Comparative study on the natural occurrence of Fusarium mycotoxins (trichothecenes and zearalenone) in corn and wheat from high- and low-risk areas for human esophageal cancer in China

A comparative study on the natural occurrence of Fusarium toxins was done with 47 corn and 30 wheat samples collected in 1989 from Linxian and Shangqiu Counties in Henan Province, People's Republic of China, high- and low-risk areas, respectively, for esophageal cancer. Three trichothecenes (deoxynivalenol [DON], 15-acetyldeoxynivalenol [15-ADON], and nivalenol [NIV]) and zearalenone (ZEA) were detected in corn samples, and DON, NIV, and ZEA were found in wheat samples. Compared with Shangqiu corn, the incidence and mean level of DON in Linxian were 2.4 and 5.8 times higher, respectively, and those of 15-ADON were 16.3 and 2.6 times higher, respectively. The incidence and level of trichothecenes in wheat samples were significantly lower than those in corn. However, the level of DON in Linxian wheat was 3.3 times higher than in Shangqiu wheat. This is the first report indicating a significant difference in the natural occurrence of Fusarium toxins in main staple foods between high- and low-risk areas for esophageal cancer in the People's Republic of China.     

Fumonisin occurrence in corn from high- and low-risk areas for human esophageal cancer in China.

Forty-seven corn samples were collected in 1989 from Linxian and Shangqiu Counties in Henan Province, the high- and low-risk areas, respectively, for human esophageal cancer in the People's Republic of China. The samples were analyzed for fumonisin (fumonisin B1 [FB1] and FB2) contamination. Of the fumonisin-positive samples, the mean levels in Linxian corn were found to be 872 ng/g for FB1 and 448 ng/g for FB2, while the Shangqiu corns had 890 ng of FB1 and 330 ng of FB2 per g. The incidence of fumonisin contamination of Linxian corn (48%) was about two times higher than that of Shangqiu corn (25%), and the former corn samples were frequently cocontaminated with trichothecenes. Fusarium species isolated from corn from Linxian County produced FB1 at levels ranging from 1,280 to 11,300 micrograms/g.     

Natural occurrence of Fusarium mycotoxins (trichothecenes and zearalenone) in barley and corn in Korea.

Barley is produced in four provinces, Chonbuk, Chonnam, Kyungbuk, and Kyungnam, and corn is mainly produced in the Kangwon province in Korea. The natural occurrence of Fusarium mycotoxins was surveyed in 39 barley and 46 corn samples from different areas. Five 8-ketotrichothecenes, namely deoxynivalenol (DON), nivalenol (NIV), 4-acetylnivalenol (4-ANIV), 3-acetyldeoxynivalenol (3-ADON), and 4,15-diacetylnivalenol (4,15-DANIV), and zearalenone (ZEA) were detected in barley. DON, NIV, and ZEA were the major contaminants in barley, with mean levels of 170, 1,011, and 287 ng/g, respectively. On the other hand, DON, 15-acetyldeoxynivalenol (15-ADON), NIV, 4-ANIV, 4,15-DANIV, and ZEA were detected in corn samples. DON and 15-ADON were the major contaminants in corn, with mean levels of 310 and 297 ng/g, respectively. The survey indicated that the natural occurrence of monoacetyl-DON and the ratios of NIV to DON in two cereals were different. In addition, this is the first report of the natural occurrence of 4,15-DANIV in cereals.     

First survey on the natural occurrence of Fusarium mycotoxins in Bulgarian wheat

Wheat for human consumption (140 samples) was collected after harvest from all regions of Bulgaria. The 1995 crop year was characterized by heavy rainfall in the spring and summer months. The internal mycoflora of wheat samples was dominated by Fusarium spp. and Alternaria spp., and storage fungi were rarely present. The samples were analysed for contamination with Fusarium mycotoxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), and zearalenone (ZEA), using enzyme immunoassay methods. DON and ZEA were the predominant toxins, with a contamination frequency of 67% and 69%, respectively. The average levels of these toxins in positive samples were 180 g/kg (DON) and 17 g/kg (ZEA), maximum concentrations were 1800 g kg^–1 and 120 g kg^–1, respectively. Acetyl derivatives of DON, namely 3-AcDON and 15-AcDON, were found in 2.1 % and 0.7% of the samples, at at maximum level of about 100 g kg^–1. Only one sample was positive for T-2 (55 g/kg), DAS was not detected. This is the first report about the natural occurrence of a range of Fusarium mycotoxins in wheat for human consumption in Bulgaria.Abbreviations 3-AcDON 3-acetyldeoxynivalenol - 15-AcDON 15-acetyldeoxynivalenol - DAS diacetoxyscirpenol - DON deoxynivalenol - EIA enzyme immunoassay - T-2 T-2 toxin - ZEA zearalenone     

Natural occurrence of Fusarium mycotoxins in field samples from the 1992 Wisconsin corn crop.

Analysis of 98 moldy corn samples collected in Wisconsin between November 1992 and January 1993 for Fusarium toxins by various immunochemical assays revealed overall average mycotoxin concentrations of 305.6, 237.7, and 904.3 ng/g for type A trichothecenes (TCTCs), deoxynivalenol (DON)-related type B TCTCs (total DON), and zearalenone (ZE), respectively. A small portion (5.1%) of the samples was found to be contaminated with high levels ( > 1 microgram/g) of type A TCTCs and total DON during the whole survey. Over 40% of the samples had 100 to 1,000 ng of total DON per g, while 17% of the samples had the same levels of type A TCTCs. The analytical data were consistent with those from mycological examinations for the samples in which various toxic Fusarium spp., including F. sporotrichioides, F. poae, and F. graminearum, were found. The samples received in November 1992 had relatively low concentrations of toxin; the average levels of type A TCTCs and total DON were 9.9 and 79 ng/g, respectively. The toxin concentrations became progressively higher in the samples received in December. The average levels for the type A TCTCs and total DON increased to 920 and 335 ng/g, respectively. However, the levels of ZE were higher in the samples collected earlier. The average levels for samples collected in November and late December were 1,195 and 242 ng/g, respectively. Analysis of selected samples by high-performance liquid chromatography monitoring with an enzyme-linked immunosorbent assay revealed that T-2 toxin, HT-2 toxin, diacetoxyscirpenol, neosolaniol, and T-2 tetraol (T-2-4ol) were common in these samples. Statistical analysis revealed a weak correlation between the levels of total type A TCTCs and total DON in the samples (r = 0.18, P = 0.09), but a strong correlation between the levels of ZE and total type B TCTCs (r = 0.75, P < 0.0001) was found. The mycotoxin levels of total type A TCTCs, total DON-related type B TCTCs, and ZE in the cobs (5.2, 3.9, and 21 micrograms/g, respectively) were considerably higher than those in the kernels (1.0, 0.5, and 0.5 microgram/g, respectively). The type A toxin levels increased from a range of 14 to 35 ng/g to a range of 110 to 538 ng/g after the moldy corn samples were held at 5 degrees C for 8 days in the laboratory.     

Mycoflora and mycotoxins natural occurrence in corn from entre rios province, Argentina

Corn samples were collected in 1999 from three departments of Entre Réos province, Argentina, and were surveyed for mould contamination and natural occurrence ofFusarium mycotoxins, ochratoxin A and aflatoxins.Fusarium verticillioides was the most prevalent fungal species recorded at all departments. Zearalenone, deoxynivalenol and ochratoxin A were not found in any samples. Only one of the 52 corn samples analysed was contaminated with aflatoxin B₁ (17 μg/kg). Fumonisin B₁ was found in 58 % of samples (range of positive samples: 47– 3,347 μg/kg), fumonisin B₂ in 33.0 % (range of positive samples: 23–537 μg/kg) and fumonisin B₃ in 25.0 % (range of positive samples: 24–287 μg/kg) of them. This is the first report on the natural occurrence of mycotoxins in corn from Entre Ríos province, Argentina. Levels of fumonisins were lower than detected in other Argentinian provinces.     

Toxin production by Fusarium species from sugar beets and natural occurrence of zearalenone in beets and beet fibers.

Fifty-five Fusarium isolates belonging to nine species were collected from fungus-invaded tissue of stored sugar beets and identified as F. acuminatum (11 isolates), F. avenaceum (1 isolate), F. culmorum (1 isolate), F. equiseti (23 isolates), F. graminearum (4 isolates), F. oxysporum (1 isolate), F. solani (4 isolates), F. sporotrichioides (7 isolates), and F. subglutinans (2 isolates). All isolates were cultured on autoclaved rice grains and assayed for toxicity by feeding weanling female rats the ground-rice cultures of the isolates in a 50% mixture with a regular diet for 5 days. Fifty-eight percent of the isolates were acutely toxic to rats, 26% caused hematuria, 18% caused hemorrhages, and 29% caused uterine enlargement. In most cases, toxicity could not be accounted for by the known toxins found. The following mycotoxins were found in extracts of the rice cultures: zearalenone (22 to 6,282 micrograms/g), chlamydosporol (HM-8) (68 to 4,708 micrograms/g), moniliformin (45 to 400 micrograms/g), deoxynivalenol (10 to 34 micrograms/g), 15-acetyldeoxynivalenol (5 to 10 micrograms/g), diacetoxyscirpenol (22 to 63 micrograms/g), monoacetoxyscirpenol (21 to 26 micrograms/g), scirpenetriol (24 micrograms/g), T-2 toxin (4 to 425 micrograms/g), HT-2 toxin (2 to 284 micrograms/g), neosolaniol (2 to 250 micrograms/g), and T-2 tetraol (4 to 12 micrograms/g). F. equiseti was the predominant species found on visibly molded beets in the field. Six of 25 moldy sugar beet root samples collected in the field contained zearalenone in concentrations ranging between 12 and 391 ng/g, whereas 10 samples from commercial stockpiles were negative for zearalenone.(ABSTRACT TRUNCATED AT 250 WORDS)     

Toxin production by Fusarium species from sugar beets and natural occurrence of zearalenone in beets and beet fibers.

Fifty-five Fusarium isolates belonging to nine species were collected from fungus-invaded tissue of stored sugar beets and identified as F. acuminatum (11 isolates), F. avenaceum (1 isolate), F. culmorum (1 isolate), F. equiseti (23 isolates), F. graminearum (4 isolates), F. oxysporum (1 isolate), F. solani (4 isolates), F. sporotrichioides (7 isolates), and F. subglutinans (2 isolates). All isolates were cultured on autoclaved rice grains and assayed for toxicity by feeding weanling female rats the ground-rice cultures of the isolates in a 50% mixture with a regular diet for 5 days. Fifty-eight percent of the isolates were acutely toxic to rats, 26% caused hematuria, 18% caused hemorrhages, and 29% caused uterine enlargement. In most cases, toxicity could not be accounted for by the known toxins found. The following mycotoxins were found in extracts of the rice cultures: zearalenone (22 to 6,282 micrograms/g), chlamydosporol (HM-8) (68 to 4,708 micrograms/g), moniliformin (45 to 400 micrograms/g), deoxynivalenol (10 to 34 micrograms/g), 15-acetyldeoxynivalenol (5 to 10 micrograms/g), diacetoxyscirpenol (22 to 63 micrograms/g), monoacetoxyscirpenol (21 to 26 micrograms/g), scirpenetriol (24 micrograms/g), T-2 toxin (4 to 425 micrograms/g), HT-2 toxin (2 to 284 micrograms/g), neosolaniol (2 to 250 micrograms/g), and T-2 tetraol (4 to 12 micrograms/g). F. equiseti was the predominant species found on visibly molded beets in the field. Six of 25 moldy sugar beet root samples collected in the field contained zearalenone in concentrations ranging between 12 and 391 ng/g, whereas 10 samples from commercial stockpiles were negative for zearalenone.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simultaneous occurrence of fumonisin B1 and other mycotoxins in moldy corn collected from the People's Republic of China in regions with high incidences of esophageal cancer.

A total of 31 corn samples collected from households in the counties of Cixian and Linxian of the People's Republic of China, where high incidences of esophageal cancer have been reported, were analyzed for fumonisin B1 (FB1), aflatoxin, and total trichothecene mycotoxins. High levels of FB1 (18 to 155 ppm; mean, 74 ppm) were found in 16 of the samples that showed heavy mold contamination. FB1, at lower levels (20 to 60 ppm; mean, 35.3 ppm), was also found in 15 samples, collected from the same households, that did not show any visible mold contamination. The levels of aflatoxin in the samples were low (1 to 38.4 ppb; mean, 8.61 ppb). High levels of total type-A trichothecenes were also found in the moldy corn samples (139 to 2,030 ppb; mean, 627 ppb). Immunochromatography of selected samples revealed that these samples contained T-2 toxin, HT-2 toxin, iso-neosolaniol, monoacetoxyscirpenol, and several other type-A trichothecenes. The concentration of total type-B trichothecenes in 15 moldy corn samples was in the range of 470 to 5,826 ppb (mean, 2,359 ppb). High levels (3.7 to 5.0 mg/g) of FB1 were produced in corn in the laboratory by five Fusarium moniliforme strains isolated from the moldy corn. These fungi were also capable of forming various nitrosamines (5 to 16 micrograms per flask) in the presence of nitrate and precursor amines.(ABSTRACT TRUNCATED AT 250 WORDS)     

Incidence ofFusaria and occurrence of selected Fusarium mycotoxins on Lolium spp. in Germany

Test plantings with varieties ofLolium multiflorum andL perenne were harvested 4 to 7 times a year in 1991 and 1992. Samples were checked for the presence ofFusaria, the mycotoxins zearalenone, T-2 toxin, and diacetoxyscirpenol (DAS). Spectrum of species and the incidence ofFusaria and fusariotoxins are discussed in relation to the influencing factors site, variety ofLolium, harvesting time and year. Depending on these factors, 41 % to 100 % of the samples wereFusarium positive. Differences in infestation with Fusarium among varieties ofLolium perenne were dependent on location and did not correlate with yield. The six species ofFusarium pathogenic toLolium spp. (F. graminearum, F. culmorum, F. avenaceum, F. oxysporum, F. solani, and F. acuminatum) totaled 35.7 % of all the isolated strains. 14 species could be isolated fromLolium samples (descending frequency):F. culmorum, F. sambucinum, F. equiseti, F. acuminatum, F. semitectum, F. oxysporum, F. subglutinans, F. avenaceum, F. sporotrichioides, F. proliferatum, F. tricinctum, F. anthophilum, F. dimerum and F. graminearum. For the detection ofFusaria a promising new immunological method is presented. It is based on the genus specific production of exopolysaccharides byFusarium species. Mycotoxin contents in grass ranged from 0.01 to 4.75 ppm for zearalenone with 67 % positive samples and 0.3 % samples above 1 ppm, 0.04 to 2.78 ppm for T-2 toxin with 25 % positive samples and 2.8 % samples above 1 ppm, and 0.003 to 0.06 for DAS with 21.6 % positive samples. In silages, no T-2 toxin was detectable. IsolatedFusarium strains were checked for the ability to produce the mycotoxins zearalenone, T-2 toxin and DAS in culture. Most of the strains were positive for at least one of the toxins.     

Mycotoxins (trichothecenes, zearalenone and fumonisins) in cereals associated with human red-mold intoxications stored since 1989 and 1991 in China

Two corn powder samples implicated in the human food poisoning that occurred in Guangxi province in 1989, and eight wheat and two barley samples linked to an episode that involved about 130,000 people in gastrointestinal disorders in Anhui province in 1991 were analyzed for trichothecenes including deoxynivalenol (DON), nivalenol (NIV) and their esters, zearalenone (ZEA) and fumonisins (FMs) by gas chromatography/mass spectroscopy and high performance liquid chromatography, and T-2 toxin by enzyme-linked immunosorbent assays. DON was detected in all samples as a major trichothecene (16-51,450 microg kg(-1)), and NIV was in one corn, one barley and all wheat at relatively low levels (10-6935 microg kg(-1)). ZEA was found in all corn and barley, and six wheat samples (46-3079 microg kg(-1)). In addition, 3-acetyl-DON (2544 microg kg(-1)) and 15-acetyl-DON (2537 microg kg(-1)) were detected separately in one corn and one wheat sample. The highest levels of these mycotoxins were found in one wheat sample associated with the human intoxication in Anhui province. FMs in corn were below 1000 microg kg(-1). Risks of DON and ZEA on the people who consumed the causative cereals were assessed.     

A survey on the occurrence of mycotoxins in wheat and maize from western Romania

Samples of wheat (n = 25) and maize (n = 30) for animal consumption, collected in 1997 after harvest from western Romania, were analyzed by enzyme immunoassays for mycotoxin contamination. Toxins analyses included deoxynivalenol (DON), 3-acetylDON, 15- acetylDON, fusarenone X (FX), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), zearalenone (ZEA), fumonisin B1 (FB1), aflatoxin B1 (AFB1), ochratoxin A (OA), and citrinin (CT). DON and acetylDONs were the major contaminants in wheat (100%) and maize (46%). Median values for DON, 3-acetylDON, and 15-acetylDON were 880 μg kg-1, 66 μg kg- 1, and 150 μg kg-1 in wheat, and 890 μg kg-1, 180 μg kg-1, and 620 μg kg- 1 in maize, respectively. Additionally, 3,15-diacetylDON was detected in some samples by HPLC-EIA analysis. All samples were negative for FX (<150 μg kg-1). T-2 was found in wheat (n = 6) and maize (n = 1) at levels between 13 and 63 μg kg- 1. DAS (2.6 μg kg-1) was found in one maize sample. ZEA occurred in all wheat and in four maize samples, median values were 10 μg kg-1 and 250 μg kg-1, respectively. One maize sample contained FB1 (140 μg kg-1). All samples were AFB1-negative (<4 μg kg-1). OA was found in one wheat sample (37 μg kg- 1), CT was found in one maize sample (580 μg kg- 1). This first reported natural occurrence of a range of mycotoxins in Romanian feeding stuff shows that DON and acetyl DONs may be present at levels which may affect animal production. This revised version was published online in June 2006 with corrections to the Cover Date.     

The effect of combinations of Fusarium mycotoxins (deoxynivalenol, zearalenone and fumonisin B1) on growth of brewing yeasts

The interactive effect of combinations of the Fusarium mycotoxins deoxynivalenol (DON), zearalenone (ZEA) and fumonisin B1 (FB1) on growth of brewing yeasts was examined. Yeast growth was assessed by measurement of dry weight or relative growth, cell number, viability and conductance change of the growth medium using direct and indirect methods. The interactive effect of a combination of these mycotoxins was subject to the ratio of toxins in the mixture and the toxicity of individual toxins on yeast growth. When a combination of mycotoxins at low concentration was added into the growth medium, no significant inhibitory effect on growth was observed compared to controls. However, when a combination of high concentrations of DON and ZEA which individually inhibited yeast growth was examined, the interactive effect was shown to pass from antagonism to synergism depending on the ratio of the toxins in the mixture. As a synergistic interaction between these Fusarium mycotoxins was observed only at high concentrations, which were far higher than would be expected in good quality grain, they are not a concern when related to yeast growth under the brewing conditions studied.     

Comparison of in vitro cytotoxicity of Fusarium mycotoxins,deoxynivalenol, T-2 toxin and zearalenone on selected human epithelial cell lines

Three human epithelial cell lines (CaCo-2, HEp-2 and HeLa) implicated as potential targets for three Fusarium toxins were tested for the extent of survival on exposure to increasing toxin concentration and incubation periods. Cytotoxicity assay using 3(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) was carried out with deoxynivalenol (DON), T-2 toxins and zearalenone (ZON) on CaCo-2, HEp-2 and HeLa cell lines. Of the three cell lines used, HeLa was the most sensitive, eliciting cell death after 2 days exposure at 100 ng ml^–1with T-2 toxin. HeLa was the only cell line to exhibit cytotoxicity towards ZON showing cell death at 1000 ng ml^–1after 2 days which increased to 4 days, showing substantial cell death at 200 ng ml^–1. HEp-2 was sensitive to DON showing cell death after 2 days (100 ng ml^–1) with complete cell death occurring at 200 ng ml^–1 after 4 days of exposure. Substantial cytoxicity of T-2 towards HEp-2 occurred after 2 days at 1000 ng ml^–1 and complete cell death occurred with 100 ng ml^–1 at day 4. The CaCo-2 cell line was generally resistant to the mycotoxins tested between 100 and 1000 ng ml^–1. This study shows that cytotoxicity of Fusarium toxins to epithelium cell lines is concentration- and time- dependant and results from ZON–HeLa interaction indicate possible cell type-mycotoxin specificity.     

Mycoflora and mycotoxins of peanut (Arachis hypogaea L.) seeds in Egypt. 1-sugar fungi and natural occurrence of mycotoxins

Sixty-four species and 2 varieties which belong to nineteen genera of fungi were identified from 40 peanut seed samples collected from different places in Egypt by using a dilution-plate method on glucose-Czapek's medium. The most frequent genera were Aspergillus (21 species & 2 varieties), Penicillium (16 species) and Fusarium (6 species). A. flavus, A. fumigatus, A. niger, P. chrysogenum and F. oxysporum were the most common fungal species. Forty seven percent of the samples proved to be toxic to brine shrimp (Artemia salina) larvae. Thin-layer Chromatographic analysis revealed that peanuts were contaminated by aflatoxins (11 samples), thrichothecene-toxins (10 samples), zearalenone (one sample) and citrinin (one sample). We believe that this is the first report of the natural occurrence of zearalenone and trichothecene-toxins in peanuts.     

Metabolic epidemiology of large bowel cancer. Fecal mutagens in high- and low-risk population for colon cancer. A preliminary report

Because of potential significance of fecal mutagens in the pathogenesis of colon cancer, the dietary pattern and fecal mutagens of 3 populations with distinct risk for the development of colon cancer, a high-risk population in New York Metropolitan area (non-Seventh-Day Adventists), a low-risk population of vegetarian Seventh-Day Adventists in New York Metropolitan area and a low-risk population in rural Kuopio, Finland were studied. The average daily intake of protein was the same in the 3 groups, but the sources were different, a greater portion coming from meat in the New York non-Seventh-Day Adventists and from vegetables in Seventh-Day Adventists. The intake of fat was lower in Seventh-Day Adventists and higher in Kuopio and in New York non-Seventh-Day Adventists. The intake of dietary fiber was high in Kuopio compared to other groups. Fecal samples collected for 2 days were freeze-dried extracted with peroxide-free diethyl ether, partially purified on a silica-gel column and assayed for mutagenicity using the Salmonella/mammalian microsome mutagenicity test. The mutagenic activity was observed with Salmonella typhimurium tester strain TA98 without microsomal activation and with TA100 with and without microsomal activation in high-risk subjects from New York consuming a high-fat, high-meat diet. The incidence of fecal mutagen activity was higher in volunteers from New York consuming a high-fat, high-meat diet compared to low-risk rural Kuopio population. None of the vegetarian Seventh-Day Adventists showed any mutagenic activity.     

Simultaneous occurrence of deoxynivalenol, zearalenone, and aflatoxin in 1982 scabby wheat from the midwestern United States.

Thirty-three samples of wheat of the 1982 crop year from Kansas and Nebraska were analyzed for deoxynivalenol, T-2 toxin, zearalenone, and aflatoxin. Deoxynivalenol was identified in 31 of 33 samples, zearalenone was identified in 3 of 33 samples, and aflatoxin B1 was identified in 23 of 31 samples. One 1982 wheat sample from Illinois and one from Texas were also contaminated with deoxynivalenol at 1,200 and 600 ng/g, respectively. None of the samples contained detectable T-2 toxin. The mean concentration of deoxynivalenol was 1,782 +/- 262 ng/g, and the concentrations of aflatoxin B1 ranged from 0.8 to 17.0 ng/g, with a mean of 3.37 +/- 0.7. Zearalenone concentrations of the three positive samples were 35, 90, and 115 ng/g. However, density segregation of two other samples which tested negative yielded light fractions, comprising less than 2% of the samples, contaminated at 230 and 254 ng of zearalenone per g; calculated zearalenone concentrations for these two samples were below the limit of detection of the method. The high frequency of aflatoxin B1 and deoxynivalenol in wheat from the 1982 crop is unprecedented, as is the simultaneous contamination of some samples with deoxynivalenol, zearalenone, and aflatoxin B1.     

Cytotoxicity of trichothecene mycotoxins isolated from Fusarium sporotrichioides (MC-72083) and Fusarium sambucinum in baby hamster kidney (BHK-21) cells

Twenty-six trichothecene mycotoxins produced by Fusarium sporotrichioides (MC-72083) and Fusarium sambucinum were screened for relative cytotoxicity in cultured baby hamster kidney (BHK-21) cells. The relative cytotoxicity was measured as LC₁₀₀. The most cytotoxic trichothecenes were T-2 toxin (5 ng/ml) and the recently isolated 4-propanoyl HT-2 (5 ng/ml) and 3-hydroxy T-2 toxin (5 ng/ml). T-2 tetraol (1 × 10⁴ ng/ml), 8--hydroxytrichothecene (1 × 10⁴ ng/ml), sporotrichiol (2 × 10⁴ ng/ml), 8-oxodiacetoxyscirpenol (6 × 10⁴ ng/ml) and 8-acetyl T-2 tetraol (1 × 10⁵ ng/ml) were the least toxic of the regular trichothecenes. None of the modified trichothecenes or the apotrichothecene were very cytotoxic: 8--hydroxysambucoin (2 × 10³ ng/ml), FS-1 (5 × 10³ ng/ml), 8--hydroxysambucoin (8 × 10⁴ ng/ml) and trichotriol (1 × 10⁵ ng/ml). The modified trichothecenes, FS-2 and FS-3, were not toxic even at 1 × 10⁵ ng/ml. The baby hamster kidney cell bioassay proved to be a very sensitive and reproducible means of screening new trichothecene mycotoxins for relative cytotoxicity.     

Spiradiclis glandulosa sp. nov. (Rubiaceae) from limestone areas in southern China

Spiradiclis glandulosa L. Wu & Q. R. Liu, a new species from limestone areas in southern China, is described and illustrated here. This new species is similar to S. umbelliformis, but can be distinguished from the latter mainly by its abaxial leaf blade with densely set yellow glandule‐like spots (vs abaxially pilosulous), calyx lobes oblong‐laceolate, ca 4–6 mm long (vs ovate‐triangular, ca 0.6 mm), corolla tube inside densely pubescent above the middle and onto lobes in both forms (vs inside with villous ring above base), and capsules villosulous (vs glabrescent).