HMGB1) protein, as one of the well-known damage-associated molecular pattern molecules (DAMPs), is enriched in chronic hepatitis B virus (HBV) infection and has a context-dependent role in autophagy, a highly conserved self-digestive process in response to environmental stress. Recent mouse studies indicate that autophagy is highly active in regulatory T (Treg)-cells. In the present study, we evaluated spontaneous and induced autophagy of peripheral Treg cells from 98 patients with chronic hepatitis B (CHB), by measuring levels of lipidated form of microtubule-associated light chain 3 (LC3-II, marker for closed autophagosomes) and observing autophagic vacuoles (AV) with transmission electron microscope. No significant difference was found in spontaneous autophagy of either Treg or CD4+ naive cells when comparing CHB patients with healthy subjects, apart from CHB-Treg showed significantly higher autophagic activity after activation by anti-CD3-CD28 beads. Besides, incubation of CHB-Treg cells with CHB-serum greatly maintained their autophagic behaviour, which could be significantly diminished by blocking HMGB1 with the neutralizing antibody. Further, we characterized time- and dose-dependent effects by recombinant HMGB1 protein on autophagy of CHB-Treg cells. We also documented a significant up-regulation of HMGB1 and its receptors [toll-like receptor (TLR4), receptor for advanced glycation end-product (RAGE)] in both peripheral and intra-hepatic microenvironments of CHB patients. Moreover, the RAGE-extracellular regulated protein kinases (ERK) axis and rapamycin-sensitive components of mammalian target of rapamycin (mTOR) pathways were demonstrated in vitro to be involved in HMGB1-induced autophagy of Treg cells. Additionally, HMGB1-induced autophagy could maintain cell survival and functional stability of CHB-Treg cells. Our findings could open new perspectives in developing therapeutic strategies to activate specific anti-HBV immunity by diminishing Treg autophagy.

Colomitides A and B: novel ketals with an unusual 2,7-dioxabicyclo[3.2.1]octane ring system from the aquatic fungus YMF 1.01029.

Two novel diastereoisomeric bicyclic ketals, colomitides A and B (1 and 2, resp.), together with the known (4RS)-3,4-dihydro-4,8-dihydroxynaphthalen-1(2H)-one (3) and preussomerin E (4), were isolated from liquid cultures of an unidentified freshwater fungus YMF 1.01029. Colomitides possess an unusual 2,7-dioxabicyclo[3.2.1]octane skeleton. The chemical structures and relative configurations of compounds 1 and 2 were elucidated by spectroscopic means, including 2D-NMR (HMBC, HMQC, TOCSY, ROESY, and (1)H,(1)H-COSY). Compounds 1, 2, and 4 showed noticeable antifungal and antibacterial activities.

Two unusual naphthalene-containing compounds from a freshwater fungus YMF 1.01029.

Two novel naphthalene-containing compounds, colelomycerones A and B (1 and 2, resp.), and three known metabolites, including preussomerin D (3), (2RS,2'SR,3'E,3SR,4E,8E)-1-O-(beta-D-glucopyranosyl)-3-hydroxy-2-[(2-hydroxyoctadec-3-enoyl)amino]-9-methyloctadeca-4,8-diene (4), and 3beta-hydroxy-5alpha,8alpha-epidioxyergosta-6,22-diene (5), were isolated from the culture broth of an unidentified freshwater water fungus YMF 1.01029. This fungus was collected from a decaying branch of an unidentified tree near Lake Fuxian in Yunnan Province, China. The structures of these five compounds were determined on the basis of their spectroscopic and mass-spectrometric data. Colelomycerones A and B (1 and 2, resp.) represent unprecendented examples of naphthalene-1,2-diones with novel cyclic acetals. Compounds 1-3 showed noticeable antifungal and antibacterial activities.

Ymf 1029A-E, preussomerin analogues from the fresh-water-derived fungus YMF 1.01029.

Five new preussomerin analogues, ymf 1029A (1), B (2), C (3), D (4), and E (5), were isolated from the liquid cultures of an unidentified freshwater fungus YMF 1.01029, along with four known compounds, preussomerin C (6), preussomerin D (7), (4RS)-4,8-dihydroxy-3,4-dihydronaphthalen-1(2H)-one (8), and 4,6,8-trihydroxy-3,4-dihydronaphthalen-1(2H)-one (9). The structures of new metabolites were determined by analysis of NMR and MS data and by analogy with the data for the known bis-spirobisnaphthalene preussomerins. In vitro immersion experiments showed that these metabolites displayed weak nematicidal activity against Bursaphelenchus xylophilus, while compound 7 was the most potent. This is the first report of these compounds, which antagonize the Bursaphelenchus xylophilus nematode.

Hydroxylation of the triterpenoid nigranoic acid by the fungus Gliocladium roseum YMF1.00133.

The ability of the fungus Gliocladium roseum YMF1.00133 to transform the bioactive nigranoic acid (=(24Z)-9,19-cyclo-3,4-secolanosta-4(28),24-diene-3,26-dioic acid) was investigated. Three new products from the co-cultures of nigranoic acid and G. roseum YMF1.00133 were obtained by employing a combination of Sephadex LH-20 and silica-gel column chromatography. The major metabolite was identified as 15beta-hydroxynigranoic acid, and the minor metabolites as 6alpha,15beta-dihydroxynigranoic acid and 7beta,15beta-dihydroxynigranoic acid by mass spectrometry and NMR spectroscopy. This is the first report of the biotransformation of the A-ring-secocycloartene triterpenoid, nigranoic acid.