Semisynthesis and insecticidal bioactivities of benzoxazole and benzoxazolone derivatives of honokiol, a naturally occurring neolignan derived from Magnolia officinalis.

Honokiol, a natural bioactive neolignan isolated from the bark and leaf of Magnolia officinalis and Magnolia obovata, exhibits many important biological properties. In continuation of our interest in discovery of the agrochemicals derived from the natural sources, thirty-seven new 8/8'-alkylthiol-benzoxazole and N-alkyl/sulfonyl-benzoxazolone derivatives of honokiol were prepared and their insecticidal activities were evaluated against the larvae of Mythimna separata Walker and Plutella xylostella Linnaeus. The results showed that eleven derivatives exhibited potent insecticidal activity against M. separata when compared with the positive control. Particularly, compound 5h displayed the most promising insecticidal activity against M. separata with the final mortality rate (FMR) of 58.6%. Meanwhile, compounds 7n (FMR = 65.3%), 7p (FMR = 61.5%), and 8c (FMR = 65.3%) demonstrated a greater insecticidal activity against P. xylostella than toosendanin, a well-known botanical insecticide. Additionally, the preliminary structure-activity relationships (SARs) were also discussed. This study indicates that these honokiol derivatives could be used as leads for the further derivation and development of the potential pesticide candidates for crop protection.

Natural product-based semisynthesis and biological evaluation of thiol/amino-Michael adducts of xanthatin derived from Xanthium strumarium as potential pesticidal agents.

Xanthatin, a natural sesquiterpene lactone, occurs as one of the major constituents of Xanthium plants (Compositae) and exhibits many important biological properties. To discover natural products-based pesticides, forty-nine Michael-type thiol/amino adducts of xanthatin were synthesized and characterized, while their pesticidal activities were investigated. Among them, compounds 2c, 2h, 2i, and 2t exhibited more potent antifungal activity against Botrytis cinerea (IC50 = 0.96, 0.38, 6.33, and 7.21 µg/mL, respectively) than xanthatin and the two commercial fungicides. Compounds 2t and 2u displayed broad-spectrum and excellent antifungal effects against all tested phytopathogenic fungi, while their IC50 values ranged from 7.21 to 75.88 µg/mL. Compounds 2a, 2f, 2l, 2m, 2v, 7c, 7e, 7h, 7i, and 7j showed moderate larvicidal activity against Plutella xylostella Linnaeus. Furthermore, compounds 2b, 7g, and 7h demonstrated significant ovicidal activity against P. xylostella with the LC50 values of 14.04, 10.00, and 11.95 mg/L, respectively. These findings suggest that thiol/amino appended in the C-13 position of xanthatin may improve antifungal and ovicidal activities for the derivatives. It was also noticed that the exocyclic double bond of xanthatin is crucial for its larvicidal activity. This work also provides some important hints for further design, synthesis, and structural modification of the xanthanolides sesquiterpene lactones toward development of the new environmentally friendly pesticides for sustainable agricultural production.

[Association between serum uric acid and early kidney damage in middle-aged and elderly].

OBJECTIVE: To investigate the association between serum uric acid (UA) and early kidney damage and the prevalence of early kidney damage [89 >or= GFR >or= 60 ml * min(-1) * (1.73m(2))(-1)] in the middle-aged and elders with normal serum creatinine. METHODS: A survey of cardiovascular risk factors, including serum UA and estimated glomerular filtration rate (eGFR) [according to MDRD (modification of diet in renal disease) equation], was carried out in a local general population of Chengdu. A total of 1023 subjects with normal serum creatinine [mean age: (63 +/- 6) years; male: female = 52.7%: 47.3%] were recruited by random sampling method. The subjects were divided into 4 groups (A, B, C, D) according to the quartiles of serum UA levels (A: UA < 282 micromol/L, B: 282 micromol/L or= 379 micromol/L). RESULTS: In the group, the prevalence of early kidney damage was 28.1% (men: 35.8% > women: 19.5%, P < 0.01). In men and women, serum UA and mild kidney dysfunction were negatively correlated, and the prevalence of early kidney damage significantly increased with the elevated level of serum UA. The prevalence of early kidney damage was higher in men than women (P < 0.01). According to the logistic regression analysis adjusting for age, gender, waist, body mass index, triglyceride, HDL-C, total cholesterol, history of hypertension and diabetes type 2, the odds ratio of the prevalence of early kidney damage were 1.0 [B: 1.740 (P = 0.151), C: 3.599 (P = 0.01) and D: 5.488 (P < 0.01) respectively]. CONCLUSION: In the middle-aged and elders with normal serum creatinine, serum UA and eGFR are negatively correlated. And serum UA level is independently associated with early kidney damage.

[Relationship between microalbuminuria and cognition in primary hypertension patients].

OBJECTIVE: To study the relationship between microalbuminuria and cognitive impairment in primary hypertensive patients. METHODS: A total of 200 hypertensive patients were included in this study. Blood pressure, body height and weight, total cholesterol, triglyceride, fasting plasma glucose, 2 hour-postprandial blood sugar, insulin level and urine protein were measured. Microalbuminuria and urine creatinine were determined in patients without proteinuria. The risk stratification of hypertension was evaluated. The cognitive function and calculate scores were tested by the Mini Mental State Examination (MMSE) and patients were divided into two groups: > 24-scores were classified as normal cognition group, < or = 24-scores as impaired cognition group. RESULTS: Among the 200 hypertensive patients, proteinuria was detected in 25 patients. There was no significant difference in the cognitive function between patients with and without proteinuria (P > 0.05). There were significant differences on age, educational level, occupation, smoking, history of coronary heart disease, history of cerebrovascular disease, the risk stratification of hypertension, microalbuminuria/creatinine ratio, postprandial insulin level, cholesterol and diastolic blood pressure between normal cognition function group and impaired cognition function group (all P < 0.05). Multivariate logistic regression analysis showed that microalbuminuria, educational level and the risk stratification of hypertension were significantly correlated to cognition impairment (all P < 0.05). CONCLUSIONS: Educational level, the risk stratification of hypertension and microalbuminuria are associated with cognitive impairment in this patient cohort.