(E)-3-[4-(Dodec­yloxy)phen­yl]-1-(2-hydroxy­phen­yl)prop-2-en-1-one

In the title compound, C27H36O3, the asymmetric unit consists of two crystallographically independent mol­ecules. The aromatic rings form dihedral angles of 17.1 (2) and 17.6 (2)° in the two molecules. In both mol­ecules, the enone groups adopt an s–cis conformation and the alkoxyl chains are in trans conformations curving out of the zigzag plane. Intra­molecular O—H⋯O hydrogen bonds involving the keto and hydr­oxy groups generate S(6) ring motifs. The mol­ecules are stacked alternately in a head-to-tail fashion along the a axis and the crystal structure is stabilized by weak C—H⋯π inter­actions. The crystal studied was a non-merohedral twin, the ratio of components being 0.788 (2):0.212 (2)

Synthesis and Antimicrobial Studies of (E)-3-(4-Alkyloxyphenyl)-1-(2-hydroxyphenyl) prop-2-en-1-one, (E)-3-(4-Alkyloxyphenyl)-1-(4-Hydroxyphenyl)prop-2-en-1-one and their Analogues

A series of (E)-3-(4-alkyloxyphenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (2a-c) and (E)-3-(4- alkyloxyphenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one (3a-c) have been synthesized via Claisen-Schmidt condensation. The compounds differ in the length of alkyl groups, CnH2n+1, where n= 10, 12 and 14. The structures of the synthesized compounds were defined by elemental analysis, IR, H and C NMR. 1 13 Antimicrobial studies were carried out against E. coli ATCC 8739 to evaluate the effect of the hydroxyl and alkyl groups of the synthesised chalcones. All the synthesized compounds have shown significant antimicrobial activities. Chalcones (2a-c) showed better antimicrobial activities compared to chalcones (3a-c) respectively, with (E)-3-(4-decyloxyphenyl)-1-(2-hydroxyphenyl) prop-2-en-1-one showed the highest antimicrobial activity among the compounds tested

(E)-1-[4-(Hexyloxy)phenyl]-3-(2-hydroxyphenyl) prop-2-en-1-one

In the title compound, C21H24O3, the enone moiety adopts an s-cis conformation and the dihedral angle between the benzene rings is 12.89 (6)�. The hexyloxy tail adopts an extended conformation. In the crystal, inversion dimers are linked by pairs of O—H� � �O hydrogen bonds and pairs of C— H� � �O interactions, forming two R2 2(7) and one R2 2(10) loops. The dimers are then arranged into sheets lying parallel to (201) and weak C—H� � �� interactions consolidate the packing

(E)-3-(4-Hexyloxyphenyl)-1-(3-hydroxyphenyl)prop-2-en-one

In the title compound, C21H24O3, the enone unit is in the s–cis configuration. The dihedral angle between the benzene rings is 2.18 (4)�. In the crystal, molecules are linked by pairs of O— HO intermolecular hydrogen bonds, forming inversion dimers. The crystal structure is also consolidated by C—H interactions

(E)-1-(4-Decyl­oxyphen­yl)-3-(4-hydroxy­phen­yl)prop-2-en-1-one

In the title compound, C25H32O3, the asymmetric unit contains two crystallographically independent mol­ecules: both enone groups adopt an s-cis configuration. In the crystal, O—H⋯O and C—H⋯O inter­molecular inter­actions form bifurcated hydrogen bonds, which generate R 1 2(6) ring motifs. These inter­molecular inter­actions link the mol­ecules into one-dimensional chains along the [10] direction. The crystal structure is further stabilized by C—H⋯π inter­actions

(E)-3-[4-(Hex­yloxy)phen­yl]-1-(2-hydroxy­phen­yl)prop-2-en-1-one

In the title compound, C21H24O3, the conformation of the enone group is s–cis. The benzene rings are inclined at an angle of 7.9 (1)°. The alk­oxy tail is planar, with a maximum deviation from the least-squares plane of 0.009 (2) Å, and adopts a trans conformation throughout. An intra­molecular O—H⋯O inter­action between the keto and hydr­oxy groups forms S(6) ring motifs. In the crystal, mol­ecules are arranged in a head-to-tail manner down the a axis and are subsequently stacked along the b axis, forming mol­ecular sheets parallel to the ab plane. The crystal structure is further stabilized by weak C—H⋯π inter­actions and short C⋯O [3.376 (2) Å] contacts

(E)-1-[4-(Hex­yloxy)phen­yl]-3-(3-hy­droxy­phen­yl)prop-2-en-1-one

There are two mol­ecules in the asymmetric unit of the title compound, C21H24O3, in which the dihedral angles between the aromatic rings are 6.4 (1) and 7.0 (1)°. The enone moiety of both mol­ecules adopts an s–cis configuration. In the crystal, inter­molecular O—H⋯O and C—H⋯O inter­actions to the same acceptor O atom generate R 2 1(6) ring motifs and further C—H⋯O inter­actions generate R 2 2(8) ring motifs. Topologically, the R 2 1(6) and R 2 2(8) ring motifs are arranged alternately, forming [001] chains of mol­ecules. The crystal structure is further stabilized by C—H⋯π inter­actions

Studies on essential oils from several zingiber spp and alpinia spp and their biological activities

The chemical composition of the essential oils of three species of Zingiber and five species of Alpinia were investigated. Extraction by hydrodistillation method yielded essential oils in range between 0.083.55%. The highest oil yield identified from the rhizome oils of Z. officinale (2.27%) and A. Iigulala (3.55%) for each genus. Identification of chemical components in essential oils by gas chromatographyl flame ion detector (GC/FID) revealed the presence of geranial (13.93%) as the major component in rhizome oil of Z. officinale while myrcene (19.67%), limonene (26.44%) and ethyl cyclohexanoate (6.84%) as major constituents in leaves, stem and rhizome oils of Zingiber sp. I respectively. Nerolidol (9.31 %) and ~-bourbonene (16.78%) were found as principal constituents in the leaves and stem oils of Zingiber sp. 2 respectively. For A. galanga, the major compositions identified were bicycogermacrene (40.03%) in the leaves oil and asaricin (34.86%) in the rhizome oil. Butyl isothiocyanate (16.14%), methyl laurate (18.285%) and a-zingiberene (36.69%) obtained from the essential oils of the leaves, stem and rhizome from A. glabra respectively. A. aqualica var.1 contained p-pinene (46.89%) in the leaves part whereas I3-caryophyllene alcohol (9.62%) was found as major component in both stem and rhizome oils. a-zingiberene (22.78%) and I3-caryophyllene (24.13%) were found as major components in the leaves and rhizome oil respectively from A. aqualica var. 2. ~elemene was found as principal constituent in all parts of A. Iigulala. Toxicity test revealed that the leaves oil from Zingiber sp. I and the rhizome oil from A. Iigulala gave the highest LCso value of 68.13 ~g!mL and 9.12 ~g!mL respectively