The chemical constituents of hexane and ethyl acetate extracts of Gardenia sootepensis (G. sootepensis) and ethyl acetate extract of Pseudomussaenda flava (P. flava) were analyzed for the first time using GC and GC-MS. For the hexane extract of G. sootepensis: Nineteen compounds were identified constituting of 74.70% of the total chromatographical fraction components. The principle compounds were 9, 12, 15-octadecatrienoic acid (23.10%) and squalene (16.50%). For the ethyl acetate extract of G. sootepensis: Sixteen compounds were identified. The main compounds were octadecane (15.40%) and eicosane (14.50%). The ethyl acetate extract of P. flava: Nine compounds were identified. The founded compounds were squalene (21.20%) and 9, 12, 15-octadecatrienoic acid (17.40%). The in vitro antibacterial activity of the leave extracts in various solvents against four bacterial strains were investigated. The hexane and ethyl acetate extracts of G. sootepensis were found to possess antibacterial activity against S. aureus and S. pyogenes with the MIC value of 10 mg/mL respectively. The hexane and ethyl acetate extracts of G. sootepensis showed significant cytotoxicity against NCI-H187 cell lines with the IC50 values of 2.25 and 2.21 µg/mL respectively. But the extracts were non-cytotoxic to MCF-7 cell line. The results revealed that all the medicinal plant extracts possessed antioxidant activity. The ethyl acetate extract of G. sootepensis and P. flava exhibited the highest antioxidant activity with the IC50 value of 6.36 ± 0.02 mg/mL. and 9.74 ± 0.09 mg/mL. Keywords: Antioxidant activity, Biological activity, Chemical constituents, Gardenia sootepensis, Pseudomussaenda flava, Leaves extracts

The essential oil of the leaves was isolated by hydrodistillation and the ethanolic extract of the flowers from Gardenia carinata Wallich. were analyzed for the first time using GC and GC-MS. For the leaves essential oil: Seventeen compounds were detected and eleven compounds were identified, corresponding to 71.10% of the total chromatographical oil compounds. The major constituents were phytol (13.80%), 3-hexene-1-ol, benzoate (12.50%), vitispirane (8.00%), hexadecanal (7.90%), β-damascenone (3.90%) and (E,E)-α-farnesene (3.80%). For the flowers extract: Seventeen compounds were identified, constituting 37.5% of the total chromatographical components. The typical compounds were heneicosane (9.70%), ethyl linolenate (5.70%), squalene (5.70%), 4-allylphenol (5.40%), stigmasterol (2.10%), n-docosane (1.60%), lupenone (1.40%), hexadecanoic acid (0.90%) and compesterol (0.70%). The leaves essential oil showed antibacterial activity against both Gram positive S. aureus with the most potent activity at 18.7 µg/disc, and Gram negative E. coli with an activity of 17.6 µg/disc. The oil was not active against Gram negative P. aeruginosa. The antioxidant activity of the leave essential oil and the ethanolic flower extract were evaluated by using the DPPH and ABTS radical scavenging assay. The leave essential oil showed medium antioxidant activity with the IC50 value of 15.24 ± 0.08 and 10.88 ± 0.05 mg/mL. The ethanolic flower extract possessed high antioxidant activity with the IC50 value of 3.68 ± 0.03 and 2.53 ± 0.03 mg/mL. Keywords: Gardenia carinata, GC-MS, Leave essential oil and ethanolic flowers extract, Antibacterial and antioxidant activities.