Henry N.C. Wong

Miltirone, a central benzodiazepine receptor partial agonist from a Chinese medicinal herb Salvia Miltiorrhiza

Ten diterpene quinones, which inhibited the binding of [3H]flunitrazepam to central benzodiazepine receptors with IC50s ranging from 0.3 to 36.2 microM, were isolated from the ethereal extract of the roots of Salvia miltiorrhiza. Among these natural products, miltirone has the highest potency (IC50 = 0.3 microM). It was orally active in an animal model used to predict clinical tranquilizing effects. Unlike diazepam, miltirone behaved as a partial agonist in the central benzodiazepine receptor binding and behavioural tests. Moreover, it produced no acute muscle relaxant effect and did not induce drug dependence and withdrawal reactions after chronic administration in mice.

Naturally occurring benzofuran: isolation, structure elucidation and total synthesis of 5-(3-hydroxypropyl)-7-methoxy-2-(3′-methoxy-4′-hydroxyphenyl)-3-benzo[b]furancarbaldehyde, a novel adenosine A1 receptor ligand isolated from salvia miltiorrhiza bunge (danshen)

Abstract A naturally occurring benzofuran, namely 5-(3-hydroxypropyl)-7-methoxy-2-(3′-methoxy-4′-hydroxyphenyl)-3-benzo[ b ]furancarbaldehyde was isolated from the roots of S. miltiorrhiza Bunge “Danshen”. Its structure was established by means of spectroscopic methods as well as by a total synthesis. Both the natural and the synthetic compounds showed a high potency (IC 50 = 17 nM and 10 nM, respectively) in the bovine adenosine A 1 radioligand binding. The title compound was isolated from the root of S. miltiorrhiza Bunge (Danshen) and its structure was established by spectroscopic methods as well as by a total synthesis.

Regiospecific synthesis of 3,4-disubstituted furans and 3-substituted furans using 3,4-Bis(tri-n-butylstannyl)furan and 3-(tri-n-butylstannyl)f

Abstract 3,4-Bis(tri-n-butylstannyl)furan and 3-(tri-n-butylstannyl)furan have been prepared and used successfully as building blocks to lead to various

Preleoheterin and leoheterin, two labdane diterpenes from Leonurus heterophyllus

Abstract Two new labdane diterpenes, namely preleoheterin and leoheterin, have been isolated from Leonurus heterophyllus. The previously known hispanolone and galeopsin have also been found in the same source. The structures of these compounds were established by spectroscopic means.

Prehispanolone, a novel platelet activating factor receptor antagonist from Leonurus heterophyllus.

1 Using an in vitro radioligand binding assay for the platelet activating factor (PAF) receptor, we have identified a novel, specific PAF antagonist, prehispanolone, from a Chinese medicinal herb Leonurus heterophyllus. 2 The presence of sodium ions inhibited specific [3H]‐PAF binding to rabbit platelet membrane with an IC50 of 5.2 mm, decreased the inhibitory potency of PAF but increased the inhibitory potency of prehispanolone. 3 Prehispanolone and several of its derivatives inhibited the binding of [3H]‐PAF to rabbit platelets with potencies closely resembling that of inhibition of PAF‐induced aggregation. 4 The integrity of the tetrahydrofuran ring of prehispanolone is critical for its interaction with the PAF receptor. 5 By hydrogenating the dihydrofuran ring and replacing the keto group of prehispanolone with a hydroxyl group, we obtained a compound, LC5507, that is more stable and more active than prehispanolone as a PAF receptor antagonist.

Prehispanolone, a labdane diterpene from Leonurus heterophyllus

Abstract A new labdane diterpene, prehispanolone, has been isolated from Leonurus heterophyllus . Its structure, 9α,13 R ;15,16-diepoxylabdan-14-en-7-one, was established by spectroscopic means as well as by examination of its derivatives.

A ligustilide dimer from Angelica sinensis.

Abstract A novel ligustilide dimer, E-232, was isolated from the roots of Angelica sinensis . Its structure was determined by spectroscopic methods. It inhibited 3 H-nitrendipine binding to the dihydropyridine-sensitive calcium channel with an ic 50 of 4 × 10 −7 M.

Chiral liquid crystalline compounds from D-(+)-Glucose

Abstract d -(+)-Glucose was used as a starting material to prepare four potentially useful chiral liquid crystalline molecules 2, 3, 4 and 5 having multiple chiral centers in their rigid cores. It is clear that 2 indeed incorporates properties essential for ferroelectric liquid crystals, i.e., a chiral smectic C phase with an induced spontaneous polarization of about 23 nC/cm2. Compound 3, on the other hand, shows only a nematic phase, while 4 merely shows a sharp melting point and 5 is an oil.

Enantioselective synthesis of chiral liquid crystalline compounds from monoterpenes

Abstract Chiral liquid crystalline compounds 1–9 have been synthesized enantioselectively from monoterpenes. The optical purities of (S)-(−)- and (R)-(+)-perillalcohol (16, 27), (S)-(−)- and (R)-(+)-1-pentyl-4-hydroxymethyl-1-cyclohexene (33, 34) and (2S,5S)-2-pentyl-5-hydroxymethyl-1-cyclohexanone (53) have been determined by 1H NMR analysis using chiral shift reagents. The mesomorphic phases and transition temperatures of compounds 2,3,5,6,7,8 and 9 have been characterized.

Arene synthesis by extrusion reaction. X: Synthesis of arenes by deoxygenation of endoxides with cyclopentadienyltitanium trichloride/lithium aluminum hydride and dicyclopentadienyltitanium dichloride/lithium aluminum hydride

Abstract The two homogeneous systems, cyclopentadienyltitanium trichloride/lithium aluminum hydride and dicyclopentadienyltitanium dichloride/lithium aluminum hydride have been utilized to deoxygenate 1,4-endoxides in tetrahydrofuran. The results show that they can provide corresponding arenes in fair fields.