Sythesis of new benzopyranone mannich bases

Reaction of 7-hydroxy-5-methoxy-2-methyl-4-oxo-benzopyran-6- carboxaldehyde [1] with formaldehyde and piperidine [or morpholine] to give the corresponding 8-substituted piperidinomethyl or morpholinomethyl derivatives [compounds 2 and 3, respectively]. When formaldehyde and diethylamine were used, bis-[6-formyl-7-hydroxy-5- methoxy-2-methyl-4-oxo-benzopyran-8-yl]-methane [4] was formed. Reaction of 1 with hydroxylamine gave the aldoxime [5], which upon reaction with acetic anhydride gave the corresponding 7-acetyloxy-6- cyano-5-methoxy-2-methyl-4-oxo-benzopyran [6]. Mild hydrolysis of [6] with sodium hydroxide gave 6-cyano-7-hydroxy-5-methoxy-2-methyl- 4-oxo-benzopyran [7]. Reaction of 7 with piperidine and formaldehyde afforded the corresponding Mannich base [8]. Reaction of 1 with urea in ethanol gave the unexpected 5-ethoxy-7-hydroxy-2-methyl-4-oxo- benzopyran [10] which reacted with piperidine and formaldehyde to give the corresponding Mannich base [11]. Reaction of 1 with acetic anhydride gave 3-[7-hydroxy-5-methoxy-2-methyl-4- oxo-benzopyran-6- yl]-acrylic acid [12], while with acetic anhydride in the presence of anhydrous sodium acetate afforded 5-methoxy-8-methyl-2,6- dioxo- [2H,5H]-benzo-[3,2-b:4,5-b']-dipyran [13]. The Mannich bases 3, 14 and the dimer 4 were obtained from compound 12. The dimer 4 could be also obtained by reaction of 1 with formaldehyde. Structures of the compounds prepared were determined by MS, 1H-NMR, IR and elemental analyses. The compounds prepared showed promising antimicrobial activity

Composition and antimicrobial activity of volatiles from the leaf, flower and fruit of pimenta officinalis [Berg.] L. and pimenta racemosa [Mill] J. W. Moore cultivated in Egypt

Volatiles prepared by hydrodistillation of leaves [L] and flowers [F1], as well as, by n-hexane extraction of fruits [Fr] of each of Pimenta officinalis [Berg.] L. and Pimenta racemosa [Mill] J.W. Moore [family Myrtaceae] were analyzed by capillary gas chromatography coupled to mass spectrometry [CGC-MS]. Individual components of the oil of each of the organs of the two species were identified by their retention times and mass spectra, which were compared with published material or with data of reference compounds. Quantitative determination was carried out based on peak area integration. The study revealed that the oxygenated compounds constitute 93.79%, 65.31% and 89.11% of the oil in L, FI and Fr of Pimenta officinalis and 69.50%, 54.45% and 78.65% of the oil in L, FI and Fr of Pimenta racemosa, respectively. They are composed mainly of eugenol and isoeugenol; being 68.50%, 53.04% and 31.18% of the oil in L, FI, and Fr of Pimenta officinalis and 57.59%, 37.65% and 48.32% of the oil in L, FI and Fr of Pimenta racemosa, respectively. The unoxygenated compounds constitute 4.95%, 30.51% and 9.73% of the oil in L, FI and Fr of Pimenta officinalis and 27.40%, 40.93% and 17.65% of the oil in L, FI and Fr of Pimenta racemosa, respectively. Myrcene is the main monoterpene hydrocarbon; being 3.41%, 10.42% and 0.16% of the oil in L, FI and Fr of Pimenta officinalis and 11.51%, 16.84% and 0.06% of the oil in L, FI and Fr of Pimenta racemosa. The essential oils of the leaves of each of the two Pimenta species exhibited significant antimicrobial activity against certain Gram-positive and Gram-negative bacteria as well as fungal strains