Thesis (Ph.D.)--Chulalongkorn University, 2011

Chemical investigations of the twigs and leaves of Miliusa mollis, and from the leaves and the stems of Miliusa cf. fusca led to the isolation of fifteen new neolignans, namely, (2S,3S)-2,3-dihydro-2-(4-methoxyphenyl)-3-methyl-5-(E)-propenylbenzofuran, (7S,8S)-threo-Δ8'-4-methoxy-8.O.4'-neolignan, (2S,3S)-5-allyl-2-(4-methoxyphenyl)-3-methyl-2,3-dihydrobenzofuran, (7S,8S)-threo-Δ8'-7-acethoxy-4-methoxy-8.O.4'-neolignan, (2R,3R)-5-allyl-2-(4-hydroxy-3-methoxyphenyl)-3-methyl-2,3-dihydrobenzofuran, (2R,3R)-5-allyl-2-(4-hydroxyphenyl)-3-methyl-2,3-dihydrobenzo furan, (2R,3R)-5-allyl-2-(4-hydroxyphenyl)-7-methoxy-3-methyl-2,3-dihydrobenzofuran, (2R,3R)-2-(4-hydroxyphenyl)-3-methyl-5-(2-oxopropyl)-2,3-dihydrobenzofuran, (7S,8R)-Δ8'-5-hydroxy-3,4,5'-trimethoxy-7.O.3',8.O.4'-neolignan, (7S,8R)-Δ8'-4-hydroxy-3,5,5'-trimethoxy-7.O.3',8.O.4'-neolignan, (7R,8R)-Δ8'-4-hydroxy-3,5'-dimethoxy-7.O.3',8.O.4'-neolignan, (7R,8R)-Δ8'-3,4,5'-trimethoxy-7.O.3',8.O.4'-neolignan, 3,4,5,4',5'-pentamethoxy-3',b-epoxy-g,2'-neolign-8'-ene, (7R,8R)- Δ8'-3,4,5,5'-tetramethoxy-7.O.3',8.O.4'-neolignan, ∆7'-9'-hydroxy-4,5,3',5'-tetramethoxy-8.O.4'-neolignan, a new phenolic glycosides, namely, tyrosol-1-O-β-xylopyranosyl-(1→6)-O-β-glucopyranoside, and a new lignan, namely, rel-(7S,8S,7'R,8'S)-5-hydroxy-3,4,3',4'-tetramethoxy-7,7'-epoxylignan. In addition, seventeen known compounds were identified including (2R,3R)-2,3-dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-methyl-5-(E)-propenylbenzofuran, conocarpan, ()-epicatechin, liriodenine, asimilobine, (–)-norushinsunine, icariside D2, decurrenal, 2-methoxy-4-[2-[2-methoxy-4-(2-propen-1-yl)phenoxy]propyl]phenol, licarin A, eusiderin D, (7S,8R)-erythro-7-hydroxy-3,4,3O-trimethoxy-∆1,3,5,1',3',5',8'-8.O.4'-neolignan, 2-(4-allyl-2,6-dimethoxyphenoxy)-1-(3,4-dimethoxyphenyl)propane, virolongin B, eusiderin C, (+)-veraguensin and (7S,8S,7'R,8'S)-3,4,5,3',4'-pentamethoxy-7,7'-epoxylignan. The structures of these compounds were determined by means of spectroscopic analysis, as well as comparison of their UV, IR, MS and NMR properties with previously reported data. These isolated compounds were evaluated for free radical scavenging, cytotoxic and anti-herpes simplex virus activities. Three compounds including (2R,3R)-2,3-dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-methyl-5-(E)-propenylbenzofuran, (--)-epicatechin and asimilobine showed weak free radical scavenging activity. Some compounds from the leaves of M. mollis and M. cf. fusca showed moderate to weak cytotoxicity. Interestingly, (7S,8R)-erythro-7-hydroxy-3,4,3'-trimethoxy-∆1,3,5,1',3',5',8'-8.O.4'-neolignan showed potent cytotoxicity against KB, MCF7 and NCI-H187 cell lines without toxicity against ATCC CCL-81 (Vero cells). In addition, (2R,3R)-2-(4-hydroxyphenyl)-3-methyl-5-(2-oxopropyl)-2,3-dihydrobenzofuran, (7S,8R)-D8¢-4-hydroxy-3,5,5¢-trimethoxy-7.O.3¢,8.O.4¢-neolignan and licarin A showed weak activity against herpes simplex type 1 and type 2.