Correlation of placental pathology with the postoperative outcomes and white matter injury in preterm infants following necrotizing enterocolitis.

BACKGROUND: To determine the association of placental pathologic lesions with postoperative outcomes, survival, and white matter injury (WMI) in preterm infants with NEC. METHODS: A retrospective chart review of 107 neonates with NEC (Bell stage > IIa) from Jan 2013- June 2020 was completed. Demographic, clinical, and outcome data were compared between infants with or without placental pathologic lesions. RESULTS: In this cohort, 59/107 (55%) infants had medical NEC, and 48 (45%) had surgical NEC. The infants had a mean gestational age of 28.1±3.7 weeks and a birth weight of 1103±647 g. Maternal vascular malperfusion (82/107, 76.6%) and acute histological chorioamnionitis (42, 39.3%) were the most common pathological placental lesions. Acute histologic chorioamnionitis with fetal inflammatory response was more common in infants with surgical NEC vs. medical NEC (35.4% vs. 15.3%; p = 0.02). The NEC Infants with WMI on brain MRI scans had a significantly higher incidence of acute histological chorioamnionitis (52% vs. 27.8%; P = 0.04). No significant differences in mortality, length of stay and postoperative outcomes in neonates with and without acute histologic chorioamnionitis with fetal inflammatory response were noted. On unadjusted logistic regression, acute histologic chorioamnionitis without fetal inflammatory response was also associated with higher odds of WMI (OR 2.81; 95% CI 1.05-7.54; p = 0.039). CONCLUSION: Acute histological chorioamnionitis without fetal inflammatory response was associated with higher odds of WMI in infants with NEC, with no significant impact on mortality and other postoperative outcomes.

Clinical outcomes and gestational age based prediction of pneumatosis intestinalis in preterm infants with necrotizing enterocolitis.

BACKGROUND: To determine the clinical implications and gestation age-specific diagnostic predictability of pneumatosis in preterm infants with necrotizing enterocolitis (NEC). METHODS: A retrospective study on abdominal radiographs comparing clinical and radiological information in infants with and without pneumatosis. RESULT: Our findings disproved our hypothesis. Pneumatosis was seen more frequently in infants with higher gestational age [28.4 (26.1-32.4) vs. 26.4 (24.3-29) weeks; p < 0.001] and birth weight [1110 (762-1768) vs. 770 (645-1022) grams; p < 0.001] and were more likely delivered vaginally (39.1% vs. 21.7%, p = 0.01). Portal venous gas was seen frequently on radiographs (10.3% vs. 0%, p < 0.001), but not pneumoperitoneum (20.7% vs. 36.7%, p = 0.02). Infants with pneumatosis frequently developed acute kidney injury, with higher serum creatinine (16.5% vs. 4.5%, p = 0.02) and frequent oliguria (12.9% vs. 2.7 %; p = 0.043) and had higher C-reactive protein levels at 24 and 96 hours (p < 0.002). Receiver operating curves for pneumatosis showed GA >28 weeks and birth weight > 1000 gm to have a sensitivity of 58.6% and specificity of 72.5%. CONCLUSION: Contrary to our hypothesis, infants who developed pneumatosis during NEC were more mature with a higher gestational age and birth weight than those who did not.

Developing nephrology services in low income countries: a case of Tanzania.

BACKGROUND: The burden of kidney diseases is reported to be higher in lower- and middle-income countries as compared to developed countries, and countries in sub-Saharan Africa are reported to be most affected. Health systems in most sub-Sahara African countries have limited capacity in the form of trained and skilled health care providers, diagnostic support, equipment and policies to provide nephrology services. Several initiatives have been implemented to support establishment of these services. METHODS: This is a situation analysis to examine the nephrology services in Tanzania. It was conducted by interviewing key personnel in institutions providing nephrology services aiming at describing available services and international collaborators supporting nephrology services. RESULTS: Tanzania is a low-income country in Sub-Saharan Africa with a population of more than 55 million that has seen remarkable improvement in the provision of nephrology services and these include increase in the number of nephrologists to 14 in 2018 from one in 2006, increase in number of dialysis units from one unit (0.03 unit per million) before 2007 to 28 units (0.5 units per million) in 2018 and improved diagnostic services with introduction of nephropathology services. Government of Tanzania has been providing kidney transplantation services by funding referral of donor and recipients abroad and has now introduced local transplantation services in two hospitals. There have been strong international collaborators who have supported nephrology services and establishment of nephrology training in Tanzania. CONCLUSION: Tanzania has seen remarkable achievement in provision of nephrology services and provides an interesting model to be used in supporting nephrology services in low income countries.

The effect of cigarillo packaging elements on young adult perceptions of product flavor, taste, smell, and appeal.

INTRODUCTION: Product packaging has long been used by the tobacco industry to target consumers and manipulate product perceptions. This study examines the extent to which cigarillo packaging influences perceptions of product flavor, taste, smell, and appeal. METHODS: A web-based experiment was conducted among young adults. Participants viewed three randomly selected cigarillo packs, varying on pack flavor descriptor, color, type, branding, and warning-totaling 180 pack images. Mixed-effects models were used to estimate the effect of pack elements on product perceptions. RESULTS: A total of 2,664 current, ever, and never little cigar and cigarillo users participated. Cigarillo packs with a flavor descriptor were perceived as having a more favorable taste (ß = 0.21, p < .001) and smell (ß = 0.14, p < .001) compared to packs with no flavor descriptor. Compared to packs with no color, pink and purple packs were more likely to be perceived as containing a flavor (ß = 0.11, p < .001), and were rated more favorably on taste (ß = 0.17, p < .001), smell (ß = 0.15, p < .001), and appeal (ß = 0.16, p < .001). While warnings on packs decreased favorable perceptions of product taste (pictorial: ß = -0.07, p = .03) and smell (text-only: ß = -0.08, p = .01; pictorial: ß = -0.09, p = .007), warnings did not moderate the effects of flavor descriptor or color. CONCLUSIONS: To our knowledge, this study provides the first quantitative evidence that cigarillo packaging alters consumers' cognitive responses, and warnings on packs do not suffice to overcome the effects of product packaging. The findings support efforts at federal, state, and local levels to prohibit flavor descriptors and their associated product flavoring in non-cigarette products such as cigarillos, along with new data that supports restrictions on flavor cues and colors.

Renal abnormalities among HIV infected children at Muhimbili National Hospital (MNH)-Dar es Salaam, Tanzania.

BACKGROUND: Human Immunodeficiency Virus infection is a multisystem disease that contributes to significant morbidity. Renal involvement is reported to be common among patients with HIV. This study was carried out to determine renal involvement using simple bedside tests combined with ultrasonography examination. METHODS: We recruited 240 children from the HIV clinic at Muhimbili National Hospital. Data were collected using structured questionnaires and included demographic, clinical information, radiological tests; renal ultrasound and laboratory tests; serum creatinine, white blood cells, CD4+ counts and percent, urine for microalbuminuria and proteinuria. RESULTS: Microalbuminuria and proteinuria were present in 20.4 % and 7.1 % respectively. Significantly higher prevalence of microalbuminuria (p < 0.01) and proteinuria p < 0.01) were noted with low CD4 percent (<25 %). Lower mean CD4+ count were noted among children with microalbuminuria [937.4 ± 595.3 cells/µL vs 1164.7 ± 664.3 cell/µL, (p < 0.05)] and proteinuria [675.5 ± 352.3 cells/µL vs 1152 ± 662 cells/µL (p < 0.001)]. Fourteen (5.8 %) HIV infected children had estimated glomerular filtration rate (eGFR of 30-59) consistent with severe renal impairment. Increased cortical echogenicity was noted in 69/153 (39.2 %) of participants who had ultrasound examination. CONCLUSION: Microalbuminuria, proteinuria and renal dysfunction were noted to be prevalent among HIV infected children indicating the need to consider routine screening of renal complications in these children.

Effects of study design and allocation on self-reported alcohol consumption: randomized trial.

BACKGROUND: What participants think about the nature of a study might affect their behaviour and bias findings. We tested two hypotheses: (1) participants told they were in an intervention trial would report lower alcohol consumption at follow-up than those told they were in a cohort study; (2) participants told they were in the intervention group in a trial would have lower alcohol consumption at follow-up than those told they were in the control group. METHODS: Students from four universities (N = 72,903) were invited to participate in a 'research project on student drinking'. Of 10,415 respondents, 6,788 were moderate to heavy drinkers and were randomized. Group A ('cohort') were informed their drinking would be assessed at baseline and again in one month. Group B ('control') were told the study was an intervention trial and they were in the control group. Group C ('intervention') were told the study was an intervention trial and they were to receive the intervention. All were assessed and directed to read identical online alcohol education material. Whether and how long they accessed the material were recorded. One month later, alcohol intake was reassessed. RESULTS: In relation to hypothesis 1, there were no differences between the groups on the prespecified outcome measures. In relation to hypothesis 2, there were no differences though all point estimates were in the hypothesized direction (that is, 'intervention' < 'control'). The 'cohort' and 'control' groups accessed the material to a similar extent (59% versus 57%) while the 'intervention' group were more likely to access it (78%) and to read it for longer (median 35 s (25th and 75th percentiles: 6, 97) versus medians of 7 s (0, 28) and 8 s (4, 42) for the 'cohort' and 'control' groups, respectively). CONCLUSIONS: Although the context given to the research participants significantly influenced access to the online information and reading time, this did not translate into any effect on drinking behaviour, for either hypothesis. This might be because of failure in the experimental paradigm or the possibility of weaker effects using the online approach. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12610000846022.

Thirty years old lady with nephrotic syndrome: a case of biopsy proven lupus nephritis in Tanzania.

We describe a case of a 30 years old female patient who presented with nephrotic syndrome and impaired renal function diagnosed to have systemic lupus erythematosus (SLE). This is the first biopsy proven lupus nephritis in Tanzania. SLE is common among females and is reported be more common among Africans as compared to other races. This patient presented with nephrotic syndrome, pleural effusion and pericardial effusion which depicts the multisystem effects of SLE. This patient was treated with cyclophosphamide in combination with steroid as induction therapy and attained remission after a month of treatment. Systemic lupus erythematosus should be considered in patients with nephrotic syndrome and these patients should have renal biopsy to determine renal involvement.

Survey of transportation procedures, management practices, and health assessment related to quality, quantity, and value for market beef and dairy cows and bulls.

This survey consisted of data collected from 23 beef harvest plants to document transportation procedures, management practices, and health assessments of market beef and dairy cows and bulls (about n ≅ 7,000 animals). Gooseneck/bumper-pulled trailers were used more often to transport dairy cattle than beef cattle to market whereas tractor-trailers were used more often to transport beef cattle than dairy cattle. All loads (n = 103) met the American Meat Institute Foundation guidelines for spacing. Loads where more than 3% of the cattle slipped during unloading were observed in 27.3% of beef loads and 29.0% of the dairy loads. Beef loads had numerically greater usage of electrical prods (32.4%) versus dairy loads (15.4%) during unloading and were more likely to have a variety of driving aids used more aggressively on them. Fewer cattle had horns, brands, and mud/manure contamination on hides than in the previous survey in 1999. The predominant hide color for beef cows was black (44.2%) whereas the predominant color for dairy cows was the Holstein pattern (92.9%). Fewer cattle displayed evidence of bovine ocular neoplasia (2.9%) than in previous surveys in 1994 (8.5%) and 1999 (4.3%). Knots on live cattle were found less in the round (0.5%) and more in the shoulder region (4.6%) than in 1999 (1.4% and 0.4%, respectively). Dairy cows were more frequently lame in 2007 (48.7%) than 1999 (39.2%) whereas beef cows had numerically less lameness (16.3% vs. 26.6%, respectively). Most beef cows (62.3%) and dairy cows (68.9%) received midpoint body condition scores (3, 4, and 5 for beef; 2 and 3 for dairy). Beef cows had higher numerical percentages of no defects present (72.0%) versus dairy cows (63.0%) when evaluated for a variety of reproductive, health, or management conditions. Continued improvements in several key factors related to transportation, management, and health were observed in this survey, which could result in increased value in market beef and dairy cows and bulls.

Gene expression in the arcuate nucleus of heifers is affected by controlled intake of high- and low-concentrate diets.

It was hypothesized that a high-concentrate diet fed during early calfhood alters the expression of genes within the arcuate nucleus that subserve reproductive competence. Beef heifers (n = 12) were weaned at approximately 3 mo of age, and after acclimation, were allocated randomly to 1 of 2 nutritional groups: 1) High Concentrate/High Gain (HC/HG), a high concentrate diet fed to promote a gain of 0.91 kg/d; or 2) High Forage/Low Gain (HF/LG), a forage-based diet fed to promote a gain of 0.45 kg/d. Experimental diets were fed under controlled intake for 91 d. At the end of 91 d, heifers were slaughtered by humane procedures, blood samples were collected, brains were removed, liver weights were determined, and rumen fluid was collected for VFA analyses. Tissue blocks containing the hypothalamus were dissected from the brains, frozen, and cut using a cryostat, and frozen sections were mounted on slides. Tissue from the arcuate nucleus (ARC) was dissected from sections for mRNA extraction. Microarray analysis was used to assess genome-wide transcription in the ARC using a 60-mer oligonucleotide 44K bovine expression array. The ADG was greater (P < 0.001) in heifers fed the HC/HG diet than in heifers fed the HF/LG diet. At slaughter, mean propionate to acetate ratios in the ruminal fluid and liver weight as a percentage of BW were increased (P < 0.005) in HC/HG compared with HF/LG heifers. Mean serum concentrations of insulin (P < 0.05) and IGF-1 (P < 0.005) were greater, and leptin tended to be greater (P = 0.1) in HC/HG heifers compared with HF/LG heifers. Approximately 345 genes were observed to be differentially expressed in the HC/HG group with approximately two-thirds of the genes exhibiting increased expression in the HC/HG group. Genes exhibiting decreased expression in the HC/HG group included agouti-related protein and neuropeptide Y, products of which are known to regulate feed intake and energy expenditure. Functional annotation of enriched Gene Ontology terms indicates that a number of biological processes within the hypothalamus are affected by consumption of high-concentrate diets, including those related to control of feed intake, regulation of cellular metabolic processes, receptor and intracellular signaling, and neuronal communication. In summary, dietary treatments shown previously to accelerate the timing of pubertal onset in heifers increased ruminal propionate, promoted enhanced metabolic hormone secretion, and altered gene expression in the ARC.

Single nucleotide polymorphisms in Brahman steers and their association with carcass and tenderness traits.

Data from purebred Brahman steers (N = 467) were used to study the association of single nucleotide polymorphisms (SNP) with carcass traits and measures of tenderness. Fall weaned calves were grazed and fed in a subtropical environment and then harvested for processing in a commercial facility. Carcass data were recorded 24 h postmortem. Muscle samples and primal ribs were obtained to measure calpastatin activity and shear force. DNA was used to determine genotypes of thyroglobulin (TG5), calpastatin (CAST) and mu-calpain (CAPN 316 and CAPN 4751) SNP. Minor allele frequencies for CAST, CAPN 316 and CAPN 4751 were 0.342, 0.031, and 0.051, respectively. CAST genotypes were associated with calpastatin enzyme activity (P < 0.01) and shear force of steaks aged for 14-day postmortem (P < 0.05). CAPN 316 genotypes were also associated with variation in shear force of steaks aged for 14 days (P < 0.05). CAPN 4751 genotypes approached significance for association with shear force of steaks after 7 and 14 days (P < 0.08). Genotypes for TG5 were non-polymorphic (i.e., minor allele frequency = 0.004) and omitted from further analyses. Neither CAST nor CAPN SNP was associated with variation in other carcass traits.

Genetic parameters for growth and carcass traits of Brahman steers.

Spring-born purebred Brahman bull calves (n = 467) with known pedigrees, sired by 68 bulls in 17 private herds in Louisiana, were purchased at weaning from 1996 through 2000 to study variation in growth, carcass, and tenderness traits. After purchase, calves were processed for stocker grazing on ryegrass, fed in a south Texas feedlot, and processed in a commercial facility. Carcass data were recorded 24 h postmortem. Muscle samples and primal ribs were taken to measure calpastatin activity and shear force. An animal model was used to estimate heritability, genetic correlations, and sire EPD. Relatively high heritability estimates were found for BW at slaughter (0.59 +/- 0.16), HCW (0.57 +/- 0.15), LM area (0.50 +/- 0.16), yield grade (0.46 +/- 0.17), calpastatin enzyme activity (0.45 +/- 0.17), and carcass quality grade (0.42 +/- 0.16); moderate heritability estimates were found for hump height (0.38 +/- 0.16), marbling score (0.37 +/- 0.16), backfat thickness (0.36 +/- 0.17), feedlot ADG (0.33 +/- 0.14), 7-d shear force (0.29 +/- 0.14), and 14-d shear force (0.20 +/- 0.11); relatively low heritability estimates were found for skeletal maturity (0.10 +/- 0.10), lean maturity (0.00 +/- 0.07), and percent KPH (0.00 +/- 0.07). Most genetic correlations were between -0.50 and +0.50. Other genetic correlations were 0.74 +/- 0.27 between calpastatin activity and 7-d shear force, 0.72 +/- 0.25 between calpastatin activity and 14-d shear force, (0.90 +/- 0.30 between yield grade and 7-d shear force, and -0.82 +/- 0.27 between backfat thickness and 7-d shear force. Heritability estimates and genetic correlations for most traits were similar to estimates reported in the literature. Sire EPD ranges for carcass traits approached those reported for sires in other breeds. The magnitude of heritability estimates suggests that improvement in carcass yield, carcass quality, and consumer acceptance traits can be made within the Brahman population.

Effects of oral vitamin D(3) supplementation and supplement withdrawal on the accumulation of magnesium, calcium, and vitamin D in the serum, liver, and muscle tissue and subsequent carcass and meat quality of Bos indicus influenced cattle.

Bos indicus crossbred cattle (n=79) were fed vitamin D(3) (0 or 3 million IU/hd/d) for 5d. Afterwards, half of each group was slaughtered immediately, while half was fed, without supplementation, for 7d before processing. Serum calcium concentration was increased (P<0.05) in cattle after supplement removal, but not immediately following supplementation. This also was observed in the M. longissimus lumborum and M. triceps brachii, but not in the M. semitendinosus. Liver biopsy vitamin D(3) concentrations were higher (P<0.05) in supplemented cattle immediately following supplementation, but were not different from controls after supplement removal. Vitamin D(3) did not affect tenderness at supplement removal day 0, but increased the tenderness of the M. longissimus lumborum and M. semitendinosus at supplement removal day 7. Vitamin D(3) supplementation improves muscle tenderness and may be more effective when supplementation is ceased 7d before slaughter, with minimum food safety concerns.

Technical note: Exit velocity as a measure of cattle temperament is repeatable and associated with serum concentration of cortisol in Brahman bulls.

The objectives of this study were 1) to compare temperament assessments, using multiple techniques and over repeated observations, to gauge temperament over the long-term and 2) to evaluate the relationship of the temperament appraisals with serum concentrations of cortisol (CS). Measures of temperament were gathered over 3 repeated observations (60-d interval) of yearling, fall-born Brahman bulls (initial BW = 320 +/- 4 kg; n = 66). Temperament assessments included exit velocity (EV), which was the rate at which the bulls exited the squeeze chute and traversed a fixed distance (1.83 m); pen scores (PEN; 1 = quiet to 5 = excited), ascertained from animal behavior while penned in small groups (n = 5); and chute scores (CHUTE; 1 = quiet to 5 = excited), determined from behavioral responses to restraint on the weigh scale. Temperament measures obtained during the initial data collection (d 0) were all positively correlated (r > or = 0.35, P < 0.005) with one another. Additionally, PEN (r = 0.29, P < 0.05) and EV (r = 0.26, P < 0.05) were positively correlated with CS, whereas CHUTE was not (r = 0.09, P = 0.46). All serial EV measures were positively correlated (r > 0.31, P < 0.02). All PEN were positively correlated (r > 0.31, P < 0.01), whereas serial measures of CHUTE were not (P > 0.3). Exit velocity was positively correlated with CS within d 0 (r = 0.26, P = 0.04) and 120 (r = 0.44, P < 0.01). The EV data obtained at d 0 were transformed into a discrete variable, EV ranking (EV RANK; 1 to 3 scale), in which 1 equated to <1 SD below the mean and 3 equated to >1 SD above the mean. Mean EV (P < 0.01) decreased from d 0 (2.82 +/- 0.07 m/sec) to 120 (2.11 +/- 0.10 m/sec). Time also influenced (P < 0.01) CS; mean CS decreased between d 0 (14.6 +/- 0.7 ng/mL) and 120 (11.1 +/- 0.8 ng/mL). Measures of EV can be a valuable tool for the assessment of cattle temperament and a possible predictor of temperament and stress responsiveness to future animal handling events.

The stereochemical outcome of electrophilic addition reactions on the 5,6-double bond in the spinosyns.

The electrophilic addition of reagents to the 5,6-double bond in spinosyn A and spinosyn D systems occurred with high pi-diastereofacial selectivity. Addition occurred preferentially from the beta face of the molecule with selectivities ranging from 5:1 to better than 30:1. Various NMR properties were investigated in order to distinguish the beta and alpha isomers with the help of theoretical models of the products. These NMR properties include a (13)C gamma effect to C-11 and vicinal coupling between H-4 and H-5. To help rationalize the selectivity, computational studies on the transition states for epoxidation were calculated using density functional theory. The results indicate that beta epoxidation is favored and that the geometries of the transition structures are consistent with torsional steering being the source of the selectivity.

Ranch-management factors associated with antibody seropositivity for Neospora caninum in consignments of beef calves in Texas, USA.

A study was conducted with a 1998 retained-ownership population of Texas (USA) beef calves to determine the ranch-management practices associated with calf seroprevalence to Neospora caninum. Management practices of 76 Texas ranches that consigned 760 calves to a retained-ownership feedlot program were reviewed from a mailed questionnaire. Ninety-nine of 760 (13%; 95% CI, 9.4%, 17.7%) calves were positive to N. caninum and 59% of the ranches consigned at least one positive calf. In the logistic multiple-regression model which controlled for overdispersion, increased odds of calf-level seropositivity was associated with seasonal calving patterns, with stocking>1cow/calfunit/2.2ha, using a round-bale feeder, allowing wildlife access to the weaning supplement, and self-reared replacement heifers. However, decreased odds of seropositivity was associated with using a cattle-working dog and with using a self-contained cattle feeder. There was substantial overdispersion due to ranch.

Synthesis and evaluation of oxodioxolenylmethyl carbamate prodrugs of pseudomycins.

With the aim of increasing therapeutic indexes of novel cyclic depsinonapeptide pseudomycins, we synthesized and evaluated a series of mono-, di-, and trioxodioxolenylmethyl carbamate prodrugs (2 and 4) of pseudomycin B 1 and pseudomycin C' 3. It is rather encouraging to note that several members of the newly synthesized prodrugs described herein (e.g., 2a, 2e, and 4e) exhibited comparable in vivo efficacy to that achieved by the parent compounds, yet free of tail vein irritation and histamine induced toxicity in vivo.

Association of serologic status for Neospora caninum with postweaning weight gain and carcass measurements in beef calves.

OBJECTIVE: To determine the seroprevalence for Neospora caninum in a population of beef calves in a feedlot and the association of serologic status with postweaning weight gain and carcass measurements. DESIGN: Longitudinal observational study. ANIMALS: 1,009 weaned beef steers from 92 herds. PROCEDURE: Samples were obtained from all steers at time of arrival at a feedlot. Serologic status for Neospora spp was determined, using an agglutination test. Results of serologic testing were compared with calf growth and carcass data, using multivariate regression with generalized estimating equations. RESULTS: Of 1,009 calves, 131 (12.98%) were seropositive, and 54 of 92 (58.7%) consignments had > or = 1 seropositive calf. Median within-consignment prevalence for consignments in which there was > or = 1 seropositive calf was 20%. Seropositive status was associated with significant reductions in average daily gain, live body weight at slaughter, and hot carcass weight and an increase in ribeye area-to-hot carcass weight ratio. Seropositive status also was associated with significant increases in cost of treatment and significant reductions in income. Sick seropositive calves had the highest cost of treatment. An economic loss of $15.62/calf was projected for seropositive calves. CONCLUSIONS AND CLINICAL RELEVANCE: Significant reductions in postweaning weight gain, carcass weight, and economic return were associated with detection of antibodies to N caninum in beef calves in a feedlot.

Syntheses and biological evaluation of novel pseudomycin side-chain analogues. Part 2.

A series of aliphatic side-chain analogues of pseudomycin was synthesized and evaluated during the course of our side-chain SAR effort. We found that several of the pseudomycin side-chain analogues (e.g., 10) exhibited good in vitro activity against all three major fungi responsible for systemic fungal infections.

Synthesis and insecticidal activity of spinosyn analogs functionally altered at the 2'-,3'- and 4'-positions of the rhamnose moiety.

In an effort to increase the insecticidal activity of the spinosyn family of naturally occurring macrolides, the 2'-, 3'- and 4'-O-desmethyl-O-acetyl analogs and the 2'-, 3'-, and 4'-O-desmethoxy analogs have been synthesized. These analogs were prepared synthetically from the minor spinosyn factors H, J, K, L and Q either via direct acylation of the corresponding factor or deoxygenation of an intermediate xanthate. The acylated analogs were all more potent insecticides against Heliothis virescens larvae than their respective parent factors, but not as potent as spinosyns A or D. The deoxy analogs were also more potent insecticides than their respective parent factors. The 2'-desmethoxy analogs showed, for the first time, analogs with insecticidal potency against H. virescens greater than that of spinosyns A and D, indicating that polarity is not well tolerated in the rhamnose moiety of spinosyn A.