Eastern North America is one of at least six regions of the world where agriculture is thought to have arisen wholly independently. The primary evidence for this hypothesis derives from morphological changes in the archaeobotanical record of three important crops--squash, goosefoot and sunflower--as well as an extinct minor cultigen, sumpweed. However, the geographical origins of two of the three primary domesticates--squash and goosefoot--are now debated, and until recently sunflower (Helianthus annuus L.) has been considered the only undisputed eastern North American domesticate. The discovery of 4,000-year-old domesticated sunflower remains from San Andrés, Tabasco, implies an earlier and possibly independent origin of domestication in Mexico and has stimulated a re-examination of the geographical origin of domesticated sunflower. Here we describe the genetic relationships and pattern of genetic drift between extant domesticated strains and wild populations collected from throughout the USA and Mexico. We show that extant domesticates arose in eastern North America, with a substantial genetic bottleneck occurring during domestication.

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Three new compounds, cadalen-15-oic acid (1), 3,7-dihydroxy-3(4H)-isocadalen-4-one (2), and dicadalenol (3), were isolated from the aerial parts of Heterotheca inuloides (Mexican arnica), together with the known compounds 7-hydroxycadalene (4), 7-hydroxy-4alphaH-3,4-dihydrocadalene (5), 1alpha-hydroxy-1(4H)-isocadalen-4-one (6), 1alpha-hydroxy-4alphaH-1,2,3,4-tetrahydrocadalen-15-oic acid (7), 7-(3,3-dimethylallyloxy)coumarin, caryolan-1,9beta-diol, and quercetin. The structures of the new compounds were elucidated by spectroscopic methods. The antiinflammatory activities of the extracts and the isolated compounds were evaluated by determining the inhibition of TPA-induced mouse ear edema. The natural products 3, caryolan-1,9beta-diol, and quercetin were the most active substances tested and displayed dose-dependent activities.

An extract from the roots of Ligusticum porteri, orally administered to groups of normal and diabetic mice, showed significant hypoglycemic and antihyperglycemic effects. Experimental type-II DM was achieved by treating mice with streptozotocin 15 min after an injection of β-nicotinamide adenine dinucleotide. (Z)-6,6',7,3'α-diligustilide (1), (Z)-ligustilide (2), 3-(Z)-butylidenephthalide (3), myristicin (4), and ferulic acid (5) were isolated from the active extract. When tested In Vivo, compounds 1-3 showed antihyperglycemic activity, with 3 being the most active. Compound 3 (56.2 mg/kg) decreased blood glucose levels in NAD-STZ-diabetic mice after an oral sucrose load, suggesting that its antihyperglycemic effect is due to inhibition of α-glucosidase at the intestinal level. Furthermore, 3 inhibited the activity of yeast-α-glucosidase (IC(50) 2.35 mM) in a noncompetitive fashion with a K(i) of 4.86 mM. Docking analysis predicted that 3 binds to the enzyme in a pocket close to the catalytic site, but different from that for acarbose, with a K(i) of 11.48 mM. Compounds 1 and 2 did not affect α-glucosidase In Vivo, but altered glucose absorption by a mechanism yet to be determined. The stimulatory effect of 5 on insulin secretion, present in high amounts in the extract, has been demonstrated in previous investigations. The present study provides scientific support of the use of L. porteri in Mexican folk medicine for the treatment of diabetes.