Bioaccumulation of pollutants in the green-lipped mussel Perna viridis: Assessing pollution abatement in Victoria Harbour and its adjacent aquaculture area, Hong Kong, and the minimal human health risks from mussel consumption.

The green-lipped mussel Perna viridis was utilised for pollution biomonitoring in Victoria Harbour and its adjacent aquaculture area in Hong Kong. P. viridis was collected from a reference site and redeployed at five study sites for five weeks during the dry and wet seasons of 2019. Our study found various polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the mussel tissue, while polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were not detected. P. viridis at the reference site generally displayed lower levels of pollutants. Comparing with previous research in the 1980s and 2000s, we observed substantial reduction in the tissue levels of PAHs, PCBs, OCPs and heavy metals in P. viridis. The human health risks associated with consuming these mussels were determined to be insignificant. Our findings imply that the Harbour Area Treatment Scheme has been effective in improving the water quality in Victoria Harbour and its adjacent aquaculture area.

Carotenoids and Vitamin A in Breastmilk of Hong Kong Lactating Mothers and Their Relationships with Maternal Diet.

Carotenoids and vitamin A are nutrients crucial to infants' development. To date, there is limited data on their availability in breastmilk and the associated dietary factors, especially in Hong Kong, where people follow a westernized Chinese diet. This study determined the selected breastmilk's carotenoid and vitamin A (retinol) contents by ultraperformance liquid chromatography with photodiode detection (UPLC-PDA) and the dietary intakes by three-day food records in 87 Hong Kong lactating mothers, who were grouped into tertiles based on their daily carotenoid intake. Low vitamin A intake (530.2 ± 34.2 µg RAE/day) and breastmilk retinol level (1013.4 ± 36.8 nmol/L) were reported in our participants, suggesting a poor vitamin A status of the lactating participants having relatively higher socioeconomic status in Hong Kong. Mothers in the highest tertile (T3) had higher breastmilk carotenoid levels than those in the lowest (T1) (p < 0.05). There were significant associations between maternal carotenoid intakes and breastmilk lutein levels in the linear regression models (p < 0.05) regardless of dietary supplement intake. Furthermore, maternal dark green vegetable intakes were associated with breastmilk retinol, lutein, and ß-carotene levels. These findings can serve as dietary references for lactating mothers to enhance breastmilk carotenoid and vitamin A contents for the benefits of child growth and development.

Positive relationship between consumption of specific fish type and n-3 PUFA in milk of Hong Kong lactating mothers.

Residents of Hong Kong have undergone a dietary transition from a traditional Chinese diet that is high in seafood to a more Western diet. This may have affected the nutritional composition of breast milk of Hong Kong mothers. The present study aims to investigate the relationship between the dietary pattern and the fatty acid profile of the breast milk of lactating women in Hong Kong. Seventy-three volunteering healthy Hong Kong lactating mothers participated in the study. Their dietary intakes were assessed by using a 3-d dietary record and FFQ. The mean n-3 fatty acid levels were approximately 0·4 % (EPA) and 0·9 % (DHA) of total fatty acids in the breast milk of lactating mothers who had exclusively breastfed their infants aged 2-6 months. Maternal dietary intakes of n-3 fatty acids were positively associated with their levels in the breast milk. The levels of maternal intakes of freshwater and saltwater fish, especially the consumption of salmon, croaker and mandarin, were significantly correlated with the content of DHA in breast milk. The present study is among the very few in the literature to determine the fatty acid profile of breast milk in Hong Kong populations and verify certain dietary factors that influence this profile. High levels of n-3 PUFA, especially DHA, were observed in the breast milk of Hong Kong lactating women. The findings may serve as a dietary reference for lactating mothers to optimise the fatty acid profile of their breast milk.

Palladium-indolylphosphine-catalyzed Hiyama cross-coupling of aryl mesylates.

Aryl mesylates are found to be applicable as electrophiles in organosilicon-mediated coupling reactions. The catalyst system comprising 2 mol % of Pd(OAc)(2) and CM-phos supporting ligand is highly effective in catalyzing Hiyama cross-coupling of various aryl and heteroaryl mesylates. Interesting acid additive effects show that the presence of 0.25-0.50 equiv of acetic acid efficiently suppresses the mesylate decomposition and generally promotes the coupling product yields.

Enantioselective hydrogenation of alpha-aminomethylacrylates containing a free NH group for the synthesis of beta-amino acid derivatives.

We describe highly enantioselective synthesis of beta-amino acid derivatives (1a-c) using asymmetric hydrogenation of alpha-aminomethylacrylates (2a-c), which contain a free basic N H group, as the key step. The alpha-aminomethylacrylates (2a-c) were prepared using the Baylis-Hillman reaction of an appropriate aldehyde with methyl acrylate followed by acetylation of the resulting allylic alcohols (4a-b) and S(N)2'-type amination of the allylic acetates (3a-b).

Formate as a CO surrogate for cascade processes: Rh-catalyzed cooperative decarbonylation and asymmetric Pauson-Khand-type cyclization reactions.

A rhodium-(S)-xyl-BINAP complex-catalyzed tandem formate decarbonylation and [2 + 2 + 1] carbonylative cyclization is described; this cooperative process utilizes formate as a condensed CO source, and the newly developed cascade protocol can be extended to its enantioselective version, providing up to 94% ee of the cyclopentenone adducts.

Easily accessible benzamide-derived P,O ligands (Bphos) for palladium-catalyzed carbon-nitrogen bond-forming reactions.

Easily accessible benzamide-derived hemilabile phosphine ligands were efficiently prepared through ortho-directed lithiation of the corresponding N,N-diethylbenzamide followed by quenching with chlorodialkylphosphines. These structurally simple hemilabile ligands were found to be highly effective in palladium-catalyzed amination of aryl and heteroaryl chlorides. Various sterically congested and functionalized aryl halide substrates were compatible in these reaction conditions. By using optimized reaction conditions, remarkable catalyst productivity (total turnover number up to 8400) was obtained.

Rhodium-catalyzed asymmetric aqueous Pauson-Khand-type reaction.

An interesting rhodium-catalyzed asymmetric aqueous Pauson-Khand-type reaction was developed. A chiral atropisomeric dipyridyldiphosphane ligand was found to be highly effective in this system. This operationally simple protocol allows both catalyst and reactants to be handled under air without precautions. Various enynes were transformed to the corresponding bicyclic cyclopentenones in good yield and enantiomeric excess (up to 95 % ee). A study of the electronic effects of the enyne substrates revealed a correlation between the electronic properties of the substrates and the ee value obtained in the product of the Pauson-Khand-type reaction. A linear free-energy relationship was observed from a Hammett study.