Pharmacologically active flavonoids from the anticancer, antioxidant and antimicrobial extracts of Cassia angustifolia Vahl.

Background: Cassia angustifolia Vahl. (commonly known as senna makkai or cassia senna), native to Saudi Arabia, Egypt, Yemen and also extensively cultivated in Pakistan, is a medicinal herb used traditionally to cure number of diseases like liver diseases, constipation, typhoid, cholera etc. This study was conducted to evaluate the in-vitro antimicrobial, antioxidant and anticancer assays and phytochemical constituents of aqueous and organic extracts of C.

Alternate biosynthesis of valerenadiene and related sesquiterpenes.

It is proposed that the biosynthesis of the sesquiterpene valerenadiene, a key intermediate in the biosynthesis of a sedative in valerian, involves cyclopropane and not cyclobutane intermediates and includes as a key step a cyclopropylcarbinylcation-cyclopropylcarbinylcation rearrangement analogous to the one observed in the conversion of presqualene to squalene in triterpene and steroid biosynthesis. Similar mechanisms are proposed for the biosynthesis of the related sesquiterpenes pacifigorgiol, tamariscene and (+)-pacifigorgia-1,10-diene.

Studies of mixed liposomes with novel sorbyl functionalized head group lipids.

Three novel polymerizable amphiphiles with a sorbyl-substituted head group were synthesized and systematically characterized. These amphiphiles are neutral in charge. None of these molecules forms vesicles by itself, presumably due to lack of amphiphilicity and/or extensive head group interaction.

Commercially processed dry ginger (Zingiber officinale): composition and effects on LPS-stimulated PGE2 production.

Using techniques previously employed to identify ginger constituents in fresh organically grown Hawaiian white and yellow ginger varieties, partially purified fractions derived from the silica gel column chromatography and HPLC of a methylene chloride extract of commercially processed dry ginger, Zingiber officinale Roscoe, Zingiberaceae, which demonstrated remarkable anti-inflammatory activity, were investigated by gas chromatography-mass spectrometry. In all, 115 compounds were identified, 88 with retention times (R(t)) >21 min and 27 with <21 min. Of those 88 compounds, 45 were previously reported by us from fresh ginger, 12 are cited elsewhere in the literature and the rest (31) are new: methyl [8]-paradol, methyl [6]-isogingerol, methyl [4]-shogaol, [6]-isoshogaol, two 6-hydroxy-[n]-shogaols (n=8 and 10), 6-dehydro-[6]-gingerol, three 5-methoxy-[n]-gingerols (n=4, 8 and 10), 3-acetoxy-[4]-gingerdiol, 5-acetoxy-[6]-gingerdiol (stereoisomer), diacetoxy-[8]-gingerdiol, methyl diacetoxy-[8]-gingerdiol, 6-(4'-hydroxy-3'-methoxyphenyl)-2-nonyl-2-hydroxytetrahydropyran, 3-acetoxydihydro-[6]-paradol methyl ether, 1-(4'-hydroxy-3'-methoxyphenyl)-2-nonadecen-1-one and its methyl ether derivative, 1,7-bis-(4'-hydroxy-3'-methoxyphenyl)-5-methoxyheptan-3-one, 1,7-bis-(4'-hydroxy-3'-methoxyphenyl)-3-hydroxy-5-acetoxyheptane, acetoxy-3-dihydrodemethoxy-[6]-shogaol, 5-acetoxy-3-deoxy-[6]-gingerol, 1-hydroxy-[6]-paradol, (2E)-geranial acetals of [4]- and [6]-gingerdiols, (2Z)-neral acetal of [6]-gingerdiol, acetaldehyde acetal of [6]-gingerdiol, 1-(4-hydroxy-3-methoxyphenyl)-2,4-dehydro-6-decanone and the cyclic methyl orthoesters of [6]- and [10]-gingerdiols.

Dolastatin 11 conformations, analogues and pharmacophore.

Twenty analogues of the natural antitumor agent dolastatin 11, including majusculamide C, were synthesized and tested for cytotoxicity against human cancer cells and stimulation of actin polymerization. Only analogues containing the 30-membered ring were active. Molecular modeling and NMR evidence showed the low-energy conformations.

Fresh organically grown ginger (Zingiber officinale): composition and effects on LPS-induced PGE2 production.

Gas chromatography in conjunction with mass spectrometry, a technique previously employed to analyze non-volatile pungent components of ginger extracts modified to trimethylsilyl derivatives, was applied successfully for the first time to analyze unmodified partially purified fractions from the dichloromethane extracts of organically grown samples of fresh Chinese white and Japanese yellow varieties of ginger, Zingiber officinale Roscoe (Zingiberaceae). This analysis resulted in the detection of 20 hitherto unknown natural products and 31 compounds previously reported as ginger constituents. These include paradols, dihydroparadols, gingerols, acetyl derivatives of gingerols, shogaols, 3-dihydroshogaols, gingerdiols, mono- and diacetyl derivatives of gingerdiols, 1-dehydrogingerdiones, diarylheptanoids, and methyl ether derivatives of some of these compounds.

Chimeragenesis of the fatty acid binding site of cytochrome P450BM3. Replacement of residues 73-84 with the homologous residues from the insect cytochrome P450 CYP4C7.

A protein fragment of P450BM3 (residues 73-84) which participates in palmitoleate binding was subjected to scanning chimeragenesis. Amino acids 73-84, 73-78, 75-80, and 78-82 were replaced with the homologous fragments of the insect terpenoid hydroxylase CYP4C7. The four chimeric proteins, C(73-84), C(73-78), C(75-80), and C(78-82), were expressed, purified, and characterized.

Structure and characterization of flavolipids, a novel class of biosurfactants produced by Flavobacterium sp. strain MTN11.

Herein we report the structure and selected properties of a new class of biosurfactants that we have named the flavolipids. The flavolipids exhibit a unique polar moiety that features citric acid and two cadaverine molecules. Flavolipids were produced by a soil isolate, Flavobacterium sp.

Dolastatin 11 connects two long-pitch strands in F-actin to stabilize microfilaments.

Dolastatin 11, a drug isolated from the Indian Ocean sea hare Dolabella auricularia, arrests cytokinesis in vivo and increases the amount of F-actin to stabilize F-actin in vitro, like phalloidin and jasplakinolide. However, according to the previous biochemical study, the binding of dolastatin 11 to F-actin does not compete with that of phalloidin, suggesting that the binding sites are different. To understand the mechanism of F-actin stabilization by dolastatin 11, we determined the position of bound dolastatin 11 in F-actin using the X-ray fiber diffraction from oriented filament sols.

HPLC-NMR/HPLC-MS analysis of the bark extract of Stauranthus perforatus.

A combination of HPLC-MS and HPLC-NMR techniques has been used to analyse the cytotoxic fractions of the dichloromethane extract of bark of Stauranthus perforatus. Six furanocoumarins (byakangelicol, heraclenin, heraclenol, imperatorin, isopimpinellin and xanthotoxin) and nine quinoline alkaloids (two known compounds, veprisine and 5-hydroxy-1-methyl-2-phenyl-4-quinolone, along with seven novel compounds, stauranthine, 3',4'-dihydroxy-3',4'-dihydroveprisine, 3',4'-dihydroxy-3',4'-dihydrostauranthine, 3',6'-dihydroxy-3',6'-dihydroveprisine, 3',6'-dihydroxy-3',6'-dihydrostauranthine, 6'-hydroxy-3'-ketoveprisine and 6'-hydroxy-3'-ketostauranthine) have been identified in the fractions.

Antiviral saponins from Tieghemella heckelii.

Arganine C (1) and a new saponin, tieghemelin (2), were isolated from Tieghemella heckelii fruits. Arganine C (1) strongly inhibited HIV entry into cells in a cell fusion assay. The less potent tieghemelin (2) was converted into arganine C (1) by reduction of its ethyl ester with sodium borohydride.

Lyngbyastatin 1 and Ibu-epilyngbyastatin 1: synthesis, stereochemistry, and NMR line broadening.

The synthesis of a lyngbyastatin 1-Ibu-epilyngbyastatin 1 mixture combined with NMR and molecular modeling studies proved that natural lyngbyastatin 1 was only one Ibu epimer rather than a mixture of both and that the configuration of this epimer in the Ibu unit was R. The substance isolated with lyngbyastatin 1 was Ibu-epidolastatin 12. The extreme broadness in the proton NMR spectra of lyngbyastatin 1 and Ibu-epidolastatin 12 was exchange broadening due to rotation about the Ibu-Ala amide bond.

Saponins from Styrax officinalis.

Three triterpene saponins named Styrax-saponin A-C (1-3) were found in pericarps of Styrax officinalis together with the deacylsaponin (4). Structural determinations were achieved using 1D-, 2D-NMR and mass spectrometry.

Isolation of two highly potent and non-toxic inhibitors of human immunodeficiency virus type 1 (HIV-1) integrase from Salvia miltiorrhiza.

Water soluble extracts of the herbal plant, Salvia miltiorrhiza (Danshen) exhibited potent effect against HIV-1 integrase activity in vitro and viral replication in vivo. We have developed an extensive purification scheme to isolate effective, non-toxic inhibitors against human immunodeficiency virus type 1 (HIV-1) using the 3'-processing activity of integrase as a purification guide and assay. Two water soluble compounds, M(5)22 and M(5)32, have been discovered by isolating them from S.