Search

As a valuable traditional Chinese herbal medicine, Radix Astragali has attracted much attention due to its extensive pharmacological activities. In this study, density functional theory (DFT) was used thermodynamically and kinetically in detail to predict the antioxidant activity and reaction mechanisms involved in the free radical scavenging reactions of three representative isoflavonoids (formononetin, calycosin, and calycosin-7-glucoside) extracted from Radix Astragali. Three main mechanisms, including hydrogen atom transfer (HAT), proton transfer after electron transfer (SET-PT), and sequential proton loss electron transfer (SPLET) were examined by calculating the thermodynamic parameters. It was found that HAT is the predominant mechanism in the gas phase, while SPLET is supported in the solvent environment. The isoflavonoids’ order of antioxidant activity was estimated as: calycosin > calycosin-7-glucoside > formononetin. For the calycosin compound, the result revealed the feasibility of double HAT mechanisms, which involve the formation of stable benzodioxazole with significantly reduced energy in the second H+/e− reaction. In addition, the potential energy profiles and kinetic calculations show that the reaction of •OH into the 3′-OH site of calycosin has a lower energy barrier (7.2 kcal/mol) and higher rate constant (4.55 × 109 M−1 s−1) compared with other reactions in the gas phase.

Prosyntexis lata Li, Shih & T. Gao sp. nov. (Figs 3–7) Type material. Holotype: CNU-HYM-MA2015108 (Figs 3, 4), female. Most of body preserved, except apex of right antenna lost; left antenna compressed diagenetically and right metatarsus fractured.The specimen is indistinct in left lateral view. Paratype: CNU-HYM-MA2015106 (Figs 5, 6), male. Most of body parts preserved except for missing apices of both antennae. CNU-HYM-MA2015109 (Fig. 7), male. Apices of forewings and hind legs missing. Etymology. The name lata is derived from the Latin word latus, referring to the broad pterostigma. Diagnosis. The new species is unique within Prosyntexis in having very long cell 1mcu (ratio of length to width more than 3). It also differs from other species, except P. gobiensis Rasnitsyn, 1993, in having 3r-m very close to 2m-cu in the forewing (ratio of length of 2m-cu to length of 3-M more than 5). Locality and horizon. Hukawng Valley, Kachin State, northern Myanmar; lowermost Cenomanian, mid-Cretaceous. Description. Holotype. Body about 6.52 mm long in lateral view, antenna 7.07 mm long in lateral view; forewing about 5.23 mm in length, maximum width 1.71 mm; hind wing about 4.01 mm in length (Fig. 3A, B). Head 0.57 mm long in lateral view. Compound eye medium sized and oval. Labial palpus with at least two palpomeres. Antenna elongate and filiform with 16 segments preserved; scape 0.23 mm long, maximum width 0.12 mm; pedicel 0.57 mm long, maximum width 0.09 mm; flagellomere I longer than scape and pedicel, 0.90 mm long, 0.10 mm wide, flagellomere II 0.66 mm long, 0.09 mm wide, as wide as remaining flagellomeres (Fig. 4B). Thorax with a deep medial membranous depression in the mesonotum bordered laterally by strong striate surfaces (Fig. 4A). Legs slender, profemur slightly longer than protibia; metafemur length 1.03 mm, metatibia 1.45 mm long, maximum width 0.13 mm. Single protibial spur, cleft apically (Fig. 4D); mesotibia with two apical spurs (Fig. 4E); metatibia with two apical spurs (the smaller spur less than half length of larger spur and not wide) (Fig. 4F). Tarsi pentamerous, basitarsomere long but shorter than remaining tarsomeres combined; tarsomere slightly elongate; pretarsal claws short, with curved apices and additional inner teeth (Fig. 4G). Forewing (Fig. 3C) with C strongly thickened; Sc+R present; costal space narrow, slightly enlarged at twothirds of its length; 1-Rs slanted toward wing apex and 0.8 as long as 1-M; pterostigma broad, oblong and 3.5× as long as wide; 1-M+Cu bent basally; distal part of 2- Rs undeveloped in both left and right forewings; 1r-rs connected to pterostigma at its base and slightly longer than 3-Rs; 2r-rs issuing from 1/3 of pterostigma and at nearly 0.4 of 2+3rm length; 2rs-m absent; 3-M extremely short and 0.2× as long as 2m-cu. Cell 1mcu subquadrate, about 2.6× as long as wide; cell 2mcu pentagonal, about 1.6× as long as wide. 2A+3A wavy medially. Hind wing (Fig. 3C) with cell r close; Sc+R present; 1-Rs about 0.99 mm in length, nearly 1.6× as long as 1-M; 1rs-m about 0.25 mm in length, short and slightly proclival; 1-M bent; 2-M+Cu present. 2rs-m, 3rs-m and 1m-cu absent; terminal abscissa of Cu and cu-a well-developed; 1-Cu and cu-a straight. Abdomen with short ovipositor sheath 1.85 mm long in ventral view and slightly protruding beyond apex of abdomen (Fig. 4C). Paratype (CNU-HYM-MA2015106). Body about 4.30 mm long in lateral view; forewing about 3.98 mm in length, maximum width 1.29 mm; hind wing about 3.02 mm in length (Figs 5, 6). Head 0.63 mm long and 0.43 mm wide in lateral view, rather small and subquadrate. Compound eyes medium sized and round. Maxillary palpus with six palpomeres (Fig. 6C); labial palpus with at least three palpomeres. Antenna elongate and filiform with 9 segments preserved; scape 0.20 mm long, maximum width 0.10 mm; pedicel 0.28 mm long, maximum width 0.10 mm, slightly swollen apically; flagellomere I longer than scape and pedicel, 0.56 mm long, 0.11 mm wide, flagellomere II 0.49 mm long, 0.11 mm wide (Fig. 6B). Thorax with deep medial membranous depression in the mesonotum bordered laterally by strong striate surfaces (Fig. 6D). Legs slender, profemur slightly longer than protibia; metafemur length 0.84 mm, metatibia 0.76 mm long, maximum width 0.14 mm. Protibia with one apical spur (Fig. 6F), mesotibia apical spurs not visible. Metatibia with two apical spurs (the smaller spur thick, less than half length of larger spur) (Fig. 6G). Tarsi pentamerous, basitarsomere long but shorter than remaining tarsomeres combined; metatarsomere elongate and claws 0.08 mm long with curved apices and additional inner teeth. Forewing (Fig. 5C) with C strongly thickened; Sc+R present; costal space distinctly narrow, slightly enlarged at the middle; basal section of Rs slanted toward wing apex and 1.6× as long as basal section of M; pterostigma broad, oblong and 2.8× as long as wide; 1-M+Cu bent basally; 2-M+Cu exceptionally short and nearly 0.05 mm long, scarcely present owing to proximal position of cua near origin of 1-Cu. 1-Rs+M 0.48 mm long and 4× as long as 2-Rs+M; end of 2-Rs very weak; 1r-rs connected to pterostigma at its base and longer than section of Rs between 1r-rs and 2r-rs; 2r-rs issuing from one-third of pterostigma and at one-third of 2+3rm length; 2rs-m absent; section of M between 2m-cu and 3rs-m extremely short and 0.2× as long as 2m-cu. Cell 1mcu subquadrate, about 3× as long as wide; cell 2mcu hexagonal, about 1.7× as long as wide. 2A+3A waved medially. Hind wing (Fig. 5C) with cell r closed and large; Sc+R present; 1-Rs about 0.86 mm in length, nearly 2× as long as 1-M; 1rs-m about 0.11 mm in length, short and slightly proclival; 1-M bent and 0.44 mm long; 2-M+Cu present and 0.20 mm long. 2rs-m, 3rs-m and 1m-cu absent; terminal abscissa of Cu and cu-a well-developed; 1-Cu and cu-a straight. Abdomen with nine distinguishable segments in lateral view. Hypopygium narrower rounded apically comparing P. aristovi sp. nov. Male genitalia (Fig. 6E) distinct, narrow, tightly closed obscuring details except gonostyle about 0.17 mm long, very narrow and with two thin threads of obscure identity at their apex. Cercus about 0.13 mm long. Paratype (CNU-HYM-MA2015109). Differs from the above paratype in shorter distance between compound eyes and postoccipital sulcus. Compound eyes rather large and oval.Antenna elongate and filiform with 16 segments, flagellomere I longer than scape and pedicel combined (Fig. 7A, B). Pronotum lateral edge slightly contracted inward. Hypopygium apparently as in other paratype. Genitalia internalized with very narrow gonostyli partially visible, with no threads visible., Published as part of LI, XIAO-QIN, RASNITSYN, ALEXANDR P., GAO, JIA, ZHANG, YAN-JIE, SHIH, CHUNG-KUN, REN, DONG, ZHAO, YUN-YUN & GAO, TAI-PING, 2023, New taxa of Sepulcidae (Hymenoptera) from mid-Cretaceous Kachin amber, pp. 133-145 in Palaeoentomology 6 (2) on pages 136-139, DOI: 10.11646/palaeoentomology.6.2.5, http://zenodo.org/record/7928967, {"references":["Rasnitsyn, A. P. (1993) New taxa of Sepulcidae. In: Ponomarenko, A. G. (Ed.), Mesozoic insects and ostracods from Asia. Transactions of the Paleontological Institute, Russian Academy of Sciences, 252, pp. 80 - 99. [In Russian]"]}

Prosyntexis antennata Li, Shih & T. Gao sp. nov. (Figs 8, 9) Type material. Holotype: CNU-HYM-MA2015107, a male specimen. Most of body preserved except left antenna broken and with apex lost, and left forewing broken. Etymology. The name antennata is derived from the Latin word antennatus referring to the long antennae. Diagnosis. The new species is unique within Prosyntexis in having cu-a behind the fork of M+Cu in the hind wing (hind wings not preserved or very incomplete in P. gouleti, P. gobiensis, P. montsecensis and P. aristovi). It also differs from other species, except for P. aristovi, in having a short and thin Sc in the forewing; and distinguished from P. aristovi by short 3-M (3r-m and 2m-cu approaching). Locality and horizon. Hukawng Valley, Kachin State, northern Myanmar; lowermost Cenomanian, mid-Cretaceous. Description. Body about 6.51 mm long in lateral view, antenna 8.31 mm long in lateral view; forewing about 5.89 mm in length, maximum width 2.56 mm; hind wing about 4.31 mm in length, maximum width 1.82 mm (Fig. 8A, B). Head 0.60 mm long and 0.68 mm height in lateral view, slightly small and subquadrate. Compound eyes slightly large and preserved in a shrunken state. In lateral view maxillary palpus with six palpomeres, palpomere I short and thick; palpomere II 0.33 mm long and swelled apically; palpomere III elongate and almost 0.71 mm long; palpomere IV 0.46 mm long; palpomere V 0.43 mm long and palpomere VI 0.44 mm. Labial palpus with two palpomeres with inflated last segment (Fig. 9C). Antenna elongate and filiform with 16 segments; scape 0.30 mm long, maximum width 0.12 mm; pedicel 0.42 mm long, maximum width 0.16 mm, slightly swollen apically; flagellomere I longer than scape and pedicel, 0.81 mm long, 0.15 mm wide, flagellomere II 0.74 mm long, 0.12 mm wide, as wide as individual widths of remaining flagellomeres (Fig. 9A). Thorax with membranous medial depression in the mesonotum bordered laterally by strong striate surfaces (Fig. 9D). Legs slender, profemur slightly longer than protibia; metafemur length 1.21 mm, metatibia 1.55 mm long, maximum width 0.22 mm. Single protibial spur, cleft apically (Fig. 9F); mesotibia with two apical spurs (Fig. 9G); metatibia with two apical spurs (smaller spur thick and less than half length of larger spur) (Fig. 9H). Tarsi pentamerous, basitarsomere long but shorter than remaining tarsomeres combined; tarsomere V not elongate; pretarsal claws short, with curved apices and additional inner teeth (Fig. 9I). Forewing (Fig. 8C) with C strongly thickened; costal space obviously narrow, slightly enlarged at middle; Sc short and thin, appearing like a crossvein before origin of Rs; 1-Rs slanted toward wing apex and twice as long as 1-M; pterostigma long and broad, oblong and 3.5× as long as wide with center translucent; M+Cu bent basally. 2-Rs+M especially short; junction of 2-Rs, 2-Rs+M and 2+3-M very weak; 1r-rs connected to pterostigma at its base and slightly shorter than section of Rs between 1r-rs and 2r-rs; 2r-rs issuing from 1/4 of pterostigma and at two-fifth of 2+3rm length; 2rs-m absent; 3-M short and 0.3× as long as 2m-cu. Cell 1mcu subquadrate, about 2.4× as long as wide; cell 2mcu hexagonal, about 2× as long as wide. 2A+3A wavy medially. Aberrant vein extending from 4-Cu near 2m-cu of left forewing, towards posterior margin of the wing (Fig. 8C). Hind wing (Fig. 8C) with basal and distal hamuli present (no intermediate ones found); cell r close; Sc+R present; 1-Rs about 1.08 mm in length, nearly 1.7× as long as 1-M; 1rs-m about 0.30 mm in length, proclival and short; 1-M bent; 2rs-m, 3rs-m and 1m-cu absent; terminal abscissa of Cu and cu-a well-developed; 1-Cu and cu-a straight, 1-Cu especially short and nearly 0.2× as long as cu-a in left hind wing; right hind wing lacking 1-Cu (cu-a coinciding with M+Cu fork). Abdomen with nine distinguishable segments in lateral view. Male genitalia (Fig. 9E) narrow, with gonostyle slender and about 0.36 mm long; cercus about 0.24 mm long., Published as part of LI, XIAO-QIN, RASNITSYN, ALEXANDR P., GAO, JIA, ZHANG, YAN-JIE, SHIH, CHUNG-KUN, REN, DONG, ZHAO, YUN-YUN & GAO, TAI-PING, 2023, New taxa of Sepulcidae (Hymenoptera) from mid-Cretaceous Kachin amber, pp. 133-145 in Palaeoentomology 6 (2) on pages 140-142, DOI: 10.11646/palaeoentomology.6.2.5, http://zenodo.org/record/7928967

Key to species of Prosyntexis 1. Forewing with pterostigma narrow; 2r-rs joining pterostigma near its apex; cell 2r more than twice as long as wide................ P. montsecensis Rasnitsyn & Ansorge, 2000 - Forewing with pterostigma wide; 2r-rs joining pterostigma before its midlength; cell 2r less than twice as long as wide.................................................................................. 2 2. Forewing with costal area normal..................................................................................... P. gobiensis Rasnitsyn, 1993 - Forewing with basal third or half of costal area narrowed............................................................................................ 3 3. Forewing with cell 1mcu small, length to width ratio far less than 2........................... P. okhotensis Rasnitsyn, 1993 - Forewing with cell 1mcu normal size, length to width ratio more than 2....................................................................... 4 4. Forewing with 3r-m joining cell 3r almost at its midlength...................................... P. sennlaubi Jouault & Nel, 2021 - Forewing with 3r-m joining cell 3r at well before its midlength.......................................................................... 5 5. Forewing with 2-Rs not behind 1m-cu (no 2-RS+M); forewing length more than 10 mm......................................................................................... P. gouleti Sharkey, 1990 - Forewing with 2-Rs behind 1m-cu (2-RS+M present); forewing length less than 10 mm...................................... 6 6. Length of 2m-cu to the length of 3-M of forewing less than 2.................................. P. aristovi Li, Shih & Gao sp. nov. - Length of 2m-cu to the length of 3-M of forewing distinctly more than 2....................................................................... 7 7. Forewing with Sc present; 1-RS almost as long as 1-Rs+M; hind wing 2-M+Cu absent.................................................................................. P. antennata Li, Shih & Gao sp. nov. - Forewing with Sc absent; 1-RS short; hind wing 2-M+Cu present............................... P. lata Li, Shih & Gao sp. nov., Published as part of LI, XIAO-QIN, RASNITSYN, ALEXANDR P., GAO, JIA, ZHANG, YAN-JIE, SHIH, CHUNG-KUN, REN, DONG, ZHAO, YUN-YUN & GAO, TAI-PING, 2023, New taxa of Sepulcidae (Hymenoptera) from mid-Cretaceous Kachin amber, pp. 133-145 in Palaeoentomology 6 (2) on pages 142-143, DOI: 10.11646/palaeoentomology.6.2.5, http://zenodo.org/record/7928967, {"references":["Rasnitsyn, A. P. & Ansorge, J. (2000) New Early Cretaceous hymenopterous insects (Insecta: Hymenoptera) from Sierra del Montsec (Spain). Palaeontologische Zeitschrift, 74, 335 - 341. https: // doi. org / 10.1007 / BF 02988105","Rasnitsyn, A. P. (1993) New taxa of Sepulcidae. In: Ponomarenko, A. G. (Ed.), Mesozoic insects and ostracods from Asia. Transactions of the Paleontological Institute, Russian Academy of Sciences, 252, pp. 80 - 99. [In Russian]","Jouault, C. & Nel, A. (2021) A new species of Prosyntexis Sharkey, 1990 (Hymenoptera: Sepulcidae) from the Lower Cretaceous Crato Formation of Brazil confirmed by geometric morphometric analysis. Palaeoentomology, 4 (2), 171 - 177. https: // doi. org / 10.11646 / palaeoentomology. 4.2.6"]}