Thevetia peruviana and Plumeria rubra (family Apocyanaceae) are shrubs cultivated in Egypt for ornamental purposes. This study was done to compare the volatile oils of T. peruviana and P. rubra which were prepared by using the hydrodistillation method from fresh flowers and leaves of each plant. Identification and quantification of the oil components were carried out by GC/MS analysis. The major components of T. peruviana flowers oil were Nonadecane (37.69 %), followed by 1-Nonylcycloheptane (18.39%), while Perilla alcohol (20.49%), β-ylangene(10.62%) and β-Elemene (7.19%) were predominant in the leaves oil. On the other hand, the major constituents of P. rubra flowers oil were Methyl dihydroepi-jasmonate (35.41%), Linalool (14.31%) and Methyl jasmonate (11.99%), while 1-Nonylcycloheptane (32.16%) and Menthol (17.89%) were of highest abundance in the leaves oil. Also, the antimicrobial activity was investigated against Staphylococcus aureus ATCC 4175, Escherichia coli ATCC 10536, Pseudomonas aeruginosa CNCM A21, and Candida albicans ATCC 60193. The minimum inhibitory concentrations (MIC) were determined and compared with those of standard antibiotics (Ofloxacin and Amphotericin B), the tested oils showed a good inhibitory effect against the investigated microbial strains with a minimum inhibitory concentration (MIC) range of 25 to 300 µg/mL except for the P. rubra leaves oil, which showed no activity against Pseudomonas aeruginosa.

Phytochemical investigation of 70% aqueous methanol extract of leaves of lemon balm (Melissa officinalisL., Lamiaceae) was subjected to different chromatographic separation techniques. The structures of isolated compounds were determined based on spectral data (UV, 1 H-NMR, 13 CNMR, and mass spectrometry). Also, assessment of the antioxidant, anticonvulsant, anti-inflammatory as well as antimicrobial activities was determined using different techniques. Result: three isoflavones;4'-methoxy genistein Biochanin A] (1),6, 8 dimethoxy-biochanin A -7 -O-α -L-rhamnopyranosyl (1'''-6'') -O - -D-glucopyranoside (2), isoflavone 6, 8dimethoxy 7-O--D rutinoside, 4'-O-α-L-rhamnopyranoside (3).Besides six known flavonoids; hyperin (4), luteolin 7-O-rhamnoside(5), scutellarein -4',7 dimethyl ether(6), nepetin -7-methyl ether(7),luteolin(8),and apigenin (9),in addition to caffeic acid(10), chlorogenic acid (11) isolated for the first time from Melissa officinalis. The examined extract revealed significant anticonvulsant activity, effective in inhibition of both acute & chronic inflammation. Scutellarein -4',7-dimethyl ether (6) showed remarkable inhibition against fungi and exhibited the highest antibacterial effect against both Gram +ve and Gram -ve bacteria. The above evidence suggests that Melissa officinalis leaves are a good supply of natural isoflavones that can be utilized to avoid convulsion, and inflammation, as well as an antioxidant and antimicrobial supplement.