CONFORMATIONALSTUDIESOF LlGNANSFROMDurio oxleyanus Griff. (Bombacaceae)

ABSTRACT Searching for secondary metabolites from the wood bark of Durio oxleyanus has afforded two new lignans, namely threo-carolignan Y (1) and erythro-carolignan Y \u27(2) together with three other known lignans erythrocarolignan X (3), boehmenan X (4) and boehmenan (5). The relative configurations of compounds 1 and 2 were establishedby J-based configurationalanalysis and 2D NOESYstudies. Keywords: carolignan, threo, erythro, Durio, Bombacacea

Isolation and absolute configuration of boehmenan from Durio affinis Becc

Boehmenan (1) is a lignan which has two feruloyl moieties at C-9 and C-9' respectively. The structural characterization of (+)-boehmenan was confirmed by H-NMR, C NMR and HRESIMS as well as by direct comparison with the literature. CD measurements established a 7S', 8R' configuration. Cytotoxicity evaluation showed that boehmenan is moderately active against the T47D cell line with IC 13.7 μg/mL and shows weak activity against the HeLa cancer cell line with IC 93.5 μg/mL. Boehmenan is also non-cytotoxic to the Vero cell line. From this study, boehmenan X and erythro-carolignan E were also obtained

Absolute structures and conformations of the spongian diterpenes spongia-13(16), 14-dien-3-one, epispongiadiol and spongiadiol

The absolute configurations of spongia-13(16),14-dien-3-one [systematic name: (3bR,5aR,9aR,9bR)-3b,6,6,9a-tetra-methyl-4,5,5a,6,8,9,9a,9b,10,11-deca- hydro-phenanthro[1,2-c]furan-7(3bH)-one], C20H28O2, (I), epispongiadiol [systematic name: (3bR,5aR,6S,7R,9aR,9bR)-7-hydr-oxy-6-hydroxy-methyl-3b,6,9a- trimethyl-3b,5,5a,6,7,9,9a,9b,10,11-deca-hydro-phenanthro[1,2-c]furan-8(4H)-one] , C20H28O4, (II), and spongiadiol [systematic name: (3bR,5aR,6S,7S,9aR,9bR)-7- hydr-oxy-6-hy-droxy-methyl-3b,6,9a-trimethyl-3b,5,5a,6,7,9,9a,9b,10, 11-deca-hydro-phenanthro[1,2-c]furan-8(4H)-one], C20H28O4, (III), were assigned by analysis of anomalous dispersion data collected at 130 K with Cu K radiation. Compounds (II) and (III) are epimers. The equatorial 3-hydroxyl group on the cyclo-hexa-none ring (A) of (II) is syn with respect to the 4-hydroxy-methyl group, leading to a chair conformation. In contrast, isomer (III), where the 3-hydroxyl group is anti to the 4-hydroxy-methyl group, is conformationally disordered between a major chair conformer where the OH group is axial and a minor boat conformer where it is equatorial. In compound (I), a carbonyl group is present at position 3 and ring A adopts a distorted-boat conformation

Antimalarial, anticancer, antimicrobial activities and chemical constituents of essential oil from the aerial parts of Cyperus kyllingia Endl.

The chemical constituents of the essential oil from Cyperus kyllingia Endl. were analyzed by a GC, GC-MS. Twenty-three compounds were identified, accounting for 93.75% of the total oil that consisted mainly of oxygenated sesquiterpenes (53.52%), particularly sesquiterpene hydrocarbons (38.97%), and carboxylic acid (1.26%). The most representative compounds were α-cadinol (19.32%), caryophyllene oxide (12.17%), α-muurolol (11.58%), α-humulene (9.85%), and α-atlantone (6.07%). The oil showed significant activities against Plasmodium falcipalum (K1, multi drug resistant strain) and NCI-H187 (Small Cell Lung Cancer) with the IC50 values of 7.52 and 7.72 μg/mL, respectively. The oil exhibited highly active against Staphylococcus aureus ATCC25923 and moderately active against Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27553, Aspergillus flavus and Candida albicans

IDENTIFICATION AND ANTIOXIDANT ACTIVITY TEST OF SOME COMPOUNDS FROM METHANOL EXTRACT PEEL OF BANANA (Musa paradisiaca Linn.)

The objective of these research was measured activity as antioxidant some compounds in methanol extracts of peel of banana (Musa paradisiaca Linn.), isolated some compounds which had activities as antioxidant, and determined this structure. Method of this study was extracted powdered peel of banana with methanol at room temperature. Extract was concentrated in vaccuo and then successively was partitioned with n-hexane, chloroform, etyl acetate, and buthanol. Antioxidant test from each fractions was measured by hydroxyl radical scavenger test with Fenton reaction method. The result of this study showed activity each fractions as  hydroxyl radical scavenger activity of chloroform, etyl acetate, and buthanol fraction were IC50 693.15; 2347.40; and 1071.14 mg/mL respectively. The isolation of secondary metabolite compounds from chloroform fraction obtained two isolate compounds. Identification by spectroscopy IR,  MS, 1H and 13C NMR one and two dimension showed that the compounds are 5,6,7,4'-tetrahidroxy-3,4-flavan-diol and a new compound cyclohexenon derivative (2-cyclohexene-1-on-2,4,4-trimethyl-3-O-2'-hydroxypropyl ether).   Keywords: antioxidant, peel of banana, Musa paradisiaca, hydroxyl radical scavenge

The 293 K structure of tetradehydrohaliclonacyclamine A

The polycyclic title compound {systematic name: (1S,16S,17S,31S)-3,20- diaza-tetra-cyclo-[15.15.0.1.1] tetra-tria-conta-6,8,23,25-tetra-ene}, CHN , has recently been isolated and characterized structurally, in solution by NMR spectroscopy and in the solid state by X-ray crystallography. At 130 K the structure is monoclinic (P21, Z = 4) and comprises two mol-ecules in the asymmetric unit with distinctly different conformations in the twelve-C-atom bridging chains. We report that, at 250 K, a phase change from monoclinic to ortho-rhom-bic (P22121, Z = 4) occurs. The higher-temperature phase is structurally characterized herein at 293 K. The two different conformers resolved in the monoclinic low-temperature form merge to give a single disordered mol-ecule in the asymmetric unit of the high-temperature phase

Chemoecological studies on marine natural products: terpene chemistry from marine mollusks

Some species of nudibranchs (Mollusca) protect themselves from predatory attacks by storing defensive terpene chemicals acquired from dietary sponges (Porifera) in specialized body parts called MDFs (mantle dermal formations), often advertising their unpalatability to potential predators by means of bright coloration patterns. Consequently, the survival of these trophic specialist species is closely related to the possibility of obtaining the defensive tools from sponges that live in their immediate vicinity; therefore, it is important to determine as precisely as possible the chemical composition of nudibranch extracts prior to any ecological studies addressing issues that involve their alimentary behavior and their defensive strategies, including the significance of their color patterns. Some of our recent studies on the chemical composition of terpene extracts from nudibranchs belonging to the genera Chromodoris and Hypselodoris are summarized. We also report the development of a method to assay extracts and purified metabolites for their feeding deterrent activity against co-occurring generalist predators. In a recent chemoecological study, showing that repugnant terpene chemicals are accumulated at extremely high concentrations in exposed parts of the nudibranchs' bodies, the feeding deterrence assays were carried out on the generalist marine shrimp Palaemon elegans, very common in the Mediterranean. We have modified this assay for use with the Australian shrimp species P. serenus, and confirmed the ecological validity of the assay by analysis of extracts from species of sponges and mollusks that live in the same habitat as P. serenus. The deterrent properties of haliclonacyclamine alkaloids isolated from the sponge Haliclona sp. were demonstrated, with the alkaloid mixture demonstrating palatability deterrence at concentrations as low as 0.05 mg/mL, and complete deterrence at 0.75 mg/mL. In contrast, the diterpene thuridillin metabolites from the sacoglossan mollusk Thuridilla splendens did not deter feeding by P. serenus

Taste and smell : a unifying chemosensory theory

Since antiquity, the sense of smell (olfaction) is considered as a distance sense, just like sight and hear-ing. Conversely, the sense of taste (gustation) is thought to operate by direct contact, similarly to touch.With the progress of natural sciences, information at molecular, anatomical, and neurobiological levelshas also contributed to the taste-smell dichotomy, but much evidence inconsistent with a sharp differenti-ation of these two senses has emerged, especially when considering species other than humans. In spite ofthis, conflicting information has been interpreted so that it could conform to the traditional differentia-tion. As a result, a confirmation bias is currently affecting scientific research on chemosensory systemsand is also hindering the development of a satisfactory narrative of the evolution of chemical communi-cation across taxa. From this perspective, the chemosensory dichotomy loses its validity and usefulness. Wethus propose the unification of all chemosensory modalities into a single sense, moving toward a synthetic,complex, and interconnected perspective on the gradual processes by which a vast variety of chemicals havebecome signals that are crucially important to communication among and within cells, organs, and or-ganisms in a wide variety of environmental conditions

Taste and Smell: A Unifying Chemosensory Theory

Since antiquity, the sense of smell (olfaction) is considered as a distance sense, just like sight and hear- ing. Conversely, the sense of taste (gustation) is thought to operate by direct contact, similarly to touch. With the progress of natural sciences, information at molecular, anatomical, and neurobiological levels has also contributed to the taste-smell dichotomy, but much evidence inconsistent with a sharp differenti- ation of these two senses has emerged, especially when considering species other than humans. In spite of this, conflicting information has been interpreted so that it could conform to the traditional differentia- tion. As a result, a confirmation bias is currently affecting scientific research on chemosensory systems and is also hindering the development of a satisfactory narrative of the evolution of chemical communi- cation across taxa. From this perspective, the chemosensory dichotomy loses its validity and usefulness. We thus propose the unification of all chemosensory modalities into a single sense, moving toward a synthetic, complex, and interconnected perspective on the gradual processes by which a vast variety of chemicals have become signals that are crucially important to communication among and within cells, organs, and or- ganisms in a wide variety of environmental conditions

Taste and Smell: A Unifying Chemosensory Theory

Since antiquity, the sense of smell (olfaction) is considered as a distance sense, just like sight and hearing. Conversely, the sense of taste (gustation) is thought to operate by direct contact, similarly to touch. With the progress of natural sciences, information at molecular, anatomical, and neurobiological levels has also contributed to the taste-smell dichotomy, but much evidence inconsistent with a sharp differentiation of these two senses has emerged, especially when considering species other than humans. In spite of this, conflicting information has been interpreted so that it could conform to the traditional differentiation. As a result, a confirmation bias is currently affecting scientific research on chemosensory systems and is also hindering the development of a satisfactory narrative of the evolution of chemical communication across taxa. From this perspective, the chemosensory dichotomy loses its validity and usefulness. We thus propose the unification of all chemosensory modalities into a single sense, moving toward a synthetic, complex, and interconnected perspective on the gradual processes by which a vast variety of chemicals have become signals that are crucially important to communication among and within cells, organs, and organisms in a wide variety of environmental condition