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A marine bacterium, designated SCSIO 03483T, was isolated from a marine sediment sample collected from the Nansha Islands in the South China Sea. The strain produced roundish colonies with diffusible yellow-coloured pigment on nutrient agar medium or marine agar 2216. Optimal growth occurred in the presence of 0–4 % (w/v) NaCl, at pH 7.0 and a temperature range of 28–37 °C. 16S rRNA gene sequence analysis indicated that the isolate belonged to the family Flavobacteriaceae and showed relatively high sequence similarity with Imtechella halotolerans K1T (92.7 %). Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that the isolate shared a lineage with members of the genera Imtechella , Joostella and Zhouia . Phospholipids were phosphatidylethanolamine, two unidentified aminolipids and three unknown polar lipids. The major respiratory quinone was MK-6 and the major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω6c/C16 : 1ω7c). The DNA G+C content of strain SCSIO 03483T was 38.4 mol%. On the basis of phenotypic, chemotaxonomic and molecular data, strain SCSIO 03483T represents a novel species in a new genus in the family Flavobacteriaceae , for which the name Sinomicrobium oceani gen. nov., sp. nov. is proposed. The type strain of Sinobacterium oceani is SCSIO 03483T ( = KCTC 23994T = CGMCC 1.12145T).

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Abstract. We analyzed seasonality and interannual variability of tropospheric hydrogen cyanide (HCN) columns in densely populated eastern China for the first time. The results were derived from solar absorption spectra recorded with a ground-based high-spectral-resolution Fourier transform infrared (FTIR) spectrometer in Hefei (31∘54′ N, 117∘10′ E) between 2015 and 2018. The tropospheric HCN columns over Hefei, China, showed significant seasonal variations with three monthly mean peaks throughout the year. The magnitude of the tropospheric HCN column peaked in May, September, and December. The tropospheric HCN column reached a maximum monthly mean of (9.8±0.78)×1015 molecules cm−2 in May and a minimum monthly mean of (7.16±0.75)×1015 molecules cm−2 in November. In most cases, the tropospheric HCN columns in Hefei (32∘ N) are higher than the FTIR observations in Ny-Ålesund (79∘ N), Kiruna (68∘ N), Bremen (53∘ N), Jungfraujoch (47∘ N), Toronto (44∘ N), Rikubetsu (43∘ N), Izana (28∘ N), Mauna Loa (20∘ N), La Reunion Maido (21∘ S), Lauder (45∘ S), and Arrival Heights (78∘ S) that are affiliated with the Network for Detection of Atmospheric Composition Change (NDACC). Enhancements of tropospheric HCN column were observed between September 2015 and July 2016 compared to the same period of measurements in other years. The magnitude of the enhancement ranges from 5 % to 46 % with an average of 22 %. Enhancement of tropospheric HCN (ΔHCN) is correlated with the concurrent enhancement of tropospheric CO (ΔCO), indicating that enhancements of tropospheric CO and HCN were due to the same sources. The GEOS-Chem tagged CO simulation, the global fire maps, and the potential source contribution function (PSCF) values calculated using back trajectories revealed that the seasonal maxima in May are largely due to the influence of biomass burning in Southeast Asia (SEAS) (41±13.1 %), Europe and boreal Asia (EUBA) (21±9.3 %), and Africa (AF) (22±4.7 %). The seasonal maxima in September are largely due to the influence of biomass burnings in EUBA (38±11.3 %), AF (26±6.7 %), SEAS (14±3.3 %), and North America (NA) (13.8±8.4 %). For the seasonal maxima in December, dominant contributions are from AF (36±7.1 %), EUBA (21±5.2 %), and NA (18.7±5.2 %). The tropospheric HCN enhancement between September 2015 and July 2016 at Hefei (32∘ N) was attributed to an elevated influence of biomass burnings in SEAS, EUBA, and Oceania (OCE) in this period. In particular, an elevated number of fires in OCE in the second half of 2015 dominated the tropospheric HCN enhancement between September and December 2015. An elevated number of fires in SEAS in the first half of 2016 dominated the tropospheric HCN enhancement between January and July 2016.

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Micromelum falcatum (LOUR.) TAN. (Rutaceae), traditionally used as Chinese folk medicine for curing infected wounds, odynolysis, and rheumatism, is widely distributed in Southeast Asia. The chemical constituents of M. falcatum had been previously investigated, and several coumarins, dihydrocinnamic acid derivatives, and two alkaloids 5,6-pyranoglycozoline and yuehchukene were obtained.1,2) The dimeric indole alkaloid yuehchukene was found to have potent anti-implantation activity.3) After further chemical investigation on the stem bark of M. falcatum, we report here the isolation of two new quinoldione alkaloids, methyl 2-(3-hydroxy-1-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinolin-3-yl)acetate (1) and 3-hydroxy-1-methyl-3-(2-oxopropyl)-quinoline-2,4(1H,3H)-dione (2), two quinolinone alkaloids previously synthesized but first isolated as natural products, N-methylflindersine (3) 4,5) and 4-hydroxy-3-methoxy-1-methyl-2(1H)-quinolinone (4), 6) and the known N-methylswietenidine-B (5).7) All isolates were tested for toxicity towards brine shrimp larvae.

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