Bioactive Compounds from Vitex leptobotrys

Abstract

A new lignan, vitexkarinol (1), as well as a known lignan, neopaulownin (2), a known chalcone, 3-(4-hydroxyphenyl)-1-(2,4,6-trimethoxyphenyl)-2-propen-1-one (3), two known dehydroflavones, tsugafolin (4) and alpinetin (5), two known dipeptides, aurantiamide and aurantiamide acetate, a known sesquiterpene, vemopolyanthofuran, and five known carotenoid metabolites, vomifoliol, dihydrovomifoliol, dehydrovomifoliol, loliolide and isololiolide, were isolated from the leaves and twigs of Vitex leptobotrys through bioassay-guided fractionation. The chalcone (3) was found to inhibit HIV-1 replication by 77% at 15.9 µM, and the two dehydroflavones (4 and 5) showed weak anti-HIV activity with IC50 values of 118 and 130 µM, respectively, while being devoid of cytotoxicity at 150 µM. A chlorophyll-enriched fraction of V. leptobotrys, containing pheophorbide a, was found to inhibit the replication of HIV-1 by 80% at a concentration of 10 µg/mL. Compounds 1 and 3 were further selected to be evaluated against 21 viral targets available at NIAID (National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD).

Quantitative Structure–Cytotoxicity Relationship of Chalcones

“…This finding is not contradictory with recent reports that chalcones exert anti-HIV activity partially or in a very narrow range of concentrations (32,33).…”

New Lignans and Iridoid Glycosides from Dipsacus asper Wall

“…Moreover, the downfield shift of C-7' (δ C : 88.9 ppm) and upfield shifts of H-9α (δ H : 3.19 ppm) and H-9β (δ H : 3.51 ppm) due to shielding by the phenyl ring at C-7 in 3 , which also supported that the phenyl ring at C-7 in 3 possessed the β-orientation, and H-7 and H-7' were threo -configuration [ 9 , 11 , 12 , 13 ]. In addition, the specific rotation of 3 was consistent with the report of vitexkarinol [ 14 ], but opposite to that of epi -pinoresionl-4, 4'-di- O -β- d -glucopyranoside [ 15 ]. On the basis of the above evidences, compound 3 was determined as (+)-(7 S , 8 S , 7' R , 8' S )-prinsepiol, and named dipsalignan B.…”

New Antiproliferative Polyunsaturated Epoxy-Heneicosane Derivatives Isolated from the Brown Alga Lobophora variegata

“…17 Since the isolated compounds in this study are structurally similar to the well-known fatty acids from omega-3 series (docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA)), we have rationalized an alternative biosynthetic approach for these compounds based on the classical pathway of unsaturated fatty acids synthesis to give DPA, followed by decarboxylation, epoxigenase and D-desaturases steps as suggested in the Scheme 1. 18 In addition to the new 3,4-epoxy-lobophorenes A and B, the known compounds β-carotene (3), 19 fucosterol (4), 20 apo-9'-fucoxanthinone (5), 21 apo-13'-fucoxanthinone (6), 21 lobophorenol B (7), 18 phytane glyceryl ether (8), 22 hepoxylin derivative (7,8-hepETE -9), 23 loliolide (10) 24 and isololoilide (11) 24 were also isolated.…”