To study chemical constituents of the leaves of Nauclea officinalis, eight alkaloids were isolated from 95% ethanol extract by various chromatographic methods. The structures were elucidated on the basis of spectroscopic data (IR, UV, ESI-MS, 1D and 2D NMR) and identified as naucleactonin C (1), strictosamide (2), vincosamide (3), pumiloside (4), angustoline (5), angustine (6), 18, 19-dihydroangustine (7) and naucleofficine D (8). Compound 1 is a new indole alkaloid. Compounds 6 and 7 were isolated from this plant for the first time.

Objective To investigate the factors associated with the success rate of external cephalic version (ECV) for singleton and non-cephalic presentation pregnancies in the third trimester.Methods A retrospective study of ECV among singleton and non-cephalic presentation pregnant women in 36-40 weeks of gestation at Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2016 to June 2018 was analyzed.Results (1) Totally,251 cases of 358 pregnant women who underwent ECV were successful,with a total success rate of 70.1％ (251/358).The success rate of multipara was 79.1％ (129/163),while 62.6％ (122/195) in primipara (P＜0.01).The total vaginal delivery rate was 52.2％ (187/358),the vaginal delivery rate of multipara was 61.3％ (100/163),while 44.6％ (87/195) in primipara (P＜0.01).(2) Spontaneous reversion occurred in 7.6％(19/251) of ECV successful women,the rate of reversion of multipara was 10.9％ (14/129),higher than that of the primipara [4.1％ (5/122);P＜0.01].(3) Among the 232 pregnant women who did not reverted after successful ECV,187 cases of successful vaginal delivery,the vaginal delivery rate was 80.6％ (187/232);the vaginal delivery rate of the multipara was 87.0％(100/115),which was higher than that of the primipara [74.4％(87/117);P＜0.01].(4) The variables significantly associated with ECV success were parity,type of breech,whether fetal presentation was in pelvic or not (all P＜0.05).The complication rate was 2.2％ (8/358),among which the incidence of fetal distress,placental abruption and transient fetal heart abnormalities were 0.6％ (2/358),0.3％ (1/358) and 1.4％ (5/358) respectively.Conclusion By close monitoring,ECV is a safe and effective procedure in selected appropriate cases,and worthy of clinical application.