Bioactive icetexane and abietane diterpenes from Isodon phyllopodus.

A new icetexane diterpenoid, 11, 12, 20α-trihydroxyl-7ß-methoxyicetexa-8, 11, 13-triene-19, 10-lactone [Phyllane A (1)], and a new abietane diterpenoid, 7ß, 20-epoxy-3ß, 17-acetoxy-abieta-8, 11, 13-teriene-11, 12-diol [phyllane B (2)], along with two known compounds (3 and 4) were isolated from the methanol (MeOH) extract of twigs and leaves of the folk medicinal Isodon phyllopodus. Their structures were determined by spectroscopic analyses including 2 D NMR spectral data, and further confirmed by X-ray single crystal diffraction. Moreover, the compounds were evaluated for their cytotoxicity and anti-HIV activities, and phyllane A showed anti-HIV activity with an IC50 value of 15.7 µM, but phyllane B was found to be cytotoxic to the A549 host cells with a CC50 value of 108.5 µM.

Design, Synthesis and Biological Evaluation of Lophanic Acid Derivatives as Antifungal and Antibacterial Agents.

In order to discover more promising antifungal and antibacterial agents, a series of new derivatives were designed and synthesized by structure modification based on the naturally occurring antimicrobial compound lophanic acid. The structures of all the target compounds were well characterized by spectroscopic data. The stereochemistry of these compounds was further determined through the X-ray diffraction analysis of 6a. The synthetic compounds were evaluated for their antimicrobial activities against filamentous fungi (T. rubrum, T. mentagrophytes), yeasts (C. neoformans, C. albicans) and Gram-positive and Gram-negative bacteria (MRSA, S. mutans, S. sobrinus, and E. coli). Among them, 3d and 3i are found as the most promising leads that showed potent inhibitory effects against all the tested fungal and bacterial strains except for E. coli. The presence of the C-20 carboxylic ester groups and the free hydroxy group at C-13 was found to be essential for the antifungal and antibacterial activities of the lophanic acid derivatives.

The Complete Mitochondrial Genome of Lepidotrigona flavibasis (Hymenoptera: Meliponini) and High Gene Rearrangement in Lepidotrigona Mitogenomes.

We reported the sequence and characteristics of the complete mitochondrial genome of an ecologically important stingless bee, Lepidotrigona flavibasis (Hymenoptera: Meliponini), that has suffered serious population declines in recent years. A phylogenetic analysis based on complete mitogenomes indicated that L. flavibasis was first clustered with another Lepidotrigona species (L. terminata) and then joined with the other two Melipona (Hymenoptera: Meliponini) stingless bees (M. scutellaris and M. bicolor), forming a single clade of stingless bees. The stingless bee clade has a closer relationship with bumblebees (Bombus) (Hymenoptera: Apidae) than with honeybees (Apis) (Hymenoptera: Apidae). Extremely high gene rearrangements involving tRNAs, rRNAs, D-loop regions, and protein-coding genes were observed in the Lepidotrigona mitogenomes, suggesting an overactive evolutionary status in Lepidotrigona species. These mitogenomic organization variations could provide a good system with which to understand the evolutionary history of Meliponini.

Chronic toxicity and biochemical response of Apis cerana cerana (Hymenoptera: Apidae) exposed to acetamiprid and propiconazole alone or combined.

Acetamiprid and ergosterol-inhibiting fungicide (EBI) are frequently applied to many flowering plants, while honey bees are pollinating agents or pollinators of the flowers. Hence honey bees are often exposed to these pesticides. But until now, the effects of theses combinations at field-realistic doses on honey bee health have been poorly investigated. In this study, we explore the synergistic mortality and some physiological effects in surviving honey bees after chronic oral exposure to acetamiprid and/or propiconazole in the laboratory. The results indicated that chronic combined exposure to acetamiprid and propiconazole produced a significant synergistic effect on mortality both for newly emerged bees (50% mortality in 7.2 days) and forager bees (50% mortality in 4.8 days). Honey bee weight of newly emerged bees was decreased after feeding food with a field concentration of acetamiprid and propiconazole, alone or combined for 10 days. Combination of acetamiprid and propiconazole also modulated the activities of P450s, GST and CAT in newly emerged bees and forager bees than either alone, but neither pesticide affected the activity of AChE. These results show that chronic combined exposure to pesticides of relatively low toxicity may caused severely physiological disruptions that could be potentially damaging for the honey bees.

Culicoides Latreille biting midges (Diptera: Ceratopogonidae) of the Dongzhaigang mangrove forest, Hainan Province, China.

The biting midge fauna of Dongzhaigang Mangrove Forest, Hainan Province, China was sampled on 14 October 2015 using three methods: a pan light trap operated from dusk until dawn the following morning and sweep net and human landing collections performed between 16:15-17:15 hr. Eight species, including two new records for China, Culicoides palawanensis and C. niphanae, and one new record for Hainan, C. circumbasalis, were collected. A key to assist with identification of specimens of these species is provided. DNA barcodes supported the morphological identification of some of these species and identified the potential presence of cryptic species and/or deep population structure in others. The newly recorded species were morphologically similar to species previously reported from Hainan, highlighting the need for further investigation into the taxonomy of biting midges in this region. Species composition and abundance varied considerably between the three collection techniques suggesting that multiple techniques likely provide a more comprehensive sample of biting midge fauna.