Isolation and identification of hydroxythiohomosildenafil in herbal dietary supplements sold as sexual performance enhancement products.

An unknown compound is detected and isolated from two herbal dietary supplements bought on the internet. The structure of the unknown compound is elucidated using ESI-MS/MS, NMR, UV and IR. The compound, named hydroxythiohomosildenafil, is identified as an analogue of sildenafil in which the oxygen atom is substituted with a sulfur atom in the pyrazolopyrimidine moiety, and a hydroxyethyl group instead of a methyl group is attached to the piperazinyl nitrogen. It is the first report of this compound being detected in herbal dietary supplements. The UV, IR and completely assigned NMR data of hydroxythiohomosildenafil is recorded.

Liquid chromatographic determination of trans-10-hydroxy-2-decenoic acid content of commercial products containing royal jelly.

Thirty-nine samples of commercial products containing royal jelly were analyzed by liquid chromatography for their trans-10-hydroxy-2-decenoic acid (10-HDA) content. Most of the samples contained 10-HDA. Samples claimed to be pure royal jelly contained 1.98 to 6.37% 10-HDA (w/w). The 10-HDA content of samples claimed to contain royal jelly as an ingredient ranged from nondetectable to 1.28% (w/w).

Aflatoxin exposure in Singapore: blood aflatoxin levels in normal subjects, hepatitis B virus carriers and primary hepatocellular carcinoma patients.

Blood screening conducted on Singaporeans over 1991-1992 showed exposure to predominantly aflatoxin B1 and to a lesser extent G1. The extent of exposure to B1 among three groups of residents in Singapore, namely normal subjects (n = 423), hepatitis B virus carriers (n = 302) and primary hepatocellular carcinoma (PHC) patients (n = 58) were extensive as reflected by the positive rates of 15.1, 0.7 and 1.7 per cent respectively. However, the degree of individual exposure to this toxin among the three groups was considered low as shown by the low respective mean blood levels of 5.4 +/- 3.2 (range 3.0-17), 7.7 (range 7.5-7.9) and 7.5 picogrammes per ml of blood. It is not immediately clear whether or not such low levels would precipitate an undesirable health effect. The higher positive rate seen in normal subjects as compared with the other groups could be due to differences in dietary intake of aflatoxin B1, differences in metabolic patterns or both. About 70 per cent of PHC patients studied were carriers. The degree of aflatoxin B1 exposure among normal subjects in Singapore was a factor of 22.1 times less than that in Japan, 40.9 times less than that in Indonesia and 51.3 times less than that in the Philippines. Similarly, the extent of exposure among hepatitis B carriers in Singapore was a factor of 8.2 times, 39.6 times and 24.2 times less than those in the other three Asiatic countries respectively. The results reflected stringent Government control over the quality of food stuff imported into this country. As Singapore imports almost all of its dietary needs from elsewhere, it can afford to be selective at a cost. Aflatoxin M1, a metabolite of B1, was most commonly encountered in the liver tissues of deceased (n = 154) who died of causes other than sickness or disease in 1992-93, consistent with our blood findings of prevalence of aflatoxin B1. High performance liquid chromatography (HPLC) with fluorescence detection using one of the aflatoxins G2 or B2 as an internal standard was used for the detection and quantification of aflatoxins. The use of an internal standard structurally and chemically similar to those required to be quantified minimizes errors in quantifications. This is because differences in the quenching of fluorescence between specimen extracts and spiked-standard extracts were internally standardized and compensated for. The presence of an internal standard also helped to locate aflatoxins of interest more accurately.(ABSTRACT TRUNCATED AT 400 WORDS)

Poisons information in Singapore.

The Poisons Information Centre (PIC) provides viral and timely information to prevent and manage poisoning episodes. Comprehensive information on household, agricultural and industrial chemicals, natural toxins, pharmaceuticals, local antidote stocks and local poisons experts is retrieved from the Centre's computerised information system and printed literature. Public subscribers can obtain poisons information through Teleview.

Drinking and driving in Singapore, 1987 to 1989.

Between 1987 and 1989 there were approximately 5,000 cases of fatal and injury-sustained road traffic accidents, of which 2.3-3.0% were alcohol related (blood alcohol levels greater than the legal limit of 80 mg% ethanol). The offenders of alcohol-related accidents are mostly Chinese (> 79%), male (> 98%), and more often 30-40 years old. The majority of the alcohol-related accidents (> 74%) took place between 8 P.M. and 4 A.M. in fine weather and light traffic. Rear-end, head-on, and side-on collisions comprised > 60% of all the alcohol-related accidents, and losing control of vehicles approximately 30%. Drunken driving cases for the same period that were not accidents showed a number of characteristics similar to those for accidents. In Singapore, motorcycle riders and pedestrians are more prone to road fatality than other road-user groups. International comparisons of road fatalities per 100,000 population gave Singapore one of the lowest accident rates (8.1-8.4) as compared with countries such as Australia, the United Kingdom, the United States, New Zealand, Canada, and Japan.

Common poisons in Singapore--past and present.

A study on past toxicological activities in Singapore enabled us to capture the trends of poisons abused in this country over the last 108 years. Until the early sixties, corrosive alkali and acids, alcohol (poisoning cases), inorganic chemicals, heavy metals and plant alkaloids were the mainstay of poisons principally used. The seventies and eighties saw a swing towards pharmaceuticals. The 1988-89 data gave alcohol (poisoning cases), pharmaceuticals, household items such as detergents, hypochlorite and antiseptic, carbon monoxide, paraquat, malathion, organic solvents (toluene and xylenes) and narcotics as the mainstay of poisons encountered. The last two classes of poisons reflect the continuing problems of glue sniffing and narcotics abuse facing Singapore.

Drinking and driving in Singapore 1987 to 1989.

In the period 1987 to 1989 there were about 5,000 cases of fatal and injury-sustained road traffic accidents, of which 2.3 to 3.0% were alcohol-related (Blood alcohol levels greater than the legal limit of 80 mg % ethanol). The offenders of alcohol-related accidents are mostly Chinese (greater than 79%), predominantly of the male gender (greater than 98%), and more often than not in the 30 to 40 age-range. The majority of the alcohol-related accidents took place between 8 p.m. to 4 a.m. (greater than 74%) under fine weather and light traffic. Rear-end, head-on and side-on collisions comprised over 60% of all the alcohol-related accidents and losing control of vehicles about 30%. Drunken driving non-accident cases for the same period showed a number of characteristics similar to those for alcohol-related accident cases. In Singapore motorcycle riders and pedestrians are more prone to road fatality than other road-user groups. International comparisons of road fatalities per 100,000 population gave Singapore one of the lowest accident rates (8.1 to 8.4) as compared to countries such as Australia, the United Kingdom, the United States, New Zealand, Canada and Japan.

Aluminium content in milk powders by inductively-coupled argon plasma--optical emission spectrometry.

Forty-four brands of milk powders and simulated milk powders were analysed for aluminium content using Inductively Coupled Plasma Spectroscopy (ICP-OES) technique. The samples covered the full range of infant food items available in Singapore--full-cream milk formula, infant formula, fortified infant formula and milk-free soy protein formula. ICP-OES technique was employed for the analysis. Most samples analysed were found to contain less than 1 mg aluminium per kg powder. The highest aluminium content found was 15.0 mg aluminium per kg powder in a milk-free soy protein formula. The study found that ICP-OES is a convenient and accurate technique for trace metal analysis. However, considerable care needs to be exercised in the selection of emission lines of the metal under analysis to avoid error caused by emission from other metal present in the sample.